Serializable：用于保存及还原对象——《Thinking in Java》随笔031
1 //: Worm.java 2 package c10; 3 4 import java.io.ByteArrayInputStream; 5 import java.io.ByteArrayOutputStream; 6 import java.io.FileInputStream; 7 import java.io.FileOutputStream; 8 import java.io.ObjectInputStream; 9 import java.io.ObjectOutputStream; 10 import java.io.Serializable; 11 12 /** 13 * @time: 上午10:35:14 14 * @date: 2017年5月1日 15 * @auther: skyfffire 16 * @version: v0.1 17 */ 18 class Data implements Serializable { 19 private static final long serialVersionUID = 20 -1235946666506705202L; 21 22 private int i; 23 24 Data(int x) { 25 i = x; 26 } 27 28 public String toString() { 29 return Integer.toString(i); 30 } 31 } 32 33 public class Worm implements Serializable { 34 private static final long serialVersionUID = 35 7755684981500799364L; 36 37 private static int r() { 38 return (int)(Math.random() * 10); 39 } 40 41 private Data[] d = 42 {new Data(r()), new Data(r()), new Data(r())}; 43 private Worm next = null; 44 private char c; 45 46 Worm(int i, char x) { 47 System.out.println("Worm constructor:" + i); 48 49 c = x; 50 51 if (--i > 0) { 52 next = new Worm(i, (char)(x + 1)); 53 } 54 } 55 56 Worm() { 57 System.out.println("Default constructor."); 58 } 59 60 public String toString() { 61 StringBuffer s = new StringBuffer(" " + c + "("); 62 63 for (int i = 0; i < d.length; i++) { 64 s.append(d[i].toString()); 65 } 66 67 s.append(')'); 68 69 if (next != null) { 70 s.append(next.toString()); 71 } 72 73 return s.toString(); 74 } 75 76 public static void main(String[] args) { 77 Worm w = new Worm(6, 'a'); 78 79 System.out.println("w = " + w); 80 81 // Object IO Stream 82 try { 83 // Output 84 ObjectOutputStream out = new ObjectOutputStream( 85 new FileOutputStream("worm.out")); 86 out.writeObject("Worm storage"); 87 out.writeObject(w); 88 out.close(); 89 90 // Input 91 ObjectInputStream in = new ObjectInputStream( 92 new FileInputStream("worm.out")); 93 String s = (String)in.readObject(); 94 Worm w2 = (Worm)in.readObject(); 95 System.out.println(s + ", w2 = " + w2); 96 in.close(); 97 } catch (Exception e) { 98 e.printStackTrace(); 99 } 100 101 // Byte IO Stream 102 try { 103 // Output 104 ByteArrayOutputStream bout = 105 new ByteArrayOutputStream(); 106 ObjectOutputStream out = 107 new ObjectOutputStream(bout); 108 out.writeObject("Worm storage"); 109 out.writeObject(w); 110 out.flush(); 111 112 // Input 113 ByteArrayInputStream bin = 114 new ByteArrayInputStream(bout.toByteArray()); 115 ObjectInputStream in = 116 new ObjectInputStream(bin); 117 String s = (String)in.readObject(); 118 Worm w3 = (Worm)in.readObject(); 119 System.out.println(s + ", w3 = " + w3); 120 121 // close IO stream 122 in.close(); 123 out.close(); 124 } catch (Exception e) { 125 e.printStackTrace(); 126 } 127 } 128 } 129 130 ///:~
输出结果：
Worm constructor:6
Worm constructor:5
Worm constructor:4
Worm constructor:3
Worm constructor:2
Worm constructor:1
w = a(842) b(627) c(504) d(753) e(709) f(651)
Worm storage, w2 = a(842) b(627) c(504) d(753) e(709) f(651)
Worm storage, w3 = a(842) b(627) c(504) d(753) e(709) f(651)
可以看到，实现了Serializable接口的类可以将对象转换为数据流并还原。
序列化(Serializable)可以说是Java中超级重要的东西了。
