CommandLineInterpreter.java Source code

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Here is the source code for CommandLineInterpreter.java

Source

/*
 * #%L
 * **********************************************************************
 * NAME          :  Michael Jedich
 * PROJECT       :  jre-version-checker
 * FILENAME      :  CommandLineInterpreter.java
 * **********************************************************************
 * %%
 * Copyright (C) 2014 Michael Jedich
 * %%
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * #L%
 */
import java.io.File;
import java.util.Scanner;

import javax.swing.JOptionPane;

import org.apache.commons.lang.SystemUtils;

/**
 * User commandline-input will get parsed here.
 *
 * @author Michael Jedich
 * @version 0.7.0
 */
public class CommandLineInterpreter {

    /**
     * Show simple help screen.
     *
     * @param mainError
     *          Error String if a specific error occurs.
     */
    private static void printHelp(final String mainError) {
        StringBuffer help = new StringBuffer();

        if (mainError != null) {
            System.err.println("ERROR:\n\t" + mainError + "! See help below.\n");
            try {
                Thread.sleep(100);
            } catch (InterruptedException e) {
            }
        }

        help.append("NAME:\n\tjre-version-checker - A simple JRE version checker.\n\n");
        help.append("USAGE:\n\tjre-version-checker.jar jre_version [resources_file] [-gui]\n\n");
        help.append("DESCRIPTION:");
        help.append("\n\t- TODO.\n");

        System.out.println(help.toString());
    }

    /**
     *
     *
     * @param version
     */
    private static boolean checkJREVersion(final float minVersion, final boolean guiAlert) {
        if (!SystemUtils.isJavaVersionAtLeast(minVersion)) {
            String message = "You need at least Java " + minVersion + " to run the application.\n"
                    + "\tYour Java version is " + SystemUtils.JAVA_VERSION + ".";
            alert(message, guiAlert);
            return false;
        }
        return true;
    }

    /**
     *
     *
     * @param file
     * @param guiAlert
     * @return
     */
    public static boolean checkResources(final File file, final boolean guiAlert) {
        Scanner input = null;
        String message = null;
        try {
            input = new Scanner(file);
            while (input.hasNextLine()) {
                String currentFilePath = input.nextLine().trim();
                if (!currentFilePath.isEmpty()) {
                    File currentFile = new File(currentFilePath);
                    if (!currentFile.exists() || !currentFile.canRead() || !currentFile.canWrite()) {
                        message = "Can not read/write resource file:\n\"" + currentFile.getAbsolutePath() + "\"";
                        alert(message, guiAlert);
                        return false;
                    }
                }
            }
        } catch (Exception e) {
            // TODO: logging
            e.printStackTrace();
        } finally {
            if (input != null) {
                input.close();
            }
        }

        return true;
    }

    /**
     *
     *
     * @param message
     * @param guiAlert
     */
    private static void alert(String message, final boolean guiAlert) {
        if (message != null) {
            System.out.println("[ERROR] " + message);
            if (guiAlert) {
                JOptionPane.showMessageDialog(null, message);
            }
        }
    }

    /**
     * Main method, command line input will get parsed here.
     *
     * @param args
     */
    public static void main(String[] args) {
        // // test-arguments:
        // args = new String[] { "1.9", "-gui" };

        boolean success = false;
        if (args.length == 1) {
            String arg = args[0].trim().replaceAll("[-]+", "");
            if (arg.equals("help") || arg.equals("h"))
                printHelp(null);
        }

        if (args.length == 0) {
            printHelp("ONE ARGUMENT NEEDED");
        } else {
            try {
                boolean guiAlert = false;
                Float minVersion = null;
                File resourcesFile = null;

                // ------------------------------------------------ //
                // --
                // ------------------------------------------------ //
                final String minJavaVersionArgument = args[0];
                if (!minJavaVersionArgument.trim().isEmpty()) {
                    try {
                        minVersion = Float.parseFloat(minJavaVersionArgument);
                    } catch (Exception e) {
                        // do nothing
                    }
                }
                if (minVersion == null || minVersion > 2 || minVersion < 1.6) {
                    printHelp("VERSION STRING IS NOT VALID");
                }

                // ------------------------------------------------ //
                // --
                // ------------------------------------------------ //
                for (int i = 1; i < (args.length <= 3 ? args.length : 3); i++) {
                    final String argument = args[i].trim();
                    if (argument.equals("-gui")) {
                        guiAlert = true;
                    } else {
                        String resourcesFilePath = argument;
                        if (!resourcesFilePath.isEmpty()) {
                            resourcesFile = new File(resourcesFilePath);
                            if (!resourcesFile.exists() || !resourcesFile.isFile() || !resourcesFile.canRead()) {
                                printHelp("RESOURCES FILE IS NOT VALID\n[" + resourcesFile.getAbsolutePath() + "]");
                            }
                        }
                    }
                }
                // ------------------------------------------------ //
                // --
                // ------------------------------------------------ //

                success = checkJREVersion(minVersion, guiAlert);

                if (success && resourcesFile != null) {
                    success = checkResources(resourcesFile, guiAlert);
                }

            } catch (Exception e) {
                success = false;
                e.printStackTrace();
            }
        }

        if (!success) {
            // set error exit code
            System.exit(1);
        }
    }
}