de.schlichtherle.truezip.sample.file.app.Application Maven / Gradle / Ivy
/*
* Copyright (C) 2005-2012 Schlichtherle IT Services.
* All rights reserved. Use is subject to license terms.
*/
package de.schlichtherle.truezip.sample.file.app;
import de.schlichtherle.truezip.file.TApplication;
import de.schlichtherle.truezip.key.pbe.swing.HurlingWindowFeedback;
import de.schlichtherle.truezip.key.pbe.swing.InvalidKeyFeedback;
import java.io.OutputStream;
import java.io.PrintStream;
/**
* Abstract base class for command line utilities.
*
* @author Christian Schlichtherle
*/
abstract class Application extends TApplication {
/** The print stream for standard output. */
protected final PrintStream out;
/** The print stream for error output. */
protected final PrintStream err;
/**
* Equivalent to
* {@link #Application(OutputStream, OutputStream, boolean)
* Application(System.out, System.err, true)}.
*/
protected Application() {
this(System.out, System.err, true);
}
/**
* Constructs a new command line utility instance.
*
* @param out the standard output stream.
* @param err the error output stream.
* @param autoFlush if the output streams are not {@link PrintStream}s,
* then they are wrapped in a new {@code PrintStream} with
* this value as the additional constructor parameter.
*/
@edu.umd.cs.findbugs.annotations.SuppressWarnings("DM_DEFAULT_ENCODING")
protected Application(
final OutputStream out,
final OutputStream err,
final boolean autoFlush) {
this.out = out instanceof PrintStream
? (PrintStream) out
: new PrintStream(out, autoFlush);
this.err = err instanceof PrintStream
? (PrintStream) err
: new PrintStream(err, autoFlush);
}
/**
* Configures the type of the feedback when prompting the user for keys
* for RAES encrypted ZIP alias ZIP.RAES alias TZP files by the Swing
* based prompting key manager.
* If this JVM is running in headless mode, then this configuration is
* ignored and the user is prompted by the console I/O based prompting
* key manager.
*/
@Override
protected void setup() {
String spec = InvalidKeyFeedback.class.getName();
String impl = HurlingWindowFeedback.class.getName();
System.setProperty(spec, System.getProperty(spec, impl));
}
/**
* Runs the work phase by calling {@link #runChecked}.
* Prints a user readable error message to the error output stream
* which was provided to the constructor if an {@link Exception occurs}.
*
* This method is {@link #run run} at least once and repeatedly called
* until {@link #runChecked} returns a non-negative integer for use as the
* {@link System#exit(int) exist status} of the VM.
* After this method, the {@link #sync} method is called in a
* finally-block.
*
* @param args an array of arguments for this command line utility.
* @return A negative integer in order to continue calling this method
* in a loop.
* Otherwise, the return value is used as the
* {@link System#exit(int) exit status} of the VM.
* @throws RuntimeException at the discretion of {@link #runChecked}.
*/
@Override
protected final int work(final String[] args) {
try {
return runChecked(args);
} catch (IllegalUsageException ex) {
err.println(ex.getLocalizedMessage());
return 1;
} catch (Exception ex) {
ex.printStackTrace(err);
return 1;
}
}
/**
* Runs this command line utility.
* Throws an exception if an error occurs.
*
* Avoid repeating this method and updating the same archive file upon
* each call!
* This would degrade the overall performance from O(n) to O(m*n),
* where m is the number of new or modified entries and n is the number
* of all entries in the archive file!
*
* @param args an array of arguments for this command line utility.
* @return A negative integer in order to continue calling this method
* in a loop.
* Otherwise, the return value is used as the
* {@link System#exit(int) exit status} of the VM.
* @throws Exception on any exception.
*/
protected abstract int runChecked(String[] args) throws Exception;
/** Indicates illegal application parameters. */
@SuppressWarnings("PackageVisibleInnerClass")
protected static class IllegalUsageException extends Exception {
private static final long serialVersionUID = 1985623981423542464L;
protected IllegalUsageException(String msg) {
super(msg);
}
} // IllegalUsageException
}