Cobertura example source code file (CommandLineBuilder.java)

This example Cobertura source code file (CommandLineBuilder.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Cobertura tags/keywords

arraylist, bufferedreader, bufferedreader, commandlinebuilder, filereader, filewriter, io, ioexception, ioexception, linesep, linesep, list, logger, string, string, util

The Cobertura CommandLineBuilder.java source code

/*
 * Cobertura - http://cobertura.sourceforge.net/
 *
 * Copyright (C) 2005 Grzegorz Lukasik
 *
 * Note: This file is dual licensed under the GPL and the Apache
 * Source License (so that it can be used from both the main
 * Cobertura classes and the ant tasks).
 *
 * Cobertura is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published
 * by the Free Software Foundation; either version 2 of the License,
 * or (at your option) any later version.
 *
 * Cobertura is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Cobertura; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA
 */

package net.sourceforge.cobertura.util;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import org.apache.log4j.Logger;

/**
 * Helper class for storing long command lines inside temporary file.
 * <p>
 * Typical usage:
 * 
 * <pre>
 *  builder = new CommandLineBuilder();
 *  builder.addArg("--someoption");
 *  builder.addArg("optionValue");
 *  ...
 *  builder.saveArgs();
 *  doSomething(builder.getCommandLineFile());
 *  builder.dispose();
 * </pre>
 * 
 * It will save options in <code>builder.getCommandLineFile(). Options
 * will be stored one in a line. To retrieve options from file helper method can
 * be used (see documentation):
 * 
 * <pre>
 * String[] args = CommandLineBuilder.preprocessCommandLineArguments(args);
 * </pre>
 * 
 * </p>
 * 
 * <p>
 * NOTICE: No protection against line separators in arguments, should be OK for
 * Cobertura needs.
 * </p>
 * <p>
 * NOTICE: This class depends on local machine settings (line separator, default
 * encoding). If arguments are saved on different machine than they are loaded,
 * results are unspecified. No problem in Cobertura.
 * </p>
 * 
 * @author Grzegorz Lukasik
 */
public class CommandLineBuilder {
	private static final Logger logger = Logger
			.getLogger(CommandLineBuilder.class);

	private static final String LINESEP = System.getProperty("line.separator");

	// File that will be used to store arguments
	private File commandLineFile = null;

	// Writer that will be used to write arguments to the file
	private FileWriter commandLineWriter = null;

	/**
	 * Creates a new instance of the builder. Instances of this class should not
	 * be reused to create many command lines.
	 * 
	 * @throws IOException
	 *             if problems with creating temporary file for storing command
	 *             line occur
	 */
	public CommandLineBuilder() throws IOException {
		commandLineFile = File.createTempFile("cobertura.", ".cmdline");
		commandLineFile.deleteOnExit();
		commandLineWriter = new FileWriter(commandLineFile);
	}

	/**
	 * Adds command line argument. Each argument can be thought as a single cell
	 * in array passed to main method. This method should not be used after
	 * arguments were saved.
	 * 
	 * @param arg command line argument to save
	 * @throws IOException
	 *             if problems with temporary file occur
	 * @throws NullPointerException 
	 *             if <code>arg is null            
	 */
	public void addArg(String arg) throws IOException {
		if( arg==null)
			throw new NullPointerException();
		commandLineWriter.write(arg + LINESEP);
	}

	
	/**
	 * Adds two command line arguments. Convienience function, calls
	 * {@link #addArg(String)} two times.   
	 * 
	 * @param arg1 first command line argument to save
	 * @param arg2 second command line argument to save
	 * @throws IOException
	 *             if problems with temporary file occur
	 * @throws NullPointerException 
	 *             if any <code>arg is null            
	 */
    public void addArg(String arg1, String arg2) throws IOException {
        addArg(arg1);
        addArg(arg2);
    }

    
	/**
	 * Saves options and made file available to use. Use method
	 * {@link #getCommandLineFile} to get the file the arguments are saved in.
	 * 
	 * @throws IOException
	 *             if problems with temporary file occur
	 */
	public void saveArgs() throws IOException {
		commandLineWriter.flush();
		commandLineWriter.close();
	}

	/**
	 * Gets absolute path to the file with saved arguments. Notice, that however
	 * this method can be used as soon as an instance of this class is created,
	 * arguments should be read from the file after a call to
	 * {@link #saveArgs} method.
	 * 
	 * @return absolute path to the file with arguments
	 */
	public String getCommandLineFile() {
		return commandLineFile.getAbsolutePath();
	}

	/**
	 * Explicity frees all resources associated with this instance. Result of
	 * any other method call after disposing an instance of this class is
	 * unspecified.
	 */
	public void dispose() {
		commandLineFile.delete();
	}

	/**
	 * Loads arguments from file if <code>--commandsfile option is used. Checks
	 * if passed array contains <code>--commandsfile String, and if
	 * so arguments from file specified in the very next array cell are read. If
	 * there are more then one <code>--commandsfile the result is unspecified. 
	 *
	 * @return The list of arguments read from commandsfile, or
	 *         <code>args if commandsfile option was not specified
	 *         or the file cannot be read.
	 * @throws NullPointerException if args is null, or any argument is null
	 * @throws IllegalArgumentException if --commandsfile is specified as last option
	 * @throws IOException if I/O related error with temporary command line file occur
	 */
	public static String[] preprocessCommandLineArguments(String[] args) throws IOException {
		boolean hasCommandsFile = false;
		String commandsFileName = null;
		for (int i = 0; i < args.length; i++) {
			if ( args[i].equals( "--commandsfile")) {
				if( i==args.length-1) {
					throw new IllegalArgumentException("'--commandsfile' specified as last option.");
				}
				hasCommandsFile = true;
				commandsFileName = args[++i];
			}
		}

		if (hasCommandsFile) {
			List arglist = new ArrayList();
			BufferedReader bufferedReader = null;

			try {
				bufferedReader = new BufferedReader(new FileReader(
						commandsFileName));
				String line;

				while ((line = bufferedReader.readLine()) != null)
					arglist.add(line);

			} catch (IOException e) {
				logger.info( "I/O error when reading temporary commands file", e);
				throw new IOException( "Unable to read temporary commands file "
						+ commandsFileName + ".");
			} finally {
				if (bufferedReader != null) {
					try {
						bufferedReader.close();
					} catch (IOException e) {
					}
				}
			}

			args = (String[]) arglist.toArray(new String[arglist.size()]);
		}
		return args;
	}
}