当url不可用时，Java捕获异常

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我正在使用Tomcat运行我的java代码，目前只要目标端点无法访问/不可用/无法获得任何响应，它就会显示大量错误。我试图在我的代码中添加catch异常，但似乎无效。

reportUrl = http：// Unavailable; HttpEntity< DrEndpointRequest> entity = new HttpEntity<>（der，headers）; 尝试 { ResponseEntity< String> response = restTemplate.exchange（reportUrl，HttpMethod.POST，entity， String 。 class ）; System.out.println（ Response - + response.getBody（）+ + response.getStatusCode（））; if （response.getStatusCode（）== HttpStatus.OK）{ trans.setDnStatus（ 已发送）; } else { trans.setDnStatus（ 失败）; } } catch （HttpStatusCodeException ex）{ System.out.println（ex.getStatusText（）+ + ex.getResponseBodyAsString（））; trans.setDnStatus（ 失败）; }

以下是tomcat中显示的错误：

2019-04-30 02：33：55.016 ERROR 4432 --- [scheduling-1] osssTaskUtils $ LoggingErrorHandler：计划任务中发生意外错误。 org.springframework.web.client.ResourceAccessException：POST请求中的http：// Unavailable的I / O错误：不可用;嵌套异常是java.UnknownHostException：在org.springframework.web.client.RestTemplate.doExecute（RestTemplate.java:743）〜[spring-web-5.1.3.RELEASE.jar：5.1.3.RELEASE]中不可用org.springframework.web.client.RestTemplate.execute（RestTemplate.java:669）〜[spring-web-5.1.3.RELEASE.jar：5.1.3.RELEASE] org.springframework.web.client.RestTemplate.exchange （RestTemplate.java:578）〜[spring-web-5.1.3.RELEASE.jar：5.1.3.RELEASE] at com.dr.scheduler.ScheduledTask.scheduleTaskWithFixedRate（ScheduledTask.java:97）〜[classes /：1.0 ]在sun.reflect.GeneratedMethodAccessor89.invoke（未知来源）〜[na：na] at sun.reflect.DelegatingMethodAccessorImpl.invoke（DelegatingMethodAccessorImpl.java:43）〜[na：1.8.0_201] at java.lang.reflect.Method .invoke（Method.java:498）〜[na：1.8.0_201] at org.springframework.scheduling.support.ScheduledMethodRunnable.run（ScheduledMethodRunnable.java:84）〜[spring-context-5.1.3.RELEASE.jar： 5.1.3.RELEASE]在org.springframework.scheduling.support.DelegatingErrorHandlin java.util.concurrent.Executors中的gRunnable.run（DelegatingErrorHandlingRunnable.java:54）〜[spring-context-5.1.3.RELEASE.jar：5.1.3.RELEASE] $ RunnableAdapter.call（Executors.java:511）[ na：1.8.0_201] at java.util.concurrent.FutureTask.runAndReset（FutureTask.java:308）[na：1.8.0_201] at java.util.concurrent.ScheduledThreadPoolExecutor $ ScheduledFutureTask.access $ 301（ScheduledThreadPoolExecutor.java:180） java [u :. java [.u :. ：1.8.0_201]引起：java.UnknownHostException：java.AbstractPlainSocketImpl.connect（AbstractPlainSocketImpl.java:184）〜[na：1.8.0_201]在java.PlainSocketImpl.connect（PlainSocketImpl.java）中不可用： 172）〜[na：1.8.0_201] java.SocksSocketImpl.connect（SocksSocketImpl.java:392）〜[na：1.8.0_201] java.Socket.connect（Socket.java:589）〜[ na：1.8.0_201] at java.Socket.connect（Socket.java:538）〜[na：1.8.0_201] at sun.NetworkClient.doConnect（NetworkClient.java:180)~ [na：1.8。 0_201] at sun.www.http.HttpClient.openServer(httpClient.java:463)~ [na：1.8.0_201] at sun.www.http.HttpClient.openServer（HttpClient.java:558)~ [ na：1.8.0_201] at sun.www.http.HttpClient。（HttpClient.java:242）〜[na：1.8.0_201] at sun.www.http.HttpClient.New（HttpClient.java:339 ）〜[na：1.8.0_201] at sun.www.http.HttpClient.New（HttpClient.java:357）〜[na：1.8.0_201] at sun.www.protocol.http.HttpURLConnection.getNewHttpClient （HttpURLConnection.java:1220）〜[na：1.8.0_201] at sun.www.protocol.http.HttpURLConnection.plainConnect0（HttpURLConnection.java:1156）〜[na：1.8.0_201] at sun.www .protocol.http.HttpURLConnection.plainConnect（HttpURLConnection.java:1050)~ [na：1.8.0_201] at sun.www。 protocol.http.HttpURLConnection.connect（HttpURLConnection.java:984）〜[na：1.8.0_201] org.springframework.http.client.SimpleBufferingClientHttpRequest.executeInternal（SimpleBufferingClientHttpRequest.java:76）〜[spring-web-5.1.3 .RELEASE.jar：5.1.3.RELEASE] at org.springframework.http.client.AbstractBufferingClientHttpRequest.executeInternal（AbstractBufferingClientHttpRequest.java:48）〜[spring-web-5.1.3.RELEASE.jar：5.1.3.RELEASE]在org.springframework.http.client.AbstractClientHttpRequest.execute（AbstractClientHttpRequest.java:53）〜[spring-web-5.1.3.RELEASE.jar：5.1.3.RELEASE] org.springframework.web.client.RestTemplate。 doExecute（RestTemplate.java:734）〜[spring-web-5.1.3.RELEASE.jar：5.1.3.RELEASE] ...省略了15个常用框架

