How to handle it when Java calls a shell script and does not receive any output?

If the Java call to the shell script does not return any results, several possible solutions can be considered.

1. Check if the shell script is executed correctly: Firstly, make sure that the shell script can be executed properly in Java by checking the log output or printed information to confirm if the shell script is being called.
2. Check if the shell script produces output by adding output information within the script, such as echo statements, to ensure there are results.
3. Review Java code to ensure proper invocation of shell scripts and correct handling of the return results. You can use either the ProcessBuilder class or the Runtime class to execute the shell scripts and retrieve the return results through the Process class.
4. Check permissions: Make sure the Java program has permission to execute the shell script, you can use the chmod command to set the execute permission for the shell script.

If none of the above methods solve the issue, you can try catching exceptions in Java and printing error messages to get a more detailed understanding of the problem.