用Jersey构建RESTful服务4--通过jersey-client客户端调用Jersey的Web服务模拟CURD

一、总体说明

通过jersey-client接口，创建客户端程序，来调用Jersey实现的RESTful服务，实现增、删、改、查等操作。服务端主要是通过内存的方式，来模拟用户的增加、删除、修改、查询等操作。二、创建服务端
1.在上文项目中，在“com.waylau.rest.resources.UserResource“中修改代码，首先创建一个HashMap，用来保存添加的用户
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private static Map<String,User> userMap = new HashMap<String,User>();

2.创建增、删、改、查 用户资源等操作

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/**

* 增加

* @param user

*/

@POST

@Consumes({MediaType.APPLICATION_XML, MediaType.APPLICATION_JSON})

public void createStudent(User user)

{

userMap.put(user.getUserId(), user );

}

/**

* 删除

* @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 );

}

/**

* 根据id查询

* @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;

}

/**

* 查询所有

* @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、创建客户端程序

1.创建包“com.waylau.rest.client”，在包下建一个UserClient.java，代码如下：

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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;

/**

* 用户客户端，用来测试资源

* @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();

}

/**

* 添加用户

*/

private static void addUser() {

System.out.println("****增加用户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();

}

/**

* 删除用户

*/

private static void delUser() {

System.out.println("****删除用户****");

Client client = ClientBuilder.newClient();

WebTarget target = client.target(serverUri + "/users/006");

Response response = target.request().delete();

response.close();

}

/**

* 修改用户

*/

private static void updateUser() {

System.out.println("****修改用户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();

}

/**

* 根据id查询用户

*/

private static void getUserById() {

System.out.println("****根据id查询用户****");

Client client = ClientBuilder.newClient().register(JacksonJsonProvider.class);// 注册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();

}

/**

* 查询所有用户

*/

private static void getAllUsers() {

System.out.println("****查询所有getAllUsers****");

Client client = ClientBuilder.newClient();

WebTarget target = client.target(serverUri + "/users");

Response response = target.request().get();

<span style="white-space:pre"> </span> String value = response.readEntity(String.class);

<span style="white-space:pre"> <span style="white-space:pre"> </span></span> System.out.println(value);

<span style="white-space:pre"> </span> response.close(); //关闭连接

}

}

四、运行

启动服务端项目，运行客户端程序UserClient，控制台输出如下
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****增加用户addUser****

****查询所有getAllUsers****

[{"userId":"006","userName":"Susan","age":"21"}]

****修改用户updateUser****

****根据id查询用户****

006Susan33

****查询所有getAllUsers****

[{"userId":"006","userName":"Susan","age":"33"}]

****删除用户****

****查询所有getAllUsers****

[]

五、总结

1.客户端如果需要进行JSON转换，需要进行JSON注册
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Client client = ClientBuilder.newClient().register(JacksonJsonProvider.class);

2.WebTarget 指明了要请求的资源的地址

3.target.request(). 后面跟的是请求的方法:POST，GET，PUT或DELETE