blips3.java

来自「翁剀JAVA语言那门课程的教案 很多人都看多他的视频教程可惜没有ppt的教案」· Java 代码 · 共 56 行

//: Blip3.java
// Reconstructing an externalizable object
import java.io.*;
import java.util.*;

class Blip3 implements Externalizable {
	int i;
	String s; // No initialization
	public Blip3() {
		System.out.println("Blip3 Constructor");
		// s, i not initialized
	}
	public Blip3(String x, int a) {
		System.out.println("Blip3(String x, int a)");
		s = x;
		i = a;
		// s & i initialized only in non-default
		// constructor.
	}
	public String toString() { return s + i; }
	public void writeExternal(ObjectOutput out)
		throws IOException {
		System.out.println("Blip3.writeExternal");
		// You must do this:
		out.writeObject(s); out.writeInt(i);
	}
	public void readExternal(ObjectInput in)
		throws IOException, ClassNotFoundException {
		System.out.println("Blip3.readExternal");
		// You must do this:
		s = (String)in.readObject();
		i =in.readInt();
	}
	public static void main(String[] args) {
		System.out.println("Constructing objects:");
		Blip3 b3 = new Blip3("A String ", 47);
		System.out.println(b3.toString());
		try {
			ObjectOutputStream o =
			new ObjectOutputStream(
			new FileOutputStream("Blip3.out"));
			System.out.println("Saving object:");
			o.writeObject(b3);
			o.close();
			// Now get it back:
			ObjectInputStream in =
			new ObjectInputStream(
			new FileInputStream("Blip3.out"));
			System.out.println("Recovering b3:");
			b3 = (Blip3)in.readObject();
			System.out.println(b3.toString());
		} catch(Exception e) {
			e.printStackTrace();
		}
	}
} ///:~