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This article mainly introduces "the methods and steps of starting remote debugging for Java project". In the daily operation, I believe that many people have doubts about the methods and steps of starting remote debugging for Java project. The editor has consulted all kinds of materials and sorted out simple and easy-to-use operation methods. I hope it will be helpful to answer the doubts of "methods and steps for opening remote debugging of Java project". Next, please follow the editor to study!

Environment

Apache-tomcat-8.5.16

Linux

How to enable remote debugging

Tomcat enables remote debugging

Method

Change to the bin directory / apache-tomcat-8.5.16/bin of your tomcat and execute:

. / catalina.sh jpda start

Execute the above command to open the remote debug. If you want to configure some information, such as the port number, please refer to the instructions below.

Parameter description

# JPDA_TRANSPORT (Optional) JPDA transport used when the "jpda start" # command is executed. The default is "dt_socket". # # JPDA_ADDRESS (Optional) Java runtime options used when the "jpda start" # command is executed The default is localhost:8000.## JPDA_SUSPEND (Optional) Java runtime options used when the "jpda start" # command is executed. Specifies whether JVM should suspend# execution immediately after startup. Default is "n". # JPDA_OPTS (Optional) Java runtime options used when the "jpda start" # command is executed. If used, JPDA_TRANSPORT, JPDA_ADDRESS,# and JPDA_SUSPEND are ignored. Thus, all required jpda# options MUST be specified. The default is:##-agentlib:jdwp=transport=$JPDA_TRANSPORT,# address=$JPDA_ADDRESS,server=y,suspend=$JPDA_SUSPEND

Operation instruction

So if you want to modify the configuration, do the following:

Configure in catalina.sh:

JPDA_TRANSPORT=dt_socket JPDA_ADDRESS=5005 JPAD_SUSPEND=n

Or you can configure it through JPDA_OPTS:

JPDA_OPTS='-agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=5005'

Springboot enables remote debugging

Remote debug maven settings

The run goal forks a process for the boot application. It is possible to specify jvm arguments to that forked process. The following configuration suspend the process until a debugger has joined on port 5005

......... Org.springframework.boot spring-boot-maven-plugin 1.1.12.RELEASE-Xdebug-Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=5005...

These arguments can be specified on the command line as well, make sure to wrap that properly, that is:

Mvn spring-boot:run-Drun.jvmArguments= "- Xdebug-Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=5005"

Jar command to turn on remote debugging

When executing the jar, add the parameters. As follows:

Java-Xdebug-Xrunjdwp:server=y,transport=dt_socket,address=8000,suspend=n-jar demo.jar

If you want to learn more about Java debugging, take a look at this. Go deep into Java debugging system

problem

If Connection refused appears.

First check the usage of port 8000:

Use:~/tomcat/logs # netstat-an | grep 8000cp 00 127.0.0.1 an 8000 0.0.0.0 LISTEN

It can be seen that the current 16808 port service is bound to a loopback address and cannot be accessed externally. That is, local debugging.

Methods:

Modify a parameter in catalina.sh.

If [- z "$JPDA_TRANSPORT"]; then JPDA_TRANSPORT= "dt_socket" fi if [- z "$JPDA_ADDRESS"]; then JPDA_ADDRESS= "0.0.0.0 then JPDA_TRANSPORT= 8000" fi if [- z "$JPDA_SUSPEND"]; then JPDA_SUSPEND= "n" fi

Change the default value (localhost:8000) to 0. 0. 0. 0. 0. JPDA_ADDRESS= for "localhost:8000". The default is local ip debugging, which means that you cannot debug remotely, and 0.0.0.0 means that all ip addresses can be debugged.

Connect remotely and then look at the port:

Root@VM-198-217-ubuntu:/opt/apache-tomcat-8.5.16/bin# netstat-an | grep 8000tcp 00 10.133.198.217 an 8000 60.177.99.27 grep 8000tcp 49998 ESTABLISHED

After the disconnection, it looks like this:

Root@VM-198-217-ubuntu:/opt/apache-tomcat-8.5.16/bin# netstat-an | grep 8000tcp 00 0.0.0.0 grep 8000tcp 8000 0.0.0.0 LISTENtcp 00 10.133.198.217V 8000 60.177.99.27R 49998 TIME_WAIT

Idea connects to a remote port for remote debug

I have enabled remote debugging and idea connection steps on the server, directly above.

Edit configurations

Remote debugging configuration

Parameter configuration

Change the address and port number in the red box to your own.

Start remote debugging

Successful interface

Ask for a try

The posture of debugging is the same as that of local debugging, so start building it!

At this point, on the "Java project to start remote debugging methods and steps" on the end of the study, I hope to be able to solve your doubts. The collocation of theory and practice can better help you learn, go and try it! If you want to continue to learn more related knowledge, please continue to follow the website, the editor will continue to work hard to bring you more practical articles!

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