stringtest.java

软通公司培训的课件和习题里面有答案。。。

package com.nine.java;

import java.text.*;
import java.util.*;

public class StringTest {
	String s = "";
	StringBuffer sb = new StringBuffer();
	SimpleDateFormat data = new SimpleDateFormat("HH:mm:ss:SSS") ;

	public void testString(){
		System.out.println(data.format(new Date()) );
		for(int i=0;i<10000;i++){
			s += " abc ";
		}
		System.out.println(data.format(new Date()));
	}
	
	public void testBufferString(){
		System.out.println(data.format(new Date()) );
		for(int i=0;i<10000;i++){
			sb.append(" abc ");
		}
		System.out.println(data.format(new Date()));
	}
	
	public static void main(String[] args) {
		StringTest t = new StringTest();
		t.testString();
		t.testBufferString();
	}

}