运行Seedstack应用程序时发生异常

Question

I have used seedstack dependecies for Hibernate and JPA to create DAO services that performs crud operations on Database. I am trying to Launch this Seedstack application module through Java application Launcher in eclipse, by SeedMain class.

In pom.xml  - dependecy for undertow is given.
    <dependency>
        <groupId>org.seedstack.seed</groupId>
        <artifactId>seed-web-undertow</artifactId>
    </dependency>

When executing the SeedMain class, I am getting the below error snakeyaml error:-
Exception in thread "main" java.lang.NoSuchMethodError: org.yaml.snakeyaml.DumperOptions.setSplitLines(Z)V
   at com.fasterxml.jackson.dataformat.yaml.YAMLGenerator.buildDumperOptions(YAMLGenerator.java:259)
   at com.fasterxml.jackson.dataformat.yaml.YAMLGenerator.<init>(YAMLGenerator.java:232)
   at com.fasterxml.jackson.dataformat.yaml.YAMLFactory._createGenerator(YAMLFactory.java:447)
   at com.fasterxml.jackson.dataformat.yaml.YAMLFactory.createGenerator(YAMLFactory.java:397)
   at org.seedstack.seed.core.internal.diagnostic.DefaultDiagnosticReporter.writeDiagnosticReport(DefaultDiagnosticReporter.java:75)
   at org.seedstack.seed.core.internal.diagnostic.DefaultDiagnosticReporter.writeDiagnosticReport(DefaultDiagnosticReporter.java:67)
   at org.seedstack.seed.core.internal.diagnostic.DiagnosticManagerImpl.dumpDiagnosticReport(DiagnosticManagerImpl.java:70)
   at org.seedstack.seed.core.SeedMain.handleException(SeedMain.java:68)
   at org.seedstack.seed.core.SeedMain.main(SeedMain.java:61)

As per my understanding the Error is due to some version inconsistency for snakeyaml , But for Seedstack as the versions for dependecies are resolved by seedstack-bom dependecy, so where exactly should I do the changes to resolve the error.

Thanks in Advance!

Answer 1

From reading the stacktrace, it seems that you have some error on startup which is handled by the handleException() method. This method then tries to write a YAML diagnostic report but ultimately fails due to the snakeyaml version issue you mentioned.

You should do two things:

• Fix the snakeyaml dependency issue by looking into the dependency tree. This kind of problem is often caused by some library that makes Maven choose an older version. SeedStack needs at least jackson-dataformat-yaml version 2.9.4 which in turn needs at least snakeyaml 1.18.
• Fix the other error by looking at the full stacktrace. When a diagnostic report cannot be written, the original exception is still printed on the console (on stderr).