Develop Reference

Trying to download files from S3 Bucket using Java SDK, Null pointer Exception on isStandardEndpoint

I'm trying to connect to S3 bucket and download files but the code throws exception:
In My code I have
ProfileCredentialsProvider pcp = new ProfileCredentialsProvider("assumed_role");
bucketName = "dev-data-extract-service-bucket";
s3Client = AmazonS3ClientBuilder.standard().withCredentials(pcp).withRegion(Regions.US_EAST_1.toString()).build();
I get NullPointerException exception on calling the following line:
fullObject = s3Client.getObject(new GetObjectRequest(bucketName, "TR09_20190205.detail"));
The reason is that host value in Endpoint is null
this is from AmazonS3Client class
private boolean isStandardEndpoint(URI endpoint) {
return endpoint.getHost().endsWith("s3.amazonaws.com");
}
And following is the stack trace
[main] DEBUG com.amazonaws.AmazonWebServiceClient - Internal logging
successfully configured to commons logger: true 15:43:45.183 [main]
DEBUG com.amazonaws.metrics.AwsSdkMetrics - Admin mbean registered
under com.amazonaws.management:type=AwsSdkMetrics 15:43:45.952 [main]
DEBUG com.amazonaws.monitoring.CsmConfigurationProviderChain - Unable
to load configuration from
com.amazonaws.monitoring.EnvironmentVariableCsmConfigurationProvider#169e6180:
Unable to load Client Side Monitoring configurations from environment
variables! 15:43:45.952 [main] DEBUG
com.amazonaws.monitoring.CsmConfigurationProviderChain - Unable to
load configuration from
com.amazonaws.monitoring.SystemPropertyCsmConfigurationProvider#35aea049:
Unable to load Client Side Monitoring configurations from system
properties variables! 15:43:45.952 [java-sdk-http-connection-reaper]
DEBUG org.apache.http.impl.conn.PoolingHttpClientConnectionManager -
Closing connections idle longer than 60000 MILLISECONDS 15:43:45.952
[main] DEBUG com.amazonaws.monitoring.CsmConfigurationProviderChain -
Unable to load configuration from
com.amazonaws.monitoring.ProfileCsmConfigurationProvider#611889f4:
Unable to load config file Exception in thread "main"
java.lang.NullPointerException at
com.amazonaws.services.s3.AmazonS3Client.isStandardEndpoint(AmazonS3Client.java:3772)
at
com.amazonaws.services.s3.AmazonS3Client.noExplicitRegionProvided(AmazonS3Client.java:3767)
at
com.amazonaws.services.s3.AmazonS3Client.bucketRegionShouldBeCached(AmazonS3Client.java:4505)
at
com.amazonaws.services.s3.AmazonS3Client.shouldPerformHeadRequestToFindRegion(AmazonS3Client.java:4501)
at
com.amazonaws.services.s3.AmazonS3Client.invoke(AmazonS3Client.java:4426)
at
com.amazonaws.services.s3.AmazonS3Client.invoke(AmazonS3Client.java:4390)
at
com.amazonaws.services.s3.AmazonS3Client.getAcl(AmazonS3Client.java:3573)
at
com.amazonaws.services.s3.AmazonS3Client.getBucketAcl(AmazonS3Client.java:1186)
at
com.amazonaws.services.s3.AmazonS3Client.getBucketAcl(AmazonS3Client.java:1176)
at
com.amazonaws.services.s3.AmazonS3Client.doesBucketExistV2(AmazonS3Client.java:1312)
at .AWSHelper.downloadFromS3Bucket(AWSHelper.java:32) at
.AWSHelper.main(AWSHelper.java:59)

I think your issue stems from way you are setting the region. I think the region is resolving to null and that this is causing your endpoint to be null.
Instead of:
s3Client = AmazonS3ClientBuilder.standard().withCredentials(pcp).withRegion(Regions.US_EAST_1.toString()).build();
Try:
s3Client = AmazonS3ClientBuilder.standard().withCredentials(pcp).withRegion(Regions.US_EAST_1).build();
The Regions class does not override the toString() method so it will not return the region name, which is what would be required for your code to work as it is.

