Core Java

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Java String contains() method explained with examples

//This will print "true" because "Game" is present in the given String
System.out.println(str.contains("Game"));

/* This will print "false" because "aGme" is not present, the characters
 * must be present in the same sequence as specified in the contains method
 */
System.out.println(str.contains("aGme"));</pre>
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Syntax of contains() method</h2>
<pre class="prettyprint prettyprinted" style="background-color: #eeeeee; box-sizing: border-box; clear: both; color: #222426; font-family: Consolas, Menlo, Monaco, "Lucida Console", "Liberation Mono", "DejaVu Sans Mono", "Bitstream Vera Sans Mono", "Courier New", monospace, sans-serif; font-size: 13px; overflow: auto; padding: 2px;">public boolean contains(CharSequence str)</pre>
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The return type is boolean which means this method returns true or false. When the character sequence found in the given string then this method returns true else it returns false.</div>
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If the CharSequence is null then this method throws NullPointerException. For example: calling this method like this would throw NullPointerException.</div>
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<pre class="prettyprint prettyprinted" style="background-color: #eeeeee; box-sizing: border-box; clear: both; color: #222426; font-family: Consolas, Menlo, Monaco, "Lucida Console", "Liberation Mono", "DejaVu Sans Mono", "Bitstream Vera Sans Mono", "Courier New", monospace, sans-serif; font-size: 13px; overflow: auto; padding: 2px;">str.contains(null);</pre>
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Java String contains() method Example</h2>
<div style="background-color: white; box-sizing: border-box; color: #222426; font-family: "PT Sans", Arial, "Helvetica Neue", Helvetica, sans-serif; font-size: 17px; margin-bottom: 26px; padding: 0px;">
The second print statement displayed false because the contains() method is case sensitive. You can also use the contains() method for case insensitive check, I have covered this at the end of this tutorial.</div>
<pre class="prettyprint prettyprinted" style="background-color: #eeeeee; box-sizing: border-box; clear: both; color: #222426; font-family: Consolas, Menlo, Monaco, "Lucida Console", "Liberation Mono", "DejaVu Sans Mono", "Bitstream Vera Sans Mono", "Courier New", monospace, sans-serif; font-size: 13px; overflow: auto; padding: 2px;">class Example{ 
 public static void main(String args[]){ 
 String str = "Do you like watching Game of Thrones"; 
 System.out.println(str.contains("like"));
 
