用Jersey構建RESTful服務4--通過jersey-client客戶端調用Jersey的Web服務模擬CURD · 用Jersey構建RESTful服務

# 用Jersey構建RESTful服務4--通過jersey-client客戶端調用Jersey的Web服務模擬CURD ## 一、總體說明通過jersey-client接口，創建客戶端程序，來調用Jersey實現的RESTful服務，實現增、刪、改、查等操作。服務端主要是通過內存的方式，來模擬用戶的增加、刪除、修改、查詢等操作。 ## 二、創建服務端 1. 在上文項目中，在“com.waylau.rest.resources.UserResource“中修改代碼，首先創建一個HashMap，用來保存添加的用戶 ``` private static Map<String,User> userMap = new HashMap<String,User>(); ``` 2. 創建增、刪、改、查用戶資源等操作 ``` /** * 增加 * @param user */ @POST @Consumes({MediaType.APPLICATION_XML, MediaType.APPLICATION_JSON}) public void createStudent(User user) { userMap.put(user.getUserId(), user ); } /** * 刪除 * @param id */ @DELETE @Path("{id}") public void deleteStudent(@PathParam("id")String id){ userMap.remove(id); } /** * 修改 * @param user */ @PUT @Consumes(MediaType.APPLICATION_XML) public void updateStudent(User user){ userMap.put(user.getUserId(), user ); } /** * 根據id查詢 * @param id * @return */ @GET @Path("{id}") @Produces({MediaType.APPLICATION_XML, MediaType.APPLICATION_JSON}) public User getUserById(@PathParam("id") String id){ User u = userMap.get(id); return u; } /** * 查詢所有 * @return */ @GET @Produces({MediaType.APPLICATION_XML, MediaType.APPLICATION_JSON}) public List<User> getAllUsers(){ List<User> users = new ArrayList<User>(); users.addAll( userMap.values() ); return users; } ``` ## 三、創建客戶端程序創建包“com.waylau.rest.client”，在包下建一個UserClient.java，代碼如下： ``` package com.waylau.rest.client; import javax.ws.rs.client.Client; import javax.ws.rs.client.ClientBuilder; import javax.ws.rs.client.Entity; import javax.ws.rs.client.WebTarget; import javax.ws.rs.core.MediaType; import javax.ws.rs.core.Response; import org.codehaus.jackson.jaxrs.JacksonJsonProvider; import com.waylau.rest.bean.User; /** * 用戶客戶端，用來測試資源 * @author waylau.com * 2014-3-18 */ public class UserClient { private static String serverUri = "http://localhost:8089/RestDemo/rest"; /** * @param args */ public static void main(String[] args) { addUser(); getAllUsers(); updateUser(); getUserById(); getAllUsers(); delUser(); getAllUsers(); } /** * 添加用戶 */ private static void addUser() { System.out.println("****增加用戶addUser****"); User user = new User("006","Susan","21"); Client client = ClientBuilder.newClient(); WebTarget target = client.target(serverUri + "/users"); Response response = target.request().buildPost(Entity.entity(user, MediaType.APPLICATION_XML)).invoke(); response.close(); } /** * 刪除用戶 */ private static void delUser() { System.out.println("****刪除用戶****"); Client client = ClientBuilder.newClient(); WebTarget target = client.target(serverUri + "/users/006"); Response response = target.request().delete(); response.close(); } /** * 修改用戶 */ private static void updateUser() { System.out.println("****修改用戶updateUser****"); User user = new User("006","Susan","33"); Client client = ClientBuilder.newClient(); WebTarget target = client.target(serverUri + "/users"); Response response = target.request().buildPut( Entity.entity(user, MediaType.APPLICATION_XML)).invoke(); response.close(); } /** * 根據id查詢用戶 */ private static void getUserById() { System.out.println("****根據id查詢用戶****"); Client client = ClientBuilder.newClient().register(JacksonJsonProvider.class);// 注冊json 支持 WebTarget target = client.target(serverUri + "/users/006"); Response response = target.request().get(); User user = response.readEntity(User.class); System.out.println(user.getUserId() + user.getUserName() + user.getAge()); response.close(); } /** * 查詢所有用戶 */ private static void getAllUsers() { System.out.println("****查詢所有getAllUsers****"); Client client = ClientBuilder.newClient(); WebTarget target = client.target(serverUri + "/users"); Response response = target.request().get(); String value = response.readEntity(String.class); System.out.println(value); response.close(); //關閉連接 } } ``` ## 四、運行啟動服務端項目，運行客戶端程序UserClient，控制臺輸出如下 ``` ****增加用戶addUser**** ****查詢所有getAllUsers**** [{"userId":"006","userName":"Susan","age":"21"}] ****修改用戶updateUser**** ****根據id查詢用戶**** 006Susan33 ****查詢所有getAllUsers**** [{"userId":"006","userName":"Susan","age":"33"}] ****刪除用戶**** ****查詢所有getAllUsers**** [] ``` ## 五、總結 1. 客戶端如果需要進行JSON轉換，需要進行JSON注冊 ``` Client client = ClientBuilder.newClient().register(JacksonJsonProvider.class); ``` 2. WebTarget 指明了要請求的資源的地址 3. target.request(). 后面跟的是請求的方法:POST，GET，PUT或DELETE **本章源碼**：[https://github.com/waylau/RestDemo/tree/master/jersey-demo4-client-curd](https://github.com/waylau/RestDemo/tree/master/jersey-demo4-client-curd)