Issue with Spark Java API, Kerberos, and Hive

I'm trying to run a spark sql test against a hive table using the Spark Java API. The problem I am having is with kerberos. Whenever I attempt to run the program I get this error message:
Caused by: org.apache.spark.sql.AnalysisException: java.lang.RuntimeException: org.apache.hadoop.security.AccessControlException: SIMPLE authentication is not enabled. Available:[TOKEN, KERBEROS];
at org.apache.spark.sql.hive.HiveExternalCatalog.withClient(HiveExternalCatalog.scala:106)
at org.apache.spark.sql.hive.HiveExternalCatalog.databaseExists(HiveExternalCatalog.scala:194)
at org.apache.spark.sql.internal.SharedState.externalCatalog$lzycompute(SharedState.scala:114)
at org.apache.spark.sql.internal.SharedState.externalCatalog(SharedState.scala:102)
at org.apache.spark.sql.hive.HiveSessionStateBuilder.externalCatalog(HiveSessionStateBuilder.scala:39)
at org.apache.spark.sql.hive.HiveSessionStateBuilder.catalog$lzycompute(HiveSessionStateBuilder.scala:54)
at org.apache.spark.sql.hive.HiveSessionStateBuilder.catalog(HiveSessionStateBuilder.scala:52)
at org.apache.spark.sql.hive.HiveSessionStateBuilder$$anon$1.<init>(HiveSessionStateBuilder.scala:69)
at org.apache.spark.sql.hive.HiveSessionStateBuilder.analyzer(HiveSessionStateBuilder.scala:69)
at org.apache.spark.sql.internal.BaseSessionStateBuilder$$anonfun$build$2.apply(BaseSessionStateBuilder.scala:293)
at org.apache.spark.sql.internal.BaseSessionStateBuilder$$anonfun$build$2.apply(BaseSessionStateBuilder.scala:293)
at org.apache.spark.sql.internal.SessionState.analyzer$lzycompute(SessionState.scala:79)
at org.apache.spark.sql.internal.SessionState.analyzer(SessionState.scala:79)
at org.apache.spark.sql.execution.QueryExecution.analyzed$lzycompute(QueryExecution.scala:57)
at org.apache.spark.sql.execution.QueryExecution.analyzed(QueryExecution.scala:55)
at org.apache.spark.sql.execution.QueryExecution.assertAnalyzed(QueryExecution.scala:47)
at org.apache.spark.sql.Dataset$.ofRows(Dataset.scala:74)
at org.apache.spark.sql.SparkSession.sql(SparkSession.scala:638)
at tester.SparkSample.lambda$0(SparkSample.java:62)
... 5 more
on this line of code:
ss.sql("select count(*) from entps_pma.baraccount").show();
Now when I run the code, I log into kerberos just fine and get this message:
18/05/01 11:21:03 INFO security.UserGroupInformation: Login successful for user <kerberos user> using keytab file /root/hdfs.keytab
I even connect to the Hive Metastore:
18/05/01 11:21:06 INFO hive.metastore: Trying to connect to metastore with URI thrift://<hiveserver>:9083
18/05/01 11:21:06 INFO hive.metastore: Connected to metastore.
But right after that I get the error. Appreciate any direction here. Here is my code:
public static void runSample(String fullPrincipal) throws IOException {
System.setProperty("hive.metastore.sasl.enabled", "true");
System.setProperty("hive.security.authorization.enabled", "true");
System.setProperty("hive.metastore.kerberos.principal", fullPrincipal);
System.setProperty("hive.metastore.execute.setugi", "true");
System.setProperty("hadoop.security.authentication", "kerberos");
Configuration conf = setSecurity(fullPrincipal);
loginUser = UserGroupInformation.getLoginUser();
loginUser.doAs((PrivilegedAction<Void>) () -> {
SparkConf sparkConf = new SparkConf().setMaster("local");
sparkConf.set("spark.sql.warehouse.dir", "hdfs:///user/hive/warehouse");
sparkConf.set("hive.metastore.uris", "thrift://<hive server>:9083");
sparkConf.set("hadoop.security.authentication", "kerberos");
sparkConf.set("hadoop.rpc.protection", "privacy");
sparkConf.set("spark.driver.extraClassPath",
"/opt/cloudera/parcels/CDH/jars/*.jar:/opt/cloudera/parcels/CDH/lib/hive/conf:/opt/cloudera/parcels/CDH/lib/hive/lib/*.jar");
sparkConf.set("spark.executor.extraClassPath",
"/opt/cloudera/parcels/CDH/jars/*.jar:/opt/cloudera/parcels/CDH/lib/hive/conf:/opt/cloudera/parcels/CDH/lib/hive/lib/*.jar");
sparkConf.set("spark.eventLog.enabled", "false");
SparkSession ss = SparkSession
.builder()
.enableHiveSupport()
.config(sparkConf)
.appName("Jim Test Spark App")
.getOrCreate();
ss.sparkContext()
.hadoopConfiguration()
.addResource(conf);
ss.sql("select count(*) from entps_pma.baraccount").show();
return null;
});
}

