PoolingHttpClientConnectionManager does not release connections - java

I am using Spring to achieve the following:
On a server, I receive data via a REST interface in an XML-Format. I want to transform the data into JSON and POST it to another Server. My code (I removed some sensitive classnames/URLs to avoid the wrath of my employer) looks like this:
Main/Configuration class:
package stateservice;
import org.apache.http.HttpHost;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import org.springframework.http.client.HttpComponentsClientHttpRequestFactory;
import org.springframework.web.client.RestTemplate;
#SpringBootApplication
public class App {
Logger log = LoggerFactory.getLogger(App.class);
public static void main(String[] args) {
System.out.println("Start!");
SpringApplication.run(StateServiceApplication.class, args);
System.out.println("End!");
}
#Bean
public RestTemplate restTemplate() {
log.trace("restTemplate()");
HttpHost proxy = new HttpHost("proxy_url", 8080);
PoolingHttpClientConnectionManager cm = new PoolingHttpClientConnectionManager();
// Increase max total connection to 200
cm.setMaxTotal(200);
cm.setDefaultMaxPerRoute(50);
RequestConfig requestConfig = RequestConfig.custom().setProxy(proxy).build();
HttpClientBuilder httpClientBuilder = HttpClientBuilder.create();
httpClientBuilder.setDefaultRequestConfig(requestConfig);
httpClientBuilder.setConnectionManager(cm);
HttpComponentsClientHttpRequestFactory requestFactory = new HttpComponentsClientHttpRequestFactory(
httpClientBuilder.build());
return new RestTemplate(requestFactory);
}
}
The class representing the RESTful interface:
package stateservice;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
import foo.bar.XmlData
#RestController
public class StateController {
private static Logger log = LoggerFactory.getLogger(DataController.class);
#Autowired
ForwarderService forwarder;
#RequestMapping(value = "/data", method = RequestMethod.POST)
public String postState(#RequestBody XmlData data) {
forwarder.forward(data);
return "Done!";
}
}
Finally, the Forwarder:
package stateservice;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.scheduling.annotation.Async;
import org.springframework.stereotype.Service;
import org.springframework.web.client.RestTemplate;
import foo.bar.Converter;
import foo.bar.XmlData;
#Service
public class ForwarderService {
private static Logger log = LoggerFactory.getLogger(ForwarderService.class);
String uri = "forward_uri";
#Autowired
RestTemplate restTemplate;
#Async
public String forward(XmlData data) {
log.trace("forward(...) - start");
String json = Converter.convert(data);
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.APPLICATION_JSON);
ResponseEntity<String> response = restTemplate.postForEntity(uri,
new HttpEntity<String>(json, headers), String.class);
// responseEntity.getBody();
// log.trace(responseEntity.toString());
log.trace("forward(...) - end");
return response.getBody();
}
}
However, the Connection Manager seldomly seems to release connections for reuse, and additionally, the system gets flooded with connections in the CLOSE_WAIT state (which can be seen using netstat). All connections in the pool get leased, but not released, and as soon as the number of connections in the CLOSE_WAIT state reaches the ulimit, I get 'Too many open files'-exceptions
Because of the multithreaded nature of the code, I suspect that sockets cannot be closed/connections be released, because some other thread is somhow blocking them.
I would really appreciate any help or any hint you can give me to solve the problem.

There is a trick with Apache HttpEntity - to release locked connection - response has to be FULLY consumed and closed. See EntityUtils and HttpEntity docs for details:
EntityUtils.consume(response);
Since version 4.3 Apache HttpClient releases connection back to the pool when #close() method is called on the CloseableHttpResponse.
However this feature is supported by Spring Web only since version 4.0.0-RELEASE, see method #close() in HttpComponentsClientHttpResponse.java:
#Override
public void close() {
// Release underlying connection back to the connection manager
try {
try {
// Attempt to keep connection alive by consuming its remaining content
EntityUtils.consume(this.httpResponse.getEntity());
} finally {
// Paranoia
this.httpResponse.close();
}
}
catch (IOException ignore) {
}
}
The key to success is the line marked by "// Paranoia" - explicit .close() call. It actually releases connection back to pool.

