Error com.google.protobuf.LazyStringArrayList in cerbos-sdk-java:0.7.0

[bbodensieck]

Hello folks,
while testing version 0.7.0 of cerbos-sdk-java I am getting the following error

can't parse JSON.  Raw result:

Handler dispatch failed: java.lang.IllegalAccessError: class dev.cerbos.api.v1.engine.Engine$Principal tried to access method 'com.google.protobuf.LazyStringArrayList com.google.protobuf.LazyStringArrayList.emptyList()' (dev.cerbos.api.v1.engine.Engine$Principal and com.google.protobuf.LazyStringArrayList are in unnamed module of loader 'app')

My Code looks like this and runs fine with e.g. cerbos-sdk-java:47d60e3

  public boolean isAllowed(Resource resource, String action) throws Exception {
    Principal principal = Principal.newInstance("usera").withRoles("some-role");
    CheckResult result = client.check(principal, resource, action);
    return result.isAllowed(action);
  }

Could you check that please?

Have a nice day,
Björn

[charithe]

Which version of Java are you using? BTW, cerbos-sdk-java:47d60e3 is a really old version and there have been many changes since. Does your code work with more recent versions like 0.6.1? Please include the full stacktrace if there's one as well.

[bbodensieck]

I am using a Mac with Apple M2 Max Chip.

java --version
openjdk 17.0.6 2023-01-17 LTS
OpenJDK Runtime Environment Corretto-17.0.6.10.1 (build 17.0.6+10-LTS)
OpenJDK 64-Bit Server VM Corretto-17.0.6.10.1 (build 17.0.6+10-LTS, mixed mode, sharing)

Code example

Principal principal = Principal.newInstance("user-id", "some-role");
Resource resource = Resource.newInstance("a-resource", "42");
CheckResult create = cerbosClient.check(principal, resource, "action");

0.7.0

Handler dispatch failed: java.lang.IllegalAccessError: class dev.cerbos.api.v1.engine.Engine$Principal tried to access method 'com.google.protobuf.LazyStringArrayList com.google.protobuf.LazyStringArrayList.emptyList()' (dev.cerbos.api.v1.engine.Engine$Principal and com.google.protobuf.LazyStringArrayList are in unnamed module of loader 'app')

Handler dispatch failed: java.lang.NoClassDefFoundError: Could not initialize class dev.cerbos.api.v1.engine.Engine$Principal

0.6.1

Handler dispatch failed: java.lang.IllegalAccessError: class dev.cerbos.api.v1.engine.Engine$Principal tried to access method 'com.google.protobuf.LazyStringArrayList com.google.protobuf.LazyStringArrayList.emptyList()' (dev.cerbos.api.v1.engine.Engine$Principal and com.google.protobuf.LazyStringArrayList are in unnamed module of loader 'app')

Handler dispatch failed: java.lang.NoClassDefFoundError: Could not initialize class dev.cerbos.api.v1.engine.Engine$Principal

47d60e3
Works

[charithe]

I am struggling to reproduce this. I suspect that it is due to a dependency clash. Can you post the output of ./gradlew dependencies please.

[bbodensieck]

runtimeClasspath - Runtime classpath of source set 'main'.
[...]
+--- com.mysql:mysql-connector-j -> 8.0.33
|    \--- com.google.protobuf:protobuf-java:3.21.9 -> 3.23.4
\--- dev.cerbos:cerbos-sdk-java:0.7.0
     +--- com.google.protobuf:protobuf-java:3.23.4
     +--- com.google.protobuf:protobuf-java-util:3.23.4
     |    +--- com.google.protobuf:protobuf-java:3.23.4
     [...]

[charithe]

I see that the MySQL connector has a dependency on a different version of protobuf. It could be a factor. I have seen bug reports on the internet where people have had similar issues due to conflicting versions of the protobuf library.

Could you please create a bare Java project with just the Cerbos SDK (no Spring Boot or any other dependencies) and try out your piece of code to see if you still get the same error?

[bbodensieck]

Good catch!

I got it working by excluding com.google.protobuf and adding it explicitly like this.

implementation('com.mysql:mysql-connector-j') {
    exclude group: 'com.google.protobuf', module: 'protobuf-java'
}
implementation 'com.google.protobuf:protobuf-java:3.23.4'
implementation 'dev.cerbos:cerbos-sdk-java:0.+'

Thank you so much.
Björn