I guess you are running Spark on YARN. You need to specify spark.yarn.principal and spark.yarn.keytab parameters. Please check running Spark on YARN documentation

Connecting to dcm4chee using dcm4che from a JAVA program

Update
I dug deeper in dcm4che's source code and found that an IncompatibleConnectionException is thrown if either
a connection is "not installed"
or the types of protocols are not set or don't match.
I don't know what it means that a connection is "installed" but this flag can be set manually, so I set it for both the local and remote connections to true (even checked them with getInstalled() whether they are "installed" - and yes they are now - previously this property was null).
And as to the protocols, they weren't specified, so for both connections I set them to DICOM.
Results: I still get the same Exception.
I'd like to establish a DICOM association between dcm4chee (2.18.3) and my JAVA application using the dcm4che (5.12.0) toolkit.
The problem is that it doesn't seem to be any documentation available on how to use dcm4che in a JAVA application, so all I can do is read dcm4che's source code and try to figure out what its classes and methods are for, but I'm stuck. If someone already has a working example it would be very helpful.
So far I have:
import org.dcm4che3.net.ApplicationEntity;
import org.dcm4che3.net.Association;
import org.dcm4che3.net.Connection;
import org.dcm4che3.net.Device;
import org.dcm4che3.net.pdu.AAssociateRQ;
import org.dcm4che3.net.pdu.PresentationContext;
...
ApplicationEntity locAE = new ApplicationEntity();
locAE.setAETitle("THIS_JAVA_APP");
Connection localConn = new Connection();
localConn.setCommonName("loc_conn");
localConn.setHostname("localhost");
localConn.setPort(11112);
localConn.setProtocol(Connection.Protocol.DICOM);
localConn.setInstalled(true);
locAE.addConnection(localConn);
ApplicationEntity remAE = new ApplicationEntity();
remAE.setAETitle("DCM4CHEE");
Connection remoteConn = new Connection();
remoteConn.setCommonName("rem_conn");
remoteConn.setHostname("localhost");
remoteConn.setPort(11112);
remoteConn.setProtocol(Connection.Protocol.DICOM);
remoteConn.setInstalled(true);
remAE.addConnection(remoteConn);
AAssociateRQ assocReq = new AAssociateRQ();
assocReq.setCalledAET(remAE.getAETitle());
assocReq.setCallingAET(locAE.getAETitle());
assocReq.setApplicationContext("1.2.840.10008.3.1.1.1");
assocReq.setImplClassUID("1.2.40.0.13.1.3");
assocReq.setImplVersionName("dcm4che-5.12.0");
assocReq.setMaxPDULength(16384);
assocReq.setMaxOpsInvoked(0);
assocReq.setMaxOpsPerformed(0);
assocReq.addPresentationContext(new PresentationContext(
1, "1.2.840.10008.1.1", "1.2.840.10008.1.2"));
Device device = new Device("device");
device.addConnection(localConn);
device.addApplicationEntity(locAE);
Association assoc = locAE.connect(remAE, assocReq);
but I don't know whether I'm on the right path doing it.
The error I get:
org.dcm4che3.net.IncompatibleConnectionException: No compatible connection to DCM4CHEE available on THIS_JAVA_APP
at org.dcm4che3.net.ApplicationEntity.findCompatibelConnection(ApplicationEntity.java:646)
at org.dcm4che3.net.ApplicationEntity.connect(ApplicationEntity.java:651)

