剑指Offer(Java)-2-替换空格

import java.io.BufferedReader;
import java.io.InputStreamReader;
 
public class Main{
    public static void main(String args[]) throws Exception{
        BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
        String str = "";
        while((str = bf.readLine())!= null){
            System.out.println(str.replaceAll(" ","%20"));
        }
        bf.close();
    }
}

public static String replaceSpace(StringBuffer str) {
    	String a=str.toString();
    	String replaceAll = a.replaceAll(" ", "%20");
		return replaceAll;
        
    }