主题：【倡议】Java SE 5.0和.NET 2.0擂台赛 -- Highway

串行化/反串行化就是所谓的Serializtion/De-serailization。在现在计算机技术中这是非常重要的一个环节。一个Object只有被串行化才可以在网络上传输，才可以保存到Disk或Database中。

串行化/反串行化根据用户的要求可能会非常的复杂（比如Versioning control, Thread status, Delegate等等东西），Java和.NET都有专门的文章介绍。今天我想测试的就是Out-of-Box性能，就是看看最基本的串行化/反串行化这两者性能如何。

最基础的串行化/反串行化程序员不用写程序，只要声明一下就可以了（详见Code）。我的实验非常简单，创建一些Object,然后放到ArrayList里去，一次性串行化/反串行化，看看其性能如何。

测试表明，.NET程序反应很快，对于小数据，少次数的调用性能很好（比Java好），但是一旦数据量变大，性能马上就开始下降。这时候Java会迎头赶上。在数据量达到3MB的时候，Java已经快出5倍以上，而在30MB的时候，会快出60倍。Java Server VM在数据量大的情况下比Client有较大优势。如果是非密集型的运算，Client VM可能更合适。

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（50000*10用的时间太长了，没有等它完成）

下面是我的源程序，非常简单。大家可以随意修改，玩弄！！！

C# Code

#region Using directives

using System;
using System.Collections;
using System.Text;
using System.IO;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Formatters.Binary;

#endregion

namespace SerialTest
{
    class Program
    {
        static void Main(string[] args)
        {
            new Program();
        }
        public Program()
        {
            ArrayList a50 = prepareData(50);
            seDesTest(a50,1000);
            ArrayList a500 = prepareData(500);
            seDesTest(a500,100);
            ArrayList a5000 = prepareData(5000);
            seDesTest(a5000,10);
            ArrayList a50000 = prepareData(50000);
            seDesTest(a50000,1);
            //ArrayList a100000 = prepareData(100000);
            //seDesTest(a100000);
        }
        private ArrayList prepareData(int num)
        {
            long start = System.Environment.TickCount;
            ArrayList a = new ArrayList();
            for(int i=0; i<num; i++) {
                MyObj aObj = new MyObj(DateTime.Now.ToString(),32,i*1000,DateTime.Now);
                a.Add(aObj);
            }
            long time = System.Environment.TickCount- start;
            //System.Console.WriteLine("Prepare time of " + num + " items: " + time+ " ms.");
            return a;
        }
    
        private void seDesTest(ArrayList a, int number)
        {
            long start = System.Environment.TickCount;
            ArrayList a1 = null;
            for (int i = 0; i < number; i++)
            {
                MemoryStream memStream = new MemoryStream();
                IFormatter formatter = new BinaryFormatter();
                formatter.Serialize(memStream, a);
                byte[] data = memStream.ToArray();

                memStream = new MemoryStream(data);
                a1 = (ArrayList)formatter.Deserialize(memStream);
            }
            long time = System.Environment.TickCount - start;
            if(a1.Count != a.Count)
            {
                System.Console.WriteLine("Error happend, Invalid test!!!");
                return;
            }
            else
            {
                System.Console.WriteLine("Serialization and Deserialization of " + a.Count.ToString() + "*" + number.ToString() + " items take:" + time + " ms.");
                //System.Console.WriteLine("Last Object: " + a1[a1.Count - 1].ToString());
            }
        }
     }
    [Serializable]
    public class MyObj
    {
        private static readonly String NEWLINE = "\r\n";
        private String m_name;
        private int m_age;
        private double m_salary;
        private DateTime m_hireDate;

        /** Creates a new instance of MyObj */
        public MyObj(String name, int age, double salary, DateTime hireDate)
        {
            m_name = name;
            m_age = age;
            m_salary = salary;
            m_hireDate = hireDate;
        }
        public MyObj() { }

        public override String ToString()
        {
            StringBuilder sb = new StringBuilder();
            sb.Append("Name: " + m_name + NEWLINE);
            sb.Append("Age: " + m_age + NEWLINE);
            sb.Append("Salary: " + m_salary + NEWLINE);
            sb.Append("Hire Date: " + m_hireDate.ToString());
            return sb.ToString();
        }
    }
}

Java Code

import java.util.*;
import java.io.*;

public class Main {

    public Main() throws Exception{
        ArrayList a50 = prepareData(50);
        seDesTest(a50,1000);
        ArrayList a500 = prepareData(500);
        seDesTest(a500,100);
        ArrayList a5000 = prepareData(5000);
        seDesTest(a5000,10);
        ArrayList a50000 = prepareData(50000);
        seDesTest(a50000,1);
        seDesTest(a50000,10);
        //ArrayList a100000 = prepareData(100000);
        //seDesTest(a100000,1);
    }
    
    private ArrayList prepareData(int num){
        long start = System.currentTimeMillis();
        ArrayList a = new ArrayList();
        for(int i=0; i<num; i++) {
            MyObj aObj = new MyObj(new Date().toString(),32,i*1000,new Date());
            a.add(aObj);
        }
        long time = System.currentTimeMillis()-start;
        //System.out.println("Prepare time of " + num + " items: " + time+ " ms.");
        return a;
    }
    
    private void seDesTest(ArrayList a, int number)throws Exception{
        long start = System.currentTimeMillis();
        ArrayList a1 = null;
        for(int i=0; i<number; i++){
        	ByteArrayOutputStream bout = new java.io.ByteArrayOutputStream();
        	ObjectOutputStream objOut = new java.io.ObjectOutputStream(bout);
        	objOut.writeObject(a);
        	byte[] data = bout.toByteArray();
        	bout.close();
        	objOut.close();
        	//deserializtion
        	ByteArrayInputStream bin = new ByteArrayInputStream(data);
        	ObjectInputStream objIn = new ObjectInputStream(bin);
       	a1 = (ArrayList)objIn.readObject();
        	bin.close();
        	objIn.close();
        }
        long time = System.currentTimeMillis()-start;
        if(a1.size() != a.size()){
            System.out.println("Error happend, Invalid test!!!");
            return;
        }
        else{ 
            System.out.println("Serialization and Deserialization of " + a.size() + "*"  + number +" items take:" + time + " ms.");            
        }
    }

    public static void main(String[] args)throws Exception {
        // TODO code application logic here
        new Main();
    }
    
}

import java.util.Date;
import java.io.Serializable;

public class MyObj implements Serializable{
    private static final String NEWLINE = "\r\n";
    private String m_name;
    private int m_age;
    private double m_salary;
    private Date m_hireDate;
    
    /** Creates a new instance of MyObj */
    public MyObj(String name, int age, double salary, Date hireDate){
        m_name = name;
        m_age = age;
        m_salary = salary;
        m_hireDate = hireDate;
    }
    public MyObj(){}
    
    public String toString()
    {
        StringBuffer sb = new StringBuffer();
        sb.append("Name: " + m_name + NEWLINE);
        sb.append("Age: " + m_age + NEWLINE);
        sb.append("Salary: " + m_salary + NEWLINE);
        sb.append("Hire Date: " + m_hireDate.toString());
        return sb.toString();
    }
}