java正则表达式替换字符串

import java.util.regex.*;

public class h2 {

public static void main(String[] args) {

Pattern p=Pattern.compile("java",Pattern.CASE_INSENSITIVE);//正则表达式，后面的参数指定忽略大小写

Matcher m=p.matcher("java Java jAva JAVA ILoveJAVA you hate Java,fkdsjkfd");//匹配的字符串

StringBuffer buf=new StringBuffer();

int i=0;

while(m.find())//

{

i++;

if(i%2==0)

{

m.appendReplacement(buf, "java");//把字符串中偶数个的变成小写

}

else

{

m.appendReplacement(buf, "JAVA");//奇数个变成大写

}

}

m.appendTail(buf);//添加尾巴

System.out.println(buf);

}

}