Related

How to create a working TCP Server socket in spring boot and how to handle the incoming message?

I have tried to implement a TCP server socket with spring integration in an allready existing spring boot application, but I am facing a problem and this problem drives me crazy...
The client is sending a message (a byte array) to the server and timesout. That's it.
I am not receiving any exceptions from the server. It seems I have provided the wrong port or somthing but after checking the port, I am sure it is the right one.
This is my annotation based configuration class:
import home.brew.server.socket.ServerSocketHandler;
import lombok.extern.log4j.Log4j2;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.integration.config.EnableIntegration;
import org.springframework.integration.dsl.IntegrationFlow;
import org.springframework.integration.dsl.IntegrationFlows;
import org.springframework.integration.ip.dsl.Tcp;
#Log4j2
#Configuration
#EnableIntegration
public class TcpServerSocketConfiguration {
#Value("${socket.port}")
private int serverSocketPort;
#Bean
public IntegrationFlow server(ServerSocketHandler serverSocketHandler) {
TcpServerConnectionFactorySpec connectionFactory =
Tcp.netServer(socketPort)
.deserializer(new CustomSerializerDeserializer())
.serializer(new CustomSerializerDeserializer())
.soTcpNoDelay(true);
TcpInboundGatewaySpec inboundGateway =
Tcp.inboundGateway(connectionFactory);
return IntegrationFlows
.from(inboundGateway)
.handle(serverSocketHandler::handleMessage)
.get();
}
#Bean
public ServerSocketHandler serverSocketHandler() {
return new ServerSocketHandler();
}
}
I wanted to make the receive functionality work before I try to send an answer, so that's why have a minimal configuration.
And the following class should process the received message from the server socket
import lombok.extern.log4j.Log4j2;
import org.springframework.messaging.Message;
import org.springframework.messaging.MessageHeaders;
import org.springframework.messaging.MessagingException;
#Log4j2
public class ServerSocketHandler {
public String handleMessage(Message<?> message, MessageHeaders messageHeaders) {
log.info(message.getPayload());
// TODO implement something useful to process the incoming message here...
return message.getPayload().toString();
}
}
The handler method from above was never invoked even once!
I have googled for some example implementations or tutorials but I haven't found anyhing what worked for me.
I allready tried the implementations of these sites:
https://vispud.blogspot.com/2019/03/how-to-implement-simple-echo-socket.html
https://docs.spring.io/spring-integration/docs/current/reference/html/ip.html#note-nio
Spring Boot TCP Client
and a bunch of sites more... but nothing helped me :-(
UPDATE 1
I have implemented a custom serializer/deserializer:
import lombok.Data;
import lombok.extern.log4j.Log4j2;
import org.springframework.core.serializer.Deserializer;
import org.springframework.core.serializer.Serializer;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
#Log4j2
#Data
public class CustomSerializerDeserializer implements Serializer<byte[]>,
Deserializer<byte[]> {
#Override
public byte[] deserialize(InputStream inputStream) throws IOException {
return inputStream.readAllBytes();
}
#Override
public void serialize(byte[] object, OutputStream outputStream) throws IOException {
outputStream.write(object);
}
}
