Compiling Java Code [B42 Version]

[visual aurora]

Wiki section on the subject: https://pzwiki.net/wiki/Java

As of B42.13 Project Zomboid uses Java Version 25 to run. To compile and run custom code for Project Zomboid: You must be using Java Version 25. Java Version 25 can be found here: (https://www.oracle.com/java/technologies/javase/jdk25-archive-downloads.html)

To compile a .java file into a .class file: You can type this command into a suitable terminal (PowerShell or preferably Command Prompt [CMD] )

⁨```
javac -cp "GameFiles\projectzomboid.jar" "path/file.java"

While making sure to replace "GameFiles" with the path to your Project Zomboid Game Files and "path/file.java" with the path to the file you want to compile

Run the command and your new .class file should be there

If there is no errors in the terminal window but your class file doesn't appear, try refreshing your explorer window


You can then drag the class file into your Game/Server files (GameFiles/zombie/iso for example) and the class files should run


If you are stuck: Don't be afraid to ask for help

[hexed badge]

You have a missing " at the end of your command

[visual aurora]

It has been corrected

[rain grotto]

@hexed badge @visual aurora Does the compiled class need to follow the exact same folder structure as the original Java package? For example, if it's zombie.network.packets.service.GlobalModDataPacket, do I need to create the folders network/packets/service and place the .class file there inside GameFiles/zombie/, just like the original structure?

[hexed badge]

From my understanding yes

[visual aurora]

Yes

[rain grotto]

thank you both of you, love you @hexed badge @visual aurora

[hexed badge]

Np

[rain grotto]

do I need to make zombie folder in ubuntu server? because in serverfiles\java there is no zombie folder

[visual aurora]

Yes

[rain grotto]

next question, i think the overide didn't work. Do I need edit these? {
"mainClass": "zombie/network/GameServer",
"classpath": [
"java/.",
"java/projectzomboid.jar"
],
"vmArgs": [
"-Djava.awt.headless=true",
"-Xms16g",
"-Xmx20g",
"-Dzomboid.steam=1",
"-Dzomboid.znetlog=1",
"-Djava.library.path=linux64/:natives/",
"-Djava.security.egd=file:/dev/urandom",
"-XX:+UseZGC",
"-XX:-OmitStackTraceInFastThrow"
]
}

[visual aurora]

You shouldn't need to edit the json file, as long as your folder structure is correct it should work

[rain grotto]

C:\Users\Administrator\Desktop\ZomboidDecompiler\bin\output\source\zombie\network\packets\service\GlobalModDataPacket.java and i compiled it GlobalModDataPacket.class

it does work when I put in client (windows) but when I tried to upload into dedicated server ubuntu, other players can't overide this and some of my feature is won't work. Any tips?

[visual aurora]

When you put the class file on your server you have to put it in the servers installation folder then manually create the zombie\network\packets\service\ path yourself, then put the GlobalModDataPacket in there yourself (if the java mod works server sided)

It is generally not recommended to force players to manually install something on their computers

If you can make it work server sided, do it that way

[rain grotto]

yeah I want to make sure that i can make it work server sided

do i need put GlobalModDataPacket.java aswell into the server side?

or just the class?