Windows命令行上基于Eclipse的应用程序输出仅在通过管道传输时可见（在cmd中不直接显示）

Question

We have a Java application based on Eclipse (main class implements IApplication ) that is started from the Windows command line. Its output on System.out is not visible/printed into the command window from which it is started. Nevertheless, when piping the output to more , the output is fine. How come?

For example, consider helloworld.exe . When running C:\\>helloworld.exe in a command window, the application simply returns. But when running C:\\>helloworld.exe | more C:\\>helloworld.exe | more , the screen shows

C:>helloworld.exe | more

hello world

C:>

On linux, the output is fine. How to see the output on Windows, too?

Some reqested information:

• The application is quite large. And I probably cannot cut it down. The output are simple calls to System.out.prinln("xxx");
• Java version 1.8.0_60 , Eclipse 3.6.2
• Using >std.txt 2>err.txt shows that output is indeed on stdout.
• Line endings are CR/LF

the .ini file is as follows

--launcher.suppressErrors
-vmargs
-Xms256m
-Xmx4096m
-Djava.naming.factory.initial=com.sun.jndi.fscontext.RefFSContextFactory
-Djava.library.path=plugins

Maybe this issue is related?

Answer 1

如果您的应用程序是通过eclipse.exe （没有附加控制台）启动的，则将调用更改为使用eclipsec.exe （已附加有控制台，请在应用程序名称中记下c ）。

Answer 2

You can launch Eclipse RCP based applications using equinox launcher as shown below:

java -jar plugins/org.eclipse.equinox.launcher_1.1.1.R36x_v20101122_1400.jar

Of course you have to find the correct version of equinox launcher you are using in your RCP Application.

This way you would see the console logs.

You can read more about it here: http://wiki.eclipse.org/index.php/Starting_Eclipse_Commandline_With_Equinox_Launcher

EDIT: The reason you don't get console logs when eclipse.exe based launcher is used is because eclipse.exe on Windows spawns a separate process which brings up another command prompt window.

Answer 3

You'd better use a framework to handle your logs like logback

This is much more portable and maintainable.

Answer 4

In your example it seems that you have created an exe from your java code. My guess is that the packager you used to create the exe made some changes to the output target because it is a wrapper for your java program. Try creating a jar instead and try executing it by java -jar helloworld.jar.

Answer 5

Is the string going to stderr in place of stdout? (or the other way around depending on your expected behaviour).

https://support.microsoft.com/en-us/kb/110930