After the client have sent a message, the custom serializer is invoked but the content ist always empty. I have no idea why.... The serializer needs a lot of time to read all bytes from the stream and in the end it is empty. The procedure is repeating all the time, so I think I have build an infinty loop by accident...
UPDATE 2
I have captured the communication between Client and server socket:
It looks like I am stuck in the handshake and therefore there is no payload...
So if anybody could help me out with this, I would be very thankful and if you need some more information, just let me know.
Thanks in advance!
Well, after a few days of analysing and coding, I found the best solution for me to handle TCP socket communications using spring integration. For other developers who are struggling with the same problems. Here is what I've done so far.
This class contains a - for me working - annotation based TCP socket connection configuration
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.integration.annotation.IntegrationComponentScan;
import org.springframework.integration.annotation.MessagingGateway;
import org.springframework.integration.channel.DirectChannel;
import org.springframework.integration.config.EnableIntegration;
import org.springframework.integration.ip.IpHeaders;
import org.springframework.integration.ip.tcp.TcpInboundGateway;
import org.springframework.integration.ip.tcp.TcpOutboundGateway;
import org.springframework.integration.ip.tcp.connection.AbstractClientConnectionFactory;
import org.springframework.integration.ip.tcp.connection.AbstractServerConnectionFactory;
import org.springframework.integration.ip.tcp.connection.TcpNetClientConnectionFactory;
import org.springframework.integration.ip.tcp.connection.TcpNetServerConnectionFactory;
import org.springframework.messaging.MessageChannel;
import org.springframework.messaging.handler.annotation.Header;
import org.springframework.web.context.request.RequestContextListener;
/**
* Spring annotation based configuration
*/
#Configuration
#EnableIntegration
#IntegrationComponentScan
public class TcpServerSocketConfiguration {
public static final CustomSerializerDeserializer SERIALIZER = new CustomSerializerDeserializer();
#Value("${socket.port}")
private int socketPort;
/**
* Reply messages are routed to the connection only if the reply contains the ip_connectionId header
* that was inserted into the original message by the connection factory.
*/
#MessagingGateway(defaultRequestChannel = "toTcp")
public interface Gateway {
void send(String message, #Header(IpHeaders.CONNECTION_ID) String connectionId);
}
#Bean
public MessageChannel fromTcp() {
return new DirectChannel();
}
#Bean
public MessageChannel toTcp() {
return new DirectChannel();
}
#Bean
public AbstractServerConnectionFactory serverCF() {
TcpNetServerConnectionFactory serverCf = new TcpNetServerConnectionFactory(socketPort);
serverCf.setSerializer(SERIALIZER);
serverCf.setDeserializer(SERIALIZER);
serverCf.setSoTcpNoDelay(true);
serverCf.setSoKeepAlive(true);
// serverCf.setSingleUse(true);
// final int soTimeout = 5000;
// serverCf.setSoTimeout(soTimeout);
return serverCf;
}
#Bean
public AbstractClientConnectionFactory clientCF() {
TcpNetClientConnectionFactory clientCf = new TcpNetClientConnectionFactory("localhost", socketPort);
clientCf.setSerializer(SERIALIZER);
clientCf.setDeserializer(SERIALIZER);
clientCf.setSoTcpNoDelay(true);
clientCf.setSoKeepAlive(true);
// clientCf.setSingleUse(true);
// final int soTimeout = 5000;
// clientCf.setSoTimeout(soTimeout);
