Heroku Java -名称或服务未知

Question

我们有一个私人空间，并提供了一个内部API的访问权限，这样我们就可以从私人空间应用程序访问它。因此，我们开发了一个演示Java应用程序来测试它。当我们尝试用HTTP连接服务时，堆栈跟踪会像这样结束。

java.net.UnknownHostException: [THE_VALID_URL] Name or service not known
java.base/java.net.Inet4AddressImpl.lookupAllHostAddr(Native Method)
at java.base/java.net.InetAddress$PlatformNameService.lookupAllHostAddr(InetAddress.java:929)
at java.base/java.net.InetAddress.getAddressesFromNameService(InetAddress.java:1519)
at java.base/java.net.InetAddress$NameServiceAddresses.get(InetAddress.java:848)
at java.base/java.net.InetAddress.getAllByName0(InetAddress.java:1509)
at java.base/java.net.InetAddress.getAllByName(InetAddress.java:1368)
at java.base/java.net.InetAddress.getAllByName(InetAddress.java:1302)
at org.apache.http.impl.conn.SystemDefaultDnsResolver.resolve(SystemDefaultDnsResolver.java:45)

当我们ping私有空间中的相应IP时，我们可以看到它已启动。但是当我们试图从Java应用程序中访问服务时，它就像上面那样结束了。

Java 代码是这样的：

RequestConfig config = RequestConfig.DEFAULT;
HttpClient client = HttpClientBuilder.create().setDefaultRequestConfig(config).build();

HttpGet httpGet = new HttpGet("[THE_VALID_URL]");
httpGet.addHeader("Content-Type", "application/json; UTF-8");

HttpResponse resp = client.execute(httpGet);

有没有人有任何想法来解决这个问题？

谢谢你。

[更新]：用这个https://stackoverflow.com/a/35327982/7595094解决

Answer 1

似乎是 DNS 名称解析的问题。在私人空间赫洛库文献中，提到

All dyno-to-dyno communication in Private Spaces takes places via the private network. 
To communicate via the private network, your process needs to bind to its dyno’s private IP address on a port between 1024 and 65535. 
The HEROKU_PRIVATE_IP environment variable contains your dyno’s private IP address.

After your process binds to the private IP address, it’s reachable on the chosen port via its DNS name and port. 
The above example would be available on this URL:

http://foo.[APP_NAME].app.localspace:5000/

因此，您可以尝试将您的API绑定到您的私有IP静态端口，并使用这个< code>http://foo。[APP _ NAME]. APP . local space:5000/格式作为URL，以便从您的java应用程序发出GET请求