1 files changed, 65 insertions, 0 deletions
diff --git a/core/modules/qemu/runvirt-plugin-qemu/src/main/java/org/openslx/runvirt/viewer/ViewerUtils.java b/core/modules/qemu/runvirt-plugin-qemu/src/main/java/org/openslx/runvirt/viewer/ViewerUtils.java
new file mode 100644
index 00000000..1ed5947a
--- /dev/null
+++ b/core/modules/qemu/runvirt-plugin-qemu/src/main/java/org/openslx/runvirt/viewer/ViewerUtils.java
@@ -0,0 +1,65 @@
+package org.openslx.runvirt.viewer;
+
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+
+import org.apache.commons.exec.CommandLine;
+import org.apache.commons.exec.DefaultExecutor;
+import org.apache.commons.exec.PumpStreamHandler;
+import org.apache.commons.io.FileUtils;
+import org.apache.commons.io.IOUtils;
+import org.apache.commons.io.output.ByteArrayOutputStream;
+
+/**
+ * Utils for viewing displays of virtual machines.
+ * 
+ * @author Manuel Bentele
+ * @version 1.0
+ */
+public class ViewerUtils
+{
+	/**
+	 * Synchronously executes a viewer program specified by a command line call.
+	 * <p>
+	 * The command line call of the viewer program consists of the program name and an optional list
+	 * of submitted command line arguments for the viewer program. The result of the executed viewer
+	 * program from the standard output is returned after the program has exited.
+	 * 
+	 * @param viewerProgram name of the viewer program.
+	 * @param viewerArguments optional command line arguments for the viewer program.
+	 * @return result of the executed viewer program from the standard output.
+	 * @throws ViewerException failed to execute the viewer program.
+	 */
+	@SuppressWarnings( "deprecation" )
+	public static String executeViewer( String viewerProgram, String[] viewerArguments ) throws ViewerException
+	{
+		final CommandLine viewerCommandLine = new CommandLine( viewerProgram );
+		final DefaultExecutor viewerExecutor = new DefaultExecutor();
+
+		// prepare viewer command to execute
+		viewerCommandLine.addArguments( viewerArguments );
+
+		// set up temporary working directory for the viewer process
+		viewerExecutor.setWorkingDirectory( FileUtils.getTempDirectory() );
+
+		// set expected exit value of the viewer process indicating a successful operation
+		viewerExecutor.setExitValue( 0 );
+
+		// set up output stream handler to retrieve the content from the viewer's standard output
+		final ByteArrayOutputStream viewerOutputStream = new ByteArrayOutputStream();
+		final PumpStreamHandler viewerOutputStreamHandler = new PumpStreamHandler( viewerOutputStream );
+		viewerExecutor.setStreamHandler( viewerOutputStreamHandler );
+
+		// execute the viewer command as blocking process
+		try {
+			viewerExecutor.execute( viewerCommandLine );
+		} catch ( IOException e ) {
+			throw new ViewerException( "Failed to execute '" + viewerProgram + "': " + e.getLocalizedMessage() );
+		}
+
+		final String viewerOuput = viewerOutputStream.toString( StandardCharsets.UTF_8 );
+		IOUtils.closeQuietly( viewerOutputStream );
+
+		return viewerOuput;
+	}
+}