return clientCf;
}
#Bean
public TcpInboundGateway tcpInGate() {
TcpInboundGateway inGate = new TcpInboundGateway();
inGate.setConnectionFactory(serverCF());
inGate.setRequestChannel(fromTcp());
inGate.setReplyChannel(toTcp());
return inGate;
}
#Bean
public TcpOutboundGateway tcpOutGate() {
TcpOutboundGateway outGate = new TcpOutboundGateway();
outGate.setConnectionFactory(clientCF());
outGate.setReplyChannel(toTcp());
return outGate;
}
This class contains a custom serializer and deserialiser
import lombok.extern.log4j.Log4j2;
import org.jetbrains.annotations.NotNull;
import org.springframework.core.serializer.Deserializer;
import org.springframework.core.serializer.Serializer;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.nio.charset.StandardCharsets;
/**
* A custom serializer for incoming and/or outcoming messages.
*/
#Log4j2
public class CustomSerializerDeserializer implements Serializer<byte[]>, Deserializer<byte[]> {
#NotNull
#Override
public byte[] deserialize(InputStream inputStream) throws IOException {
byte[] message = new byte[0];
if (inputStream.available() > 0) {
message = inputStream.readAllBytes();
}
log.debug("Deserialized message {}", new String(message, StandardCharsets.UTF_8));
return message;
}
#Override
public void serialize(#NotNull byte[] message, OutputStream outputStream) throws IOException {
log.info("Serializing {}", new String(message, StandardCharsets.UTF_8));
outputStream.write(message);
outputStream.flush();
}
}
In the following classes you can implement some buisness logic to process incoming ...
import lombok.extern.log4j.Log4j2;
import org.springframework.integration.annotation.MessageEndpoint;
import org.springframework.integration.annotation.ServiceActivator;
import org.springframework.stereotype.Component;
#Log4j2
#Component
#MessageEndpoint
public class ClientSocketHandler {
#ServiceActivator(inputChannel = "toTcp")
public byte[] handleMessage(byte[] msg) {
// TODO implement some buisiness logic here
return msg;
}
}
and outgoing messages.
import lombok.extern.log4j.Log4j2;
import org.springframework.integration.annotation.MessageEndpoint;
import org.springframework.integration.annotation.ServiceActivator;
import org.springframework.stereotype.Component;
#Log4j2
#Component
#MessageEndpoint
public class ClientSocketHandler {
#ServiceActivator(inputChannel = "toTcp")
public byte[] handleMessage(byte[] msg) {
// implement some business logic here
return msg;
}
}
Hope it helps. ;-)
How are you communicating with this server? By default the connection factory is configured to require the input to be terminated by CRLF (e.g. Telnet). You have to configure a different deserializer if your client uses something else to indicate a message end.
Also, your method signature is incorrect; it should be:
public String handleMessage(byte[] message, MessageHeaders messageHeaders) {
String string = new String(message);
System.out.println(string);
return string.toUpperCase();
}
This works fine for me with Telnet:
$ telnet localhost 1234
Trying ::1...
Connected to localhost.
Escape character is '^]'.
foo
FOO
^]
telnet> quit
Connection closed.
And here is a version that works with just LF (e.g. netcat):
#Bean
public IntegrationFlow server(ServerSocketHandler serverSocketHandler) {
return IntegrationFlows.from(Tcp.inboundGateway(
Tcp.netServer(1234)
.deserializer(TcpCodecs.lf())
.serializer(TcpCodecs.lf())))
.handle(serverSocketHandler::handleMessage)
.get();
}
$ nc localhost 1234
foo
FOO
^C