 /* this will print false as the contains() method is
 * case sensitive. Here we have mentioned letter "l" 
 * in upper case and in the actual string we have this
 * letter in the lower case. 
 */
 System.out.println(str.contains("Like")); 
 System.out.println(str.contains("Game")); 
 System.out.println(str.contains("Game of")); 
 }
}</pre>
<div style="background-color: white; box-sizing: border-box; color: #222426; font-family: "PT Sans", Arial, "Helvetica Neue", Helvetica, sans-serif; font-size: 17px; margin-bottom: 26px; padding: 0px;">
Output:</div>
<pre class="prettyprint prettyprinted" style="background-color: #eeeeee; box-sizing: border-box; clear: both; color: #222426; font-family: Consolas, Menlo, Monaco, "Lucida Console", "Liberation Mono", "DejaVu Sans Mono", "Bitstream Vera Sans Mono", "Courier New", monospace, sans-serif; font-size: 13px; overflow: auto; padding: 2px;">true
false
true
true</pre>
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Example 2: Using Java String contains() method in the if-else statement</h2>
<pre class="prettyprint prettyprinted" style="background-color: #eeeeee; box-sizing: border-box; clear: both; color: #222426; font-family: Consolas, Menlo, Monaco, "Lucida Console", "Liberation Mono", "DejaVu Sans Mono", "Bitstream Vera Sans Mono", "Courier New", monospace, sans-serif; font-size: 13px; overflow: auto; padding: 2px;">class Example{ 
 public static void main(String args[]){ 
 String str = "This is an example of contains()"; 
 /* Using the contains() method in the if-else statements, since
 * this method returns the boolean value, it can be used
 * in the if else conditions whenever needed.
 */
 if(str.contains("example")){
 System.out.println("The word example is found in given string");
 }
 else{
 System.out.println("The word example is not found in the string");
 }
 }
}</pre>
<div style="background-color: white; box-sizing: border-box; color: #222426; font-family: "PT Sans", Arial, "Helvetica Neue", Helvetica, sans-serif; font-size: 17px; margin-bottom: 26px; padding: 0px;">
Output:</div>
<pre class="prettyprint prettyprinted" style="background-color: #eeeeee; box-sizing: border-box; clear: both; color: #222426; font-family: Consolas, Menlo, Monaco, "Lucida Console", "Liberation Mono", "DejaVu Sans Mono", "Bitstream Vera Sans Mono", "Courier New", monospace, sans-serif; font-size: 13px; overflow: auto; padding: 2px;">The word example is found in given string</pre>
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Java String contains() method for case insensitive check</h2>
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We have seen above that the contains() method is case sensitive, however with a little trick, you can use this method for case insensitive checks. Lets take an example to understand this:</div>
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Here we are using the <a href="https://beginnersbook.com/2013/12/java-string-tolowercase-method-example/" style="box-sizing: border-box; color: #7dc246; font-weight: bold !important; text-decoration-line: none; transition: all 0.1s ease-in-out;">toLowerCase() method</a> to convert both the strings to lowercase so that we can perform case insensitive check using contains() method. We can also use toUpperCase() method for this same purpose as shown in the example below.</div>
<pre class="prettyprint prettyprinted" style="background-color: #eeeeee; box-sizing: border-box; clear: both; color: #222426; font-family: Consolas, Menlo, Monaco, "Lucida Console", "Liberation Mono", "DejaVu Sans Mono", "Bitstream Vera Sans Mono", "Courier New", monospace, sans-serif; font-size: 13px; overflow: auto; padding: 2px;">class Example{ 
 public static void main(String args[]){ 
 String str = "Just a Simple STRING"; 
 String str2 = "string";
 //Converting both the strings to lower case for case insensitive checking
 System.out.println(str.toLowerCase().contains(str2.toLowerCase()));
 
 //You can also use the upper case method for the same purpose.
 System.out.println(str.toUpperCase().contains(str2.toUpperCase()));
 }
}</pre>
<div style="background-color: white; box-sizing: border-box; color: #222426; font-family: "PT Sans", Arial, "Helvetica Neue", Helvetica, sans-serif; font-size: 17px; margin-bottom: 26px; padding: 0px;">
Output:</div>
<pre class="prettyprint prettyprinted" style="background-color: #eeeeee; box-sizing: border-box; clear: both; color: #222426; font-family: Consolas, Menlo, Monaco, "Lucida Console", "Liberation Mono", "DejaVu Sans Mono", "Bitstream Vera Sans Mono", "Courier New", monospace, sans-serif; font-size: 13px; overflow: auto; padding: 2px;">true
true</pre>
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Reference:</h4>
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<a href="https://docs.oracle.com/javase/7/docs/api/java/lang/String.html#contains(java.lang.CharSequence)" rel="noopener" style="box-sizing: border-box; color: #7dc246; font-weight: bold !important; text-decoration-line: none; transition: all 0.1s ease-in-out;" target="_blank">String Contains() method – JavaDoc</a></div>
</div>

Java String contains() method explained with examples

Java String contains() method checks whether a particular string is a part of another string or not. This method returns true if a specif...

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Java – String indexOf() Method Example

