RestTemplate笔记

目录

一、RestTemplate设置toke

二、RestTemplate发送POST

三、RestTemplateUtils工具类代码

四、例子

---

一、RestTemplate设置toke

可以使用RestTemplate的拦截器来设置token。示例代码如下：

 // 创建RestTemplate实例
RestTemplate restTemplate = new RestTemplate();
// 创建拦截器
ClientHttpRequestInterceptor interceptor = (request, body, execution) -> {
    // 设置token
    request.getHeaders().set("Authorization", "Bearer " + token);

    // 继续执行请求
    return execution.execute(request, body);
};
// 将拦截器添加到RestTemplate实例中
restTemplate.setInterceptors(Collections.singletonList(interceptor));
// 发送请求
String result = restTemplate.getForObject(url, String.class);

其中，token是要设置的token值。

二、RestTemplate发送POST

使用RestTemplate发送POST请求并携带请求体可以通过以下代码实现：

RestTemplate restTemplate = new RestTemplate();HttpHeaders headers = new HttpHeaders();

headers.setContentType(MediaType.APPLICATION_JSON);



Map<String, String> requestBody = new HashMap<>();

requestBody.put("key1", "value1");

requestBody.put("key2", "value2");



HttpEntity<Map<String, String>> requestEntity = new HttpEntity<>(requestBody, headers);



ResponseEntity<String> responseEntity = restTemplate.postForEntity(url, requestEntity, String.class);String responseBody = responseEntity.getBody();

其中，需要设置请求头的Content-Type为application/json，并将请求体封装到HttpEntity中，最后调用RestTemplate的postForEntity方法发送POST请求并获取响应体。

三、RestTemplateUtils工具类代码

@Component
public class RestTemplateUtils {
    private static final Logger LOGGER = LoggerFactory.getLogger(RestTemplateUtils.class);

    @Resource
    private RestTemplate restTemplate;

    /**
     * http get 请求
     *
     * @param url url
     * @param responseType response类型
     * @param <T> 类型参数
     * @return response body
     */
    public <T> T get(String url, ParameterizedTypeReference<T> responseType) {
        return http(url, HttpMethod.GET, null, responseType);
    }

    /**
     * http post 请求
     *
     * @param url url
     * @param request 请求体
     * @param responseType response类型
     * @param <T> 类型参数
     * @return response body
     */
    public <T> T post(String url, Object request, ParameterizedTypeReference<T> responseType) {
        return http(url, HttpMethod.POST, request, responseType);
    }

    /**
     * http 请求
     *
     * @param url url
     * @param httpMethod method
     * @param request request
     * @param responseType response类型
     * @param <T> 类型参数
     * @return response body
     */
    public <T> T http(String url, HttpMethod httpMethod, Object request, ParameterizedTypeReference<T> responseType) {
        HttpHeaders httpHeaders = new HttpHeaders();
        httpHeaders.setContentType(MediaType.APPLICATION_JSON);
        HttpEntity<Object> requestData = new HttpEntity<>(request, httpHeaders);
        ResponseEntity<T> responseEntity;
        try {
            responseEntity = restTemplate.exchange(url, httpMethod, requestData, responseType);
        } catch (RestClientException e) {
            LOGGER.error("RestClientException when exchange", e);
            throw new DemoException(e, ErrorEnum.HTTP_REQUEST_ERROR);
        }
        if (responseEntity.getStatusCode() != HttpStatus.OK) {
            LOGGER.error("http request has response but status is not ok");
            throw new DemoException(ErrorEnum.HTTP_REQUEST_ERROR);
        }
        T body = responseEntity.getBody();
        if (body == null) {
            LOGGER.error("http request has response but response body is null");
            throw new DemoException(ErrorEnum.HTTP_REQUEST_ERROR);
        }
        return body;
    }

}

四、实例

@RestController
@RequestMapping(value = "hello", produces = MediaType.APPLICATION_JSON_VALUE)
public class HelloController {
    private static final Logger LOGGER = LoggerFactory.getLogger(HelloController.class);

    @Resource
    private RestTemplateUtils restTemplateUtils;

    @GetMapping(value = "/request-get")
    public ResultVo<Void> requestGet() {
        String url = "http://localhost:8888/employee/query/2";
        ResultVo<EmployeeVo> resultVo = restTemplateUtils.get(url,
                new EmployeeVoParameterizedTypeReference());
        LOGGER.info("code: {}", resultVo.getCode());
        EmployeeVo employeeVo = resultVo.getResult().getData().get(0);
        LOGGER.info("employeeVo: {}", new Gson().toJson(employeeVo));
        return ResultVoUtils.success(null);
    }

    @GetMapping(value = "/request-post")
    public ResultVo<Void> requestPost() {
        Book book = new Book();
        book.setAuthor("吴军");
        book.setPublisher("人民邮电出版社");
        book.setName("数学之美");
        String url = "http://localhost:8888/v1/book/one-book";
        ResultVo<Book> resultVo = restTemplateUtils.post(url,
                book, new BookParameterizedTypeReference());
        LOGGER.info("code: {}", resultVo.getCode());
        Book responseBook = resultVo.getResult().getData().get(0);
        LOGGER.info("employeeVo: {}", new Gson().toJson(responseBook));
        return ResultVoUtils.success(null);
    }

    private static class EmployeeVoParameterizedTypeReference extends ParameterizedTypeReference<ResultVo<EmployeeVo>> {
    }

    ;

    private static class BookParameterizedTypeReference extends ParameterizedTypeReference<ResultVo<Book>> {
    }

    ;


}