How to parse REST API STREAM

I am sending a get request to the server and server returns the following two responses. These responses are received as the event occurs on servers in streams (like id1,id2,id3,id4.....and so on) not in one shot.
Now, I need to take these response one by one and parse it and then save it the objects for further use.
How do i achieve this java 8 and spring MVC?
id: 1
data: {"event_type":"ABC","business_call_type":"XYZ","agent_number":"nnn","call_recording":null,"number":"0000","uuid":"a","call_direction":"Outbound","caller":"+100000000000","customer_number":"+100000000000","version":"1.0","k_number":"+917303454203","type":"AGENT_CALL","unique_id":"0","call_solution":"xx","FreeSWITCH_IPv4":"11111","Event_Date_Local":"2020-03-28 11:46:47"}
id: 2
data: {"event_type":"AGENT_ANSWER","business_call_type":"Outbound","agent_number":"+1111111111","call_recording":null,"number":"+22222222","uuid":"bbbbbbbbbbbbbb","call_direction":"Outbound","caller":"+100000000000","customer_number":"+100000000000","version":"1.0","k_number":"+1111111111","type":"AGENT_ANSWER","unique_id":"bbbbbbbbbb","call_solution":"xx","FreeSWITCH_IPv4":"0.0.0.0","Event_Date_Local":"2020-03-28 11:47:00"}
below is the code used foe above json parsing.
import java.util.HashMap;
import java.util.logging.Logger;
import javax.annotation.PostConstruct;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.stereotype.Service;
import org.springframework.util.concurrent.ListenableFuture;
import org.springframework.util.concurrent.ListenableFutureCallback;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.client.AsyncRestTemplate;
import org.springframework.web.client.HttpClientErrorException;
import org.springframework.web.context.request.async.DeferredResult;
import com.psg.async_tasks.controller;
import com.psg.dao.CtiIntegrationdao;
// #Controller
#Service
public class ListningService {
private static final Logger logger = Logger.getLogger(ListningService.class.getName());
#Autowired
CtiIntegrationdao daoCtiInt;
//#RequestMapping({"list"})
#PostConstruct
public void ListningReponse() {
HashMap<String,String> results=daoCtiInt.getKnolarity_Config();
String endpoint;
endpoint=results.get("30");
endpoint=endpoint.replace("<<AUTH>>",results.get("26"));
logger.info(endpoint);
logger.info("============================================================================================#postconstruct=========");
AsyncRestTemplate asyncrestTemplate = new AsyncRestTemplate();
try {
final DeferredResult<String> result = new DeferredResult<>();
ListenableFuture<ResponseEntity<String>> futureEntity = asyncrestTemplate.getForEntity(endpoint, String.class);
logger.info("IN TRY");
logger.info(futureEntity.toString());
futureEntity.addCallback(new ListenableFutureCallback<ResponseEntity<String>>() {
#Override
public void onSuccess(ResponseEntity<String> result) {
String[] idno = result.getBody().split("\\R", 3);
System.out.println("==================="+idno[0]);
String responseBody =result.getBody().replaceAll("id: (\\d+)","").replace("data: ","");;
logger.info("-----responsebody-----"+responseBody);
logger.info("-----responsebody-----"+result.getBody());
// logger.info("-----responsebody-----"+result.getBody().getAgent_number());
// logger.info("-----responsebody-----"+result.getBody().getBusiness_call_type());
// logger.info("-----responsebody-----"+result.getBody().getCall_duration());
// logger.info("-----responsebody-----"+result.getBody().getCall_recording());
// logger.info("-----responsebody-----"+result.getBody().getCall_solution());
// logger.info("-----responsebody-----"+result.getBody().getCall_Type());
// logger.info("-----responsebody-----"+result.getBody().getDestination());
}
#Override
public void onFailure(Throwable ex) {
result.setErrorResult(ex.getMessage());
logger.info("------------Failure Block"+result.toString());
}
});
}catch(HttpClientErrorException ex) {
logger.info(ex.getMessage());
}catch(Exception ex) {
ex.printStackTrace();
}
}
}

Apache kafka embedded kafka junit test - application starting when I run unit test

