一文帶你搞懂Java中Get和Post的使用

2022-11-17 14:00:23

1 Get請求資料

專案地址：https://github.com/Snowstorm0/learn-get-post

1.1 Controller

檔名MyController，內容為：

@RestController
@RequestMapping("/homepage")
publicclass MyController {
    @Autowired
    MyService myService;

    @GetMapping("/learnGet")
    public String learnGet(){
        return myService.learnGet();
    }
}

1.2 Service

檔名MyService，內容為：

@Service
@EnableScheduling
publicclass MyService {
    public String learnGet(){
        Long timeLong = System.currentTimeMillis();
        SimpleDateFormat timeFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); //設定格式
        String timeString = timeFormat.format(timeLong);
        return timeString;
    }
}

1.3 Application

在application.properties設定：

# 設定埠號
server.port=8888

1.4 Postman

設定Get，地址為：http://localhost:8888/homepage/returnTime 。

即可獲得當前時間戳。

2 Post接收資料

專案地址：https://github.com/Snowstorm0/learn-get-post

2.1 Controller

檔名MyController，內容為：

@RestController
@RequestMapping("/homepage")
publicclass MyController {
    @Autowired
    MyService myService;
    @PostMapping("/postReceive")
    public Map<String, Object> postReceive(@RequestParam("number") int number, @RequestParam("name") String name) {
        return myService.postReceive(number, name);
    }
    @PostMapping("/postReceiveByMap")
    public Map<String, Object> postReceiveByMap(@RequestParam Map<String, Object> map) {
        System.out.println("map:" + map + "n");
        return myService.postReceiveByMap(map);
    }
}

2.2 Service

檔名MyService，內容為：

@Service
@EnableScheduling
publicclass MyService {
    public Map<String, Object> postReceive(int number, String name){
        Map<String, Object> res = new HashMap<>();
        res.put("number", number);
        res.put("name", name);
        return res;
    }
    public Map<String, Object> postReceiveByMap(Map<String, Object> map){
        int number = map.get("number") == null ? 0 : Integer.parseInt((String) map.get("number"));
        String name = map.get("name") == null ? "" : (String)map.get("name");
        Map<String, Object> res = new HashMap<>();
        res.put("number", number);
        res.put("name", name);
        System.out.println("map:" + map + "n");
        System.out.println("res:" + res + "n");
        return res;
    }

2.3 Application

在application.properties設定：

# 設定埠號
server.port=8888

2.4 Postman

設定Get，地址為：http://localhost:8888/homepage/returnTime 。

即可獲得輸出。

3 Post傳送資料

專案地址：https://github.com/Snowstorm0/learn-post-send

需要注意，RestTemplate在postForObject時，用MultiValueMap，不可使用HashMap。

3.1 Controller

檔名MyController，內容為：

@RestController
@RequestMapping("/homepage")
publicclass MyController {

    @Autowired
    MyService myService;

    @PostMapping("/postSend")
    public Map<String, Object> postSend() {
        return myService.postSend();
    }
}

3.2 Service

檔名MyService，內容為：

@Service
@EnableScheduling
publicclass MyService {
    @Resource
    private RestTemplate restTemplate;
    String URL = "http://localhost:8888/homepage/postReceiveByMap";

    public Map<String, Object> postSend(){
        Map<String, Object> sendData = new HashMap<>();
        sendData.put("number", 3);
        sendData.put("name", "張三");
        ResponseEntity<ResponseResult> responseData = restTemplate.postForEntity(URL, sendData, ResponseResult.class);
        Map<String, Object> returnData = new HashMap<>();
        returnData.put("StatusCode:", responseData.getStatusCode());
        returnData.put("Body:", responseData.getBody());
        return returnData;
    }
}

3.3 ResponseResult

publicclass ResponseResult {

    privateint number;
    private String name;

    public ResponseResult(){
    }

    public int getNumber() {
        return number;
    }
    public void setNumber(int number) {
        this.number = number;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }

    @Override
    public String toString() {
        return"ResponseResult [number=" + number + ",name=" + name + "]";
    }
}

3.4 Config

@Configuration
publicclass Config {
    @Bean
    public RestTemplate restTemplate(RestTemplateBuilder builder){
        return builder.build();
    }
}