javalin: 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);