我尝试过： i添加

catch（HttpStatusCodeException ex）{ System.out.println（ex.getStatusText（）++ ex.getResponseBodyAsString（））; trans.setDnStatus（失败）; }

但没有工作

解决方案

LoggingErrorHandler：计划任务中发生意外错误。 org.springframework.web.client.ResourceAccessException：POST请求中的http：// Unavailable的I / O错误：不可用;嵌套异常是java.UnknownHostException：在org.springframework.web.client.RestTemplate.doExecute（RestTemplate.java:743）〜[spring-web-5.1.3.RELEASE.jar：5.1.3.RELEASE]中不可用org.springframework.web.client.RestTemplate.execute（RestTemplate.java:669）〜[spring-web-5.1.3.RELEASE.jar：5.1.3.RELEASE] org.springframework.web.client.RestTemplate.exchange （RestTemplate.java:578）〜[spring-web-5.1.3.RELEASE.jar：5.1.3.RELEASE] at com.dr.scheduler.ScheduledTask.scheduleTaskWithFixedRate（ScheduledTask.java:97）〜[classes /：1.0 ]在sun.reflect.GeneratedMethodAccessor89.invoke（未知来源）〜[na：na] at sun.reflect.DelegatingMethodAccessorImpl.invoke（DelegatingMethodAccessorImpl.java:43）〜[na：1.8.0_201] at java.lang.reflect.Method .invoke（Method.java:498）〜[na：1.8.0_201] at org.springframework.scheduling.support.ScheduledMethodRunnable.run（ScheduledMethodRunnable.java:84）〜[spring-context-5.1.3.RELEASE.jar： 5.1.3.RELEASE]在org.springframework.scheduling.support.DelegatingErrorHandlin java.util.concurrent.Executors中的gRunnable.run（DelegatingErrorHandlingRunnable.java:54）〜[spring-context-5.1.3.RELEASE.jar：5.1.3.RELEASE]

RunnableAdapter .call（Executors.java:511）[na：1.8.0_201] at java.util.concurrent.FutureTask.runAndReset（FutureTask.java:308）[na：1.8.0_201] at java.util.concurrent.ScheduledThreadPoolExecutor ScheduledFutureTask.access

I am running my java code using Tomcat,currently it shows bunch of errors whenever the target endpoint is not reachable/unavailable/cant get any response. I tried to add catch exception in my code but it seems not working.

reportUrl = "Unavailable"; HttpEntity<DrEndpointRequest> entity = new HttpEntity<>(der, headers); try { ResponseEntity<String> response = restTemplate.exchange(reportUrl, HttpMethod.POST, entity, String.class); System.out.println("Response-- " + response.getBody() + " " + response.getStatusCode()); if (response.getStatusCode() == HttpStatus.OK) { trans.setDnStatus("Sent"); } else { trans.setDnStatus("Failed"); } } catch (HttpStatusCodeException ex) { System.out.println(ex.getStatusText() + " " + ex.getResponseBodyAsString()); trans.setDnStatus("Failed"); }

below is the error shown in tomcat :