I am developing an asynchronous mail server in spring boot using kafka.
I have written tests with embedded kafka which starts its own kafka topic in a random port and use it for testing.
When I started this application context is loading and its expecting for kafka cluster in my local. I need to stop application conext from loading.
I replicated the code from https://github.com/code-not-found/spring-kafka/blob/master/spring-kafka-unit-test-classrule/src/test/java/com/codenotfound/kafka/producer/SpringKafkaSenderTest.java which works absolutely fine. When I followed same style in my project, I can see actual apllication starting.
SpringKafkaSenderTest .java
package com.mailer.embeddedkafkatests;
import static org.junit.Assert.assertTrue;
import java.util.Map;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.TimeUnit;
import org.apache.kafka.clients.consumer.ConsumerConfig;
import org.apache.kafka.clients.consumer.ConsumerRecord;
import org.apache.kafka.common.serialization.StringDeserializer;
import org.junit.After;
import org.junit.Before;
import org.junit.ClassRule;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.kafka.core.DefaultKafkaConsumerFactory;
import org.springframework.kafka.listener.ContainerProperties;
import org.springframework.kafka.listener.KafkaMessageListenerContainer;
import org.springframework.kafka.listener.MessageListener;
import org.springframework.kafka.test.rule.EmbeddedKafkaRule;
import org.springframework.kafka.test.utils.ContainerTestUtils;
import org.springframework.kafka.test.utils.KafkaTestUtils;
import org.springframework.test.annotation.DirtiesContext;
import org.springframework.test.context.junit4.SpringRunner;
import com.mailer.model.Mail;
import com.mailer.producer.KafkaMessageProducer;
import com.mailer.serializer.MailSerializer;
#RunWith(SpringRunner.class)
#SpringBootTest
#DirtiesContext
public class SpringKafkaSenderTest {
private static final Logger LOGGER =
LoggerFactory.getLogger(SpringKafkaSenderTest.class);
private static String SENDER_TOPIC = "sender.t";
#Autowired
private KafkaMessageProducer sender;
private KafkaMessageListenerContainer<String, Mail> container;
private BlockingQueue<ConsumerRecord<String, Mail>> records;
#ClassRule
public static EmbeddedKafkaRule embeddedKafka =
new EmbeddedKafkaRule(1, true, SENDER_TOPIC);
#Before
public void setUp() throws Exception {
// set up the Kafka consumer properties
Map<String, Object> consumerProperties =
KafkaTestUtils.consumerProps("sender", "false",
embeddedKafka.getEmbeddedKafka());
consumerProperties.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class);
consumerProperties.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, MailSerializer.class);
// create a Kafka consumer factory
DefaultKafkaConsumerFactory<String, Mail> consumerFactory =
new DefaultKafkaConsumerFactory<String, Mail>(
consumerProperties);//, new StringDeserializer(), new JsonDeserializer<>(Mail.class));
// set the topic that needs to be consumed
ContainerProperties containerProperties =
new ContainerProperties(SENDER_TOPIC);
// create a Kafka MessageListenerContainer
container = new KafkaMessageListenerContainer<>(consumerFactory,
containerProperties);
// create a thread safe queue to store the received message
records = new LinkedBlockingQueue<>();
// setup a Kafka message listener
container
.setupMessageListener(new MessageListener<String, Mail>() {
#Override
public void onMessage(
ConsumerRecord<String, Mail> record) {
LOGGER.debug("test-listener received message='{}'",
record.toString());
records.add(record);
}
});
// start the container and underlying message listener
container.start();
// wait until the container has the required number of assigned partitions
ContainerTestUtils.waitForAssignment(container,
embeddedKafka.getEmbeddedKafka().getPartitionsPerTopic());
}
#After
public void tearDown() {
// stop the container
container.stop();
}
#Test
public void testSend() throws InterruptedException {
// send the message
Mail mail = new Mail();
mail.setFrom("vinoth#local.com");
sender.sendMessage(mail);
Thread.sleep(4000);
// check that the message was received
ConsumerRecord<String, Mail> received =
records.poll(10, TimeUnit.SECONDS);
// Hamcrest Matchers to check the value
assertTrue(received.value().getFrom().equals(mail.getFrom()));
System.out.println(received.value().getFrom());
// assertThat(received, hasValue(mail));
// AssertJ Condition to check the key
// assertThat(received).has(key(null));
}
}
Why would you like to stop the spring context from loading? Isn't the purpose of this junit to test your spring application?
In any case just remove the #SpringBootTest annotation and the spring context will not load.

How to use #Startup Annotation for Service that Pushes Data to Websocket?

