Springboot发送http请求(使用RestTemplate)

零、关键类介绍

public class HttpEntity<T> {
    public static final HttpEntity<?> EMPTY = new HttpEntity();
    private final HttpHeaders headers;
    @Nullable
    private final T body;

    protected HttpEntity() {
        this((Object)null, (MultiValueMap)null);
    }

    public HttpEntity(T body) {
        this(body, (MultiValueMap)null);
    }

    public HttpEntity(MultiValueMap<String, String> headers) {
        this((Object)null, headers);
    }

    public HttpEntity(@Nullable T body, @Nullable MultiValueMap<String, String> headers) {
        this.body = body;
        HttpHeaders tempHeaders = new HttpHeaders();
        if (headers != null) {
            tempHeaders.putAll(headers);
        }

        this.headers = HttpHeaders.readOnlyHttpHeaders(tempHeaders);
    }
    ... ...
}

public class HttpHeaders implements MultiValueMap<String, String>, Serializable {
	... ...
}

一、包引入

import org.springframework.http.*;
import org.springframework.util.DigestUtils;
import org.springframework.util.LinkedMultiValueMap;
import org.springframework.util.MultiValueMap;
import org.springframework.web.client.RestTemplate;

二、Get请求

RestTemplate restTemplate = new RestTemplate();
String reqUrl = String.format("http://jx-bd-server04.zeus.lianjia.com:16300/scheduler/task/kill?taskId=%d&userCode=%d", taskId, userId);
String response = restTemplate.getForObject(reqUrl, String.class);

三、post请求

RestTemplate restTemplate = new RestTemplate();
// 设置headers
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.APPLICATION_FORM_URLENCODED);

// 设置body
MultiValueMap<String, String> body = new LinkedMultiValueMap<>();
body.add("id", "123456");

//设置请求实体
HttpEntity<MultiValueMap<String, String>> requestEntity = new HttpEntity<>(body, headers);
try {
    // 发送请求
    ResponseEntity<String> response = restTemplate.postForEntity(url, requestEntity, String.class);
    return response.getBody();
} catch (Exception e) {
    return e.getMessage();
}

四、get请求，带Headers

RestTemplate restTemplate = new RestTemplate();
// 设置headers
HttpHeaders headers = new HttpHeaders();
// headers.setContentType(MediaType.APPLICATION_FORM_URLENCODED);
headers.add("appKey", "data_quality");
headers.add("ts", "1638331856505");
headers.add("sign", "4a1e98c5faf2a867af5afc83d81ab2ce");
//设置请求实体
HttpEntity<String> requestEntity = new HttpEntity<>(headers);
try {
    ResponseEntity<String> responseEntity = restTemplate.exchange(url, HttpMethod.GET, requestEntity, String.class);
    System.out.println(responseEntity.getBody());
} catch (Exception e) {
    System.out.println(e.getMessage());
}