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The method <code style="background-color: #eeeeee; box-sizing: border-box; font-family: "PT Sans", Arial, "Helvetica Neue", Helvetica, sans-serif;">indexOf()</code> is used for finding out the index of the specified character or substring in a particular String. There are 4 variations of this method: <code style="background-color: #eeeeee; box-sizing: border-box; font-family: "PT Sans", Arial, "Helvetica Neue", Helvetica, sans-serif;">int indexOf(int ch)</code>: It returns the index of the first occurrence of character ch in a String. <code style="background-color: #eeeeee; box-sizing: border-box; font-family: "PT Sans", Arial, "Helvetica Neue", Helvetica, sans-serif;">int indexOf(int ch, int fromIndex)</code>: It returns the index of first occurrence if character ch, starting from the specified index “fromIndex”. <code style="background-color: #eeeeee; box-sizing: border-box; font-family: "PT Sans", Arial, "Helvetica Neue", Helvetica, sans-serif;">int indexOf(String str)</code>: Returns the index of string str in a particular String. <code style="background-color: #eeeeee; box-sizing: border-box; font-family: "PT Sans", Arial, "Helvetica Neue", Helvetica, sans-serif;">int indexOf(String str, int fromIndex)</code>: Returns the index of string str, starting from the specified index “fromIndex”.</div>
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All the above variations returns -1 if the specified char/substring is not found in the particular <code style="background-color: #eeeeee; box-sizing: border-box; font-family: "PT Sans", Arial, "Helvetica Neue", Helvetica, sans-serif;">String</code>.</div>
<h3 style="background-color: white; box-sizing: border-box; color: #444542; font-family: "PT Sans", "Trebuchet MS", "Lucida Grande", Arial, "Helvetica Neue", Helvetica, sans-serif; font-size: 22px; line-height: 1.2; margin: 0px 0px 16px;">
Example</h3>
<pre class="prettyprint prettyprinted" style="background-color: #eeeeee; box-sizing: border-box; clear: both; color: #222426; font-family: Consolas, Menlo, Monaco, "Lucida Console", "Liberation Mono", "DejaVu Sans Mono", "Bitstream Vera Sans Mono", "Courier New", monospace, sans-serif; font-size: 13px; overflow: auto; padding: 2px;">public class IndexOfExample{
 public static void main(String args[]) {
 String str1 = new String("This is a BeginnersBook tutorial");
 String str2 = new String("Beginners");
 String str3 = new String("Book");
 String str4 = new String("Books");
 System.out.println("Index of B in str1: "+str1.indexOf('B'));
 System.out.println("Index of B in str1 after 15th char:"+str1.indexOf('B', 15));
 System.out.println("Index of B in str1 after 30th char:"+str1.indexOf('B', 30));
 System.out.println("Index of string str2 in str1:"+str1.indexOf(str2));
 System.out.println("Index of str2 after 15th char"+str1.indexOf(str2, 15));
 System.out.println("Index of string str3:"+str1.indexOf(str3));
 System.out.println("Index of string str4"+str1.indexOf(str4));
 System.out.println("Index of harcoded string:"+str1.indexOf("is"));
 System.out.println("Index of hardcoded string after 4th char:"+str1.indexOf("is", 4));
 }
}</pre>
<div style="background-color: white; box-sizing: border-box; color: #222426; font-family: "PT Sans", Arial, "Helvetica Neue", Helvetica, sans-serif; font-size: 17px; margin-bottom: 26px; padding: 0px;">
Output:</div>
<pre class="prettyprint prettyprinted" style="background-color: #eeeeee; box-sizing: border-box; clear: both; color: #222426; font-family: Consolas, Menlo, Monaco, "Lucida Console", "Liberation Mono", "DejaVu Sans Mono", "Bitstream Vera Sans Mono", "Courier New", monospace, sans-serif; font-size: 13px; overflow: auto; padding: 2px;">Index of B in str1: 10
Index of B in str1 after 15th char:19
Index of B in str1 after 30th char:-1
Index of string str2 in str1:10
Index of str2 after 15th char-1
Index of string str3:19
Index of string str4-1
Index of harcoded string:2
Index of hardcoded string after 4th char:5</pre>
</div>

Java – String indexOf() Method Example

The method indexOf() is used for finding out the index of the specified character or substring in a particular String. There are 4 varia...

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Difference between >>= and >>>=

