Swagger-codegen: NPE at ModelImpl

Created on 8 Aug 2017 · 4Comments · Source: swagger-api/swagger-codegen

I currently facing this stack trace

java.lang.RuntimeException: Could not process operation:
  Tag: AssetGroups
  Operation: addAssets
  Resource: put /api/v2/assetGroups/{id}/assetList
  Definitions: {Addresses=io.swagger.models.ModelImpl@9901aa0, 
AppHost=io.swagger.models.ModelImpl@8456d641, ....
  Exception: null
        at io.swagger.codegen.DefaultGenerator.processOperation(DefaultGenerator.java:861)
        at io.swagger.codegen.DefaultGenerator.processPaths(DefaultGenerator.java:763)
       at io.swagger.codegen.DefaultGenerator.generateApis(DefaultGenerator.java:388)
       at io.swagger.codegen.DefaultGenerator.generate(DefaultGenerator.java:700)

after upgrading from swagger-codegen-maven-plugin 2.2.2 to 2.2.3 where I generate java source from swagger spec

Need suggestion on how to look for abnormalities in my swagger spec file which can cause this issue ( or this can just be regression )

Thanks

Swagger-codegen version

2.2.3

Source

dantran

Most helpful comment

Also seeing this issue with swagger-codegen 2.2.3.

anweiss on 10 Aug 2017

👍2

All 4 comments

Also seeing this issue with swagger-codegen 2.2.3.

anweiss on 10 Aug 2017

👍2

The line at the top of your is thrown here.

If you think your swagger spec is failing validation now, you can validate via command line.

This is the command (installed from brew install swagger-codegen on mac)

$ swagger-codegen help validate
NAME
        swagger-codegen-cli validate - Validate specification

SYNOPSIS
        swagger-codegen-cli validate (-i <spec file> | --input-spec <spec file>)

OPTIONS
        -i <spec file>, --input-spec <spec file>
            location of the swagger spec, as URL or file (required)

If your spec passes validation, I'd recommend debugging locally. The maven plugin is just a maven options wrapper around swagger-codgen's core, which you can also access via swagger-codegen-cli. Here are the steps if you're not familiar with it (I'm assuming you have IntelliJ available if you're using the maven plugin):

clone the repo
git checkout v2.2.3
compile: mvn clean package -Dmaven.test.skip=true -DskipTests
setup remote debugging to wait until a debugger is attached. I use the command:
export JAVA_OPTS="-agentlib:jdwp=transport=dt_socket,server=y,address=5009,suspend=y"
In IntelliJ, create a new remote debugging configuration (see IntelliJ docs), and point to the address from the previous bullet (5009)
Set a breakpoint in DefaultGenerator.java
Run your codegen (from cloned repo's root):
java $JAVA_OPTS -jar ./modules/swagger-codegen-cli/target/swagger-codegen-cli.jar \ generate -i yourswagger.json -l java -o ./output #etc
Run the remote debugger configuration in IntelliJ and step through the debugger
When you're done, unset the JAVA_OPTS variable or close your shell session 💃

For 2.2.3, swagger parser and swagger core dependencies were updated (commit). It's possible the NPE is from a type pulled in from there. I did some investigation into DefaultGenerator.java changes between 2.2.2 and 2.2.3, and I don't see anywhere that a NPE would have been introduced.

I hope that helps.