我正在使用Restlet来实现Web服务。客户端(也使用Restlet)对服务器进行多次连续调用,但在少量调用成功完成后,进一步调用会挂起服务器,显示消息:
信息:停止接受新的连接和交易。考虑增加最大线程数。
我试过了:
getContext().getParameters().add("maxThreads", "200");
但这没有用。在任何情况下,似乎客户端应该能够进行无限数量的呼叫,并且增加maxThreads只会增加限制。看起来我没有释放一些资源或在每次客户电话后断开连接,但我不知道该怎么做。
以下(我可以做的很小)独立程序演示了这个问题。它启动一个简单的服务器,然后客户端多次调用它:
/** You may copy, modify, and re-use this code as you see fit - Jim Irrer */
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import org.restlet.Application;
import org.restlet.Component;
import org.restlet.Request;
import org.restlet.Response;
import org.restlet.Restlet;
import org.restlet.Server;
import org.restlet.data.MediaType;
import org.restlet.data.Method;
import org.restlet.data.Protocol;
import org.restlet.data.Status;
import org.restlet.representation.InputRepresentation;
import org.restlet.representation.Representation;
import org.restlet.resource.ClientResource;
import org.restlet.resource.Directory;
public class SimpleServerPut extends Component implements Runnable {
private static final int PORT = 8080;
private static int readToByteArray(InputStream inputStream, byte[] buf) throws IOException {
int length = 0;
int b;
while ((b = inputStream.read()) != -1) {
buf[length++] = (byte)b;
}
return length;
}
@Override
public void run() {
getContext().getParameters().add("maxThreads", "200");
// Create the HTTP server and listen on port PORT
SimpleServerPut simpleServer = new SimpleServerPut();
Server server = new Server(Protocol.HTTP, PORT, simpleServer);
simpleServer.getClients().add(Protocol.FILE);
// Create an application
Application application = new Application(simpleServer.getContext()) {
@Override
public Restlet createRoot() {
return new Directory(getContext(), "C:");
}
};
// Attach the application to the component and start it
simpleServer.getDefaultHost().attach("/stuff/", application);
try {
server.start();
}
catch (Exception ex) {
ex.printStackTrace();
}
}
@Override
public void handle(Request request, Response response) {
// assume the worst
response.setStatus(Status.CLIENT_ERROR_METHOD_NOT_ALLOWED);
response.setEntity("No no - Bad client! Only do PUTs.", MediaType.TEXT_PLAIN);
try {
if (request.getMethod() == Method.PUT) {
InputStream inputStream = request.getEntity().getStream();
byte[] buf = new byte[64*1024];
int totalLength = readToByteArray(inputStream, buf);
response.setStatus(Status.SUCCESS_OK);
String msg = "Number of bytes received: " + totalLength;
response.setEntity(msg, MediaType.TEXT_PLAIN);
System.out.println("server: " + msg);
return;
}
}
catch (Exception ex) {
ex.printStackTrace();
}
}
private static String callServer() throws IOException {
String urlText = "http://localhost:" + PORT + "/";
ClientResource clientResource = new ClientResource(urlText);
clientResource.setReferrerRef(urlText);
byte[] buf = new byte[1000];
for (int i = 0; i < buf.length; i++) {
buf[i] = (byte)((int)'a' + (i%26));
}
ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(buf);
Representation representation = new InputRepresentation(byteArrayInputStream, MediaType.APPLICATION_OCTET_STREAM);
Representation representation2 = clientResource.put(representation);
byte[] responseBuf = new byte[16*1024];
int length = readToByteArray(representation2.getStream(), responseBuf);
Response response = clientResource.getResponse();
Status status = response.getStatus();
return "status: " + status + " message: " + new String(responseBuf, 0, length);
}
// Start server and call it a bunch of times
public static void main(String[] args) throws Exception {
SimpleServerPut simpleServer = new SimpleServerPut();
new Thread(simpleServer).start();
Thread.sleep(200); // cheap trick to make sure that server is running
// make a bunch of client calls
for (int t = 0; t < 100; t++) {
System.out.println("client count: " + (t+1) + " " + callServer());
}
System.exit(0);
}
}
答案 0 :(得分:5)
我们只能通过直接停止ClientResource的关联客户端来解决问题(使用Restlet版本2.0.15):
Client c = (Client)clientResource.getNext();
try {
c.stop();
} catch (Exception e) {
//handle exception
}
答案 1 :(得分:4)
添加一行,以便客户端释放资源:
Response response = clientResource.getResponse();
Status status = response.getStatus();
clientResource.release(); // add this line
到客户端,一切正常。最终,如果客户端死亡,服务器会超时,但这需要一段时间。
答案 2 :(得分:1)
我已经解决了下载Restlet API
的最后一个稳定版本的问题显然,我一直使用的.jar是一个旧版本,release()
命令没有任何效果。
在更新之前,客户端日志仅输出客户端的开头:
Sep 05, 2012 9:50:19 AM org.restlet.engine.http.connector.HttpClientHelper start
INFO: Starting the default HTTP client
现在它也在输出停止:
Sep 05, 2012 9:50:19 AM org.restlet.engine.http.connector.HttpClientHelper stop
INFO: Stopping the default HTTP client
答案 3 :(得分:0)
除了调用ClientResource.release()之外,您可能还想在表示上调用exhaust()。
Representation responseRepresentation = response.getEntity();
if (responseRepresentation != null) {
try {
responseRepresentation.exhaust();
} catch (IOException e) {
// handle exception
}
responseRepresentation.release();
}
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