dom4j、Xstream、orika等类库简单使用

最近用xml的数据格式比较多，所以简单记录一下这些类库的使用。

dom4j

dom4j用dom模型的方式解析xml数据。

<!--依赖包-->
<dependency>
            <groupId>org.dom4j</groupId>
            <artifactId>dom4j</artifactId>
            <version>2.1.3</version>
        </dependency>



<!--book.xml文件，后面使用-->
<?xml version="1.0" encoding="utf-8"?>
<bookstore>

    <book category="COOKING">
        <title lang="en">Everyday Italian</title>
        <author>Giada De Laurentiis</author>
        <year>2005</year>
        <price>30.00</price>
    </book>

    <book category="CHILDREN">
        <title lang="en">Harry Potter</title>
        <author>J K. Rowling</author>
        <year>2005</year>
        <price>29.99</price>
    </book>

    <book category="WEB">
        <title lang="en">XQuery Kick Start</title>
        <author>James McGovern</author>
        <author>Per Bothner</author>
        <author>Kurt Cagle</author>
        <author>James Linn</author>
        <author>Vaidyanathan Nagarajan</author>
        <year>2003</year>
        <price>49.99</price>
    </book>

    <book category="WEB">
        <title lang="en">Learning XML</title>
        <author>Erik T. Ray</author>
        <year>2003</year>
        <price>39.95</price>
    </book>

</bookstore>

 @Test
    public void testDom4j() throws DocumentException, IOException {

        //获取文件对象
        File file=new File("book.xml");
        //创建解析器
        SAXReader reader = new SAXReader();
        //通过解析器获取文件内容，返回Document对象
        Document document = reader.read(file);
        //通过Document对象获取节点
        Element rootElement = document.getRootElement();
        //获取节点名
        System.out.println(rootElement.getName());
        //将节点对象转换为xml字符串
        System.out.println(rootElement.asXML());

    }

Xstream

Xstream通过反射，将JavaBean个xml进行互相转换，也可以进行JavaBean和Json数据之间的转换。

<dependency>
            <groupId>com.thoughtworks.xstream</groupId>
            <artifactId>xstream</artifactId>
            <version>1.4.11.1</version>
        </dependency>

<!-- 处理json转换时需要这个json处理包 -->
<dependency>
    <groupId>org.codehaus.jettison</groupId>
    <artifactId>jettison</artifactId>
    <version>1.4.1</version>
</dependency>

xml和javaBean之间转换

@Data
@AllArgsConstructor
public class User {

    private String name;
    private Integer id;
    private String sex;
    private Integer age;
}

@Data
@AllArgsConstructor
public class Person {
    private String name;
    private Integer id;
    private String sex;
}

@Test
public  void testX(){
    //使用Stax不需要加入其他jar包做驱动
    XStream stream = new XStream(new StaxDriver());

    //给根节点起别名，默认是类名
    stream.alias("users",User.class);
    //给字段起别名
    stream.aliasField("姓名",User.class,"name");

    //将bean转换为xml格式
    String s = stream.toXML(new User("Jack",12666,"男",45));
    System.out.println(s);
    //从xml格式中获取对象
    System.out.println(stream.fromXML(s));

    //将bean以xml方式序列化到输出流中
    stream.toXML(new User("Jack",12666,"男",45),new FileWriter(new File("user.xml")));


}


<?xml version="1.0" ?><users><姓名>Jack</姓名><id>12666</id><sex>男</sex><age>45</age></users>
Security framework of XStream not initialized, XStream is probably vulnerable.
User(name=Jack, id=12666, sex=男, age=45)

json和javabean之间转换,有两种驱动选择：

 //json驱动，自带的，只能写不能读
XStream stream = new XStream(new JsonHierarchicalStreamDriver());
stream.allowTypes(new Class[]{User.class});
String xml = stream.toXML(new User("Jack", 12666, "男", 45));
System.out.println(xml);

//如其名字，分层显示
{"com.cgl.ek.pojo.User": {
  "name": "Jack",
  "id": 12666,
  "sex": "男",
  "age": 45
}}

//内部实现一个方法，去掉根节点
XStream streamJson = new XStream(new JsonHierarchicalStreamDriver(){
    public HierarchicalStreamWriter createWriter(Writer out) {
        return new JsonWriter(out, JsonWriter.DROP_ROOT_MODE);
    }
});
String xmlJson = streamJson.toXML(new User("Jack", 12666, "男", 45));
System.out.println(xmlJson);

//没有根节点
{
  "name": "Jack",
  "id": 12666,
  "sex": "男",
  "age": 45
}


 //从json字符串中还原对象,需要json包
XStream jStream = new XStream(new JettisonMappedXmlDriver());
Object o = jStream.fromXML(xml);
String toXML = jStream.toXML(new User("Jack", 12666, "男", 45));
System.out.println(toXML);

{"com.cgl.ek.pojo.User":{"name":"Jack","id":12666,"sex":"男","age":45}}

XStream jnStream = new XStream(new JettisonMappedXmlDriver());
//jnStream.alias("user",User.class);
jnStream.setMode(XStream.ID_REFERENCES);//这里可以设置模式
String toXML2 = jnStream.toXML(new User("Jack", 12666, "男", 45));
System.out.println(toXML2);

//多出一个@ID字段
 {"com.cgl.ek.pojo.User":{"@id":1,"name":"Jack","id":12666,"sex":"男","age":45}}

orika core

这个库用来进行对象之间的拷贝，像BeanUtils，不同的是使用字节码生成数据。

 @Test
    public void testBean(){
        //获取映射工厂
        DefaultMapperFactory.Builder builder = new DefaultMapperFactory.Builder();
        DefaultMapperFactory factory = builder.build();
        //User中的数据拷贝到Person中，字段对应，剩下的用默认，最后注册
        factory.classMap(User.class, Person.class).field("name","name").byDefault().register();
        User u=new User("Jack",12666,"男",45);
        //映射装饰
        MapperFacade facade = factory.getMapperFacade();
        //开始拷贝
        Person person = facade.map(u, Person.class);
       
        System.out.println(person);
    }

//没有的字段不会映射过去
Person(name=Jack, id=12666, sex=男)