1. Can I use the Java-Editor in teaching at school? Can my pupils use it at home?
Yes, the Java-Editor is freeware, especially developed for teaching purposes.
2. Is it possible to execute Java programs with the Java-Editor?
Yes, of course, but the Java JDK has to be installed on your system.
3. If I compile a Java file test.java, the file test.class is generated, but also a file test$.class. Is this a temporary file which I can delete?
The event methods in GUI programs use anonymous classes. For these classes, the compiler creates separate class files with the $ in the name which are necessary to execute the Java program.
4. Is it possible to separate Java files from class files?
Yes, add -d <directory for class files> as a compiler parameter. Your class files will then be placed in the specified directory. For the Java interpreter to find the class files, you must also add the directory in the Classpath-User of the interpreter configuration.
5. Which access rights does the Java-Editor require?
It needs write permissions in the folders where your Java source files are located, and in the temporary files folder.
6. Is the Java-Editor network-compatible?
The Java-Editor supports local drives, network drives and the UNC notation for direct network access, e. g. \\server\folder\program.java. This applies to Java files, the documentation files, and the entire JDK.
7. Can the Java-Editor be installed on a server?
Yes, this is my preferred installation for using it in a classroom. The JDK is installed on each computer, but the Java-Editor is only installed on the server. This way it is convenient to update to a new Java-Editor version, as only the server must be modified.
8. Where does the Java-Editor store configuration data?
During the installation, you decide whether the Java-Editor uses ini-files or the windows registry for configuration data. The configuration in the Java section is protected. It is stored in the HKEY_LOCAL_MACHINE\Software\JavaEditor hive of the registry or in the file JEMachine.ini. User-specific settings are stored separately for each user in the hive KEY_CURRENT_USER\Software\JavaEditor or in the file JEUser.ini. The Dump button in the configuration window opens a text file which contains the current storage locations.
The Java-Editor looks after a file JEMachine.INI in its folder. If this file exists, it uses ini files, otherwise it uses the windos registry to store configuration data.
9. My Java program doesn't start. What can I do?
If your Java program is compiled without errors but your program does not start, it is likely that runtime errors occur during the execution. You can use the RunJava.bat file for further analysing the problem. Open the interpreter configuration and click on RunJava.bat to edit the batch file which is used to start your Java program. Replace @ECHO OFF with @ECHO ON and insert PAUSE at the end of the file. Save the modified RunJava.bat and select DOS Window from the window menu. This opens a console window with the folder of RunJava.bat as current folder. Type in RunJava.bat and analyse the error messages.
10. Is it possible to use a dark background color to relieve the eyes?
Yes, select the space element in the color configuration and right click on the desired background color.
11. How can I integrate a jar file with useful classes in my projects?
Select Edit for Classpath-User in the interpreter configuration and add the jar file.
12. Deinstallation doesn't work. What can I do?
If deinstallation with the setup program doesn't work just delete the Java-Editor folder. Then open the registry with regedit and delete the hives HKEY_LOCAL_MACHINE\Software\JavaEditor and HKEY_CURRENT_USER\Software\JavaEditor.
13. During compilation the Java-Editor switches between text and graphical screen.
In this case, the fullscreen mode is enabled for the console. You can check this by opening a console by executing the cmd command.
Press Alt+Return to switch from fullscreen mode to window mode once, then right click on the window title and select properties. In the options tab select the window mode to make it permanent.
14. How can I get code completion for foreign classes?
You need the JavaDoc documentation for the foreign classes. Open documentation in the configuration and use Edit for JavaDoc-Folders. Add the folder with the JavaDoc documentation.
If the JavaDoc documentation is missing, you can create it if you have the source files. Open the source files in the Java-Editor and call the JavaDoc command from the start menu.
15. Sometimes the Java-Editor crashes without error message. What can I do?
Look in your current folder. Is there a file hs_err_pid<number>.log? Then the Java virtual machine caused the crash. Update your Java Runtime Environment to the latest version. http://www.java.com/en/download/manual.jsp
16. Why is the GUI-App on my Surface so small?
Swing-Applications are not DPI-aware. A workaround is described at: https://stackoverflow.com/questions/30555401/java-disable-dpi-aware-not-working
Use Java FX instead of Swing.
17. Why does the debugger don't show parameters and local variables?
You need the compiler parameter “-g”. Set Java compiler parameter to standard (“-deprecation -g) in the configuration.
18. How can I use the serial interface?
The package jSerialComm.jar is integrated via Classpath-User. A description of the API is available at https://fazecast.github.io/jSerialComm/