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:

參考:http://hw1287789687.iteye.com/blog/2150892