Java Debuger

 

Example

 

 

java -Xdebug -Xnoagent -Djava.compiler=NONE  -Xrunjdwp:transport=dt_socket,server=y

,address=8888,suspend=n

Debugger Launch Parameters

 

 

Launch Parameter or Subparameter	Description
-Xdebug	Enables the application to be debugged.
-Xnoagent	Disables the sun.tools.debug agent so that the JPDA debugger can properly attach its own agent.
-Djava.compiler=NONE	Disables the JIT (Just-In-Time) compiler.
-Xrunjdwp	Loads the reference implementation of the Java Debug Wire Protocol, which enables remote debugging.
transport	Name of the transport to be used when debugging the application. The value can be dt_shmem (for a shared memory connection) ordt_socket (for a socket connection). Shared memory connections are available only on Windows machines.
server	If this value equals n, the application attempts to attach to the debugger at the address specified in the address subparameter. If this value equals y, the application listens for a connection at this address.
address	For socket connections, specifies a port number used for communi-cation between the debugger and the application. For shared memory connections, specifies a name that refers to the shared memory to be used. This name can consist of any combination of characters that are valid in filenames on a Windows machine except the backslash. You use this name in the Name field of the Attach dialog box when you attach the debugger to the running application.
suspend	If the value is n, the application starts immediately. If the value is y, the application waits until a debugger has attached to it before executing.

 

 Attach Dialog Box Fields

 

Field	Description
Connector	Specifies the type of JPDA connector to use. On Windows machines, you can choose between shared memory connectors and socket connectors. On other systems, you can only use a socket connector. For both shared memory connectors and socket connectors, there are Attach and Listen variants. You can use an Attach connector to attach to a running application. You can use a Listen connector if you want the running application to initiate the connection to the debugger. If you use the Listen connector, multiple applications running on different JVMs can connect to the debugger.
Transport	Specifies the JPDA transport protocol to use. This field is automatically filled in according to what you have selected in the Connector field.
Host	(Only for socket attach connections.) The host name of the computer where the debugged application is running.
Port	(Only for socket connections.) The port number that the application attaches to or listens on. You can assign a port number in the address subparameter of theXrunjdwp parameter that you pass to the JVM of the application that is to be debugged. If you do not use this suboption, a port number is assigned automatically, and you can determine the assigned port number by looking at the output of the process.
Timeout	The number of seconds that the debugger waits for a connection to be established.
Name	(Only for shared memory connections.) Specifies the shared memory to be used for the debugging session. This value must correspond to the value of theaddress subparameter of the Xrunjdwp parameter that you pass to the JVM of the application that is to be debugged.
Local Address	(Only for socket listen connections.) The host name of the computer that you are running on.