Getting Null Pointer Exception error when I try to run Application.java file

[prashanthsammanu]

I have followed all the steps as per the documentation to setup the development environment in local. It would be a great help if I can know where I went wrong

[zhaojj2209]

As per our developer guidelines, to start the dev server, please run ./gradlew serverRun.

[prashanthsammanu]

Task :serverRun FAILED
{"severity":"INFO","instanceId":"dev_server_instance_id","message":"Instance startup: dev_server_instance_id","event":"INSTANCE_LOG","instanceEvent":"STARTUP"}
2023-03-03 14:37:56.886:INFO :oejs.Server:main: jetty-10.0.13; built: 2022-12-07T20:13:20.134Z; git: 1c2636ea05c0ca8de1ffd6ca7f3a98ac084c766d; jvm 19.0.1+10-21
2023-03-03 14:37:56.898:SEVERE:teammates.main.Application$1:lifeCycleFailure:62: Instance failed to start/stop: dev_server_instance_id
Exception in thread "main" java.io.IOException: Failed to bind to 0.0.0.0/0.0.0.0:8080
at org.eclipse.jetty.server.ServerConnector.openAcceptChannel(ServerConnector.java:344)
at org.eclipse.jetty.server.ServerConnector.open(ServerConnector.java:304)
at org.eclipse.jetty.server.Server.lambda$doStart$0(Server.java:402)
at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183)
at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197)
at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:179)
at java.base/java.util.Spliterators$ArraySpliterator.forEachRemaining(Spliterators.java:1006)
at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:509)
at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:499)
at java.base/java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:150)
at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:173)
at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
at java.base/java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:596)
at org.eclipse.jetty.server.Server.doStart(Server.java:398)
at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:93)
at teammates.main.Application.main(Application.java:80)
Caused by: java.net.BindException: Address already in use
at java.base/sun.nio.ch.Net.bind0(Native Method)
at java.base/sun.nio.ch.Net.bind(Net.java:555)
at java.base/sun.nio.ch.ServerSocketChannelImpl.netBind(ServerSocketChannelImpl.java:344)
at java.base/sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:301)
at org.eclipse.jetty.server.ServerConnector.openAcceptChannel(ServerConnector.java:339)
... 15 more

FAILURE: Build failed with an exception.

• What went wrong:
  Execution failed for task ':serverRun'.

Process 'command '/Library/Java/JavaVirtualMachines/jdk-19.jdk/Contents/Home/bin/java'' finished with non-zero exit value 1

• Try:

Run with --stacktrace option to get the stack trace.
Run with --info or --debug option to get more log output.
Run with --scan to get full insights.

• Get more help at https://help.gradle.org

BUILD FAILED in 4s
6 actionable tasks: 3 executed, 3 up-to-date

I am getting these errors while trying to start dev server. Can you please help me in fixing this issue?

[samuelfangjw]

You already have another instance of the backend server running in the background. You need to kill the existing process on port 8080.

[prashanthsammanu]

I have killed that process. But I am still facing the same issue in browser, whereas in IDE I can see the status as Executing - 85% in Terminal. Am I missing something?

[samuelfangjw]

Need to build frontend files before they can be served by the backend server.

See the next step in the developer guidelines: https://teammates.github.io/teammates/development.html#building-front-end-files

[prashanthsammanu]

I have followed the steps.

Now both the servers are pointing to the same page i.e; http://localhost:4200/web/front/home , http://localhost:8080/web/front/home

Is this right?