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<pre class="lang-java prettyprint prettyprinted" style="background-color: #eeeeee; border: 0px; color: #393318; font-family: Consolas, Menlo, Monaco, 'Lucida Console', 'Liberation Mono', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', 'Courier New', monospace, sans-serif; font-size: 13px; margin-bottom: 1em; max-height: 600px; overflow: auto; padding: 5px; width: auto; word-wrap: normal;"><code style="border: 0px; font-family: Consolas, Menlo, Monaco, 'Lucida Console', 'Liberation Mono', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', 'Courier New', monospace, sans-serif; margin: 0px; padding: 0px; white-space: inherit;">>> Signed right shift
>>> Unsigned right shift</code></pre>
<pre class="lang-java prettyprint prettyprinted" style="background-color: #eeeeee; border: 0px; color: #393318; font-family: Consolas, Menlo, Monaco, 'Lucida Console', 'Liberation Mono', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', 'Courier New', monospace, sans-serif; font-size: 13px; margin-bottom: 1em; max-height: 600px; overflow: auto; padding: 5px; width: auto; word-wrap: normal;"><code style="border: 0px; font-family: Consolas, Menlo, Monaco, 'Lucida Console', 'Liberation Mono', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', 'Courier New', monospace, sans-serif; margin: 0px; padding: 0px; white-space: inherit;"><div style="background-color: white; border: 0px; clear: both; color: #222426; font-family: Arial, 'Helvetica Neue', Helvetica, sans-serif; font-size: 15px; line-height: 19.5px; margin-bottom: 1em; padding: 0px; white-space: normal;">
he bit pattern is given by the left-hand operand, and the number of positions to shift by the right-hand operand. The unsigned right shift operator <code style="background-color: #eeeeee; border: 0px; font-family: Consolas, Menlo, Monaco, 'Lucida Console', 'Liberation Mono', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', 'Courier New', monospace, sans-serif; font-size: 13px; margin: 0px; padding: 1px 5px; white-space: pre-wrap;">>>></code> shifts a zero into the leftmost position,</div>
<div style="background-color: white; border: 0px; clear: both; color: #222426; font-family: Arial, 'Helvetica Neue', Helvetica, sans-serif; font-size: 15px; line-height: 19.5px; margin-bottom: 1em; padding: 0px; white-space: normal;">
while the leftmost position after <code style="background-color: #eeeeee; border: 0px; font-family: Consolas, Menlo, Monaco, 'Lucida Console', 'Liberation Mono', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', 'Courier New', monospace, sans-serif; font-size: 13px; margin: 0px; padding: 1px 5px; white-space: pre-wrap;">>></code> depends on sign extension.</div>
<div style="background-color: white; border: 0px; clear: both; color: #222426; font-family: Arial, 'Helvetica Neue', Helvetica, sans-serif; font-size: 15px; line-height: 19.5px; margin-bottom: 1em; padding: 0px; white-space: normal;">
In simple words <code style="background-color: #eeeeee; border: 0px; font-family: Consolas, Menlo, Monaco, 'Lucida Console', 'Liberation Mono', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', 'Courier New', monospace, sans-serif; font-size: 13px; margin: 0px; padding: 1px 5px; white-space: pre-wrap;">>>></code> always shifts a zero into the leftmost position whereas <code style="background-color: #eeeeee; border: 0px; font-family: Consolas, Menlo, Monaco, 'Lucida Console', 'Liberation Mono', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', 'Courier New', monospace, sans-serif; font-size: 13px; margin: 0px; padding: 1px 5px; white-space: pre-wrap;">>></code> shifts based on sign of the number i.e. 1 for negative number and 0 for positive number.</div>
<hr style="background-color: #dddddd; border: 0px; color: #dddddd; font-family: Arial, 'Helvetica Neue', Helvetica, sans-serif; font-size: 15px; height: 1px; line-height: 19.5px; margin-bottom: 20px; white-space: normal;" />
<div style="background-color: white; border: 0px; clear: both; color: #222426; font-family: Arial, 'Helvetica Neue', Helvetica, sans-serif; font-size: 15px; line-height: 19.5px; margin-bottom: 1em; padding: 0px; white-space: normal;">
For example try with negative numbers.</div>
<pre class="lang-java prettyprint prettyprinted" style="border: 0px; color: #393318; font-family: Consolas, Menlo, Monaco, 'Lucida Console', 'Liberation Mono', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', 'Courier New', monospace, sans-serif; margin-bottom: 1em; max-height: 600px; overflow: auto; padding: 5px; width: auto; word-wrap: normal;"><code style="border: 0px; font-family: Consolas, Menlo, Monaco, 'Lucida Console', 'Liberation Mono', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', 'Courier New', monospace, sans-serif; margin: 0px; padding: 0px; white-space: inherit;">int c = -153;
System.out.printf("%32s%n",Integer.toBinaryString(c >>= 2));
System.out.printf("%32s%n",Integer.toBinaryString(c <<= 2));
System.out.printf("%32s%n",Integer.toBinaryString(c >>>= 2));
System.out.println(Integer.toBinaryString(c <<= 2));

