利用流实现类的深克隆

public class Test implements Serializable {    private Entity entity;    public Entity getEntity() {        return entity;    }    public void setEntity(Entity entity) {        this.entity = entity;    }    /**     * 先将类实现序列化接口，将类写入流再读出，实际上是实现了类的深克隆     * @throws Exception     */    public void writeAndReadObject() throws Exception {        Entity entity = new Entity();        entity.setS("111");        Test test = new Test();        test.setEntity(entity);        //将对象写入流        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();        ObjectOutputStream objectOutputStream = new ObjectOutputStream(byteArrayOutputStream);        objectOutputStream.writeObject(test);        //从流中读对象        ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(byteArrayOutputStream.toByteArray());        ObjectInputStream objectInputStream = new ObjectInputStream(byteArrayInputStream);        Test t = (Test) objectInputStream.readObject();        System.out.println(test.getClass() == t.getClass());//true        System.out.println(test.getEntity()==t.getEntity());//false        System.out.println(test.getEntity().getS().equals(t.getEntity().getS()));//true    }    public static void main(String[] args) throws Exception {        Test test = new Test();        test.writeAndReadObject();    }}

public class Entity implements Serializable {    private String s;    public String getS() {        return s;    }    public void setS(String s) {        this.s = s;    }}