springboot 请求外部接口方法

直接上代码：

1、定义配置类

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.client.ClientHttpRequestFactory;
import org.springframework.http.client.SimpleClientHttpRequestFactory;
import org.springframework.web.client.RestTemplate;

@Configuration
public class HttpApiConfig {
    @Bean
    public RestTemplate restTemplate(ClientHttpRequestFactory factory) {
        return new RestTemplate(factory);
    }

    @Bean
    public ClientHttpRequestFactory simpleClientHttpRequestFactory() {
        SimpleClientHttpRequestFactory factory = new SimpleClientHttpRequestFactory();
        factory.setReadTimeout(5000);
        factory.setConnectTimeout(5000);
        return factory;
    }
}

2、定义服务

import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Service;
import org.springframework.util.MultiValueMap;
import org.springframework.web.client.RestTemplate;

import java.util.Map;

@Service
public class HttpUtils {

    private final RestTemplate restTemplate;

    public HttpUtils(RestTemplate restTemplate) {
        this.restTemplate = restTemplate;
    }

    // Get请求
    public String Get(String url, Map<String, Object> params) {
        String uri = buildUri(url, params);
        ResponseEntity<String> response = restTemplate.getForEntity(uri, String.class);
        return response.getBody();
    }

    // Post请求(JSON请求头)
    public String JPost(String url, Map<String, Object> params) {
        HttpEntity<Map<String, Object>> request = new HttpEntity<>(params, jsonHeaderBuilder());
        ResponseEntity<String> response = restTemplate.postForEntity(url, request, String.class);
        return response.getBody();
    }

    // Post请求(URL请求头)
    public String UPost(String url, MultiValueMap<String, String> params) {
        HttpEntity<MultiValueMap<String, String>> request = new HttpEntity<>(params, urlHeaderBuilder());
        ResponseEntity<String> response = restTemplate.postForEntity(url, request, String.class);
        return response.getBody();
    }

    // 拼接Url和参数
    private String buildUri(String url, Map<String, Object> params) {
        StringBuilder sb = new StringBuilder(url);
        sb.append("?");
        for (Map.Entry<String, Object> entry : params.entrySet()) {
            sb.append(entry.getKey()).append("=").append(entry.getValue()).append("&");
        }
        sb.deleteCharAt(sb.length() - 1);
        return sb.toString();
    }

    // 构建Url请求头
    private HttpHeaders urlHeaderBuilder() {
        HttpHeaders h = new HttpHeaders();
        h.setContentType(MediaType.APPLICATION_FORM_URLENCODED);
        return h;
    }

    // 构建Json请求头
    private HttpHeaders jsonHeaderBuilder() {
        HttpHeaders h = new HttpHeaders();
        h.setContentType(MediaType.APPLICATION_JSON);
        return h;
    }
}

3、实例（参考）

POST请求，参数带在URL上

MultiValueMap<String, String> requestPara = new LinkedMultiValueMap<>();
requestPara.add("id", id);
requestPara.add("name", name);
StringBuilder sb = new StringBuilder(baseUrl);
sb.append("/oh/yeah");
String response = httpUtils.UPost(sb.toString(), requestPara);

GET和JPOST请求是常用的，参数添加与UPost类似，类型变一下。

Map<String, Object> requestPara = new HashMap<>();
requestPara.put("id", id);
requestPara.put("name", name);
StringBuilder sb = new StringBuilder(baseUrl);
sb.append("/oh/yeah");