Java 中replaceAll忽略大小寫

原文：http://hw1287789687.iteye.com/blog/2150897

Java 中replaceAll如何忽略大小寫呢?

方式一:在正則表達式前面添加(?i)

 @Test
     public void test_replaceAll33(){
         String input = "I like Java,jAva is very easy and jaVa is so popular.";
         String replacement="cccc";

         System.out.println(input);
         System.out.println(input.replaceAll("(?i)java", replacement));
     }

 測試結果:

 

 

方式二:使用Matcher 的appendReplacement 方法

 @Test
     public void test_replaceAll(){
         String input = "I like Java,jAva is very easy and jaVa is so popular.";
         String regex = "java";
         String replacement="cccc";

         StringBuffer sb =replaceAll2(input, regex, replacement);
         System.out.println(input);
         System.out.println(sb);

     }
     /***
      * replaceAll,忽略大小寫
      * @param input
      * @param regex
      * @param replacement
      * @return
      */
     public StringBuffer replaceAll2(String 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;
     }

 測試結果:

 

 

方式三:使用Matcher 的replaceAll

 /***
      * replaceAll,忽略大小寫
      *
      * @param input
      * @param regex
      * @param replacement
      * @return
      */
     public String replaceAll3(String 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;
     }

     @Test
     public void test_replaceAll3() {
         String input = "I like Java,jAva is very easy and jaVa is so popular.";
         String regex = "java";
         String replacement = "cccc";

         String sb = replaceAll3(input, regex, replacement);
         System.out.println(input);
         System.out.println(sb);

     }

 測試結果: