spingboot2.x转发或代理别人的流式接口

1.需求描述

现有别人的流式接口，一般我们会使用Nginx进行代理就完事了，但是实际工作中有不少毛病非得用SpringBoot给做转发，美名其曰用后端服务去调用别家的流式接口，这样一来就需要后端去尝试转发流式接口了。

2.代码实操

2.1.测试contrller

@Slf4j
@RestController
@RequestMapping("/proxy")
public class StreamForwardingController {

    @Autowired
    private ModelService modelService;

    @PostMapping("/model")
    public ResponseEntity<byte[]> proxyStream(@RequestHeader HttpHeaders headers, @RequestBody JSONObject req) {
        return modelService.callModelApI(req);
    }
}

2.2.测试service

public interface ModelService {

    /**
     * 根据情况调用流式接口
     * @param param
     * @return
     */
    ResponseEntity<byte[]> callModelApI(JSONObject param);

}

2.3.测试impl

@Service
@Slf4j
public class ModelServiceImpl implements ModelService {

    @Autowired
    private StreamProxyService streamProxyService;

    @Override
    public ResponseEntity<byte[]> callModelApI(JSONObject param) {
        log.info("开始调用流式接口...");
        log.info("请求参数：{}",param.toString());
		
		//这里存一些你需要的业务数据
        String xxx = param.getString("xxx");
        String yyy = param.getString("yyy");

        //预处理
        if(StringUtils.isEmpty(xxx) || StringUtils.isEmpty(yyy)){
            log.error("请求参数为空");
            return null;
        }

        //组装模型请求对象
        JSONObject req = new JSONObject(); //组装请求对象
        String targetUrl = "http://xxx/xxx/xxx/xxx"; //获取流式接口请求地址
        log.info("流式接口地址：{}", targetUrl);
        log.info("流式报文：{}", req);

        //调用流式接口
        HttpHeaders headers = new HttpHeaders();//header设置
        headers.add("Content-Type", "application/json");
        HttpEntity<JSONObject> requestEntity = new HttpEntity<>(req,headers);//header和body设置
        return streamProxyService.proxyStream(targetUrl, requestEntity); //这个才是重点
    }
}

2.4.测试操作类（重点）

@Slf4j
@Service
public class StreamProxyService {

    private final RestTemplate restTemplate;

    public StreamProxyService(RestTemplate restTemplate) {
        //设置操作流格式转换
        restTemplate.getMessageConverters().add(new StringHttpMessageConverter());
        this.restTemplate = restTemplate;
    }

    public ResponseEntity<byte[]> proxyStream(String targetUrl, HttpEntity<JSONObject> requestEntity) {
        //HttpHeaders headers = requestEntity.getHeaders();
        //如有需要对headers进行处理
        if(targetUrl.contains("https")){
            SSLIgnore.ignoreSSL(); //如果是调用https开头的流式接口的话，你可能需要执行这一段代码
        }
        return restTemplate.exchange(targetUrl, HttpMethod.POST, requestEntity, byte[].class);
    }

2.5.其他辅助类

package xxx;

import javax.net.ssl.HostnameVerifier;
import javax.net.ssl.HttpsURLConnection;
import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLSession;
import javax.net.ssl.TrustManager;
import javax.net.ssl.X509TrustManager;
import java.security.KeyManagementException;
import java.security.NoSuchAlgorithmException;
import java.security.cert.X509Certificate;

public class SSLIgnore {

    public static void ignoreSSL() {
        try {
            // 创建一个信任所有证书的 TrustManager
            TrustManager[] trustAllCerts = new TrustManager[]{
                    new X509TrustManager() {
                        public X509Certificate[] getAcceptedIssuers() {
                            return null;
                        }

                        public void checkClientTrusted(X509Certificate[] certs, String authType) {
                        }

                        public void checkServerTrusted(X509Certificate[] certs, String authType) {
                        }
                    }
            };

            // 创建 SSLContext 并初始化它使用我们的信任管理器
            SSLContext sslContext = SSLContext.getInstance("SSL");
            sslContext.init(null, trustAllCerts, new java.security.SecureRandom());

            // 设置默认的 SSL 连接工厂
            HttpsURLConnection.setDefaultSSLSocketFactory(sslContext.getSocketFactory());

            // 忽略主机名验证
            HttpsURLConnection.setDefaultHostnameVerifier(new HostnameVerifier() {
                public boolean verify(String hostname, SSLSession session) {
                    return true;
                }
            });
        } catch (NoSuchAlgorithmException | KeyManagementException e) {
            e.printStackTrace();
        }
    }
}

3.操作测试

直接在Postman里面测试即可，没有啥特殊配置。