java - RestTemplate Exchange 超时但 PostMan 可以工作

Question

我尝试使用 Spring 的 RestTemplate 发出简单的 GET 请求。

RestTemplate restTemplate = new RestTemplate();
HttpHeaders headers headers = new HttpHeaders() {
            {
                String auth = username + ":" + password;
                byte[] encodedAuth = Base64.getEncoder().encode(auth.getBytes(StandardCharsets.US_ASCII));
                String authHeader = "Basic " + new String(encodedAuth);
                set(HttpHeaders.AUTHORIZATION, authHeader);
                //set(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_JSON.toString());
            }
        };

ResponseEntity<FileTypeList> response = restTemplate.exchange(endpoint + FILES, HttpMethod.GET, new HttpEntity(headers), FileTypeList.class);
return response.getBody() != null ? response.getBody().getFileTypes() : Collections.emptyList();

此调用出现超时错误:

java.net.ConnectException: Connection timed out: connect
    at java.net.DualStackPlainSocketImpl.waitForConnect(Native Method) ~[na:1.8.0_161]
    at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:85) ~[na:1.8.0_161]
    at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350) ~[na:1.8.0_161]
    at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206) ~[na:1.8.0_161]
    at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188) ~[na:1.8.0_161]
    at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172) ~[na:1.8.0_161]
    at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392) ~[na:1.8.0_161]
    at java.net.Socket.connect(Socket.java:589) ~[na:1.8.0_161]
    at sun.security.ssl.SSLSocketImpl.connect(SSLSocketImpl.java:673) ~[na:1.8.0_161]

但是当我尝试与 Postman 进行相同的调用时，它可以正常工作。

端点是https://verda.borsaistanbul.com/files

Spring RestTemplate 与 Postman 有何不同？

Answer 1

Rest 模板允许您设置代理。有多种方法可以做到这一点，最简单的方法如下:

在创建RestTemplate之前，使用以下代码设置代理:

Properties props = System.getProperties();
props.put("http.proxyHost", "your.proxy.server");
props.put("http.proxyPort", "80");

请注意，这将为 JVM 中的 while Java 应用程序设置代理。

设置代理的另一种方法如下，它将仅为您当前的代码设置代理:

SimpleClientHttpRequestFactory clientHttpReq = new SimpleClientHttpRequestFactory();
Proxy proxy = new Proxy(Proxy.Type.HTTP, new InetSocketAddress("your.proxy.server", 80));
clientHttpReq.setProxy(proxy);
RestTemplate restTemplate = new RestTemplate(clientHttpReq);