This is the Java EE7 #Startup annotation for reference. I am using the latest GlassFish server and IntelliJ to run the server.
I need to instantiate this service so that it can send packets of data periodically to a websocket for processing, but the fact that I use
session.getBasicRemote().sendObject(message);
in the end forces me to throw IOException and EncodeException.
This is bad as #Startup or #Singleton disallows usage of Exceptions when instantiating:
war exploded: java.io.IOException: com.sun.enterprise.admin.remote.RemoteFailureException: Error occurred during deployment: Exception while deploying the app [keyBoard_war_exploded] : The lifecycle method [printSchedule] must not throw a checked exception.
Here is my code:
package site.xxxx.models;
import site.xxxx.message.Message;
import site.xxxx.message.TextMessage;
import site.xxxx.modules.Packet;
import site.xxxx.websocket.MainServerEndpoint;
import javax.annotation.PostConstruct;
import javax.ejb.Schedule;
import javax.ejb.Singleton;
import javax.ejb.Startup;
import javax.json.Json;
import javax.json.JsonObject;
import javax.websocket.EncodeException;
import javax.websocket.Session;
import java.io.IOException;
import java.util.Set;
#Startup
#Singleton
public class Service {
private static Service service;
Set<Session> peers = MainServerEndpoint.peers;
#PostConstruct
public void mainLoop() throws IOException, EncodeException, InterruptedException {
sendSpamPacket();
}
private void sendSpamPacket() throws IOException, EncodeException {
JsonObject ret = Json.createObjectBuilder()
.add("type", "textMessage")
.add("text", "ayyyy")
.build();
Packet packet = new Packet(new TextMessage(ret));
MainServerEndpoint.sendPacket(packet);
//results in calling session.getBasicRemote().sendObject(message);
}
}

Set the time out on Rest end points

I am trying to impose time limit on http end points.
In the example below, I am aiming that this method shall be executed before 5 seconds. If it is taking more time, I would like to throw exception and return error to client.
Spring : 4.1.7
Jersey 1.1.9
Code
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.Produces;
import javax.ws.rs.core.Response;
#Path("/pets")
#Component
public class PetsController {
#GET
#Produces({MediaTypeApi.JSON, MediaTypeApi.XML})
//Timeout of 5 secs
public List<Pet> getPets() {
//Return
}
}
Any idea to handle this in better way considering optimum utilization of threads.
EDIT
When writing this answer I didn't notice the version of Jersey OP is using. The async API was added in Jersey 2 therefore this answer is not an answer given OP's constraints.
EDIT 2
Apart from upgrading your Jersey libs you might consider migrating your api to Spring MVC and using their async API (available from Spring 3.2). Handling timeouts the Spring way (using the DeferredResult object):
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.context.request.async.DeferredResult;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.CompletionException;
#RestController
#RequestMapping("/api")
public class AsyncController {
private static final TIMEOUT = 5000L;
private final AService aService;
#Inject
public AsyncController(final AService aService) {
this.aService = aService;
}
#RequestMapping(value = "/async-endpoint", method = RequestMethod.GET)
public DeferredResult<ResponseEntity<ADto>> asyncEndpoint() {
DeferredResult<ResponseEntity<ADto>> deferredResult = new DeferredResult<>(TIMEOUT);
CompletableFuture
.supplyAsync(() -> aService.aVeryExpensiveOperation())
.thenAccept(result -> {
deferredResult.setResult(new ResponseEntity<>(result, HttpStatus.OK));
})
.exceptionally(throwable -> {
deferredResult.setErrorResult(
throwable instanceof CompletionException ? throwable.getCause() : throwable);
return null;
});
return deferredResult;
}
}
ORIGINAL ANSWER:
There is an example in Jersey Asynchronous Server API Documentation doing exactly what you want:
import javax.ws.rs.container.Suspended;
import javax.ws.rs.container.TimeoutHandler;
import javax.ws.rs.core.Response;
import java.util.concurrent.TimeUnit;
#Path("/resource")
public class AsyncResource {
#GET
#Path("/timeoutAsync")
public void asyncGetWithTimeout(#Suspended final AsyncResponse asyncResponse) {
asyncResponse.setTimeoutHandler(new TimeoutHandler() {
#Override
public void handleTimeout(AsyncResponse asyncResponse) {
asyncResponse.resume(Response.status(Response.Status.SERVICE_UNAVAILABLE).entity("Operation time out.").build());
}
});
asyncResponse.setTimeout(5, TimeUnit.SECONDS);
new Thread(new Runnable() {
#Override
public void run() {
String result = veryExpensiveOperation();
asyncResponse.resume(result);
}
private String veryExpensiveOperation() {
return "Very Expensive Operation with Timeout";
}
}).start();
}
}
Please note that in a real life scenario you'd probably use a threadpool thread instead of creating it yourself like in this Jersey example

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