Could it be, that You are missing a Device instance from Your setup? It seems, that You need a Device, to which You attach both ApplicationEntity and Connection.
Looking at FindSCU.java source from dcm4che source.
private final Device device = new Device("findscu");
private final ApplicationEntity ae = new ApplicationEntity("FINDSCU");
private final Connection conn = new Connection();
public FindSCU() throws IOException {
device.addConnection(conn);
device.addApplicationEntity(ae);
ae.addConnection(conn);
}
I also think, that maybe the local Connection object can be instantiated without any parameters as the FindSCU example here demonstrates. Maybe the parameters are confusing it somehow, especially considering, that you have both local and remote connections pointing to localhost:11112.
But yes, one has to agree, that the documentation for dcm4che3 API is totally inadequate.

Here is the working code: (I don't know if it's the minimal solution, feel free to experiment with it...)
ApplicationEntity locAE = new ApplicationEntity();
locAE.setAETitle("THIS_JAVA_APP");
locAE.setInstalled(true);
Connection localConn = new Connection();
localConn.setCommonName("loc_conn");
localConn.setHostname("localhost");
localConn.setPort(11112);
localConn.setProtocol(Connection.Protocol.DICOM);
localConn.setInstalled(true);
locAE.addConnection(localConn);
ApplicationEntity remAE = new ApplicationEntity();
remAE.setAETitle("DCM4CHEE");
remAE.setInstalled(true);
Connection remoteConn = new Connection();
remoteConn.setCommonName("rem_conn");
remoteConn.setHostname("localhost");
remoteConn.setPort(11112);
remoteConn.setProtocol(Connection.Protocol.DICOM);
remoteConn.setInstalled(true);
remAE.addConnection(remoteConn);
AAssociateRQ assocReq = new AAssociateRQ();
assocReq.setCalledAET(remAE.getAETitle());
assocReq.setCallingAET(locAE.getAETitle());
assocReq.setApplicationContext("1.2.840.10008.3.1.1.1");
assocReq.setImplClassUID("1.2.40.0.13.1.3");
assocReq.setImplVersionName("dcm4che-5.12.0");
assocReq.setMaxPDULength(16384);
assocReq.setMaxOpsInvoked(0);
assocReq.setMaxOpsPerformed(0);
assocReq.addPresentationContext(new PresentationContext(
1, "1.2.840.10008.1.1", "1.2.840.10008.1.2"));
Device device = new Device("device");
device.addConnection(localConn);
device.addApplicationEntity(locAE);
Executor exec = (Runnable command) -> {};
device.setExecutor(exec);
Association assoc = locAE.connect(localConn, remoteConn, assocReq);
And the relevant dcm4chee log:
2018-03-02 23:21:42,832 INFO THIS_JAVA_APP->DCM4CHEE (TCPServer-1) [org.dcm4cheri.net.FsmImpl] received AAssociateRQ
appCtxName: 1.2.840.10008.3.1.1.1/DICOM Application Context Name
implClass: 1.2.40.0.13.1.3
implVersion: dcm4che-5.12.0
calledAET: DCM4CHEE
callingAET: THIS_JAVA_APP
maxPDULen: 16378
asyncOpsWindow:
pc-1: as=1.2.840.10008.1.1/Verification SOP Class
ts=1.2.840.10008.1.2/Implicit VR Little Endian
2018-03-02 23:21:42,843 INFO THIS_JAVA_APP->DCM4CHEE (TCPServer-1) [org.dcm4cheri.net.FsmImpl] sending AAssociateAC
appCtxName: 1.2.840.10008.3.1.1.1/DICOM Application Context Name
implClass: 1.2.40.0.13.1.1.1
implVersion: dcm4che-1.4.34
calledAET: DCM4CHEE
callingAET: THIS_JAVA_APP
maxPDULen: 16352
asyncOpsWindow:
pc-1: 0 - acceptance
ts=1.2.840.10008.1.2/Implicit VR Little Endian
After you have the association, see this other post for how to perform a C-FIND.