2019-04-30 02:33:55.016 ERROR 4432 --- [ scheduling-1] o.s.s.s.TaskUtils$LoggingErrorHandler : Unexpected error occurred in scheduled task. org.springframework.web.client.ResourceAccessException: I/O error on POST request for "Unavailable": Unavailable; nested exception is java.UnknownHostException: Unavailable at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:743) ~[spring-web-5.1.3.RELEASE.jar:5.1.3.RELEASE] at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:669) ~[spring-web-5.1.3.RELEASE.jar:5.1.3.RELEASE] at org.springframework.web.client.RestTemplate.exchange(RestTemplate.java:578) ~[spring-web-5.1.3.RELEASE.jar:5.1.3.RELEASE] at com.dr.scheduler.ScheduledTask.scheduleTaskWithFixedRate(ScheduledTask.java:97) ~[classes/:1.0] at sun.reflect.GeneratedMethodAccessor89.invoke(Unknown Source) ~[na:na] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_201] at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_201] at org.springframework.scheduling.support.ScheduledMethodRunnable.run(ScheduledMethodRunnable.java:84) ~[spring-context-5.1.3.RELEASE.jar:5.1.3.RELEASE] at org.springframework.scheduling.support.DelegatingErrorHandlingRunnable.run(DelegatingErrorHandlingRunnable.java:54) ~[spring-context-5.1.3.RELEASE.jar:5.1.3.RELEASE] at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [na:1.8.0_201] at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308) [na:1.8.0_201] at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180) [na:1.8.0_201] at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294) [na:1.8.0_201] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_201] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_201] at java.lang.Thread.run(Thread.java:748) [na:1.8.0_201] Caused by: java.UnknownHostException: Unavailable at java.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:184) ~[na:1.8.0_201] at java.PlainSocketImpl.connect(PlainSocketImpl.java:172) ~[na:1.8.0_201] at java.SocksSocketImpl.connect(SocksSocketImpl.java:392) ~[na:1.8.0_201] at java.Socket.connect(Socket.java:589) ~[na:1.8.0_201] at java.Socket.connect(Socket.java:538) ~[na:1.8.0_201] at sun.NetworkClient.doConnect(NetworkClient.java:180) ~[na:1.8.0_201] at sun.www.http.HttpClient.openServer(HttpClient.java:463) ~[na:1.8.0_201] at sun.www.http.HttpClient.openServer(HttpClient.java:558) ~[na:1.8.0_201] at sun.www.http.HttpClient.(HttpClient.java:242) ~[na:1.8.0_201] at sun.www.http.HttpClient.New(HttpClient.java:339) ~[na:1.8.0_201] at sun.www.http.HttpClient.New(HttpClient.java:357) ~[na:1.8.0_201] at sun.www.protocol.http.HttpURLConnection.getNewHttpClient(HttpURLConnection.java:1220) ~[na:1.8.0_201] at sun.www.protocol.http.HttpURLConnection.plainConnect0(HttpURLConnection.java:1156) ~[na:1.8.0_201] at sun.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:1050) ~[na:1.8.0_201] at sun.www.protocol.http.HttpURLConnection.connect(HttpURLConnection.java:984) ~[na:1.8.0_201] at org.springframework.http.client.SimpleBufferingClientHttpRequest.executeInternal(SimpleBufferingClientHttpRequest.java:76) ~[spring-web-5.1.3.RELEASE.jar:5.1.3.RELEASE] at org.springframework.http.client.AbstractBufferingClientHttpRequest.executeInternal(AbstractBufferingClientHttpRequest.java:48) ~[spring-web-5.1.3.RELEASE.jar:5.1.3.RELEASE] at org.springframework.http.client.AbstractClientHttpRequest.execute(AbstractClientHttpRequest.java:53) ~[spring-web-5.1.3.RELEASE.jar:5.1.3.RELEASE] at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:734) ~[spring-web-5.1.3.RELEASE.jar:5.1.3.RELEASE] ... 15 common frames omitted

What I have tried: i added

catch (HttpStatusCodeException ex) { System.out.println(ex.getStatusText() + " " + ex.getResponseBodyAsString()); trans.setDnStatus("Failed"); }

but not working

解决方案

LoggingErrorHandler : Unexpected error occurred in scheduled task. org.springframework.web.client.ResourceAccessException: I/O error on POST request for "Unavailable": Unavailable; nested exception is java.UnknownHostException: Unavailable at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:743) ~[spring-web-5.1.3.RELEASE.jar:5.1.3.RELEASE] at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:669) ~[spring-web-5.1.3.RELEASE.jar:5.1.3.RELEASE] at org.springframework.web.client.RestTemplate.exchange(RestTemplate.java:578) ~[spring-web-5.1.3.RELEASE.jar:5.1.3.RELEASE] at com.dr.scheduler.ScheduledTask.scheduleTaskWithFixedRate(ScheduledTask.java:97) ~[classes/:1.0] at sun.reflect.GeneratedMethodAccessor89.invoke(Unknown Source) ~[na:na] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_201] at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_201] at org.springframework.scheduling.support.ScheduledMethodRunnable.run(ScheduledMethodRunnable.java:84) ~[spring-context-5.1.3.RELEASE.jar:5.1.3.RELEASE] at org.springframework.scheduling.support.DelegatingErrorHandlingRunnable.run(DelegatingErrorHandlingRunnable.java:54) ~[spring-context-5.1.3.RELEASE.jar:5.1.3.RELEASE] at java.util.concurrent.Executors

RunnableAdapter.call(Executors.java:511) [na:1.8.0_201] at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308) [na:1.8.0_201] at java.util.concurrent.ScheduledThreadPoolExecutor

ScheduledFutureTask.access