c = 153;
System.out.printf("%32s%n",Integer.toBinaryString(c >>= 2));
System.out.printf("%32s%n",Integer.toBinaryString(c <<= 2));
System.out.printf("%32s%n",Integer.toBinaryString(c >>>= 2));
System.out.printf("%32s%n",Integer.toBinaryString(c <<= 2));</code></pre>
<div style="background-color: white; border: 0px; clear: both; color: #222426; font-family: Arial, 'Helvetica Neue', Helvetica, sans-serif; font-size: 15px; line-height: 19.5px; margin-bottom: 1em; padding: 0px; white-space: normal;">
output:</div>
<pre class="lang-java prettyprint prettyprinted" style="border: 0px; color: #393318; font-family: Consolas, Menlo, Monaco, 'Lucida Console', 'Liberation Mono', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', 'Courier New', monospace, sans-serif; margin-bottom: 1em; max-height: 600px; overflow: auto; padding: 5px; width: auto; word-wrap: normal;"><code style="border: 0px; font-family: Consolas, Menlo, Monaco, 'Lucida Console', 'Liberation Mono', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', 'Courier New', monospace, sans-serif; margin: 0px; padding: 0px; white-space: inherit;">11111111111111111111111111011001
11111111111111111111111101100100
 111111111111111111111111011001
11111111111111111111111101100100
 100110
 10011000
 100110
 10011000</code></pre>
</code></pre>
</div>

Difference between >>= and >>>=

>> Signed right shift >>> Unsigned right shift he bit pattern is given by the left-hand operand, and the numb...

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Java Finalize Method: When and How to Implement It?

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When an object becomes <a href="http://java.sun.com/docs/books/performance/1st_edition/html/JPAppGC.fm.html" style="background-color: #fffffd; color: #720101; font-family: Molengo; font-size: 15.4px; line-height: 21.56px; text-decoration: none;" target="_blank">unreachable</a>, it is flagged as collected by the garbage collector. If it has a finalize() method, it is marked for finalization and put in a finalization queue. After finalization, it becomes finalized. If it does not have a finalize() method, it is directly marked as finalized without being inserted in the finalization queue. The finalization queue is subject to memory limitations like the application itself. One cannot precisely guess when or how often the content of the finalization queue will be processed, though the lower the remaining amount of memory, the higher the probability this process will happen 'soon'. Once an object has been finalized, it is ready for deallocation. Java guarantees thatfinalize() is never called more than once on an object. If there is no more hard reference to this object after finalization, then the memory used for this object is released. In other words, finalization does not guarantee memory recollection.  
<h4 style="background-color: #fffffd; color: #070101; font-family: Molengo; font-size: 15.4px; line-height: 21.56px; margin: 20px 0px 5px; position: relative;">
Do's</h4>
<ul style="background-color: #fffffd; color: #070101; font-family: Molengo; font-size: 15.4px; line-height: 21.56px; margin: 0.5em 0px; padding: 0px 2.5em;">
<li style="margin: 0px 0px 0.25em; padding: 0px;">Do call the super implementation of finalize() - If you implement afinalize() method in an object, make sure this method calls finalize()on the super object (i.e. super.finalize()).</li>
<li style="margin: 0px 0px 0.25em; padding: 0px;">Double-check that resources have been released - Let's assume an object is referencing a file or any other non memory resource. It is considered a safe practice to double-check that such resource and been <a href="http://tshikatshikaaa.blogspot.nl/2012/08/how-to-silently-close-resources-in-java.html" style="color: #720101; text-decoration: none;">closed and released properly</a> in a finalize() method.</li>
</ul>
<h4 style="background-color: #fffffd; color: #070101; font-family: Molengo; font-size: 15.4px; line-height: 21.56px; margin: 20px 0px 5px; position: relative;">
Don't</h4>
<ul style="background-color: #fffffd; color: #070101; font-family: Molengo; font-size: 15.4px; line-height: 21.56px; margin: 0.5em 0px; padding: 0px 2.5em;">
<li style="margin: 0px 0px 0.25em; padding: 0px;">Don't do the job of the garbage collector - Let's assume an object has a list (for example). Do not implement a finalize() method to clear the list of its elements in order to free memory. It is an unnecessary overhead. The garbage collector will do this for you very efficiently and automatically.</li>
<li style="margin: 0px 0px 0.25em; padding: 0px;">Do not wait for finalize() to release resources - Assuming resource object A has a reference to resource B, and object B has a reference to A. Assuming both A and B wait until the call of finalize() to release their reference to each other. This may never happen, especially if there is a static final reference to A or B elsewhere in the application. Resources should be released explicitly as soon as they are not required by the application anymore. Don't wait for a call to finalize().</li>
<li style="margin: 0px 0px 0.25em; padding: 0px;">The call order of finalize() methods is unpredictable - Don't make any assumptions about the call order of finalize() methods.</li>
<li style="margin: 0px 0px 0.25em; padding: 0px;">Don't create a hard reference to a finalized object - The finalize() method is called when an object has become unreachable. Do not create a hard reference, for example by adding it to a list in another object, because this will prevent its memory recollection.</li>
</ul>
If you are implementing a mechanism monitoring the memory usage of your application, you may call <a href="http://docs.oracle.com/javase/6/docs/api/java/lang/System.html#runFinalization%28%29" style="background-color: #fffffd; color: #720101; font-family: Molengo; font-size: 15.4px; line-height: 21.56px; text-decoration: none;" target="_blank">System.runFinalization()</a> to facilitate the deallocation process and memory recollection (if necessary).</div>