Edit
Apparently, I solved the problem. Changing the executor from
Executor exec = (Runnable command) -> {};
device.setExecutor(exec);
to
ExecutorService executorService = Executors.newSingleThreadExecutor();
ScheduledExecutorService scheduledExecutorService = Executors.newSingleThreadScheduledExecutor();
device.setExecutor(executorService);
device.setScheduledExecutor(scheduledExecutorService);
made it so my application correctly received the association response from the server. This might serve as reference for someone else.
Thank you for sharing your code. It was really helpful to me.
Original Post
I am unable to perform the connection with a code similar to the solution you proposed. I am trying to request an association with a dcm4chee-arc-light with dcm4che (both 5.14.1), and I have as it follows:
Device device = new Device(deviceName);
ApplicationEntity locAE = new ApplicationEntity(localAE);
Connection conn = new Connection();
Connection remote = new Connection();
AAssociateRQ rq = new AAssociateRQ();
device.addConnection(conn);
device.addApplicationEntity(locAE);
locAE.addConnection(conn);
ApplicationEntity remAE = new ApplicationEntity();
remAE.setAETitle(remoteAE);
remote.setCommonName("rem_conn");
remote.setHostname(remoteIP);
remote.setPort(remotePort);
remote.setProtocol(Connection.Protocol.DICOM);
remAE.addConnection(remote);
rq.setCalledAET(remAE.getAETitle());
rq.setCallingAET(locAE.getAETitle());
rq.setApplicationContext("1.2.840.10008.3.1.1.1");
rq.setImplClassUID("1.2.40.0.13.1.3");
rq.setImplVersionName("dcm4che-5.14.1");
rq.setMaxPDULength(16384);
rq.setMaxOpsInvoked(0);
rq.setMaxOpsPerformed(0);
rq.addPresentationContext(new PresentationContext(
1, "1.2.840.10008.5.1.4.1.2.2.1", "1.2.840.10008.1.2"));
Executor exec = (Runnable command) -> {};
device.setExecutor(exec);
//Opens association and connects to remote server
Association as = locAE.connect(conn, remote, rq);
But when trying to connect to a remote AET, it doesn't seem to receive the AAssociation response from the remote AET. My Java application hangs in Sta5 (waiting for association response) while the server hangs in Sta6 (ready for data transfer).
Java log:
[main] INFO org.dcm4che3.net.Connection - Initiate connection from 0.0.0.0/0.0.0.0:0 to localhost:11112
[main] INFO org.dcm4che3.net.Connection - Established connection Socket[addr=localhost/127.0.0.1,port=11112,localport=50101]
[main] DEBUG org.dcm4che3.net.Association - /127.0.0.1:50101>localhost/127.0.0.1:11112(1): enter state: Sta4 - Awaiting transport connection opening to complete
[main] INFO org.dcm4che3.net.Association - DEVICEAE->DCMQRSCP(1) << A-ASSOCIATE-RQ
[main] DEBUG org.dcm4che3.net.Association - A-ASSOCIATE-RQ[
calledAET: DCMQRSCP
callingAET: DEVICEAE
applicationContext: 1.2.840.10008.3.1.1.1 - DICOM Application Context Name
implClassUID: 1.2.40.0.13.1.3
implVersionName: dcm4che-5.14.1
maxPDULength: 16378
maxOpsInvoked/maxOpsPerformed: 1/1
PresentationContext[id: 1
as: 1.2.840.10008.5.1.4.1.2.2.1 - Study Root Query/Retrieve Information Model - FIND
ts: 1.2.840.10008.1.2 - Implicit VR Little Endian
]
]
[main] DEBUG org.dcm4che3.net.Association - DEVICEAE->DCMQRSCP(1): enter state: Sta5 - Awaiting A-ASSOCIATE-AC or A-ASSOCIATE-RJ PDU
Server log:
19:11:29,397 INFO - Accept connection Socket[addr=/127.0.0.1,port=50101,localport=11112]
19:11:29,397 DEBUG - /127.0.0.1:11112<-/127.0.0.1:50101(3): enter state: Sta2 - Transport connection open
19:11:29,416 INFO - DCMQRSCP<-DEVICEAE(3) >> A-ASSOCIATE-RQ
19:11:29,416 DEBUG - A-ASSOCIATE-RQ[
calledAET: DCMQRSCP
callingAET: DEVICEAE
applicationContext: 1.2.840.10008.3.1.1.1 - DICOM Application Context Name
implClassUID: 1.2.40.0.13.1.3
implVersionName: dcm4che-5.14.1
maxPDULength: 16378
maxOpsInvoked/maxOpsPerformed: 1/1
PresentationContext[id: 1
as: 1.2.840.10008.5.1.4.1.2.2.1 - Study Root Query/Retrieve Information Model - FIND
ts: 1.2.840.10008.1.2 - Implicit VR Little Endian
]
]
19:11:29,419 DEBUG - DCMQRSCP<-DEVICEAE(3): enter state: Sta3 - Awaiting local A-ASSOCIATE response primitive
19:11:29,419 INFO - DCMQRSCP<-DEVICEAE(3) << A-ASSOCIATE-AC
19:11:29,419 DEBUG - A-ASSOCIATE-AC[
calledAET: DCMQRSCP
callingAET: DEVICEAE
applicationContext: 1.2.840.10008.3.1.1.1 - DICOM Application Context Name
implClassUID: 1.2.40.0.13.1.3
implVersionName: dcm4che-5.14.1
maxPDULength: 16378
maxOpsInvoked/maxOpsPerformed: 1/1
PresentationContext[id: 1
result: 0 - acceptance
ts: 1.2.840.10008.1.2 - Implicit VR Little Endian
]
]
19:11:29,427 DEBUG - DCMQRSCP<-DEVICEAE(3): enter state: Sta6 - Association established and ready for data transfer
I feel like I am missing something, but I cannot find the source of the problem. Any help is appreciated, as I am still new to dcm4che and DICOM protocol.
Thank you.

