JAVA序列化与反序列化三种格式存取（默认格式、XML格式、JSON格式）

什么是序列化  
java中的序列化(serialization)机制能够将一个实例对象的状态信息写入到一个字节流中，使其可以通过socket进行传输、或者持久化存储到数据库或文件系统中；然后在需要的时候，可以根据字节流中的信息来重构一个相同的对象。序列化机制在java中有着广泛的应用，EJB、RMI等技术都是以此为基础的。 

正确使用序列化机制  
一般而言，要使得一个类可以序列化，只需简单实现 java.io.Serializable 接口即可（ 还要实现无参数的构造方法 ）。该接口是一个标记式接口，它本身不包含任何内容，实现了该接口则表示这个类准备支持序列化的功能。如下例定义了类Person，并声明其可以序列化。

上面两段来源： http://lionheart.iteye.com/blog/139540

 

 

 

public class Person implements Serializable {

    private static final long serialVersionUID = 1L;

    private String name;;
    private int age;
    public Person(){

    }
    public Person(String str,int n){
        System.out.println("Inside Person's Constructor");
        name = str;
        age = n;
    }
    public String getName() {
        return name;
    }
    public int getAge() {
        return age;
    }
}

 

下面为三种格式转换的代码:

1.默认格式.

 

public class SerializeToFlatFile {
    public static void main(String[] args) {
        SerializeToFlatFile ser = new SerializeToFlatFile();
        ser.savePerson();
        ser.restorePerson();
    }

    public void savePerson(){
        Person myPerson = new Person("Jay", 24);
        try{
            FileOutputStream fos = new FileOutputStream("E:\\person.txt");
            ObjectOutputStream oos = new ObjectOutputStream(fos);
            System.out.println("Person--Jay,24---Written");

            oos.writeObject(myPerson);
            oos.flush();
            oos.close();
        }catch(Exception e){
            e.printStackTrace();
        }
    }

    @SuppressWarnings("resource")
    public void restorePerson(){
        try{
            FileInputStream fls = new FileInputStream("E:\\person.txt");
            ObjectInputStream ois = new ObjectInputStream(fls);

            Person myPerson = (Person)ois.readObject();
            System.out.println("\n---------------------\n");
            System.out.println("Person --read:");
            System.out.println("Name is:"+myPerson.getName());
            System.out.println("Age is :"+myPerson.getAge());

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

 

输出结果： sr test.serializable.Person       I ageL namet Ljava/lang/String;xp   t Jay

 

2.XML格式

 

//参考:http://www.cnblogs.com/bluesky5304/archive/2010/04/07/1706061.html
public class SerializeXML {

    public static void main(String[] args) {
        SerializeXML ser = new SerializeXML();
        ser.serializeToXml();
        ser.deSerializeFromXml();
    }
    public void serializeToXml(){
        Person[] myPersons = new Person[2];
        myPersons[0] = new Person("Jay", 24);
        myPersons[1] = new Person("Tom", 23);

        XStream xStream = new XStream();
        xStream.alias("Person", Person.class);
        try{
            FileOutputStream foStream = new FileOutputStream("E:\\persons.xml");
            xStream.toXML(myPersons,foStream);
        }catch(Exception e){
            e.printStackTrace();
        }
    }
    public void deSerializeFromXml(){
        XStream xStream = new XStream();
        xStream.alias("Person", Person.class);
        Person[] myPersons = null;
        try{
            FileInputStream flStream = new FileInputStream("E:\\persons.xml");
            myPersons = (Person[])xStream.fromXML(flStream);
            if(myPersons!=null){
                for(Person person:myPersons){
                    System.out.println(person.getName());
                    System.out.println(person.getAge());
                }
            }
        }catch(Exception e){
            e.printStackTrace();
        }
    }
}

 

输出结果：

 

<Person-array>
  <Person>
    <name>Jay</name>
    <age>24</age>
  </Person>
  <Person>
    <name>Tom</name>
    <age>23</age>
  </Person>
</Person-array>

 

3.JSON格式

 

//参考:http://www.cnblogs.com/hoojo/archive/2011/04/22/2025197.html
public class SerializeJSON {

    public static void main(String[] args) {
        SerializeJSON serializeJSON = new SerializeJSON();
        serializeJSON.writeJSON();
        serializeJSON.readJSON();
    }

    public void writeJSON(){
        XStream xStream = new XStream(new JettisonMappedXmlDriver());
        Person person = new Person("geniushehe", 16);
        try {
            FileOutputStream fos = new FileOutputStream("E:\\json.js");
            xStream.setMode(XStream.NO_REFERENCES);
            xStream.alias("Person", Person.class);
            xStream.toXML(person, fos);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
    }
    public void readJSON(){
        XStream xStream = new XStream(new JettisonMappedXmlDriver());
        Person person = null;
        try {
            FileInputStream fis = new FileInputStream("E:\\json.js");
            xStream.setMode(XStream.NO_REFERENCES);
            xStream.alias("Person", Person.class);
            person = (Person)xStream.fromXML(fis);
            System.out.println(person.getName());
            System.out.println(person.getAge());
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
    }
}

输出结果：

 

 

{"Person":{"name":"geniushehe","age":16}}