java序列化（对象流）

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序列化

• 目的：将对象保存到硬盘中，或者网络中传输对象
• 机制：将Java对象转换为字节序列，序列可以保存硬盘，或网络传输
• 代码：实现Serializable或者Externalizable接口
• 序列化版本标识符：private static final long serialVersionUID
• 注意：不能序列化static修饰的成员变量；对象中的任何成员变量必须实现Serializable接口

class Person implements Serializable {    private static final long serialVersionUID = 124213453255L;    private String name;    private int age;    public Person(String name, int age) {        super();        this.name = name;        this.age = age;    }    @Override    public String toString() {        return "Person [name=" + name + ", age=" + age + "]";    }}

对象流

• ObjectOutputStream:将Java对象写入IO流(序列化Serialize)
• ObjectInputStream:从IO流中恢复Java对象
• 注意：不能序列化static修饰的成员变量；对象中的任何成员变量必须实现Serializable接口

@Test    public void testObjectOutputStream() {        Person p1 = new Person("张三",20);        Person p2 = new Person("李四",20);        ObjectOutputStream oos = null;        try {            oos = new ObjectOutputStream(new FileOutputStream("person.txt"));            oos.writeObject(p1);            oos.flush();            oos.writeObject(p2);            oos.flush();        } catch (IOException e) {            e.printStackTrace();        } finally {            if (oos != null) {                try {                    oos.close();                } catch (IOException e) {                    e.printStackTrace();                }            }        }    }

@Test    public void testObjectInputStream() {        ObjectInputStream ois = null;        try {            ois = new ObjectInputStream(new FileInputStream("person.txt"));            Person p1 = (Person)ois.readObject();            System.out.println(p1);            Person p2 = (Person)ois.readObject();            System.out.println(p2);        } catch (Exception e) {            e.printStackTrace();        } finally {            if (ois != null) {                try {                    ois.close();                } catch (IOException e) {                    // TODO Auto-generated catch block                    e.printStackTrace();                }            }        }    }

Person [name=张三, age=20]
Person [name=李四, age=20]