Package com.day.util

Class ProcessRunner

java.lang.Object
com.day.util.ProcessRunner
All Implemented Interfaces:
Runnable
public class ProcessRunner extends Object implements Runnable
The ProcessRunner class helps running external processes. This encompasses redirection of stdin, stdout and stderr as well as optionally waiting for the completion of the process. This implementation is based on the Runtime.exec(String) method and does not yet support passing specific environments or decomposed comand lines.

This class can be used in two ways. If you don't care about waiting for the processes completion and return code, you might do it like this :

Runnable pr = new ProcessRunner("command", null, null, null);
new Thread(pr).start();

If on the other hand you want to capture all output and also keep an eye on the time the process takes to execute (or wait indefinitely), you might use the class like this :

ProcessRunner pr = new ProcessRunner("command", in, out, err);
pr.run(0);
int rc = pr.getReturnCode();
Since:
coati Audience wad

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final int
    PROCESS_ABORTED
    Constant to indicate the process has been aborted
    static final int
    PROCESS_RUNNING
    Constant to indicate the process is running

  • Constructor Summary

    Constructors
    Constructor
    Description
    ProcessRunner(String cmdLine)
    Creates a new ProcessRunner to execute the given command line containing the command to execute and all relevant command arguments with no redirection of stdin, stdout and stderr.
    ProcessRunner(String cmdLine, InputStream stdin, OutputStream stdout, OutputStream stderr)
    Creates a new ProcessRunner to execute the given command line containing the command to execute and all relevant command arguments.

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    getReturnCode()
    Returns the return code from running the command line.
    void
    run()
    Runs the process sending the input data and capturing output data.
    void
    run(long waitTime)
    Executes the command line and waits for the completion of the prcoess.

    Methods inherited from class java.lang.Object

    equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Field Details

    • PROCESS_RUNNING

      public static final int PROCESS_RUNNING
      Constant to indicate the process is running
      See Also:

    • PROCESS_ABORTED

      public static final int PROCESS_ABORTED
      Constant to indicate the process has been aborted
      See Also:

  • Constructor Details

    • ProcessRunner

      public ProcessRunner(String cmdLine, InputStream stdin, OutputStream stdout, OutputStream stderr)
      Creates a new ProcessRunner to execute the given command line containing the command to execute and all relevant command arguments. The stdin InputStream can be used to feed input data to the command executed, while the output (stdout and stderr) are redirected to the given OutputStreams or the process defaults (System.out and System.err, resp.).

      None of the streams is closed after running the command line. This is the sole duty of the client of this class.

      Parameters:
      cmdLine - This commandline is given to the Runtime.exec(String) contains all the command arguments and is split up with a StringTokenizer. See the API docs on the Runtime.exec(String) method for details.
      stdin - The InputStream containing data to be handed to the process as stdin. Set this to null if the process should not get any input. This stream is completely read after the process is started and sent to the process. Therefor the stream should be available.
      stdout - The OutputStream to send the stdout output of the process to. If this is null, stdout output is written to System.out.
      stderr - The OuputStream to send the stderr output of the process to. If this is null, stderr output is written to System.err.

    • ProcessRunner

      public ProcessRunner(String cmdLine)
      Creates a new ProcessRunner to execute the given command line containing the command to execute and all relevant command arguments with no redirection of stdin, stdout and stderr.
      Parameters:
      cmdLine - This commandline is given to the Runtime.exec(String) contains all the command arguments and is split up with a StringTokenizer. See the API docs on the Runtime.exec(String) method for details.

  • Method Details

    • run

      public void run(long waitTime)
      Executes the command line and waits for the completion of the prcoess. The process runs in its own thread which is marked as daemon thread. That is as soon as the Java VM is about to end, the process will also forcibly stopped and does not run to completion.
      Parameters:
      waitTime - The number of milliseconds to wait for the completion of the process. If the time has ellapsed before the process has terminated, the process will be forcibly terminated. If this value is negative, the process runs completely detached, while a value of zero indicates to wait indeterminate for the completion of the process.

    • getReturnCode

      public int getReturnCode()
      Returns the return code from running the command line. As long as the command is running, the method returns PROCESS_RUNNING. After the process has terminated, the method returns the return code from the process or PROCESS_ABORTED if the command has been terminated due to a timeout.
      Returns:
      The return code from the process or either PROCESS_RUNNING or PROCESS_ABORTED.

    • run

      public void run()
      Runs the process sending the input data and capturing output data.

      Do not directly call this method. Instead either use new Thread(new ProcessRunner(cmd)).start() or use the run(long) method.

      Specified by:
      run in interface Runnable