Unsupported major.minor version 52.0

[biswajitroy04]

Hi ,
My application uses com.github.sarxos.webcam.Webcam libraries and that's why it needs JRE 1.8 and my application is working in my local since I have JRE 1.8 in my local but while I am deploying my application in "http://security-ecam.rhcloud.com/" OpenShift I am getting below Exception

java.lang.UnsupportedClassVersionError: com/TestJava : Unsupported major.minor version 52.0 (unable to load class com.TestJava)
org.apache.catalina.loader.WebappClassLoader.findClassInternal(WebappClassLoader.java:2961)
org.apache.catalina.loader.WebappClassLoader.findClass(WebappClassLoader.java:1210)
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1690)
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1571)

So how to deploy and run the app in server using JRE <1.8

Thanks
Biswajit Roy

[biswajitroy04]

I have fixed this by compiling the libraries in JDK 1.7 now this is working in my local tomcat with JVM 1.7 but I am getting below error while deploying the application in openshift.redhat.com. I don't know RedHat environment details :(

which basically says

Caused by: java.lang.RuntimeException: Library 'OpenIMAJGrabber' was not loaded successfully from file '/var/lib/openshift/56081b1789f5cf12fc000062/jbossews/tmp/BridJExtractedLibraries9012739367972665359/OpenIMAJGrabber.so'

StackTrace:
com.github.sarxos.myWebcam.WebcamException: java.util.concurrent.ExecutionException: com.github.sarxos.myWebcam.WebcamException: Cannot execute task at com.github.sarxos.myWebcam.WebcamDiscoveryService.getWebcams(WebcamDiscoveryService.java:124) at com.github.sarxos.myWebcam.Webcam.getWebcams(Webcam.java:816) at com.github.sarxos.myWebcam.Webcam.getDefault(Webcam.java:879) at com.github.sarxos.myWebcam.Webcam.getDefault(Webcam.java:856) at com.github.sarxos.myWebcam.Webcam.getDefault(Webcam.java:834) at com.TestJava.doGet(TestJava.java:38) at javax.servlet.http.HttpServlet.service(HttpServlet.java:620) at javax.servlet.http.HttpServlet.service(HttpServlet.java:727) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) at org.apache.catalina.valves.RemoteIpValve.invoke(RemoteIpValve.java:683) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1042) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:607) at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:745) Caused by: java.util.concurrent.ExecutionException: com.github.sarxos.myWebcam.WebcamException: Cannot execute task at java.util.concurrent.FutureTask.report(FutureTask.java:122) at java.util.concurrent.FutureTask.get(FutureTask.java:188) at com.github.sarxos.myWebcam.WebcamDiscoveryService.getWebcams(WebcamDiscoveryService.java:116) ... 27 more Caused by: com.github.sarxos.myWebcam.WebcamException: Cannot execute task at com.github.sarxos.myWebcam.WebcamProcessor$AtomicProcessor.process(WebcamProcessor.java:72) at com.github.sarxos.myWebcam.WebcamProcessor.process(WebcamProcessor.java:140) at com.github.sarxos.myWebcam.WebcamTask.process(WebcamTask.java:46) at com.github.sarxos.myWebcam.ds.buildin.WebcamDefaultDriver$WebcamNewGrabberTask.newGrabber(WebcamDefaultDriver.java:46) at com.github.sarxos.myWebcam.ds.buildin.WebcamDefaultDriver.getDevices(WebcamDefaultDriver.java:118) at com.github.sarxos.myWebcam.WebcamDiscoveryService$WebcamsDiscovery.call(WebcamDiscoveryService.java:36) at com.github.sarxos.myWebcam.WebcamDiscoveryService$WebcamsDiscovery.call(WebcamDiscoveryService.java:1) at java.util.concurrent.FutureTask.run(FutureTask.java:262) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) ... 1 more Caused by: java.lang.RuntimeException: Failed to allocate new instance of type class com.github.sarxos.myWebcam.ds.buildin.natives.OpenIMAJGrabber at org.bridj.cpp.CPPRuntime.newCPPInstance(CPPRuntime.java:674) at org.bridj.cpp.CPPRuntime$CPPTypeInfo.initialize(CPPRuntime.java:828) at org.bridj.cpp.CPPRuntime$CPPTypeInfo.initialize(CPPRuntime.java:755) at org.bridj.CRuntime$CTypeInfo.initialize(CRuntime.java:209) at org.bridj.BridJ.initialize(BridJ.java:970) at org.bridj.NativeObject.(NativeObject.java:23) at org.bridj.StructObject.(StructObject.java:14) at org.bridj.cpp.CPPObject.(CPPObject.java:27) at com.github.sarxos.myWebcam.ds.buildin.natives.OpenIMAJGrabber.(OpenIMAJGrabber.java:64) at com.github.sarxos.myWebcam.ds.buildin.WebcamDefaultDriver$WebcamNewGrabberTask.handle(WebcamDefaultDriver.java:56) at com.github.sarxos.myWebcam.WebcamProcessor$AtomicProcessor.run(WebcamProcessor.java:81) ... 3 more Caused by: java.lang.RuntimeException: Library 'OpenIMAJGrabber' was not loaded successfully from file '/var/lib/openshift/56081b1789f5cf12fc000062/jbossews/tmp/BridJExtractedLibraries9012739367972665359/OpenIMAJGrabber.so' at org.bridj.BridJ.getNativeLibrary(BridJ.java:922) at org.bridj.BridJ.getNativeLibrary(BridJ.java:901) at org.bridj.BridJ.getNativeLibrary(BridJ.java:513) at org.bridj.cpp.CPPRuntime.newCPPInstance(CPPRuntime.java:627) ... 13 more Mail Sent

