Java 如何对文件进行多个Object对象流的读写操作

思路：把已经序列化的对象存入容器（如LinkedList<?>）中，然后用ObjectInputStream和ObjectOutputStream对这个实例化的LinkedList<?>对象进行读写。

测试主程序：

<pre class="java" name="code">/**   
* @Title: FileRW.java
* @Package com.file
* @Description: 文件、文件夹的创建、写入练习。读写是使用对象流实现。
* @author 慢跑学Android
* @date 2011-11-19 下午03:53:01
* @version V1.0   
*/
package com.file;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.LinkedList;


public class FileRW {
	private String dirPath;
	private String filename;
	
	public static void main(String[] args) {
		String path = "C:\\晓声";
		String fileName = "test.txt";
		FileRW fileRW = new FileRW(path, fileName);
		LinkedList<TestMessage> msgOut = new LinkedList<TestMessage>();
		LinkedList<TestMessage> msgIn = null;
		
		msgOut.add(new TestMessage("柯南", "偶像"));
		msgOut.add(new TestMessage("卡卡西", "好样的"));
		msgOut.add(new TestMessage("Android", "Android"));
		msgOut.add(new TestMessage("哈哈", "测试下喔"));
		fileRW.writeObject(path, fileName, msgOut);
		
		msgIn = fileRW.readObject(path,fileName);
		
		for(TestMessage temp:msgIn)	{
			System.out.println(temp.getName() + temp.getData());
		}
		
	}
	
	public FileRW(String dirPath, String filename) {
		this.dirPath = dirPath;
		this.filename = filename;
		if (creatDir()) {			
			creatFile();
		}
	}

	
	private boolean creatDir() {
		if (null != dirPath) {
			File path = new File(dirPath);
			if (path.exists()) {
				return true;
			}
			if (true == path.mkdirs() ) {
				return true;
			}
		}
		return false;
	}

	private void creatFile() {
		if (null != filename) {
			File file = new File(dirPath, filename);
			if (false == file.exists()) {
				try {
					file.createNewFile();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
		}
	}
	

	/**
	* @Title: writeObject
	* @Description: Write a object to a file.
	* @param path the directory of the target file
	* @param filename the name of the target file
	* @param msg the type of the object
	* @return void
	* @throws
	*/
	private void writeObject(String path, String filename, LinkedList<TestMessage> msg) {
		File file = new File(path, filename);
		if (false == file.isFile()) {
			return ;
		}
		
		try {
			// The value "false" for FileOutputStream means that overwrite this file,
			// if it is "true",append the new data to this file.
			ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream(file,false));
			oos.writeObject(msg);
			oos.flush();
			oos.close();
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
	
	/**
	* @Title: readObject
	* @Description: Read a object from a file.
	* @param path the directory of the target file
	* @param filename the name of the target file
	* @return LinkedList<TestMessage>
	* @throws
	*/
	@SuppressWarnings("unchecked")
	private LinkedList<TestMessage> readObject(String path, String filename) {
		File file = new File(path, filename);
		ObjectInputStream ois = null;
		LinkedList<TestMessage> msgAll = null;
		
		try {
			ois = new ObjectInputStream(new FileInputStream(file));
			try {
				msgAll = (LinkedList<TestMessage>)ois.readObject();
				
			} catch (ClassNotFoundException e) {
				e.printStackTrace();
			}
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			try {
				ois.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
		
		return msgAll;
	}
}
</pre>

测试程序中的消息包定义：

/**   
* @Title: TestMessage.java
* @Package com.file
* @Description: FileRW的消息流
* @author 慢跑学Android
* @date 2011-11-19 下午04:35:11
* @version V1.0   
*/
package com.file;


public class TestMessage implements java.io.Serializable {
	private String name;
	private String data;
	
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public String getData() {
		return data;
	}
	public void setData(String data) {
		this.data = data;
	}
	public TestMessage(String name, String msg) {
		this.name = name;
		data = msg;
	}
}

程序运行结果：

参考资料：ObjectInputStream类和ObjectOutputStream类的使用