Command.java

/*******************************************************************************
 * Copyright (c) 2009, 2025 Mountainminds GmbH & Co. KG and Contributors
 * This program and the accompanying materials are made available under
 * the terms of the Eclipse Public License 2.0 which is available at
 * http://www.eclipse.org/legal/epl-2.0
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *    Marc R. Hoffmann - initial API and implementation
 *
 *******************************************************************************/
package org.jacoco.cli.internal;

import java.io.PrintWriter;
import java.io.StringWriter;

import org.kohsuke.args4j.Option;

/**
 * Common interface for all commands.
 */
public abstract class Command {

    /**
     * Common command line prefix.
     */
    public static final String JAVACMD = "java -jar jacococli.jar ";

    /**
     * Flag whether help should be printed for this command.
     */
    @Option(name = "--help", usage = "show help", help = true)
    public boolean help = false;

    /**
     * Flag whether output to stdout should be suppressed.
     */
    @Option(name = "--quiet", usage = "suppress all output on stdout")
    public boolean quiet = false;

    /**
     * @return Short description of the command.
     */
    public abstract String description();

    /**
     * @return name of the command
     */
    public String name() {
        return getClass().getSimpleName().toLowerCase();
    }

    /**
     * @param parser
     *            parser for this command
     * @return usage string displayed for help
     */
    public String usage(final CommandParser parser) {
        final StringWriter writer = new StringWriter();
        parser.printSingleLineUsage(writer, null);
        return JAVACMD + name() + writer;
    }

    /**
     * Executes the given command.
     *
     * @param out
     *            std out
     * @param err
     *            std err
     * @return exit code, should be 0 for normal operation
     * @throws Exception
     *             any exception that my occur during execution
     */
    public abstract int execute(PrintWriter out, PrintWriter err)
            throws Exception;

    /**
     * Prints textual help for this command.
     *
     * @param writer
     *            output destination
     */
    protected void printHelp(final PrintWriter writer) {
        final CommandParser parser = new CommandParser(this);
        writer.println(description());
        writer.println();
        writer.println("Usage: " + parser.getCommand().usage(parser));
        parser.printUsage(writer, null);
    }

}