[sarxos]

Hi @biswajitroy04,

Thank you for the report.

I checked the 0.3.10 version available from Maven:

$ javap -verbose Webcam.class | grep major
$ javap -verbose Webcam.class | grep minor

The output is:

major version: 50
minor version: 0

The above points out it's 1.6. I did the same with the 0.3.11-SNAPSHOT and effect was the same. I suppose that problematic class in your case was simply TestJava which has been compiled with 1.8. Just guess this is your project's main class.

In regards to the second issue - this may be caused either by:

1. The fact that you are running this application in cloud env (trying to open UVC webcam on the server side), and the cloud does not give you permission to load native code (OpenIMAJGrabber.so), or
2. The fact that you renamed package to myWebcam (this should go in pair with the change in corresponding folder in src/main/resources (I remember BridJ having some problems to locate *.so objects in such a case).

But are you really trying to open UVC in a cloud? Or did you want to use some IP camera and simply forget to set appropriate capture driver?

[biswajitroy04]

Thanks a lot for your reply. I will check all these aspects and yes I need
to modify the codes to use it as an IP camera.

Thanks
Biswajit

On Mon, Sep 28, 2015 at 12:54 PM, Bartosz Firyn notifications@github.com
wrote:

Hi @biswajitroy04 https://github.com/biswajitroy04,

Thank you for the report.

I checked the 0.3.10
http://search.maven.org/remotecontent?filepath=com/github/sarxos/webcam-capture/0.3.10/webcam-capture-0.3.10.jar
version available from Maven:

$ javap -verbose Webcam.class | grep major
$ javap -verbose Webcam.class | grep minor

The output is:

major version: 50
minor version: 0

The above points out it's 1.6. I did the same with the 0.3.11-SNAPSHOT
https://oss.sonatype.org/service/local/artifact/maven/redirect?r=snapshots&g=com.github.sarxos&a=webcam-capture&v=0.3.11-SNAPSHOT
and effect was the same. I suppose that problematic class in your case was
simply TestJava which has been compiled with 1.8. Just guess this is your
project's main class.

In regards to the second issue - this may be caused either by:

1. The fact that you are running this application in cloud env (trying
   to open UVC webcam on the server side), and the cloud does not give you
   permission to load native code (OpenIMAJGrabber.so), or
2. The fact that you renamed package to myWebcam (this should go in
   pair with the change in corresponding folder in src/main/resources (I
   remember BridJ having some problems to locate *.so objects in such a case).

But are you really trying to open UVC in a cloud? Or did you want to
use some IP camera and simply forget to set appropriate capture driver?

—
Reply to this email directly or view it on GitHub
#397 (comment)
.

[sarxos]

Hi @biswajitroy04,

Ok, in regards of the major/minor version issue I'm almost 100% sure that TestJava is to blame.

To switch from UVC to IP camera just replace the capture driver:

static {
    Webcam.setDriver(new IpCamDriver(new IpCamStorage("cameras.xml")));
}

(keep in mind that you have to have cameras.xml pre-created, example can be found here)

By doing the above the issue with OpenIMAJGrabber will disappear. FYI, here are some examples using IP cameras:

https://github.com/sarxos/webcam-capture/tree/master/webcam-capture-drivers/driver-ipcam/src/examples/java

And here is small low latency streaming example using IP cameras on a web service backend which transmit images to the GUI through WebSocket.

Take care!

[sarxos]

I forget to put a link to the example. Here it is:

https://github.com/sarxos/webcam-capture/tree/master/webcam-capture-examples/webcam-capture-websockets

[sarxos]

@biswajitroy04, I'm closing this ticket. Please comment here if you have any further questions in regards to this.