How to determine a word contain or not in a sentence using java ???

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COMPLETE SOURCE CODE FOR : DetermineStringContainSubstring.java
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public class DetermineStringContainSubstring
{
public static void main(String[]args)
{
 String a="Welcome to java world";

 String substring1="Welcome to java world";
 String substring2="elc";
 String substring3="Wel";
 String substring4=" t";
 String substring5="rld";

 //CHECK MATCH WHOLE WORD
 if(a.matches(substring1))
 {
  System.out.println("substring1 match to a");
 }

 //CHECK SUBSTRING NOT LOCATE AT START OR END OF STRING
 if(a.indexOf(substring2)>0)
 {
  System.out.println("substring2 contain in a");
 }

 //CHECK SUBSTRING NOT LOCATE AT START OR END OF STRING
 if(a.indexOf(substring4)>0)
 {
  System.out.println("substring4 contain in a");
 }

 //CHECK SUBSTRING LOCATE AT START OF STRING
 if(a.startsWith(substring3))
 {
  System.out.println("substring3 contain in a");
 }

 //CHECK SUBSTRING LOCATE AT END OF STRING
 if(a.endsWith(substring5))
 {
  System.out.println("substring5 contain in a");
 }
}
}

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JUST COMPILE AND EXECUTE IT
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