Java ReplaceAll is case insensitive

How does ReplaceAll ignore capitalization in Java?

Method One: Add in front of the regular expression (? i)

Java code

1. @Test   
2.     public void test_replaceall33 () {  
3.         string input =  "I  like java,java is very easy and java is so popular. ";   
4.         string replacement=
5.   
6.          SYSTEM.OUT.PRINTLN (input);   
7.          System.out.println (Input.replaceall (
8.     }  

@Testpublic void Test_replaceall33 () {String input = "I like Java,java are very easy and Java are so popular."; String replacement= "CCCC"; SYSTEM.OUT.PRINTLN (input); System.out.println (Input.replaceall ("(? i) Java", replacement));}

Test results:

Mode two: Using the Appendreplacement method of Matcher

Java code

2. @Test
4. public void Test_replaceall () {
6. String input = "I like Java,java are very easy and Java are so popular.";
8. String regex = "Java";
10. String replacement="CCCC";
14. StringBuffer SB =replaceall2 (input, regex, replacement);
16. SYSTEM.OUT.PRINTLN (input);
18. System.out.println (SB);
22. }
24. /*** 
26. * ReplaceAll, ignoring case
28. * @param input
30. * @param regex
32. * @param replacement
34. * @return
36. */
38. Public StringBuffer replaceAll2 (String input,string regex,string replacement) {
40. Pattern p = pattern.compile (regex,pattern.case_insensitive);
42. Matcher m = p.matcher (input);
44. StringBuffer sb = new StringBuffer ();
46. Boolean result = M.find ();
48. While (result)
50. {
52. M.appendreplacement (SB, replacement);
54. result = M.find ();
56. }
58. M.appendtail (SB);
60. return SB;
62. }

@Testpublic void Test_replaceall () {String input = "I like Java,java are very easy and Java are so popular.";        String regex = "Java";        String replacement= "CCCC";                StringBuffer SB =replaceall2 (input, regex, replacement);        SYSTEM.OUT.PRINTLN (input);        System.out.println (SB);} /*** * ReplaceAll, ignoring case * @param input * @param regex * @param replacement * @return */public stringbuffer replaceAll2 (Str ing input,string regex,string replacement) {Pattern p = pattern.compile (regex,pattern.case_insensitive);        Matcher m = p.matcher (input);        StringBuffer sb = new StringBuffer ();        Boolean result = M.find ();        while (result)        {            m.appendreplacement (SB, replacement);            result = M.find ();        }        M.appendtail (SB);        return SB;}

Test results:

Method Three: Use Matcher's ReplaceAll

Java code

2. /***
4. * ReplaceAll, ignoring case
6. *
8. * @param input
10. * @param regex
12. * @param replacement
14. * @return
16. */
18. Public string ReplaceAll3 (String input, string regex, string replacement) {
20. Pattern p = pattern.compile (regex, pattern.case_insensitive);
22. Matcher m = p.matcher (input);
24. String result = M.replaceall (replacement);
26. return result;
28. }
32. @Test
34. public void Test_replaceall3 () {
36. String input = "I like Java,java are very easy and Java are so popular.";
38. String regex = "Java";
40. String replacement = "CCCC";
44. String sb = ReplaceAll3 (input, regex, replacement);
46. SYSTEM.OUT.PRINTLN (input);
48. System.out.println (SB);
52. }

/*** * ReplaceAll, ignoring case *  * @param input * @param regex * @param replacement * @return */public String replaceAll3 (Str ing input, string regex, string replacement) {Pattern p = pattern.compile (regex, pattern.case_insensitive); Matcher m = p.matcher (input); String result = M.replaceall (replacement); return result;} @Testpublic void Test_replaceall3 () {String input = "I like Java,java are very easy and Java are so popular."; String regex = "Java"; String replacement = "CCCC"; String sb = ReplaceAll3 (input, regex, replacement); SYSTEM.OUT.PRINTLN (input); System.out.println (SB);}

Test results: Reference: http://hw1287789687.iteye.com/blog/2150892

Java ReplaceAll is case insensitive