Java Finalize Method: When and How to Implement It?

When an object becomes unreachable , it is flagged as collected by the garbage collector. If it has a finalize() method, it is marked ...

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Java Abstract Class vs Interface Pros and Con's

<div dir="ltr" style="text-align: left;" trbidi="on">
This a quick reminder about pros and con's of Java abstract classes and interfaces: 
<h4 style="background-color: #fffffd; color: #070101; font-family: Molengo; font-size: 15.4px; line-height: 21.56px; margin: 20px 0px 5px; position: relative;">
Interface</h4>
<ul style="background-color: #fffffd; color: #070101; font-family: Molengo; font-size: 15.4px; line-height: 21.56px; margin: 0.5em 0px; padding: 0px 2.5em;">
<li style="margin: 0px 0px 0.25em; padding: 0px;">A class can implement multiple interfaces</li>
<li style="margin: 0px 0px 0.25em; padding: 0px;">An interface cannot provide any code at all</li>
<li style="margin: 0px 0px 0.25em; padding: 0px;">An interface can only define public static final constants</li>
<li style="margin: 0px 0px 0.25em; padding: 0px;">An interface cannot define instance variables</li>
<li style="margin: 0px 0px 0.25em; padding: 0px;">Adding a new method has ripple effects on implementing classes (design maintenance)</li>
<li style="margin: 0px 0px 0.25em; padding: 0px;">JAXB cannot <a href="http://tshikatshikaaa.blogspot.nl/2012/08/jaxb-annotation-summary-advanced-topics_7.html" style="color: #720101; text-decoration: none;">deal with interfaces</a></li>
<li style="margin: 0px 0px 0.25em; padding: 0px;">An interface cannot extends or implement an abstract class</li>
<li style="margin: 0px 0px 0.25em; padding: 0px;">All interface methods are public</li>
</ul>
In general, interfaces should be used to define contracts (what is to be achieved, not how to achieve it). 
<h4 style="background-color: #fffffd; color: #070101; font-family: Molengo; font-size: 15.4px; line-height: 21.56px; margin: 20px 0px 5px; position: relative;">
Abstract Class</h4>
<ul style="background-color: #fffffd; color: #070101; font-family: Molengo; font-size: 15.4px; line-height: 21.56px; margin: 0.5em 0px; padding: 0px 2.5em;">
<li style="margin: 0px 0px 0.25em; padding: 0px;">A class can extend at most one abstract class</li>
<li style="margin: 0px 0px 0.25em; padding: 0px;">An abstract class can contain code</li>
<li style="margin: 0px 0px 0.25em; padding: 0px;">An abstract class can define both static and instance constants (final)</li>
<li style="margin: 0px 0px 0.25em; padding: 0px;">An abstract class can define instance variables</li>
<li style="margin: 0px 0px 0.25em; padding: 0px;">Modification of existing abstract class code has ripple effects on extending classes (implementation maintenance)</li>
<li style="margin: 0px 0px 0.25em; padding: 0px;">Adding a new method to an abstract class has no ripple effect on extending classes</li>
<li style="margin: 0px 0px 0.25em; padding: 0px;">An abstract class can implement an interface</li>
<li style="margin: 0px 0px 0.25em; padding: 0px;">Abstract classes can implement private and protected methods</li>
</ul>
Abstract classes should be used for (partial) implementation. They can be a mean to restrain the way API contracts should be implemented.</div>

