1、XML資料型別輸出：

一、 總體說明

XML和JSON 是最為常用的資料交換格式。本例子演示如何將java物件，轉成XML輸出。

二、流程

1.在上文的例子中，建立一個包“com.waylau.rest.bean”

2.在該包下建立一個JAVA類"User"

1. package com.waylau.rest.bean;  
2. import javax.xml.bind.annotation.XmlRootElement;  
3. /* 
4.  * 使用者 bean 
5.  * @author waylau.com 
6.  * 2014-3-17
    
7.  */
8. @XmlRootElement
9. publicclass User {  
10.     private String userId;  
11.     private String userName;  
12.     private String age;  
13.     public User() {};  
14.     public User(String userId, String userName, String age) {  
15.         this.userId = userId;  
16.         this.userName = userName;  
17.         this.age = age;  
18.     }  
19.     public String getUserId() {  
20.         return userId;  
21.     }  
22.     publicvoid setUserId(String userId) {  
23.         this.userId = userId;  
24.     }  
25.     public String getUserName() {  
26.         return userName;  
27.     }  
28.     publicvoid setUserName(String userName) {  
29.         this.userName = userName;  
30.     }  
31.     public String getAge() {  
32.         return age;  
33.     }  
34.     publicvoid setAge(String age) {  
35.         this.age = age;  
36.     }  
37. }  

package com.waylau.rest.bean;
import javax.xml.bind.annotation.XmlRootElement;
/*
 * 使用者 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;
	}
}

3.在“com.waylau.rest.resources”中，增加資源“UserResource“，程式碼如下：

1. package com.waylau.rest.resources;  
2. import java.util.ArrayList;  
3. import java.util.HashMap;  
4. import java.util.List;  
5. import java.util.Map;  
6. import javax.ws.rs.Path;  
7. import javax.ws.rs.Produces;  
8. import javax.ws.rs.PathParam;  
9. import javax.ws.rs.core.MediaType;  
10. import javax.ws.rs.DELETE;  
11. import javax.ws.rs.GET;  
12. import javax.ws.rs.POST;  
13. import javax.ws.rs.PUT;  
14. import com.waylau.rest.bean.User;  
15. @Path("/users")  
16. publicclass UserResource {  
17.     privatestatic Map<String,User> userMap = new HashMap<String,User>();//儲存使用者
18.      /** 
19.      * 查詢所有 
20.      * @return 
21.      */
22.     @GET
23.     @Produces(MediaType.APPLICATION_XML)  
24.     public List<User> getAllUsers(){       
25.         List<User> users = new ArrayList<User>();  
26.         User u1 = new User("001","WayLau","26");  
27.         User u2 = new User("002","King","23");  
28.         User u3 = new User("003","Susan","21");  
29.         userMap.put(u1.getUserId(), u1);  
30.         userMap.put(u2.getUserId(), u2);  
31.         userMap.put(u3.getUserId(), u3);  
32.         users.addAll( userMap.values() );  
33.         return users;  
34.     }  
35.     @GET
36.     @Path("/getUserXml")  
37.     @Produces(MediaType.APPLICATION_XML)  
38.     public User getUserXml() {  
39.      User user  = new User();  
40.      user.setAge("21");  
41.      user.setUserId("004");  
42.      user.setUserName("Amand");  
43.      return user;  
44.     }  
45. }  

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，輸出單個物件

在瀏覽器輸入 http://localhost:8089/RestDemo/rest/users  輸出物件的集合

2、資料輸出為JSON型別：

一、 總體說明

XML和JSON 是最為常用的資料交換格式。本例子演示如何將java物件，轉成JSON輸出。

二、流程

1.在上文專案中，

在“com.waylau.rest.resources.UserResource“中增加程式碼，程式碼如下：

1. @GET
2. @Path("/getUserJson")    
3. @Produces(MediaType.APPLICATION_JSON)    
4. public User getUserJson() {    
5.  User user  = new User();    
6.  user.setAge("27");    
7.  user.setUserId("005");    
8.  user.setUserName("Fmand");    
9.  return user;    
10. }   

    @GET  
    @Path("/getUserJson")  
    @Produces(MediaType.APPLICATION_JSON)  
    public User getUserJson() {  
     User user  = new User();  
     user.setAge("27");  
     user.setUserId("005");  
     user.setUserName("Fmand");  
     return user;  
    } 

MediaType.APPLICATION_JSON 說明輸出的是JSON格式

期望獲取到json的資料，此時，專案報錯

1. org.glassfish.jersey.message.internal.MessageBodyProviderNotFoundException: MessageBodyWriter not found for media type=application/json, type=class com.waylau.rest.bean.User, genericType=class com.waylau.rest.bean.User.  
2.     at org.glassfish.jersey.message.internal.WriterInterceptorExecutor$TerminalWriterInterceptor.aroundWriteTo(WriterInterceptorExecutor.java:247)  
3.     at org.glassfish.jersey.message.internal.WriterInterceptorExecutor.proceed(WriterInterceptorExecutor.java:162)  
4.     at org.glassfish.jersey.filter.LoggingFilter.aroundWriteTo(LoggingFilter.java:293)  
5.     at org.glassfish.jersey.message.internal.WriterInterceptorExecutor.proceed(WriterInterceptorExecutor.java:162)  
6.     at org.glassfish.jersey.server.internal.JsonWithPaddingInterceptor.aroundWriteTo(JsonWithPaddingInterceptor.java:103)  
7.     at org.glassfish.jersey.message.internal.WriterInterceptorExecutor.proceed(WriterInterceptorExecutor.java:162)  
8.     at org.glassfish.jersey.server.internal.MappableExceptionWrapperInterceptor.aroundWriteTo(MappableExceptionWrapperInterceptor.java:88)  
9.     at org.glassfish.jersey.message.internal.WriterInterceptorExecutor.proceed(WriterInterceptorExecutor.java:162)  
10.     at org.glassfish.jersey.message.internal.MessageBodyFactory.writeTo(MessageBodyFactory.java:1154)  
11.     at org.glassfish.jersey.server.ServerRuntime$Responder.writeResponse(ServerRuntime.java:571)  
12.     at org.glassfish.jersey.server.ServerRuntime$Responder.processResponse(ServerRuntime.java:378)  
13.     at org.glassfish.jersey.server.ServerRuntime$Responder.process(ServerRuntime.java:368)  
14.     at org.glassfish.jersey.server.ServerRuntime$1.run(ServerRuntime.java:262)  