Selenium - Firefox - Java - Gecko - Warning message

I get a warn message when I try this code but the test case execute successfully.
Code
package test;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.firefox.FirefoxDriver;
public class teatcalss {
public static void main(String[] args) {
// declaration and instantiation of objects/variables
System.setProperty("webdriver.gecko.driver", "D:\\java\\geckodriver-v0.14.0-win64\\geckodriver.exe");
WebDriver driver = new FirefoxDriver();
String baseUrl = "http://newtours.demoaut.com";
String expectedTitle = "Welcome: Mercury Tours";
String actualTitle = "";
// launch Firefox and direct it to the Base URL
driver.get(baseUrl);
// get the actual value of the title
actualTitle = driver.getTitle();
/*
* compare the actual title of the page witht the expected one and print
* the result as "Passed" or "Failed"
*/
if (actualTitle.contentEquals(expectedTitle)){
System.out.println("Test Passed!");
} else {
System.out.println("Test Failed");
}
//close Firefox
driver.close();
// exit the program explicitly
System.exit(0);
}
}
Warning message
1486664295999 geckodriver INFO Listening on 127.0.0.1:44072
Feb 09, 2017 10:18:16 AM org.openqa.selenium.remote.ProtocolHandshake createSession
INFO: Attempting bi-dialect session, assuming Postel's Law holds true on the remote end
log4j:WARN No appenders could be found for logger (org.apache.http.client.protocol.RequestAddCookies).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
1486664297761 mozprofile::profile INFO Using profile path C:\Users\Radwa\AppData\Local\Temp\rust_mozprofile.DhhwmmiiHibT
1486664297779 geckodriver::marionette INFO Starting browser C:\Program Files (x86)\Mozilla Firefox\firefox.exe
1486664297822 geckodriver::marionette INFO Connecting to Marionette on localhost:10262
[GFX1-]: CreateShaderResourceView failed for format87
1486664301804 Marionette INFO Listening on port 10262
[GFX1-]: CreateShaderResourceView failed for format87
Feb 09, 2017 10:18:29 AM org.openqa.selenium.remote.ProtocolHandshake createSession
INFO: Detected dialect: W3C
Test Passed!

