java使用教程怎样实现简单的RESTful接口 java使用教程的REST接口开发技巧​

@RestController

@Controller

@ResponseBody

pom.xml

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

import java.util.HashMap;
import java.util.Map;

@RestController
@RequestMapping("/api/messages") // 统一前缀，这是个好习惯
public class SimpleMessageController {

    // 假设我们有个简单的存储
    private Map<String, String> messages = new HashMap<>();

    public SimpleMessageController() {
        messages.put("hello", "世界你好！");
        messages.put("greeting", "很高兴见到你。");
    }

    /**
     * 获取一条消息
     * 访问路径示例: GET /api/messages/get?key=hello
     */
    @GetMapping("/get")
    public String getMessage(@RequestParam String key) {
        // 简单模拟，实际情况会从数据库等获取
        return messages.getOrDefault(key, "消息未找到。");
    }

    /**
     * 创建或更新一条消息
     * 访问路径示例: POST /api/messages/add
     * 请求体: {"key": "new", "value": "这是新消息"}
     */
    @PostMapping("/add")
    public String addOrUpdateMessage(@RequestBody Map<String, String> payload) {
        String key = payload.get("key");
        String value = payload.get("value");
        if (key != null && value != null) {
            messages.put(key, value);
            return "消息 '" + key + "' 已保存。";
        }
        return "请求参数不完整。";
    }

    /**
     * 获取所有消息 (虽然简单，但展示了如何返回复杂结构)
     * 访问路径示例: GET /api/messages/all
     */
    @GetMapping("/all")
    public Map<String, String> getAllMessages() {
        return messages;
    }
}

@SpringBootApplication

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class MyApplication {
    public static void main(String[] args) {
        SpringApplication.run(MyApplication.class, args);
    }
}

http://localhost:8080/api/messages/get?key=hello

spring-boot-starter-web

@SpringBootApplication

spring-boot-starter-data-jpa

spring-boot-starter-security

/users

/getUser

/users/{id}

/v1/users

Accept

@SpringBootTest

@WebMvcTest

MockMvc

import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.web.servlet.WebMvcTest;
import org.springframework.test.web.servlet.MockMvc;

import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.content;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;

@WebMvcTest(SimpleMessageController.class) // 只测试这个控制器
public class SimpleMessageControllerTest {

    @Autowired
    private MockMvc mockMvc;

    @Test
    void testGetMessageSuccess() throws Exception {
        mockMvc.perform(get("/api/messages/get?key=hello"))
               .andExpect(status().isOk())
               .andExpect(content().string("世界你好！"));
    }

    @Test
    void testGetMessageNotFound() throws Exception {
        mockMvc.perform(get("/api/messages/get?key=nonexistent"))
               .andExpect(status().isOk()) // 即使没找到，业务逻辑返回的也是字符串，HTTP状态码是200
               .andExpect(content().string("消息未找到。"));
    }

    @Test
    void testAddMessage() throws Exception {
        String requestBody = "{\"key\": \"testKey\", \"value\": \"testValue\"}";
        mockMvc.perform(post("/api/messages/add")
                .contentType("application/json") // 告诉服务器发送的是JSON
                .content(requestBody))
               .andExpect(status().isOk())
               .andExpect(content().string("消息 'testKey' 已保存。"));

        // 验证是否真的添加成功了，可以再发一个GET请求
        mockMvc.perform(get("/api/messages/get?key=testKey"))
               .andExpect(status().isOk())
               .andExpect(content().string("testValue"));
    }
}