Java 中replaceAll忽略大小写（转）

https://blog.csdn.net/u012109105/article/details/47003949

　　方式一:在正则表达式前面添加(?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));  
}

　　测试结果

　　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,忽略大小写 
 * @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;  
}

　　测试结果

　　方式三:使用Matcher 的replaceAll

/*** 
 * replaceAll,忽略大小写 
 *  
 * @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);  

}

　　测试结果

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