序列化心得-优快云博客

本文介绍了一个使用Java实现对象序列化的具体案例。通过定义Fruit和Apple两个类，并实现序列化接口，演示了如何自定义序列化过程，以及如何保存和读取序列化后的对象。特别关注了transient关键字的作用及序列化过程中自定义方法的应用。

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package SerializeDemo;

import java.io.*;

public class Fruit  implements Serializable {
	int size = 42;

	Fruit(String s) {
		System.out.println("fruit...");
	}
	Fruit() {
		System.out.println("fruit...");
	}

}

package SerializeDemo;

import java.io.*;

public class Apple extends Fruit{

	int as = 3;

	private transient String s = "I'm not serializable..." ;

	public Apple() {
//		super("aa");
		System.out.println("the as is :" + as);
	}

	public void writeObject(ObjectOutputStream os) {
		try {
			os.defaultWriteObject();
			os.writeObject(s);
		} catch (IOException e) {
			e.printStackTrace();
		}

		System.out.println("invoke the writeObject...");

	}


	public void readObject(ObjectInputStream os) {
		System.out.println("invoke the readObject...");
		try {
			os.defaultReadObject();
//			s = (String)os.readObject();
		} catch (IOException e) {
			e.printStackTrace();
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
		}
	}

	public Apple readApple(FileInputStream is) {
		Apple a = null;
		try {
			ObjectInputStream ois = new ObjectInputStream(is);			
			a = (Apple)ois.readObject();			
			ois.close();			
		}
		catch(Exception e) {
			e.printStackTrace();
		}
		return a;
	}

	public void saveApple(FileOutputStream os,Object obj) {
		try {
			ObjectOutputStream oos = new ObjectOutputStream(os);
			oos.writeObject(obj);
			oos.close();
		}
		catch(Exception e) {
			e.printStackTrace();
		}
	}

	public static void main(String[] args) {
		try {
			FileOutputStream fos = new FileOutputStream("Apple.txt");
			FileInputStream fis = new FileInputStream("Apple.txt");

			Apple a = new Apple();
			a.size = 20;  //super original 42
			a.as = 20;

			a.saveApple(fos, a);
			Apple b = a.readApple(fis);
//			System.out.println("b.size is:"+b.size+"\tb.as is:"+b.as);
			System.out.println("b.size is:"+b.size+"\tb.as is:"+b.as+"\tb.food is:"+b.s);

		}
		catch(Exception e) {
			e.printStackTrace();
		}	
	}
}