## 一、 總體說明
XML和JSON 是最為常用的數據交換格式。本例子演示如何將java對象，轉成XML輸出。
## 二、流程
1.在上文的例子中，創建一個包“com.waylau.rest.bean”
2.在該包下創建一個JAVA類"User"
~~~
package com.waylau.rest.bean;
import javax.xml.bind.annotation.XmlRootElement;
/*
* 用戶 bean
* @author waylau.com
* 2014-3-17
*/
@XmlRootElement
public class User {
private String userId;
private String userName;
private String age;
public User() {};
public User(String userId, String userName, String age) {
this.userId = userId;
this.userName = userName;
this.age = age;
}
public String getUserId() {
return userId;
}
public void setUserId(String userId) {
this.userId = userId;
}
public String getUserName() {
return userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
public String getAge() {
return age;
}
public void setAge(String age) {
this.age = age;
}
}
~~~
注意：該類上面增加了一個注解“@XmlRootElement”，在將該類轉化成XML時，說明這個是XML的根節點。
3.在“com.waylau.rest.resources”中，增加資源“UserResource“，代碼如下：
~~~
package com.waylau.rest.resources;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.PathParam;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.DELETE;
import javax.ws.rs.GET;
import javax.ws.rs.POST;
import javax.ws.rs.PUT;
import com.waylau.rest.bean.User;
@Path("/users")
public class UserResource {
private static Map<String,User> userMap = new HashMap<String,User>();//存儲用戶
/**
* 查詢所有
* @return
*/
@GET
@Produces(MediaType.APPLICATION_XML)
public List<User> getAllUsers(){
List<User> users = new ArrayList<User>();
User u1 = new User("001","WayLau","26");
User u2 = new User("002","King","23");
User u3 = new User("003","Susan","21");
userMap.put(u1.getUserId(), u1);
userMap.put(u2.getUserId(), u2);
userMap.put(u3.getUserId(), u3);
users.addAll( userMap.values() );
return users;
}
@GET
@Path("/getUserXml")
@Produces(MediaType.APPLICATION_XML)
public User getUserXml() {
User user = new User();
user.setAge("21");
user.setUserId("004");
user.setUserName("Amand");
return user;
}
}
~~~
其中MediaType.APPLICATION_XML?說明了是以XML形式輸出
在瀏覽器輸入http://localhost:8089/RestDemo/rest/users/getUserXml，輸出單個對象
在瀏覽器輸入 http://localhost:8089/RestDemo/rest/users ?輸出對象的集合
