stringbuffertest.java

java手机程序设计入门配套的源代码 很详细 感觉很好

import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
public class StringBufferTest extends MIDlet
{	
	public StringBufferTest() 
	{
	}
	public void startApp()
	{
		Runtime rt = Runtime.getRuntime() ;
		long diffstart = rt.totalMemory()-rt.freeMemory();
		System.out.println("Memory used Start:" + diffstart) ;
		
		/*
		String sum = "" ;
		for(int i=0 ; i< 5000 ; i++)
		{
			sum = sum + "+" + i ;
		}
		*/
		StringBuffer sum = new StringBuffer("");
		for(int i=0 ; i< 5000 ; i++)
		{
			sum = sum.append("+").append(i) ;
		}
		
		long diffend = rt.totalMemory()-rt.freeMemory();
		System.out.println("Memory used End:" + diffend) ;
		
		System.out.println("Memory used after operation:" + (diffend-diffstart)) ;
		
	}
	public void pauseApp() 
	{
	}
	public void destroyApp(boolean unconditional) 
	{
	}
}