zippoy / jdivisitor

Java library for building custom debugger applications using the Java Debug Interface (JDI) and the visitor design pattern

JDIVisitor

JDIVisitor is a Java library for building custom debugger applications using the Java Debug Interface (JDI) and the visitor design pattern. It draws inspiration from jfager's jdiscript project. However, JDIVisitor eschews jdiscript's script-like design in favour of a more Java-esque library. An advantage of using the visitor pattern is that the visitor object can encapsulate and maintain state as it handles JDI events, allowing for complex debugger applications to be constructed.

License

GNU GPL v2.0

Usage

The following steps can be used to create your custom debugger application:

1. Implement an EventRequestor class that requests specific JDI events that will be handled by your debugger
2. Implement an EventVisitor class that describes how to handle the JDI events enabled in Step 1
3. Connect to the target virtual machine using either the LocalVMLauncher class (creates and starts a local virtual machine in debug mode) or the RemoteVMConnector class (attach to a virtual machine already running in debug mode over a network). Note that using the RemoteVMConnector and an appropriately-configured sandbox is the safer choice if you are working with malicious Java applications
4. Instantiate a Debugger object using the VirtualMachine object returned from Step 3
5. Call the debugger's requestEvents method with the EventRequestor implemented in Step 1
6. Call the debugger's run method with the EventVisitor implemented in Step 2

Examples

See https://github.com/adrianherrera/jdivisitor-examples.