xstream实现对象的序列化和反序列化（Java）

概述

　　最新整理Java方面XML序列化和反序列化的常用工具类，找到了dom4j和xstream。dom4j相对小巧，很好的解读xml；但是对于对象的xml序列化和反序列化，我还是比较喜欢xsteam（ps：个人爱好吧），这里整理xstream的入门基础知识；

使用

引用maven内容

        <dependency>
            <groupId>com.thoughtworks.xstream</groupId>
            <artifactId>xstream</artifactId>
            <version>1.4.8</version>
        </dependency>

别名配置的方式

1、可以通过类注解实现@XStreamAlias,比如XStreamAlias("book");

采用这种方式的时候，需要注意xStream实例化的时候，加上 xStream.processAnnotations(Bookstore.class); //通过注解方式的，一定要有这句话

2、可以通过配置Xstream设置实现；比如xStream.alias("book",book.class);

其他注意事项

1、将某一个类的属性，作为xml头信息的属性，而不是子节点  ，需要使用useAttributeFor，比如：xStream.useAttributeFor(book.class,"id");

2、隐藏跟属性节点的时候，需要使用addImplicitCollection，比如：xStream.addImplicitCollection(Bookstore.class,"books");

3、在Spring Boot下使用，XML转对象时，同一个类无法进行转换，原因是因为SpringBoot重新加载了对象；若未指定classloader的时候，SpringBoot未正确使用classloader，需要指定classloader，需要在方法中指定加载的类，添加如下代码： xstream.setClassLoader(clazz.getClassLoader());

完整代码如下：

Bookstore类：

package com.dbgo.xmldemo;
import com.thoughtworks.xstream.annotations.XStreamAlias;
import java.util.List;
@XStreamAlias("bookstore")
public class Bookstore {
    private List<book> books;

    public Bookstore(List<book> books) {
        this.books = books;
    }
    public List<book> getBooks() {
        return books;
    }
    public void setBooks(List<book> books) {
        this.books = books;
    }
}

book类

package com.dbgo.xmldemo;

import com.thoughtworks.xstream.annotations.XStreamAlias;

@XStreamAlias("book")
public class book {
    private Integer id;
    private String name;
    private String author;
    private String year;
    private double price;

    public book(Integer id, String name, String author, String year, double price) {
        this.id = id;
        this.name = name;
        this.author = author;
        this.year = year;
        this.price = price;
    }

    ....省略get/set属性....
}

使用类注解解析方法

   protected static void XstreamDemo(String xmsource)
    {
        XStream xStream=new XStream();
        xStream.addImplicitCollection(Bookstore.class,"books");
        xStream.processAnnotations(Bookstore.class); //通过注解方式的，一定要有这句话
        xStream.processAnnotations(book.class);
　　　　 xstream.setClassLoader(Bookstore.class.getClassLoader());//在spring boot一定加上这句话
        Object bookstore2= xStream.fromXML(xmsource);

        String xmocontent=xStream.toXML(bookstore2);
        System.out.println(xmocontent);
        //Bookstore bookstore1= (Bookstore)xStream.fromXML(xmocontent);

    }

使用非类注解方法

   protected static void XstreamDemo(String xmsource)
    {
        XStream xStream=new XStream();
        xStream.alias("book",book.class);
        xStream.alias("bookstore",Bookstore.class);
        xStream.useAttributeFor(book.class,"id");
        xStream.addImplicitCollection(Bookstore.class,"books");       
        Object bookstore2= xStream.fromXML(xmsource);
        Bookstore bookstore=new Bookstore(new ArrayList<>());
        bookstore.getBooks().add(new book(1,"zhang","hi","23",34));
        String xmocontent=xStream.toXML(bookstore);
        System.out.println(xmocontent);
        //Bookstore bookstore1= (Bookstore)xStream.fromXML(xmocontent);

    }

xml报文如下

String xmlSource="<?xml version="1.0" encoding="UTF-8"?>" +
                "<bookstore>" +
                "    <book id="1">" +
                "        <name>冰与火之歌</name>" +
                "        <author>乔治马丁</author>" +
                "        <year>2014</year>" +
                "        <price>89</price>" +
                "    </book>" +
                "    <book id="2">" +
                "        <name>安徒生童话</name>" +
                "        <year>2004</year>" +
                "        <price>77</price>" +
                "        <author>English</author>" +
                "    </book>    " +
                "</bookstore>";

参考博客

java生成解析xml的另外两种方法Xstream  https://www.cnblogs.com/happyPawpaw/p/4972650.html

java+xstream实现xml序列化  https://blog.csdn.net/jaryle/article/details/54893582

Bookstore.class