When something goes wrong, SeedStack does its best to provide detailed information about the failure. This can take two forms: the detailed exception system and the diagnostic dump.

Detailed exception system

All SeedStack exceptions extend BaseException which is a RuntimeException. This means that you are not required to catch framework exceptions although you can do so if needed.

All SeedStack exceptions display a detailed information report about the failure. Consider this example:

org.seedstack.seed.SeedException: [CORE] Unexpected exception

Unexpected exception during Seed startup or shutdown.


1. Unable to provision, see the following errors:
   1) Error injecting org.seedstack.seed.core.ConfigurationIT$Holder using
    Reason: [CORE] Unable to inject configuration value
     while locating org.seedstack.seed.core.ConfigurationIT$Holder
   1 error @(

2. [CORE] Unable to inject value from configuration key 'missingProperty' in field 'configObject2' of class
   'org.seedstack.seed.core.ConfigurationIT.Holder'. @(

3. [CORE] Missing mandatory configuration key 'missingProperty'. @(

Ensure that the configuration key 'missingProperty' is present and that the configuration source is correctly detected.

Online information


You can find the following information in this exception report:

  • The exception type: SeedException.
  • The module and the error code: CORE and Unexpected exception.
  • The textual description of the error: «Unexpected exception during Seed startup or shutdown».
  • A list of causes which is built from the Java exception chaining mechanism:
    • A Guice ProvisionException which occurred when trying to inject a class,
    • A SeedException which occurred when the configuration custom injector failed to the configObject2 field,
    • Another SeedException which occurred because the missingKey configuration key was mandatory and is missing.
  • The fix which is an advice on how to fix the root cause, i.e. the missing configuration key.
  • The online information which is an URL pointing to a Web resource related to the root cause.
  • The detailed stacktrace of the chained exceptions.

Diagnostic dump

When an exception is thrown on startup or shutdown, a YAML diagnostic file is dumped in a temporary directory. A diagnostic dump contains a lot of information about the SeedStack runtime. It can be helpful to do advanced diagnostics.

A warning log will tell where the diagnostic file is saved.


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