This is a known message. See here for more info and discussion.
Bottom line, it's not an error, it won't break anything. If something gets screwed up, then that's when it's a good time to investigate. As it is right now, you can safely ignore it.

You can use the below code with your scripts, which will redirects these low level logs to a separate file rather than the console -
System.setProperty(FirefoxDriver.SystemProperty.DRIVER_USE_MARIONETTE,"true");
System.setProperty(FirefoxDriver.SystemProperty.BROWSER_LOGFILE,"C:\\temp\\logs.txt");
For more information, you check refer this article - Disable Firefox logs

Self-Connect to Websocket Spring server from JUnit test

I have an app that exposes Websocket/SockJS/Stomp server endpoints and would like to run a JUnit tests that runs client (Java STOMP client, also from Spring) against it, to test "sending" features.
I have a test like
public void measureSpeedWithWebsocket() throws Exception {
final Waiter subscribeWaiter = new Waiter();
new Thread(() -> {
// Prepare connection
WebsocketClient listener = new WebsocketClient("/mytopic/stomp");
try {
listener.connectAndSubscribe();
subscribeWaiter.resume();
} catch (Exception e) {
e.printStackTrace();
}
}).start();
subscribeWaiter.await(); // Wait for connection.
Here I made use of Waiter from https://github.com/jhalterman/concurrentunit, which effect is basically to delay main thread of the test till secondary thread call resume(). This is likely wrong, because Spring server that is running in the context has to react
I am getting the following error
[INFO ] 2017-02-03 12:36:12.402 [Thread-19] WebsocketClient - Listening
[INFO ] 2017-02-03 12:36:12.403 [Thread-19] WebsocketClient - Connecting to ws://localhost:8083/user...
2017-02-03 12:36:14.097 ERROR 9956 --- [ Thread-19] o.s.w.socket.sockjs.client.SockJsClient : Initial SockJS "Info" request to server failed, url=ws://localhost:8083/user
org.springframework.web.client.ResourceAccessException: I/O error on GET request for "http://localhost:8083/user/info": Connection refused: connect; nested exception is java.net.ConnectException: Connection refused: connect
at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:633) ~[spring-web-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:595) ~[spring-web-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at org.springframework.web.socket.sockjs.client.RestTemplateXhrTransport.executeInfoRequestInternal(RestTemplateXhrTransport.java:138) ~[spring-websocket-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at org.springframework.web.socket.sockjs.client.AbstractXhrTransport.executeInfoRequest(AbstractXhrTransport.java:155) ~[spring-websocket-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at org.springframework.web.socket.sockjs.client.SockJsClient.getServerInfo(SockJsClient.java:286) ~[spring-websocket-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at org.springframework.web.socket.sockjs.client.SockJsClient.doHandshake(SockJsClient.java:254) ~[spring-websocket-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at org.springframework.web.socket.messaging.WebSocketStompClient.connect(WebSocketStompClient.java:274) [spring-websocket-4.3.3.RELEASE.jar:4.3.3.RELEASE]
at org.springframework.web.socket.messaging.WebSocketStompClient.connect(WebSocketStompClient.java:255) [spring-websocket-4.3.3.RELEASE.jar:4.3.3.RELEASE]
(...)
at java.lang.Thread.run(Thread.java:745) ~[na:1.8.0_74]
Caused by: java.net.ConnectException: Connection refused: connect
How I can possibly make a proper test that "self-connects" to the websocket offered by my Spring Boot application?

If you are using Spring Boot than you are a lucky one :).
Here is an example http://rafaelhz.github.io/testing-websockets/ how you can test the web sockets, which perfectly works in Spring Boot and can helps you a lot. I am trying to do the same in Spring MVC but unfortunately that doesn't work in Spring MVC.