I found out that you can debug Vanilla Minecraft with IntelliJ recently. Heres how

1) Go to the Minecraft Launcher and add -agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=5009 to your JVM arguments

2) Launch Minecraft normally

3) In IntelliJ go to Run > Attach to Process

4) Select net.minecraft.launchwrapper.Launch

Hope this helps someone

 

 

You are also able to hot-swap code directly into the running program. If you want to you can also change the JVM to use DCEVM (Dynamic Code Evolution VM) for even more advanced hot-swap, but Mojang's default JVM arguments (specifically the -XX:+UseG1GC argument) cause a crash when using this JVM. The final arguments that I use are

-Xms1536M
-Xmx2048M
-XX:+UnlockExperimentalVMOptions
-XX:G1NewSizePercent=20
-XX:G1ReservePercent=20
-XX:MaxGCPauseMillis=50
-XX:G1HeapRegionSize=32M
-agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=5009

If you are using DCEVM as an alternate JVM add -XXaltjvm=dcevm to the arguments

For more help read community.liferay/blogs/java-classes-instant-reloading-using-dcevm-hotswap-agent and GitHub/DCEVM

Edited November 23, 20186 yr by Cadiboo

Info on how to do it with eclipse can be found here https://stackoverflow.com/questions/25388758/how-do-i-attach-to-a-process-in-eclipse?rq=1

On 11/23/2018 at 8:43 PM, Cadiboo said:

You are also able to hot-swap code directly into the running program. If you want to you can also change the JVM to use DCEVM (Dynamic Code Evolution VM) for even more advanced hot-swap, but Mojang's default JVM arguments (specifically the -XX:+UseG1GC argument) cause a crash when using this JVM. The final arguments that I use are

-Xms1536M
-Xmx2048M
-XX:+UnlockExperimentalVMOptions
-XX:G1NewSizePercent=20
-XX:G1ReservePercent=20
-XX:MaxGCPauseMillis=50
-XX:G1HeapRegionSize=32M
-agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=5009

If you are using DCEVM as an alternate JVM add -XXaltjvm=dcevm to the arguments

For more help read community.liferay/blogs/java-classes-instant-reloading-using-dcevm-hotswap-agent and GitHub/DCEVM

 

Is this still valid?

I'm trying it with IntelliJ, and in the settings it's saying that it can't find a valid install of DCEVM... even though I just installed it.

[EDIT: Nevermind, I fixed that problem... it had selected the wrong SDK directory. But it is saying that it "couldn't get dceversion of C:/.../java/jdk1.8.0_211_DCEVM" (the directory I installed it to. Basically made a copy of the JDK directory and selected that as the install location, so that I still had a clean install.)

 

I did notice that the latest version on the DCEVM downloads page was for SDK version 1.8.0_181 however. Is that compatible? I mean, I guess I'll find out if it works or not, but is there a new site for it or something? This post was made about two years ago now...

 

Edited March 16, 20205 yr by Intrepid249
updated information

1.12 is no longer supported on these forums due to age, this thread is over a year old.

 

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