LaunchingConnector

LaunchingConnector is a component of the Java Platform Debugger Architecture (JPDA) that provides the means to start a new Java Virtual Machine (VM) for debugging. It is a type of Connector in the Java Debug Interface (JDI) and is used by debuggers and IDEs to launch a target VM with debugging enabled rather than attaching to an already-running process.

In the JDI API, LaunchingConnector is an interface that extends Connector and exposes a method to obtain a map of default arguments. Implementations define how a target VM is started, including which command line options and environment settings are used. The most common implementation is the CommandLineLaunch connector, which starts the target VM as a separate process using the system command line. The default argument set typically includes entries for specifying the main class (or application to run), VM options, class paths, boot class paths, and a suspend flag that controls whether the target VM pauses at startup until a debugger attaches.

Usage generally follows a standard workflow: obtain the LaunchingConnector from the VirtualMachineManager, retrieve and customize its default arguments, and invoke the launcher to start the target VM. The process returns a VirtualMachine instance representing the newly launched VM, which can then be controlled by the debugger to set breakpoints, inspect state, and perform debugging operations.

Launching connectors are contrasted with other JPDA connectors such as AttachingConnector (which connects to an already running VM) and ListeningConnector (which waits for a connection). They are essential for IDE-based debugging workflows that require starting a target program under debugger control, providing a structured and configurable way to initialize the debugging session.

See also: Java Debug Wire Protocol (JDWP), JPDA, JDI, AttachingConnector, ListeningConnector.