Getting IllegalArgumentException when creating a gson object

Actual behavior (the bug) A description of what happened

Hi,

I’m porting a java microservice from spark to javalin and so, am invokng gson.fromJson in order to create a pojo like:

Descriptor descriptor = new Gson().fromJson(ctx.body(), Descriptor.class);

This currently results in the following error:

java.lang.IllegalArgumentException: class org.eclipse.jetty.server.handler.ErrorHandler declares multiple JSON fields named _listeners
	at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.getBoundFields(ReflectiveTypeAdapterFactory.java:172)
	at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.create(ReflectiveTypeAdapterFactory.java:102)
	at com.google.gson.Gson.getAdapter(Gson.java:458)
	at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.createBoundField(ReflectiveTypeAdapterFactory.java:117)
	at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.getBoundFields(ReflectiveTypeAdapterFactory.java:166)
	at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.create(ReflectiveTypeAdapterFactory.java:102)
	at com.google.gson.Gson.getAdapter(Gson.java:458)
	at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.createBoundField(ReflectiveTypeAdapterFactory.java:117)
	at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.getBoundFields(ReflectiveTypeAdapterFactory.java:166)
	at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.create(ReflectiveTypeAdapterFactory.java:102)
	at com.google.gson.Gson.getAdapter(Gson.java:458)
	at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.createBoundField(ReflectiveTypeAdapterFactory.java:117)
	at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.getBoundFields(ReflectiveTypeAdapterFactory.java:166)
	at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.create(ReflectiveTypeAdapterFactory.java:102)
	at com.google.gson.Gson.getAdapter(Gson.java:458)
	at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.createBoundField(ReflectiveTypeAdapterFactory.java:117)
	at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.getBoundFields(ReflectiveTypeAdapterFactory.java:166)
	at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.create(ReflectiveTypeAdapterFactory.java:102)
	at com.google.gson.Gson.getAdapter(Gson.java:458)
	at com.google.gson.internal.bind.CollectionTypeAdapterFactory.create(CollectionTypeAdapterFactory.java:53)
	at com.google.gson.Gson.getAdapter(Gson.java:458)
	at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.createBoundField(ReflectiveTypeAdapterFactory.java:117)
	at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.getBoundFields(ReflectiveTypeAdapterFactory.java:166)
	at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.create(ReflectiveTypeAdapterFactory.java:102)
	at com.google.gson.Gson.getAdapter(Gson.java:458)
	at com.google.gson.Gson.fromJson(Gson.java:926)
	at com.google.gson.Gson.fromJson(Gson.java:892)
	at com.google.gson.Gson.fromJson(Gson.java:841)
	at com.google.gson.Gson.fromJson(Gson.java:813)
	at Reason.lambda$main$5(Reason.java:125)
	at io.javalin.security.SecurityUtil.noopAccessManager(SecurityUtil.kt:22)
	at io.javalin.Javalin.lambda$addHandler$0(Javalin.java:606)
	at io.javalin.core.JavalinServlet$service$2$1.invoke(JavalinServlet.kt:46)
	at io.javalin.core.JavalinServlet$service$2$1.invoke(JavalinServlet.kt:17)
	at io.javalin.core.JavalinServlet$service$1.invoke(JavalinServlet.kt:143)
	at io.javalin.core.JavalinServlet$service$2.invoke(JavalinServlet.kt:41)
	at io.javalin.core.JavalinServlet.service(JavalinServlet.kt:107)
	at io.javalin.core.util.JettyServerUtil$initialize$httpHandler$1.doHandle(JettyServerUtil.kt:72)
	at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:203)
	at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:480)
	at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1557)
	at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:201)
	at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1247)
	at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:144)
	at org.eclipse.jetty.server.handler.HandlerList.handle(HandlerList.java:61)
	at org.eclipse.jetty.server.handler.StatisticsHandler.handle(StatisticsHandler.java:174)
	at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)
	at org.eclipse.jetty.server.Server.handle(Server.java:502)
	at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:364)
	at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:260)
	at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:305)
	at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:103)
	at org.eclipse.jetty.io.ChannelEndPoint$2.run(ChannelEndPoint.java:118)
	at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.runTask(EatWhatYouKill.java:333)
	at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.doProduce(EatWhatYouKill.java:310)
	at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.tryProduce(EatWhatYouKill.java:168)
	at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.produce(EatWhatYouKill.java:132)
	at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:765)
	at org.eclipse.jetty.util.thread.QueuedThreadPool$2.run(QueuedThreadPool.java:683)
	at java.base/java.lang.Thread.run(Thread.java:834)

Let me know what you think - thanks

John

Expected behavior

A description of what you expected to happen

I’m expecting a related pojo to be created from the json body.

To Reproduce Steps to reproduce the behavior

Invoke gson.fromJson like so, in order to create a related pojo:

Descriptor descriptor = new Gson().fromJson(ctx.body(), Descriptor.class);

Additional context Add any other context about the bug here

json body looks like this:

{"entity$":"-/-/descriptor","pid":"b0ci9d","x":"804","y":"393","rid":"lap0pp","rtype":"describes","properties":[{"type":"8","name":"name","value":"test"},{"type":"10","name":"test","value":"if its nice outside then I want to be active"}],"sources":["01nyjg"],"targets":["x9qznr"],"type":"common","id":"tz6kfq","role":"reason","cmd":"add_descriptor","plugin$":{"name":"reason","tag":"-","fullname":"reason"},"tx$":"vzl5xvamabqm","sync$":true,"custom$":{},"remote$":true}

Equivalent spark line looks like this, works:

Descriptor descriptor = new Gson().fromJson(request.body(), Descriptor.class);

[uover82]

Thanks for this feedback, @ernestas2k

I’ve updated/ tested with this constructor change, getting similar results as before.

I’m also noticing some possible duplicate entities resulting from recursion that could be impacting, so investigating this.

I’ll let you know what I find.

[uover82]

Thanks for this update, tipsy. I may be dealing with multiple processes. Would be it reasonable to start/ manage multiple servers to handle/send these (sse) events? Otherwise, think I might need some sort of ipc/ messaging.