config.md

Default config.json example

{
	"vm": {
		"host": "localhost",
		"port": "5006"
	},
	"entrypoint": {
		"className": "app.experiments.ObjectRefSimulation",
		"methodName": "main",
		"methodArguments": [
			"java.lang.String[]"
		],
		"repBefore": 0
	},
	"endpoint": {
		"className": "java.lang.Runtime",
		"methodName": "exec",
		"methodArguments": [
			"java.lang.String"
		],
		"repBefore": 0
	},
	"maxObjectDepth" : 14,
	"logging": {
		"outputName" : "JDIOutput",
		"extension": "tr"
	}
}
}

Using multiple configurations

By default, JavaCallstackExtractor looks for a file named config.json. However, you can specify a custom configuration file by passing its name as a program argument to JavaCallstackExtractor (e.g., via Run Configurations in Eclipse).

Configuration Explained

vm

Defines the target Java Virtual Machine to attach to.

• host : The hostname of the target VM (typically "localhost" for local debugging)
• port : The port exposed by the target VM (should match the port in the JDWP setup, default is "5006")

endpoint

Specifies where the call stack extraction should stop.

• className : Fully qualified name of the class containing the target method
• methodName : Name of the method where the breakpoint will be set
• methodArguments : A list of parameter types (in order) as fully qualified class names
• repBefore : Number of times to skip the breakpoint before triggering

entrypoint

Specifies the entry point in the same way as the endpoint

Example :
Let’s say your main() method launches the epic journey of a brave hero. But—before launching it—you get jealous and decide that your hero should never get any rest...

In this case:

• The entry method is: main(String[] args), note that only the name of the method is actually important
• The breakpoint is: method rest() in the class Hero

"sourceMethod": "main",
"breakpoint": {
  "className": "your.package.Hero",
  "methodName": "rest",
  "methodArguments": []
}

maxObjectDepth

Sets the maximum recursion depth of the object graph. Use a negative number for unlimited depth.

logging

Controls how the output is formatted and where it is saved.

• outputName : Base name of the output file
• extension : File extension (default is "tr"). This is important for compatibility with import tools like FamixJavaTrace.