Java Abstract Class vs Interface Pros and Con's

This a quick reminder about pros and con's of Java abstract classes and interfaces: Interface A class can implement multiple interf...

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Reading a file into collection or Array

<span class="kwd" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: darkblue; margin: 0px; padding: 0px;">public<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;"> <span class="typ" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: #2b91af; margin: 0px; padding: 0px;">String<span class="pun" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">[]<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;"> readLines<span class="pun" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">(<span class="typ" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: #2b91af; margin: 0px; padding: 0px;">String<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;"> filename<span class="pun" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">)<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;"> <span class="kwd" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: darkblue; margin: 0px; padding: 0px;">throws<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;"> <span class="typ" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: #2b91af; margin: 0px; padding: 0px;">IOException<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;"> <span class="pun" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">{<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">
 <span class="typ" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: #2b91af; margin: 0px; padding: 0px;">FileReader<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;"> fileReader <span class="pun" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">=<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;"> <span class="kwd" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: darkblue; margin: 0px; padding: 0px;">new<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;"> <span class="typ" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: #2b91af; margin: 0px; padding: 0px;">FileReader<span class="pun" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">(<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">filename<span class="pun" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">);<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">
 <span class="typ" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: #2b91af; margin: 0px; padding: 0px;">BufferedReader<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;"> bufferedReader <span class="pun" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">=<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;"> <span class="kwd" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: darkblue; margin: 0px; padding: 0px;">new<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;"> <span class="typ" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: #2b91af; margin: 0px; padding: 0px;">BufferedReader<span class="pun" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">(<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">fileReader<span class="pun" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">);<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">
 <span class="typ" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: #2b91af; margin: 0px; padding: 0px;">List<span class="pun" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;"><<span class="typ" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: #2b91af; margin: 0px; padding: 0px;">String<span class="pun" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">><span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;"> lines <span class="pun" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">=<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;"> <span class="kwd" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: darkblue; margin: 0px; padding: 0px;">new<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;"> <span class="typ" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: #2b91af; margin: 0px; padding: 0px;">ArrayList<span class="pun" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;"><<span class="typ" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: #2b91af; margin: 0px; padding: 0px;">String<span class="pun" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">>();<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">
 <span class="typ" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: #2b91af; margin: 0px; padding: 0px;">String<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;"> line <span class="pun" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">=<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;"> <span class="kwd" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: darkblue; margin: 0px; padding: 0px;">null<span class="pun" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">;<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">
 <span class="kwd" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: darkblue; margin: 0px; padding: 0px;">while<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;"> <span class="pun" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">((<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">line <span class="pun" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">=<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;"> bufferedReader<span class="pun" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">.<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">readLine<span class="pun" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">())<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;"> <span class="pun" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">!=<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;"> <span class="kwd" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: darkblue; margin: 0px; padding: 0px;">null<span class="pun" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">)<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;"> <span class="pun" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">{<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">
 lines<span class="pun" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">.<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">add<span class="pun" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">(<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">line<span class="pun" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">);<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">
 <span class="pun" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">}<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">
 bufferedReader<span class="pun" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">.<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">close<span class="pun" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">();<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">
 <span class="kwd" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: darkblue; margin: 0px; padding: 0px;">return<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;"> lines<span class="pun" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">.<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">toArray<span class="pun" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">(<span class="kwd" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: darkblue; margin: 0px; padding: 0px;">new<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;"> <span class="typ" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: #2b91af; margin: 0px; padding: 0px;">String<span class="pun" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">[<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">lines<span class="pun" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">.<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">size<span class="pun" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">()]);<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">
 <span class="pun" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">}<span class="pln" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">
<span class="pun" style="border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border: 0px; color: black; margin: 0px; padding: 0px;">}</code></pre>
<pre class="lang-java prettyprint prettyprinted" style="background-color: #eeeeee; border: 0px; font-family: Consolas, Menlo, Monaco, 'Lucida Console', 'Liberation Mono', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', 'Courier New', monospace, sans-serif; font-size: 13px; margin-bottom: 1em; max-height: 600px; overflow: auto; padding: 5px; width: auto; word-wrap: normal;">Unit Test:</pre>
<pre class="lang-java prettyprint prettyprinted" style="background-color: #eeeeee; border: 0px; font-family: Consolas, Menlo, Monaco, 'Lucida Console', 'Liberation Mono', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', 'Courier New', monospace, sans-serif; font-size: 13px; margin-bottom: 1em; max-height: 600px; overflow: auto; padding: 5px; width: auto; word-wrap: normal;"><pre class="lang-java prettyprint prettyprinted" style="border: 0px; color: #393318; font-family: Consolas, Menlo, Monaco, 'Lucida Console', 'Liberation Mono', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', 'Courier New', monospace, sans-serif; margin-bottom: 1em; max-height: 600px; overflow: auto; padding: 5px; width: auto; word-wrap: normal;"><pre class="lang-java prettyprint prettyprinted" style="border: 0px; font-family: Consolas, Menlo, Monaco, 'Lucida Console', 'Liberation Mono', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', 'Courier New', monospace, sans-serif; margin-bottom: 1em; max-height: 600px; overflow: auto; padding: 5px; width: auto; word-wrap: normal;"><code style="border: 0px; font-family: Consolas, Menlo, Monaco, 'Lucida Console', 'Liberation Mono', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', 'Courier New', monospace, sans-serif; margin: 0px; padding: 0px; white-space: inherit;">import java.io.IOException;

