java替换字符串和用indexof查找字符

java自带替换

String s="hlz_and_hourui哈哈";
String new_S=s.replaceAll("哈", "笑毛");
System.out.println(new_S);

则输出为:"hlz_and_hourui笑毛笑毛";

 package find_repalce_keywords;

 import java.io.BufferedReader;
 import java.io.IOException;
 import java.io.InputStreamReader;

 public class find_repalce_keywords {

     public static void main(String[] args) {

         String s="hlz_and_hourui哈哈";
         //java自带替换
         String new_S=s.replaceAll("哈", "笑毛");
         System.out.println(new_S);
         String input = null;
         String finding=null;
         System.out.println("enter a string:");
         System.out.flush();

         try {
             input=getString();
         } catch (IOException e) {
             e.printStackTrace();
         }
         System.out.println("输入你想查找的词");
         try {
             finding=getString();
         } catch (IOException e) {
             e.printStackTrace();
         }
         FindAndRepace far=new FindAndRepace();
             far.repalce(input, finding);

     }

     //I/O操作
     public static String getString() throws IOException {
         InputStreamReader isr=new InputStreamReader(System.in);
         BufferedReader br=new BufferedReader(isr);
         String s=br.readLine();
         return s;
     }
 }

 class FindAndRepace
 {
     int i=0;
     public int repalce(String str,String finding)
     {
         if(str.indexOf(finding, i)!=-1)
         {

             System.out.print("要找的"+finding+"在"+(str.indexOf(finding, i)+1)+"||||");
             i=str.indexOf(finding, i)+1;
             repalce(str, finding);//递归
         }
         else
         {
             System.out.println("搜索结束");
         }
         return i;
     }

 }

运行效果：