Restlet，无法处理ConnectionException

Question

我有以下代码：

private Job[] synchro(URI u)  {
        try{
            Client client = new Client(new Context(),Protocol.HTTP);
            Reference samplesUri = new Reference(u+"/synchrojobs/");

            ClientResource cr = new ClientResource(client.getContext(),Method.POST,samplesUri);
            cr.setChallengeResponse(ChallengeScheme.HTTP_BASIC, "xxx", "uxxx");
            Job[] back = persistence.all().toArray(new Job[persistence.all().size()]);
            for(Job trace : back){
                logger.debug(String.format("Sending synchro for %s status:%s time:%s",trace.getId().toString(),trace.getStatus(),trace.getLastStatusChangeDate().toString()));
            }
            Representation res = cr.post(new JacksonRepresentation<Job[]>(back));
            Job[] result = this.mapper.readValue(res.getStream(),Job[].class);
            cr.release();
            res.release();

            logger.info(String.format("Found %s jobs from %s",result.length,u));

            return result;
        }catch(Exception e){
            logger.error("Error synchronizing jobs:"+e.getMessage());
            return new Job[0];
        }
    }

如果对方没有连接，会抛出一个异常，但是在我的block中没有被捕获，它会在外部弹出，为什么会发生这种情况？

Answer 1

事实上，这样的错误是由客户端连接器和包装器在restlet异常中直接抛出的。

我做了一些测试，抛出了一个带有原因java.net.ConnectException的Restlet ResourceException。但是我可以使用try / catch (异常)来捕获它。如下所示：

mai 12, 2015 7:18:54 PM org.restlet.engine.connector.HttpClientHelper start
INFOS: Starting the internal HTTP client
mai 12, 2015 7:18:54 PM org.restlet.resource.ClientResource retry
INFOS: A recoverable error was detected (1000), attempting again in 2000 ms.
mai 12, 2015 7:18:56 PM org.restlet.resource.ClientResource retry
INFOS: A recoverable error was detected (1000), attempting again in 2000 ms.
Connection Error (1000) - The connector failed to connect to the server

at org.restlet.resource.ClientResource.doError(ClientResource.java:590)
    at org.restlet.resource.ClientResource.handleInbound(ClientResource.java:1153)
    at org.restlet.resource.ClientResource.handle(ClientResource.java:1048)
    at org.restlet.resource.ClientResource.handle(ClientResource.java:1023)
    at org.restlet.resource.ClientResource.handle(ClientResource.java:928)
    at org.restlet.resource.ClientResource.get(ClientResource.java:636)
    at test.TestClient.main(TestClient.java:9)
Caused by: java.net.ConnectException: Connexion refusée
    at java.net.PlainSocketImpl.socketConnect(Native Method)
    at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:339)
    at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:200)
    at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:182)
    at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
    at java.net.Socket.connect(Socket.java:579)
    at sun.net.NetworkClient.doConnect(NetworkClient.java:175)
    at sun.net.www.http.HttpClient.openServer(HttpClient.java:432)
    at sun.net.www.http.HttpClient.openServer(HttpClient.java:527)
    at sun.net.www.http.HttpClient.<init>(HttpClient.java:211)
    at sun.net.www.http.HttpClient.New(HttpClient.java:308)
    at sun.net.www.http.HttpClient.New(HttpClient.java:326)
    at sun.net.www.protocol.http.HttpURLConnection.getNewHttpClient(HttpURLConnection.java:997)
    at sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:933)
    at sun.net.www.protocol.http.HttpURLConnection.connect(HttpURLConnection.java:851)
    at org.restlet.engine.connector.HttpUrlConnectionCall.sendRequest(HttpUrlConnectionCall.java:356)

也许您可以尝试使用try / catch(Throwable)来查看实际抛出了哪个异常？

此外，您能告诉我们Restlet的版本和您使用的客户端连接器吗？在我的测试中，我使用的是Restlet的2.3.1版本...

希望对你有帮助，蒂埃里