net.psexton.authzwriter.Main.java Source code

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Here is the source code for net.psexton.authzwriter.Main.java

Source

/*
 *  This file is part of AuthzWriter.
 *
 *  AuthzWriter 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 3 of the License, or
 *  (at your option) any later version.
 *
 *  AuthzWriter 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 AuthzWriter.  If not, see <http://www.gnu.org/licenses/>.
 */

package net.psexton.authzwriter;

import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import org.apache.commons.cli.CommandLine;
import org.apache.commons.cli.CommandLineParser;
import org.apache.commons.cli.Option;
import org.apache.commons.cli.OptionBuilder;
import org.apache.commons.cli.Options;
import org.apache.commons.cli.ParseException;
import org.apache.commons.cli.PosixParser;

/**
 *
 * @author PSexton
 */
public class Main {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        new Main(args);
    }

    public Main(String[] args) {
        Option reader = OptionBuilder.withArgName("reader").hasArgs()
                .withDescription("give this user read privledges").create("reader");
        Option writer = OptionBuilder.withArgName("writer").hasArgs()
                .withDescription("give this user read/write privledges").create("writer");
        Option file = OptionBuilder.withArgName("file").hasArgs().withDescription("path to output file")
                .create("file");
        Options options = new Options();
        options.addOption(reader);
        options.addOption(writer);
        options.addOption(file);

        CommandLineParser parser = new PosixParser();
        try {
            List<String> readers = new ArrayList<String>();
            List<String> writers = new ArrayList<String>();

            CommandLine line = parser.parse(options, args);
            if (line.hasOption("reader")) {
                // handle r case
                String[] usernames = line.getOptionValues("reader");
                readers = Arrays.asList(usernames);
            }
            if (line.hasOption("writer")) {
                // handle w case
                String[] usernames = line.getOptionValues("writer");
                writers = Arrays.asList(usernames);
            }

            String fileBody = createFileBody(readers, writers);
            if (line.hasOption("file")) {
                String filePath = line.getOptionValue("file");
                writeToFile(fileBody, filePath);
            } else {
                System.out.println(fileBody);
            }
        } catch (ParseException ex) {
            throw new RuntimeException(ex);
        }

    }

    private String createFileBody(List<String> readers, List<String> writers) {
        /*
         * Structure of file should be:
         * 
         * [groups]
         * readers = user1, user2, user3
         * writers = user4, user5, user6
         * 
         * [/]
         * @readers = r
         * @writers = rw
         */

        final String NEWLINE = System.getProperty("line.separator");
        StringBuilder builder = new StringBuilder();

        // groups header
        builder.append("[groups]" + NEWLINE);
        // groups body
        builder.append("readers = " + makeCommaSeparatedList(readers) + NEWLINE);
        builder.append("writers = " + makeCommaSeparatedList(writers) + NEWLINE);
        // blank line spacer
        builder.append(NEWLINE);
        // path body
        builder.append("[/]" + NEWLINE);
        builder.append("@readers = r" + NEWLINE);
        builder.append("@writers = rw" + NEWLINE);

        return builder.toString();
    }

    /**
     * Given a String body and a file path, writes fileBody to filePath
     * @param fileBody
     * @param filePath 
     */
    private void writeToFile(String fileBody, String filePath) {
        File file = new File(filePath);
        try {
            PrintWriter writer = new PrintWriter(new BufferedWriter(new FileWriter(file)));
            writer.print(fileBody);
            writer.flush();
            writer.close();
        } catch (IOException ex) {
            throw new RuntimeException(ex);
        }
    }

    /**
     * Given a List of Strings, returns a single string containing them comma and space separated
     * @param entries
     * @return 
     */
    private String makeCommaSeparatedList(List<String> entries) {
        int numEntries = entries.size();
        if (numEntries == 0)
            return "";
        else if (numEntries == 1)
            return entries.get(0);
        else {
            String returnVal = entries.get(0);
            for (int i = 1; i < numEntries; i++)
                returnVal = returnVal + ", " + entries.get(i);
            return returnVal;
        }
    }

}