本篇代码均已上传到GITHUB,https://github.com/IloveZiHan/restfultemplate.git
介绍
我们之前都使用过HttpClient来发送HTTP请求,但我们很多时间都需要将HttpClient请求或者响应的数据转换为Java对象,HttpClient需要我们自己手动来解析。我们今天要介绍的Spring REST Template比HttpClient用起来更加方便简洁。
背景
案例分为两个部分:
CRM_MANAGEMENT——后台主要提供RESTFUL Service服务,因为尽量使案例简单,所以数据部分是直接使用内存中的列表来模拟
PORTAL——门户,也就是前端系统,用来处理浏览器提交的请求,接收到用户请求会使用
Spring REST Template
来提交RESTFUL Service请求
环境说明
本案例基于Maven构建,使用Spring Boot 2.x开发
可以选择IDEA或者Eclipse导入案例运行
项目开发
CRM_DOMAIN实体
POM依赖
pom.xml
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<parent>
<artifactId>resttemplate_common</artifactId>
<groupId>com.itheima</groupId>
<version>0.0.1-SNAPSHOT</version>
</parent>
<modelVersion>4.0.0</modelVersion>
<artifactId>crm_domain</artifactId>
<packaging>jar</packaging>
</project>
User实体类
package com.itheima.crm.domain; public class User { private Integer id; // id private String username; // 用户名 private String password; // 密码 public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } public boolean matchUsernameAndPassword(String username, String password) { if(this.username.equals(username) && this.password.equals(password)) { return true; } else { return false; } } }
ResResult——封装响应结果
package com.itheima.crm.domain; /** * 响应结果 */ public class ResResult { private Boolean success; // 是否操作成功 private String message; // 消息 public ResResult() { } public ResResult(Boolean success, String message) { this.success = success; this.message = message; } public Boolean getSuccess() { return success; } public void setSuccess(Boolean success) { this.success = success; } public String getMessage() { return message; } public void setMessage(String message) { this.message = message; } }
CRM_MANAGEMENT后台
POM依赖
pom.xml
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<artifactId>crm_management</artifactId>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.1.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>com.itheima</groupId>
<artifactId>crm_domain</artifactId>
<version>0.0.1-SNAPSHOT</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
RESTFUL Service接口开发
package com.itheima.crm.webservice; import com.itheima.crm.domain.ResResult; import com.itheima.crm.domain.User ; import com.itheima.crm.service.UserService; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.*; import java.util.List; "/user") (public class UserRestService { private UserService userService; /** * 注册服务 * @param user 用户 * @return */ (method = RequestMethod.POST) public ResResult regist( User user) { try { userService.regist(user); return new ResResult(true, "添加成功"); } catch (Exception e) { e.printStackTrace(); return new ResResult(false, "添加失败"); } } /** * 登录服务 * @param username 用户名 * @param password 密码 * @return */ (value = "/{username}/{password}", method = RequestMethod.GET) public User login( ("username") String username, ("password") String password) { try { return userService.login(username, password); } catch (Exception e) { return null; } } (method = RequestMethod.GET) public List<User> findAll() { return userService.findAll(); } }
Service层开发
UserService接口
package com.itheima.crm.service; import com.itheima.crm.domain.User ; import java.util.List; public interface UserService { void regist(User user); User login(String username, String password); List<User> findAll(); }
UserServiceImpl实现类
package com.itheima.crm.service; import com.itheima.crm.dao.UserDao; import com.itheima.crm.domain.User; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; import java.util.List; public class UserServiceImpl implements UserService{ private UserDao userDao; public void regist(User user) { userDao.save(user); } public User login(String username, String password) { return userDao.findOne(username, password); } public List<User> findAll() { return userDao.findAll(); } }
DAO层开发
UserDao接口
package com.itheima.crm.dao; import com.itheima.crm.domain.User ; import java.util.List; public interface UserDao { /** * 保存用户 * @param user 用户 */ void save(User user); User findOne(String username, String password); List<User> findAll(); }
UserDaoImpl实现类
package com.itheima.crm.dao; import com.itheima.crm.domain.User; import org.springframework.stereotype.Repository; import java.util.ArrayList; import java.util.List; public class UserDaoImpl implements UserDao{ private List<User> users = new ArrayList<>(); public void save(User user) { users.add(user); } public User findOne(String username, String password) { User userTmp = new User(); userTmp.setUsername(username); userTmp.setPassword(password); for(User user : users) { if(user.matchUsernameAndPassword(username, password)) { return user; } } return null; } public List<User> findAll() { return users; } public UserDaoImpl() { // 添加一些测试的用户 User user1 = new User(); user1.setId(1); user1.setUsername("zhangsan"); user1.setPassword("0"); User user2 = new User(); user2.setId(2); user2.setUsername("lisi"); user2.setPassword("0"); User user3 = new User(); user3.setId(3); user3.setUsername("wangwu"); user3.setPassword("0"); User user4 = new User(); user4.setId(4); user4.setUsername("zhaoliu"); user4.setPassword("0"); users.add(user1); users.add(user2); users.add(user3); users.add(user4); } }