org.glassfish.jersey.message.internal.MessageBodyProviderNotFoundException: MessageBodyWriter not found for media type=application/json, type=class com.waylau.rest.bean.User, genericType=class com.waylau.rest.bean.User.
	at org.glassfish.jersey.message.internal.WriterInterceptorExecutor$TerminalWriterInterceptor.aroundWriteTo(WriterInterceptorExecutor.java:247)
	at org.glassfish.jersey.message.internal.WriterInterceptorExecutor.proceed(WriterInterceptorExecutor.java:162)
	at org.glassfish.jersey.filter.LoggingFilter.aroundWriteTo(LoggingFilter.java:293)
	at org.glassfish.jersey.message.internal.WriterInterceptorExecutor.proceed(WriterInterceptorExecutor.java:162)
	at org.glassfish.jersey.server.internal.JsonWithPaddingInterceptor.aroundWriteTo(JsonWithPaddingInterceptor.java:103)
	at org.glassfish.jersey.message.internal.WriterInterceptorExecutor.proceed(WriterInterceptorExecutor.java:162)
	at org.glassfish.jersey.server.internal.MappableExceptionWrapperInterceptor.aroundWriteTo(MappableExceptionWrapperInterceptor.java:88)
	at org.glassfish.jersey.message.internal.WriterInterceptorExecutor.proceed(WriterInterceptorExecutor.java:162)
	at org.glassfish.jersey.message.internal.MessageBodyFactory.writeTo(MessageBodyFactory.java:1154)
	at org.glassfish.jersey.server.ServerRuntime$Responder.writeResponse(ServerRuntime.java:571)
	at org.glassfish.jersey.server.ServerRuntime$Responder.processResponse(ServerRuntime.java:378)
	at org.glassfish.jersey.server.ServerRuntime$Responder.process(ServerRuntime.java:368)
	at org.glassfish.jersey.server.ServerRuntime$1.run(ServerRuntime.java:262)

此時，需要獲取json轉換包的支援 。

可以由多種方式實現：MOXy、JSON-P、Jackson、Jettison等，本例為Jackson。

4. 專案中引入jackson-all-1.9.11.jar

5.在“com.waylau.rest”目錄下建立RestApplication.java

1. package com.waylau.rest;  
2. import org.codehaus.jackson.jaxrs.JacksonJsonProvider;  
3. import org.glassfish.jersey.filter.LoggingFilter;  
4. import org.glassfish.jersey.server.ResourceConfig;  
5. /** 
6.  * 應用 
7.  * @author waylau.com 
8.  * 2014-3-18 
9.  */
10. publicclass RestApplication extends ResourceConfig {  
11.     public RestApplication() {  
12.      //服務類所在的包路徑
13.      packages("com.waylau.rest.resources");  
14.      //註冊JSON轉換器
15.      register(JacksonJsonProvider.class);  
16.     }  
17. }  

package com.waylau.rest;

import org.codehaus.jackson.jaxrs.JacksonJsonProvider;
import org.glassfish.jersey.filter.LoggingFilter;
import org.glassfish.jersey.server.ResourceConfig;
 
/**
 * 應用
 * @author waylau.com
 * 2014-3-18
 */
public class RestApplication extends ResourceConfig {
    public RestApplication() {
 
     //服務類所在的包路徑
     packages("com.waylau.rest.resources");
     //註冊JSON轉換器
     register(JacksonJsonProvider.class);
 
    }
}

6.修改web.xml，初始化從RestApplicaton進入應用，如下：

1. <servlet>
2.      <servlet-name>Way REST Service</servlet-name>
3.      <servlet-class>org.glassfish.jersey.servlet.ServletContainer</servlet-class>
4.       <init-param>
5.            <param-name>javax.ws.rs.Application</param-name>
6.            <param-value>com.waylau.rest.RestApplication</param-value>
7.        </init-param>
8.     <load-on-startup>1</load-on-startup>
9.   </servlet>
10.   <servlet-mapping>
11.     <servlet-name>Way REST Service</servlet-name>
12.     <url-pattern>/rest/*</url-pattern>
13.   </servlet-mapping>

<servlet>  
     <servlet-name>Way REST Service</servlet-name>
	 <servlet-class>org.glassfish.jersey.servlet.ServletContainer</servlet-class>
	  <init-param>
	       <param-name>javax.ws.rs.Application</param-name>
	       <param-value>com.waylau.rest.RestApplication</param-value>
	   </init-param>
	 
    <load-on-startup>1</load-on-startup>
  </servlet>
  
  <servlet-mapping>
    <servlet-name>Way REST Service</servlet-name>
    <url-pattern>/rest/*</url-pattern>
  </servlet-mapping>