Http 客戶端主機名為空？

Question

當HttpPost方法使用請求正文到 URI“ https://app_server.test.com:9100/processes ”使用HttpClient執行HttpPost ，我得到一個異常：主機名可能不為空

示例代碼：

HttpPost postRequest = new HttpPost("https://app_server.test.com:9100/processes.ashx"); 
StringEntity input = new StringEntity(jsonstring); 
input.setContentType("application/json"); 
postRequest.setEntity(input); 
HttpResponse response = httpClient.execute(postRequest);

堆棧跟蹤：

java.lang.IllegalArgumentException: Host name may not be null
    at org.apache.http.HttpHost.<init>(HttpHost.java:79) ~[httpcore-4.2.2.jar:4.2.2]
    at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:501) ~[httpclient-4.2.3.jar:4.2.3]
    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:906) ~[httpclient-4.2.3.jar:4.2.3]
    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:805) ~[httpclient-4.2.3.jar:4.2.3]
    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:784) ~[httpclient-4.2.3.jar:4.2.3]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_181]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_181]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_181]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_181]
    at org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:215) ~[spring-web-4.0.5.RELEASE.jar:4.0.5.RELEASE]
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132) ~[spring-web-4.0.5.RELEASE.jar:4.0.5.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104) ~[spring-webmvc-4.0.5.RELEASE.jar:4.0.5.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:749) ~[spring-webmvc-4.0.5.RELEASE.jar:4.0.5.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:689) ~[spring-webmvc-4.0.5.RELEASE.jar:4.0.5.RELEASE]
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:83) ~[spring-webmvc-4.0.5.RELEASE.jar:4.0.5.RELEASE]
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:938) ~[spring-webmvc-4.0.5.RELEASE.jar:4.0.5.RELEASE]
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:870) ~[spring-webmvc-4.0.5.RELEASE.jar:4.0.5.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:961) ~[spring-webmvc-4.0.5.RELEASE.jar:4.0.5.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:863) ~[spring-webmvc-4.0.5.RELEASE.jar:4.0.5.RELEASE]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:646) ~[tomcat-embed-core-7.0.54.jar:7.0.54]
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:837) ~[spring-webmvc-4.0.5.RELEASE.jar:4.0.5.RELEASE]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:727) ~[tomcat-embed-core-7.0.54.jar:7.0.54]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303) ~[tomcat-embed-core-7.0.54.jar:7.0.54]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) ~[tomcat-embed-core-7.0.54.jar:7.0.54]
    at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:77) ~[spring-web-4.0.5.RELEASE.jar:4.0.5.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.0.5.RELEASE.jar:4.0.5.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) ~[tomcat-embed-core-7.0.54.jar:7.0.54]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) ~[tomcat-embed-core-7.0.54.jar:7.0.54]
    at org.apache.catalina.filters.RequestDumperFilter.doFilter(RequestDumperFilter.java:203) ~[tomcat-embed-core-7.0.54.jar:7.0.54]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) ~[tomcat-embed-core-7.0.54.jar:7.0.54]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) ~[tomcat-embed-core-7.0.54.jar:7.0.54]
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220) ~[tomcat-embed-core-7.0.54.jar:7.0.54]
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122) [tomcat-embed-core-7.0.54.jar:7.0.54]
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501) [tomcat-embed-core-7.0.54.jar:7.0.54]
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950) [tomcat-embed-core-7.0.54.jar:7.0.54]
    at org.apache.catalina.valves.RemoteIpValve.invoke(RemoteIpValve.java:683) [tomcat-embed-core-7.0.54.jar:7.0.54]
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171) [tomcat-embed-core-7.0.54.jar:7.0.54]
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) [tomcat-embed-core-7.0.54.jar:7.0.54]
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116) [tomcat-embed-core-7.0.54.jar:7.0.54]
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408) [tomcat-embed-core-7.0.54.jar:7.0.54]
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1040) [tomcat-embed-core-7.0.54.jar:7.0.54]
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:607) [tomcat-embed-core-7.0.54.jar:7.0.54]
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1720) [tomcat-embed-core-7.0.54.jar:7.0.54]
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1679) [tomcat-embed-core-7.0.54.jar:7.0.54]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_181]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_181]
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-7.0.54.jar:7.0.54]
    at java.lang.Thread.run(Thread.java:748) [na:1.8.0_181]

Answer 1

您沒有添加如何創建 httpClient 以及您使用什么 httpClient。 我嘗試以下代碼（使用 org.apache.httpcomponents.httpclient，版本 4.5.6）

    try
    {
        HttpClient   httpClient  = new DefaultHttpClient();
        HttpPost     postRequest = new HttpPost("https://google.com");
        StringEntity input       = new StringEntity("ttt");
        input.setContentType("application/json");
        postRequest.setEntity(input);
        HttpResponse response = httpClient.execute(postRequest);
    }
    catch (final Exception e)
    {
        System.out.print(e);
    }

它返回正確的響應“HTTP/1.1 405 Method Not Allowed”。

很奇怪，您在堆棧跟蹤中有許多 spring 框架類。 你使用一些 spring-frameworks http 客戶端嗎？

我推薦你：

1. 更新您的 httpclient 版本（使用最新版本），

2. 嘗試使用其他 url，例如 google.com 等（當然，您收到了 http 錯誤，例如 405，但您可以看到代碼是正確的），

3. 嘗試使用其他 httpClient 類或其他方式來做到這一點（因為 httpClient 現在已被棄用），