# 用Jersey構建RESTful服務2--JAVA對象轉成XML輸出 ## 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](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](http://localhost:8089/RestDemo/rest/users) 輸出對象的集合  **本章源碼**：[https://github.com/waylau/RestDemo/tree/master/jersey-demo2-xml](https://github.com/waylau/RestDemo/tree/master/jersey-demo2-xml)