上一篇《Spring MVC测试框架详解——服务端测试》已经介绍了服务端测试，接下来再看看如果测试Rest客户端，对于客户端测试以前经常使用的方法是启动一个内嵌的jetty/tomcat容器，然后发送真实的请求到相应的控制器；这种方式的缺点就是速度慢；自Spring 3.2开始提供了对RestTemplate的模拟服务器测试方式，也就是说使用RestTemplate测试时无须启动服务器，而是模拟一个服务器进行测试，这样的话速度是非常快的。

2 RestTemplate客户端测试

整个环境在上一篇《Spring MVC测试框架详解——服务端测试》基础上进行构建。

UserRestController控制器

@RestController
@RequestMapping("/users")
public class UserRestController {

    private UserService userService;

    @Autowired
    public UserRestController(UserService userService) {
        this.userService = userService;
    }

    @RequestMapping(value = "/{id}", method = RequestMethod.GET, produces = MediaType.APPLICATION_JSON_VALUE)
    public User findById(@PathVariable("id") Long id) {
        return userService.findById(1L);
    }

    @RequestMapping(method = RequestMethod.POST)
    public ResponseEntity<User> save(@RequestBody User user, UriComponentsBuilder uriComponentsBuilder) {
        //save user
        user.setId(1L);
        MultiValueMap headers = new HttpHeaders();
        headers.set("Location", uriComponentsBuilder.path("/users/{id}").buildAndExpand(user.getId()).toUriString());
        return new ResponseEntity(user, headers, HttpStatus.CREATED);
    }

    @RequestMapping(value = "/{id}", method = RequestMethod.PUT, consumes = MediaType.APPLICATION_JSON_VALUE)
    @ResponseStatus(HttpStatus.NO_CONTENT)
    public void update(@RequestBody User user) {
        //update by id
    }

    @RequestMapping(value = "/{id}", method = RequestMethod.DELETE)
    public void delete(@PathVariable("id") Long id) {
        //delete by id
    }
}