Attaching to a JVM Suspended on Start

The target JVM can be invoked and then suspended before executing the main() function. The debugger can then attach to the suspended target JVM. There are two ways to attach the debugger to the target JVM: via shared memory or a network socket.

Shared Memory

Shared memory has the fastest debugging performance if it is supported by your JVM platform. The debugger and the target JVM must be executing on the same computer. The user-specified address parameter is optional -- if not specified, then the target JVM will print out the shared memory address that it will use.

JDK 1.6

jdk1.6/bin/java -agentlib:jdwp=transport=dt_shmem,server=y,address=javadebug test.Test args

JDK 1.5

jdk1.5/bin/java -agentlib:jdwp=transport=dt_shmem,server=y,address=javadebug test.Test args

JDK 1.4

j2sdk1.4/bin/java -Xdebug -Xrunjdwp:transport=dt_shmem,server=y,address=javadebug test.Test args

JDK 1.3

jdk1.3/bin/java -classic -Xdebug -Xnoagent -Djava.compiler=NONE -Xrunjdwp:transport=dt_shmem,server=y,address=javadebug test.Test args

Socket

A network socket can connect the debugger and the target JVM that can be running on the same computer or on different computers. The user-specified address (port number) parameter is optional -- if not specified, then the target JVM will print out the port number that it will use.

JDK 1.6

jdk1.6/bin/java -agentlib:jdwp=transport=dt_socket,server=y,address=8000 test.Test args

JDK 1.5

jdk1.5/bin/java -agentlib:jdwp=transport=dt_socket,server=y,address=8000 test.Test args

JDK 1.4

j2sdk1.4/bin/java -Xdebug -Xrunjdwp:transport=dt_socket,server=y,address=8000 test.Test args

JDK 1.3

jdk1.3.x/bin/java -classic -Xdebug -Xnoagent -Djava.compiler=NONE -Xrunjdwp:transport=dt_socket,server=y,address=8000 test.Test args

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