1 files changed, 169 insertions, 0 deletions
diff --git a/api/src/main/java/org/openslx/taskmanager/api/SystemCommandTask.java b/api/src/main/java/org/openslx/taskmanager/api/SystemCommandTask.java
new file mode 100644
index 0000000..ea71ea5
--- /dev/null
+++ b/api/src/main/java/org/openslx/taskmanager/api/SystemCommandTask.java
@@ -0,0 +1,169 @@
+package org.openslx.taskmanager.api;
+
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.nio.charset.StandardCharsets;
+
+import org.apache.log4j.Logger;
+
+public abstract class SystemCommandTask extends AbstractTask
+{
+
+	private static final Logger log = Logger.getLogger( SystemCommandTask.class );
+
+	private String[] command = null;
+	
+	private Process process = null;
+
+
+	@Override
+	protected final boolean execute()
+	{
+		command = initCommandLine();
+		if ( command == null || command.length == 0 ) {
+			return processEnded( -1 );
+		}
+
+		ProcessBuilder pb = new ProcessBuilder( command );
+		pb.directory( new File( "/" ) );
+
+		try {
+
+			// Create process
+			process = pb.start();
+			final Process p = process;
+			processStarted();
+			p.getOutputStream();
+
+			// Read its stdout
+			Thread stdout = new Thread( new Runnable() {
+				@Override
+				public void run()
+				{
+					try {
+						BufferedReader reader = new BufferedReader( new InputStreamReader( p.getInputStream() ) );
+						String line;
+						while ( ( line = reader.readLine() ) != null ) {
+							synchronized ( p ) {
+								processStdOut( line );
+							}
+						}
+					} catch ( IOException e ) {
+					}
+				}
+			} );
+			// Read its stderr
+			Thread stderr = new Thread( new Runnable() {
+				@Override
+				public void run()
+				{
+					try {
+						BufferedReader reader = new BufferedReader( new InputStreamReader( p.getErrorStream() ) );
+						String line;
+						while ( ( line = reader.readLine() ) != null ) {
+							synchronized ( p ) {
+								processStdErr( line );
+							}
+						}
+					} catch ( IOException e ) {
+					}
+				}
+			} );
+
+			stdout.start();
+			stderr.start();
+
+			// Wait for everything
+			stdout.join();
+			stderr.join();
+			process.waitFor();
+
+			return processEnded( process.exitValue() );
+
+		} catch ( IOException e ) {
+			log.warn( "Process of task " + getId() + " died." );
+			processStdErr( e.toString() );
+			return processEnded( -2 );
+		} catch ( InterruptedException e ) {
+			Thread.currentThread().interrupt();
+			return false;
+		} catch ( Exception e ) {
+			log.warn( "Unexpected exception when executing " + getId() + ": " + e.toString() );
+			processStdErr( e.toString() );
+			return processEnded( -3 );
+		} finally {
+			if ( process != null )
+				process.destroy();
+		}
+	}
+	
+	/**
+	 * Write data to the process's stdin.
+	 * 
+	 * @param data stuff to write
+	 * @return success or failure mapped to a boolean in a really complicated way
+	 */
+	protected final boolean toStdIn(byte[] data)
+	{
+		try {
+			process.getOutputStream().write( data );
+		} catch ( IOException e ) {
+			e.printStackTrace();
+			return false;
+		}
+		return true;
+	}
+
+	/**
+	 * Write text to the process's stdin.
+	 * 
+	 * @param text stuff to write
+	 * @return success or failure mapped to a boolean in a really complicated way
+	 */
+	protected final boolean toStdIn(String text)
+	{
+		return toStdIn( text.getBytes( StandardCharsets.UTF_8 ) );
+	}
+
+	/**
+	 * Called to get the command line. Each argument should be a separate array
+	 * element. Returning null means the task should not run (as the arguments
+	 * were probably faulty).
+	 * 
+	 * @return List of arguments. First element is the command itself.
+	 */
+	protected abstract String[] initCommandLine();
+
+	/**
+	 * Called when the process has been successfully started.
+	 */
+	protected void processStarted()
+	{
+	}
+
+	/**
+	 * Called when the process has finished running
+	 * 
+	 * @param exitCode the process' exit code
+	 * @return 
+	 */
+	protected abstract boolean processEnded( int exitCode );
+
+	/**
+	 * Called when a line has been read from the process' stdout.
+	 * 
+	 * @param line The line read from the process, without any newline characters
+	 */
+	protected abstract void processStdOut( String line );
+
+	/**
+	 * Called when a line has been read from the process' stderr.
+	 * Trailing newline is removed.
+	 * 
+	 * @param line The line read from the process, without any newline characters
+	 */
+	protected abstract void processStdErr( String line );
+
+}