String,StringBuilder,StringBuffer时间比较

 1 package com.cst.iprocess.controller;
 2 import java.util.Date;
 3 
 4 public class test {
 5 
 6     public static void main(String[] args) {
 7         //String,StringBuilder,StringBuffer时间比较
 8         //String
 9         String str = "";
10         long starTime = System.currentTimeMillis();
11         for(int i = 0;i<10000;i++) {
12             str=str+i;
13         }
14         long endTime = System.currentTimeMillis();
15         long time = endTime - starTime;
16         System.out.println("String的执行时间为："+time);
17         
18         //StringBuilder
19         StringBuilder std = new StringBuilder();
20          starTime = System.currentTimeMillis();
21         for(int i = 0;i<10000;i++) {
22             std.append(i);
23         }
24          endTime = System.currentTimeMillis();
25          time = endTime - starTime;
26          System.out.println("StringBuilder的执行时间为："+time);
27          
28         //StringBuffer
29         StringBuffer stb = new StringBuffer();
30          starTime = System.currentTimeMillis();
31         for(int i = 0;i<10000;i++) {
32             stb.append(i);
33         }
34          endTime = System.currentTimeMillis();
35          time = endTime - starTime;
36          System.out.println("StringBuffer的执行时间为："+time);
37     }
38 }
39   

1 String的执行时间为：145 
2 StringBuilder的执行时间为：1 
3 StringBuffer的执行时间为：0