WebService CXF JAXB角色及简单使用

WebService传递XML文档，当然也可以传递JSON对象。这节我只针对传递XML，那么JAVA绑定成XML，服务端将XML解析成Java对象有什么工具可用吗，其实这样的工具多的是。这里我选择一个比较简单的JAXB工具来讲解一下。 
    JAXB（Java Architecture for XML Binding）提供了一个快速而方便的方式绑定XML Schemas和java，使java程序员能够很方便的在java应用程序中处理XML数据。JAXB提供了将XML文档解组为java内容树的方法，以及将java内容树重新编组回XML文档的方法。JAXB同样也提供了一种从java对象生成XML Schema的方式。

 

一、JAXB充当的角色

   

 

 

JAXB中常用的注解

 

 

 

 二、简单示例

    1、@XmlRootElement

        POJO:

       

package org.wy.pojo;

import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement
public class User {
	private String name = "wy";
	private String sex = "man";
    public int age = 20;
    
    
	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}
}	

 

       

JaxbTest.java

 

package org.wy.jaxb;

import java.io.StringReader;

import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Marshaller;
import javax.xml.bind.Unmarshaller;

import org.wy.pojo.User;


public class JaxbTest {

	public static void main(String[] args) throws JAXBException {
		JAXBContext context = JAXBContext.newInstance(User.class);
		
		//JavaObject ---> XML
		Marshaller marshaller = context.createMarshaller();  
		User user = new User();
		marshaller.marshal(user, System.out);
		
		System.out.println();
		
		// XML---> JavaObject
		Unmarshaller unmarshaller = context.createUnmarshaller();
		String str = "<user><age>23</age></user>";
		user = (User)unmarshaller.unmarshal(new StringReader(str));
		System.out.println(user.age);
	}

}

 

输出结果：

 

<?xml version="1.0" encoding="UTF-8" standalone="yes"?><user><age>20</age><name>wy</name></user>
23

 

从输出结果看到 性别没有转换到xml中，原因可以从后接口XmlAccessorType.java中找到原因

我们可以看到如下

 

@Inherited @Retention(RUNTIME) @Target({PACKAGE, TYPE})
public @interface XmlAccessorType {

    /**
     * Specifies whether fields or properties are serialized. 
     * 
     * @see XmlAccessType
     */
    XmlAccessType value() default XmlAccessType.PUBLIC_MEMBER;
}

 默认处理方式PUBLIC_MEMBER，处理public的。但是name是private的也转换成功了，原因是name被设置成了属性。

 

XmlAccessorType 有几种处理方式哪？

  查看枚举类XmlAccessType.java

  

public enum XmlAccessType {
    /**
     * Every getter/setter pair in a JAXB-bound class will be automatically
     * bound to XML, unless annotated by {@link XmlTransient}.
     *
     * Fields are bound to XML only when they are explicitly annotated
     * by some of the JAXB annotations.
     */
    PROPERTY,
    /**
     * Every non static, non transient field in a JAXB-bound class will be automatically
     * bound to XML, unless annotated by {@link XmlTransient}.
     *
     * Getter/setter pairs are bound to XML only when they are explicitly annotated
     * by some of the JAXB annotations.
     */
    FIELD,
    /**
     * Every public getter/setter pair and every public field will be
     * automatically bound to XML, unless annotated by {@link XmlTransient}.
     *
     * Fields or getter/setter pairs that are private, protected, or 
     * defaulted to package-only access are bound to XML only when they are
     * explicitly annotated by the appropriate JAXB annotations.
     */
    PUBLIC_MEMBER,
    /**
     * None of the fields or properties is bound to XML unless they
     * are specifically  annotated with some of the JAXB annotations.
     */
    NONE
}

 

 

当然JAXB也支持修改XML文档的根节点名称和命名空间，修改方式如下

@XmlRootElement(name="userwy", namespace="user-wy")

 

 

2、@XmlAccessorType

 

    POJO：

   

package org.wy.pojo;

import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement
@XmlAccessorType(XmlAccessType.PROPERTY)
public class User {
	private String name = "wy";
	private String sex = "man";
    public int age = 20;
    
    
	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}
}	

 

输出结果：

 

<?xml version="1.0" encoding="UTF-8" standalone="yes"?><user><name>wy</name></user>
20

 

 

将@XmlAccessorType(XmlAccessType.FIELD)

 

输出结果：

<?xml version="1.0" encoding="UTF-8" standalone="yes"?><user><name>wy</name><sex>man</sex><age>20</age></user>
23

 

 

 3、@XmlJavaTypeAdapter

   复杂对象

   POJO：

  

package org.wy.pojo;

import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.adapters.XmlJavaTypeAdapter;

@XmlRootElement
@XmlAccessorType(XmlAccessType.PROPERTY)
public class User {
	private String name = "wy";
	private String sex = "man";
    public int age = 20;
    
    private Address address;
    
	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	@XmlJavaTypeAdapter(AddressAdapter.class)
	public Address getAddress() {
		return address;
	}

	public void setAddress(Address address) {
		this.address = address;
	}
	
	
}	

 

Address.java接口

package org.wy.pojo;

public interface Address {
   public String getAddress();
}

 

AddressImpl.java

  

package org.wy.pojo;

public class AddressImpl implements Address{
    private String address;

	public String getAddress() {
		return address;
	}

	public void setAddress(String address) {
		this.address = address;
	}

}

 

AddressAdapter.java

package org.wy.pojo;

import javax.xml.bind.annotation.adapters.XmlAdapter;

public class AddressAdapter extends XmlAdapter<String, Address> {

	@Override
	public Address unmarshal(String v) throws Exception {
		AddressImpl address = new AddressImpl();
		address.setAddress(v);
		return address;
	}

	@Override
	public String marshal(Address v) throws Exception {
		return v.getAddress();
	}

}

 

JaxbTest.java

 

  

package org.wy.jaxb;

import java.io.StringReader;

import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Marshaller;
import javax.xml.bind.Unmarshaller;

import org.wy.pojo.AddressImpl;
import org.wy.pojo.User;


public class JaxbTest {

	public static void main(String[] args) throws JAXBException {
		JAXBContext context = JAXBContext.newInstance(User.class);
		
		//JavaObject ---> XML
		Marshaller marshaller = context.createMarshaller();  
		User user = new User();
		AddressImpl address = new AddressImpl();
		address.setAddress("BeiJing");
		user.setAddress(address);
		marshaller.marshal(user, System.out);
		
		System.out.println();
		
		// XML---> JavaObject
		Unmarshaller unmarshaller = context.createUnmarshaller();
		String str = "<user><age>23</age></user>";
		user = (User)unmarshaller.unmarshal(new StringReader(str));
		System.out.println(user.age);
	}

}

 

输出结果：

 

<?xml version="1.0" encoding="UTF-8" standalone="yes"?><user><address>BeiJing</address><name>wy</name></user>
20