Spring OXM-XStream流化对象-CSDN博客

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概述

XStream为java.io.ObjectInputStream和ObjectOutputStream提供了替代的实现,允许以对象流方式进行XML序列化或者反序列化操作。

这对于处理集合对象非常有用(List<User> users),在内存中只保留一个User对象流。很显然,我们应该使用基于流而非DOM的XML解析器读取XML,以提高性能。

创建一个输出流,我们不得不提到HierarchicalStreamWriter. 它是一个接口,字面意思就是层级关系的输出流。 XStream默认提供了几个常用的实现类用于输出,比如CompactWriter和PrettyPrintWriter。

示例

package com.xgj.oxm.xstream.quickDemo.streamObject;

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.PrintWriter;
import java.util.Date;

import com.thoughtworks.xstream.XStream;
import com.thoughtworks.xstream.io.xml.PrettyPrintWriter;
import com.xgj.oxm.xstream.quickDemo.domain.LoginLog;
import com.xgj.oxm.xstream.quickDemo.domain.User;

public class ObjectStreamDemo {

    private static XStream xstream;

    static {
        xstream = new XStream();
    }

    /**
     * 
     * 
     * @Title: objectToXml
     * 
     * @Description: JAVA对象转化为XML
     * 
     * @throws Exception
     * 
     * @return: void
     */
    public void objectToXml() throws Exception {
        // (1)实例化序列化对象
        User user = getUser();
        // (2)创建一个PrintWriter对象,用于输出。
        PrintWriter pw = new PrintWriter("D:\\ObjectStreamSample.xml");
        // (3)创建一个HierarchicalStreamWriter的实现类来创建输出
        PrettyPrintWriter ppw = new PrettyPrintWriter(pw);
        // (4)创建对象输出流
        ObjectOutputStream out = xstream.createObjectOutputStream(ppw);
        out.writeObject(user);
        out.close();
    }

    /**
     * 
     * 
     * @Title: xmlToObject
     * 
     * @Description: XML转化为JAVA对象
     * 
     * @return
     * @throws Exception
     * 
     * @return: User
     */
    public User xmlToObject() throws Exception {
        // (1)我们需要通过对象流进行输入操作,需要FileReader和BufferedReader
        FileReader fr = new FileReader("D:\\ObjectStreamSample.xml");
        BufferedReader br = new BufferedReader(fr);
        //(2)创建对象输入流
        ObjectInputStream input = xstream.createObjectInputStream(br);
        // (3)创建对象,通过ObjectInputStream中的readObject()方法将对象从XML文件中读取出来。
        User user = (User) input.readObject();
        return user;

    }


    /**
     * 
     * 
     * @Title: getUser
     * 
     * @Description: 初始化转换对象
     * 
     * @return
     * 
     * @return: User
     */
    public static User getUser() {
        LoginLog log1 = new LoginLog();
        LoginLog log2 = new LoginLog();
        log1.setIp("192.168.1.91");
        log1.setLoginDate(new Date());
        log2.setIp("192.168.1.92");
        log2.setLoginDate(new Date());
        User user = new User();
        user.setId(1);
        user.setUserName("xstream");
        user.addLoginLog(log1);
        user.addLoginLog(log2);
        return user;
    }

    public static void main(String[] args) throws Exception {
        ObjectStreamDemo converter = new ObjectStreamDemo();
        converter.objectToXml();
        User u = converter.xmlToObject();
        for (LoginLog log : u.getLogs()) {
            if (log != null) {
                System.out.println("访问IP: " + log.getIp());
                System.out.println("访问时间: " + log.getLoginDate());
            }
        }

    }

}

示例源码

代码已托管到Github—> github.com/yangshangwe…