com.bahmanm.karun.PacmanConfHelper.java Source code

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Here is the source code for com.bahmanm.karun.PacmanConfHelper.java

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/*
 * Karun, a package manager for ArchLinux based on 'pacman'.
 * Copyright (C) 2011  Bahman Movaqar
 *
 * This program 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.
 * 
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
 * USA.
 */
package com.bahmanm.karun;

import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.apache.commons.lang.StringUtils;

/**
 * PacmanConfHelper
 * 
 * @author Bahman Movaqar (Bahman AT BahmanM.com)
 */
public class PacmanConfHelper {

    private static final String PACMAN_CONF_PATH = "/etc/pacman.conf";
    /** Absolute path to 'pacman.conf' */
    private String confPath;
    /** Pacman's DB path */
    private String dbPath = "/var/lib/pacman/";
    /** Pacman's cache directory */
    private String cacheDir = "/var/cache/pacman/pkg/";
    /** Pacman's repositories */
    private ArrayList<String> repos = new ArrayList<String>();
    /** Singleton object */
    private static PacmanConfHelper pacmanConfHelper;

    // Getter block
    public String getCacheDir() {
        return cacheDir;
    }

    public String getConfPath() {
        return confPath;
    }

    public String getDbPath() {
        return dbPath;
    }

    public ArrayList<String> getRepos() {
        return repos;
    }
    //

    /**
     * Singleton constructor
     * 
     * @return Singleton object
     * @throws PacmanConfPathException
     * @throws FileNotFoundException
     * @throws IOException 
     */
    public synchronized static PacmanConfHelper get()
            throws PacmanConfPathException, FileNotFoundException, IOException {
        if (PacmanConfHelper.pacmanConfHelper == null)
            PacmanConfHelper.pacmanConfHelper = new PacmanConfHelper();
        return PacmanConfHelper.pacmanConfHelper;
    }

    /**
     * Default constructor
     */
    private PacmanConfHelper() throws PacmanConfPathException, FileNotFoundException, IOException {
        this(PACMAN_CONF_PATH);
    }

    /**
     * Singleton constructor
     * 
     * @return Singleton object
     * @throws PacmanConfPathException
     * @throws FileNotFoundException
     * @throws IOException 
     */
    public synchronized static PacmanConfHelper get(String confPath)
            throws PacmanConfPathException, FileNotFoundException, IOException {
        if (PacmanConfHelper.pacmanConfHelper == null)
            PacmanConfHelper.pacmanConfHelper = new PacmanConfHelper(confPath);
        return PacmanConfHelper.pacmanConfHelper;
    }

    /**
     * Constructor
     * 
     * @param confPath Absolute path to 'pacman.conf'.
     */
    private PacmanConfHelper(String confPath) throws PacmanConfPathException, FileNotFoundException, IOException {
        // Check for existence
        File f = new File(confPath);
        if (!f.exists() || !f.canRead() || !f.isFile()) {
            throw new PacmanConfPathException(confPath);
        }

        this.confPath = confPath;
        extractInfo();
    }

    /**
     * Extracts valuable info from 'pacman.conf'.
     */
    private void extractInfo() throws FileNotFoundException, IOException {
        FileInputStream fis = new FileInputStream(confPath);
        DataInputStream dis = new DataInputStream(fis);
        BufferedReader br = new BufferedReader(new InputStreamReader(dis));
        String line;
        try {
            while ((line = br.readLine()) != null) {
                line = StringUtils.normalizeSpace(line);
                if (line.startsWith("#")) {
                    continue;
                } else if (line.startsWith("[") && line.endsWith("]")) {
                    String section = line.substring(1, line.length() - 1);
                    if (!section.equals("options")) {
                        repos.add(section);
                    }
                } else if (line.startsWith("DBPath")) {
                    dbPath = line.split("=")[1].trim();
                } else if (line.startsWith("CacheDir")) {
                    cacheDir = line.split("=")[1].trim();
                }
            }
        } catch (IOException ex) {
            Logger.getLogger(PacmanConfHelper.class.getName()).log(Level.SEVERE, null, ex);
            try {
                br.close();
                dis.close();
                fis.close();
            } catch (IOException ioex) {
                throw new IOException("Error closing stream or reader: " + ioex.getMessage());
            }
        }
    }

}