There is an issue with the output printing

[muyishi]

[ndoschek]

Hi @muyishi, thanks for reaching out!

Could you please provide more details using the standard issue template?
In particular, it would help to know the Theia IDE version and OS you're using.

I just tried with the latest version of Theia and couldn't reproduce the problem, so more context would be appreciated to help investigate further. TIA!

[muyishi]

It is just a simple Java project, and there are some issues when printing values with the standard output stream in the main method。
The code runs by right clicking “Run Java” or “Debug Java”，
The screenshot below for details：

This is my development environment：
OS Name: Microsoft Windows 11 Pro
OS Version: 10.0.26200 N/A Build 26200
System Locale: zh-cn;Chinese (China)

Java version：
openjdk version "21.0.8" 2025-07-15 LTS
OpenJDK Runtime Environment Temurin-21.0.8+9 (build 21.0.8+9-LTS)
OpenJDK 64-Bit Server VM Temurin-21.0.8+9 (build 21.0.8+9-LTS, mixed mode, sharing)

Theia IDE Version： 1.66.200
I forgot which version the problem existed from, but versions v1.66.200, 1.65.100, v1.64.100, and so on do exist

[muyishi]

But adding a breakpoint in the last line to run debug mode is OK：

[ndoschek]

Hi again @muyishi, thanks for the additional details!
I ran a similar Java program and, on my side, all sysouts are correctly printed to the debug console as I would expect them to.

In your latest screenshot, I can also see the three log lines appearing in your console. Could you clarify what exactly you're expecting to see there? It's not entirely clear to me what seems to be missing for you 🤔.

[muyishi]

This is the code in my main method:

        System.out.println("Hello, World!");    
        List<String> list = null;
        System.out.println(list);
        System.out.println("abc");

I right-click and then click Run Java, but the Debug Console output is incomplete, only:

Hello, World!

The correct output should be:

Hello, World!
null
abc

Copy my code into your main method without adding any breakpoints, then click run and see what Debug Console outputs

[ndoschek]

Hi,
I tested the same code in the latest Theia IDE and all three lines are printed as expected in the Debug Console for me:

As mentioned, I also see the output already in your previous screenshot: #625 (comment)

Perhaps it might be related to your project setup?
If you're seeing incomplete output, one possibility is that the setting java.debug.settings.forceBuildBeforeLaunch is turned off, this would cause outdated class files to be run.
Try enabling that setting, or manually rebuild the project before running. Let me know if that helps!