@Controller：修飾class，用來建立處理http請求的物件
@RestController：Spring4之後加入的註解，原來在@Controller中返回json需要@ResponseBody來配合，如果直接用@RestController替代@Controller就不需要再配置@ResponseBody，預設返回json格式。

@RequestMapping：配置url對映

package com.skymr.demo.controller.api;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

import com.skymr.demo.web.User;

@RestController
@RequestMapping(value = "/user")
public class UserController {

	// 建立一個執行緒安全的map
	private Map<Integer, User> userMap = Collections.synchronizedMap(new HashMap<Integer, User>());

	@RequestMapping(value = "/{id}", method = RequestMethod.GET)
	public User getUser(@PathVariable Integer id) {
		// 請求/user/{id}，取得User
		// @PathVariable將url中的id繫結到引數id上
		return userMap.get(id);
	}

	@RequestMapping(value = "/", method = RequestMethod.GET)
	public List<User> getUsers() {
		// 取得 所有的User
		return new ArrayList<User>(userMap.values());
	}

	@RequestMapping(value = "/", method = RequestMethod.POST)
	public String postUser(@ModelAttribute User user) {
		//RequestAttribute, 與@ModelAttribute
		//怎麼通過RequestParam傳參
		// 建立使用者
		userMap.put(user.getId(), user);
		return "success";
	}

	@RequestMapping(value = "/", method = RequestMethod.PUT)
	public String putUser(@ModelAttribute User u) {
		User user = userMap.get(u.getId());
		if (user == null) {
			return "failed: no user.";
		}
		user.setAge(u.getAge());
		user.setName(user.getName());
		return "success";
	}
	@RequestMapping(value = "/{id}", method = RequestMethod.DELETE)
	public String deleteUser(@PathVariable Integer id){
		userMap.remove(id);
		return "success";
	}
}
 

package com.skymr.demo;

import static org.hamcrest.CoreMatchers.equalTo;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.content;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;

import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.http.MediaType;
import org.springframework.test.context.junit4.SpringRunner;
import org.springframework.test.web.servlet.MockMvc;
import org.springframework.test.web.servlet.MvcResult;
import org.springframework.test.web.servlet.ResultHandler;
import org.springframework.test.web.servlet.request.MockMvcRequestBuilders;
import org.springframework.test.web.servlet.setup.MockMvcBuilders;

import com.skymr.demo.controller.api.UserController;

@RunWith(SpringRunner.class)
@SpringBootTest(classes = Springboot01Application.class)
public class Springboot02ApplicationTests {
	
	
	//spring mvc測試
	private MockMvc mvc;

	@Before
	public void setUp() throws Exception {
		mvc = MockMvcBuilders.standaloneSetup(new UserController()).build();
	}
	
	@Test
	public void testUserCtrl() throws Exception{
		mvc.perform(MockMvcRequestBuilders.post("/user/").param("id", "1")
				.param("age", "20")
				.param("name", "skymr")
				.accept(MediaType.APPLICATION_JSON_UTF8)
				).andExpect(status().isOk())
				.andExpect(content().string(equalTo("success")));
		
		mvc.perform(MockMvcRequestBuilders.put("/user/").param("id", "1")
				.param("age", "21")
				.param("name", "skymr1")
				.accept(MediaType.APPLICATION_JSON_UTF8)
				).andExpect(status().isOk())
				.andExpect(content().string(equalTo("success")));
		
		mvc.perform(MockMvcRequestBuilders.get("/user/1")
				.accept(MediaType.APPLICATION_JSON_UTF8)
				).andExpect(status().isOk())
				.andDo(new ResultHandler() {
					@Override
					public void handle(MvcResult result) throws Exception {
						System.out.println("---" + result.getResponse().getContentAsString());
					}
				});
		
		mvc.perform(MockMvcRequestBuilders.delete("/user/1")
				.accept(MediaType.APPLICATION_JSON_UTF8)
				).andExpect(status().isOk())
				.andExpect(content().string(equalTo("success")));
		
		mvc.perform(MockMvcRequestBuilders.get("/user/")
				.accept(MediaType.APPLICATION_JSON_UTF8)
				).andExpect(status().isOk())
				.andExpect(content().string(equalTo("[]")));
	}
}
 

至此，我們通過引入web模組（沒有做其他的任何配置），就可以輕鬆利用Spring MVC的功能，以非常簡潔的程式碼完成了對User物件的RESTful API的建立以及單元測試的編寫。其中同時介紹了Spring MVC中最為常用的幾個核心註解：@Controller,@RestController,RequestMapping以及一些引數繫結的註解：@PathVariable,@ModelAttribute,@RequestParam等。