Spring Boot入口
配置文件(application.properties)
server.port=9001 server.servlet.context-path=/
入口
package com.itheima.crm; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; public class Application { public static void main(String[] args) { SpringApplication.run(Application.class, args); } }
RESTFUL Service接口调用URL
添加用户
Requsest URL: http://localhost:9001/user/ Request Method: POST
根据用户名密码查询用户
Requsest URL: http://localhost:9001/user/用户名/密码 Request Method: GET
查询所有用户
Requeset URL: http://localhost:9001/user/ Request Method: GET
PORTAL门户
POM依赖
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.1.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<modelVersion>4.0.0</modelVersion>
<artifactId>portal</artifactId>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.28</version>
</dependency><dependency>
<groupId>com.itheima</groupId>
<artifactId>crm_domain</artifactId>
<version>0.0.1-SNAPSHOT</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
Controller开发
package com.itheima.portal.controller; import com.itheima.crm.domain.ResResult; import com.itheima.crm.domain.User; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.RequestBody; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; import org.springframework.web.client.RestTemplate; import javax.servlet.http.HttpServletResponse; import java.io.IOException; import java.util.Collections; import java.util.HashMap; import java.util.Map; "/user") (public class UserController { private RestTemplate restTemplate; private String USERSERVICE_URL = "http://localhost:9001/user"; ("/login") public Map login(String username, String password) { // 构建要传递的参数 Map<String, String> params = new HashMap<>(); params.put("username", username); params.put("password", password); // 发送GET请求 User user = restTemplate.getForObject(USERSERVICE_URL + "/{username}/{password}", User.class, params); Map<String, Object> result = new HashMap<>(); if(user != null) { result.put("success", true); } else { result.put("success", false); result.put("message", "登录失败"); } return result; } ("/regist") public ResResult login( User user) throws IOException { // 使用REST Template发送POST请求 return restTemplate.postForObject(USERSERVICE_URL + "/", user, ResResult.class); } }
Spring Boot入口
配置文件(application.properties)
server.port=9002 server.servlet.context-path=/
入口
package com.itheima.portal; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.context.annotation.Bean; import org.springframework.web.client.RestTemplate; public class Application { public static void main(String[] args) { SpringApplication.run(Application.class, args); } /** * 创建RestTemplate Bean */ public RestTemplate restTemplate() { return new RestTemplate(); } }
前端页面
导入jquery.js
login.html登录页面
<html lang="`"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>登录</title> <script src="jquery-1.11.3.js"></script> </head> <body> <table class="table"> <tr> <td>用户名</td> <td><input type="text" id="username"></td> </tr> <tr> <td>密码</td> <td><input type="text" id="password"></td> </tr> <tr> <td></td> <td> <button id="btn">登录</button> <button id="btn1">注册</button> </td> </tr> </table> <script type="text/javascript"> $(function() { $('#btn').click(function() { $.get('user/login?username=' + $('#username').val() + '&password=' + $('#password').val(), function(data) { if(!data.success) { alert(data.message); } else { window.location.href = "success.html"; } }); }); $('#btn1').click(function() { var user = { username: $('#username').val(), password: $('#password').val() }; $.ajax({ type:'POST', url:'user/regist', dataType:"json", contentType:"application/json", data:JSON.stringify(user), success:function(data){ if(!data.success) { alert(data.message); } else { alert("注册成功!"); } } }); }); }); </script> </body> </html>
success.html登录成功页面
<html lang="en"> <head> <meta charset="UTF-8"> <title>登录成功</title> </head> <body> <h1>登录成功</h1> </body> </html>
总结
Spring REST Template比HttpClient更加快捷方便的调用RS服务,它自动封装和解析Java对象。而且可以很方便的与Spring整合,快速注入Spring的bean对象。
注意
注意Jquery
$.get
、$.post
、$.ajax
的区别
$.get(url, json对象)
表示发送一个get请求,使用queryString的方式提交。url?username=tom...
$.post(url, json对象)
表示发送一个post请求,数据部分类似于提交表单。
$.ajax
可以选择数据传递的格式、类型等。我们要将一个json串发送到spring mvc@RequestBody
来接收需要使用$.ajax
。下面是示例代码
$.ajax({ type:'POST', url:'user/regist', dataType:"json", contentType:"application/json", data:JSON.stringify(user), success:function(data){ if(!data.success) { alert(data.message); } else { alert("注册成功!"); } } });