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本文介绍restTemplate基础用法。

Java中get和post的用法请参考：https://mp.weixin.qq.com/s/mC0D1nuCqIori5bWtLorWQ

1 提供get/post接口

1.1 Controller

@RestController
@RequestMapping("/homepage")
public class MyController {@AutowiredMyService myService;// 提供get接口@GetMapping("/provideGet")public Map provideGet(){return myService.provideGet();}// 提供post接口@PostMapping("/providePost")public Map providePost(@RequestParam("number") int number, @RequestParam("name") String name) {return myService.providePost(number, name);}// 提供map参数的post接口@PostMapping("/providePostByMap")public Map providePostByMap(@RequestParam Map map) {return myService.providePostByMap(map);}// 调用get接口@GetMapping("/useGet")public Map useGet() {return myService.useGet();}
}

1.2 Service

@Service
@EnableScheduling
public class MyService {public Map provideGet() {Map res = new HashMap<>();res.put("number", "3");res.put("name", "张三get");System.out.println("provideGet res:" + res + "\n");return res;}public Map providePost(int number, String name) {Map res = new HashMap<>();res.put("number", number);res.put("name", name);return res;}public Map providePostByMap(Map 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 res = new HashMap<>();res.put("number", number);res.put("name", name);System.out.println("providePostByMap res:" + res + "\n");return res;}
}

2 调用get/post接口

使用restTemplate调用get/post接口。

• getForObject():返回值是HTTP协议的响应体
• getForEntity():返回的是ResponseEntity，ResponseEntity是对HTTP响应的封装，除了包含响应体，还包含HTTP状态码、contentType、contentLength、Header等信息

2.1 Controller

@RestController
@RequestMapping("/homepage")
public class MyController {    @AutowiredMyService myService;// 调用get接口@GetMapping("/useGet")public Map useGet() {return myService.useGet();}// 调用get接口验证账号密码@GetMapping("/useGetByPsw")public Map useGetByPsw() {return myService.useGetByPsw();}// 调用post接口@PostMapping("/usePost")public Map usePost() {return myService.usePost();}
}

2.2 Service

@Service
@EnableScheduling
public class MyService {@Resourceprivate RestTemplate restTemplate;String getURL = "http://localhost:8081/homepage/provideGet";String postURL = "http://localhost:8081/homepage/providePostByMap";public Map useGet() {// getForObject返回值是HTTP协议的响应体String strObject = restTemplate.getForObject(getURL, String.class);JSONObject jsonObject = JSONObject.parseObject(strObject);// getForEntity返回的是ResponseEntity，是对HTTP响应的封装ResponseEntity responseData = restTemplate.getForEntity(getURL, ResponseResult.class);Map returnData = new HashMap<>();returnData.put("StatusCode:", responseData.getStatusCode());returnData.put("Body:", responseData.getBody());System.out.println("useGet jsonObject:" + jsonObject + "\n");System.out.println("useGet responseData:" + responseData + "\n");System.out.println("useGet returnData:" + returnData + "\n");return returnData;}public Map useGetByPsw() {RestTemplateBuilder builder = new RestTemplateBuilder();RestTemplate restTemplate = builder.basicAuthentication("username", "password").build();// getForEntity返回的是ResponseEntity，是对HTTP响应的封装ResponseEntity responseData = restTemplate.getForEntity(getURL, ResponseResult.class);Map returnData = new HashMap<>();returnData.put("StatusCode:", responseData.getStatusCode());returnData.put("Body:", responseData.getBody());System.out.println("useGetByPsw returnData:" + responseData + "\n");System.out.println("useGetByPsw returnData:" + returnData + "\n");return returnData;}public Map usePost() {//RestTemplate在postForObject时，用MultiValueMap，不可使用HashMap。MultiValueMap sendData = new LinkedMultiValueMap<>();sendData.add("number", "3");sendData.add("name", "张三post");// getForObject返回值是HTTP协议的响应体String strObject = restTemplate.postForObject(postURL, sendData, String.class);JSONObject jsonObject = JSONObject.parseObject(strObject);// getForEntity返回的是ResponseEntity，是对HTTP响应的封装ResponseEntity responseData = restTemplate.postForEntity(postURL, sendData, ResponseResult.class);Map returnData = new HashMap<>();returnData.put("StatusCode:", responseData.getStatusCode());returnData.put("Body:", responseData.getBody());System.out.println("usePost jsonObject:" + jsonObject + "\n");System.out.println("usePost responseData:" + responseData + "\n");System.out.println("usePost returnData:" + returnData + "\n");return returnData;}
}

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