public class FileArrayProviderTest {

@Test
 public void testFileArrayProvider() throws IOException {
 FileArrayProvider fap = new FileArrayProvider();
 String[] lines = fap
 .readLines("src/main/java/com/acme/FileArrayProvider.java");
 for (String line : lines) {
 System.out.println(line);
 }
 }
}</code></pre>
</pre>
<pre class="lang-java prettyprint prettyprinted" style="border: 0px; color: #393318; font-family: Consolas, Menlo, Monaco, 'Lucida Console', 'Liberation Mono', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', 'Courier New', monospace, sans-serif; margin-bottom: 1em; max-height: 600px; overflow: auto; padding: 5px; width: auto; word-wrap: normal;"><code style="border: 0px; font-family: Consolas, Menlo, Monaco, 'Lucida Console', 'Liberation Mono', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', 'Courier New', monospace, sans-serif; margin: 0px; padding: 0px; white-space: inherit;">
</code></pre>
<h2 style="border: 0px; color: #393318; font-family: Consolas, Menlo, Monaco, 'Lucida Console', 'Liberation Mono', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', 'Courier New', monospace, sans-serif; margin-bottom: 1em; max-height: 600px; overflow: auto; padding: 5px; text-align: center; width: auto; word-wrap: normal;">
OR</h2>
<div>

</div>
<div>
<pre class="lang-java prettyprint prettyprinted" style="border: 0px; color: #393318; font-family: Consolas, Menlo, Monaco, 'Lucida Console', 'Liberation Mono', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', 'Courier New', monospace, sans-serif; margin-bottom: 1em; max-height: 600px; overflow: auto; padding: 5px; width: auto; word-wrap: normal;"><code style="border: 0px; font-family: Consolas, Menlo, Monaco, 'Lucida Console', 'Liberation Mono', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', 'Courier New', monospace, sans-serif; margin: 0px; padding: 0px; white-space: inherit;">import java.io.File;

import java.nio.charset.Charset;
import java.nio.file.Files;
import java.nio.file.Path;

// ...

Path filePath = new File("fileName").toPath();
Charset charset = Charset.defaultCharset(); 
List<String> stringList = Files.readAllLines(filePath, charset);
String[] stringArray = stringList.toArray(new String[]{});</code></pre>
</div>
</pre>
</div>

Reading a file into collection or Array

import java . io . BufferedReader ; import java . io . FileReader ; import java . io . IOException ; import java . util . ArrayLi...

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