DbManager.java Source code

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Here is the source code for DbManager.java

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/*
 * Copyright  2009 Perseus Project - Tufts University <http://www.perseus.tufts.edu>
 *
 * This file is part of DbUtilPerseus.
 *
 * DbUtilPerseus 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.
 * DbUtilPerseus 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 DbUtilPerseus.  If not, see <http://www.gnu.org/licenses/>.
 */

//package eu.himeros.util;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.Statement;

/**
 * Manage Db connections providing shortcuts for Statements, PreparedStatements
 * and ResultSets.
 * 
 * @author Federico Boschetti <federico.boschetti.73@gmail.com>
 */
public class DbManager {
    public Connection con;
    public Statement stmt;
    public PreparedStatement pstmt;
    public ResultSet rst;

    public Statement[] stmts;
    public PreparedStatement[] pstmts;
    public ResultSet[] rsts;

    private String driverName;
    private String dbName;

    private boolean dbArray;
    private int stmtsSize;
    private int pstmtsSize;
    private int rstsSize;

    /**
     * Initialize a generic DbManager.
     * 
     * @param driver
     *            the driver.
     * @param database
     *            the database name.
     * @param login
     *            the login.
     * @param passwd
     *            the password.
     */
    public DbManager(String driver, String database, String login, String passwd) {
        dbArray = false;
        try {
            initDb(driver, database, login, passwd);
            stmt = con.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_UPDATABLE);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * Initialize the DbManager, using hsqldb defaults.
     */
    public DbManager() {
        dbArray = false;
        try {
            initDb("hsqldb", ".", "sa", "");
            stmt = con.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_UPDATABLE);

        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * Initialize the DbManager.
     * 
     * @param driver
     *            the driver.
     * @param database
     *            the database name.
     * @param login
     *            the login.
     * @param passwd
     *            the password.
     * @param stmtsSize
     *            the max number of Statement instances.
     * @param pstmtsSize
     *            the max number of PreparedStatement instances.
     * @param rstsSize
     *            the max number of ResultSet instances.
     */
    public void dbManager(String driver, String database, String login, String passwd, int stmtsSize,
            int pstmtsSize, int rstsSize) {
        dbArray = true;
        this.stmtsSize = stmtsSize;
        this.pstmtsSize = pstmtsSize;
        this.rstsSize = rstsSize;
        try {
            initDb(driver, database, login, passwd);
            if (stmtsSize > 0) {
                stmts = new Statement[stmtsSize];
                for (int i = 0; i < stmtsSize; i++) {
                    stmts[i] = con.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);
                }
            }
            if (pstmtsSize > 0) {
                pstmts = new PreparedStatement[pstmtsSize];
            }
            if (rstsSize != 0) {
                rsts = new ResultSet[rstsSize];
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * Initialize the DbManager.
     * 
     * @param driver
     *            the driver.
     * @param database
     *            the database name.
     * @param login
     *            the login.
     * @param passwd
     *            the password.
     * @param stmtsSize
     *            the max number of Statement instances.
     * @param pstmtsSize
     *            the max number of PreparedStatement instances.
     * @param rstsSize
     *            the max number of ResultSet instances.
     */
    public DbManager(String driver, String database, String login, String passwd, int stmtsSize, int pstmtsSize,
            int rstsSize) {
        dbManager(driver, database, login, passwd, stmtsSize, pstmtsSize, rstsSize);
    }

    /**
     * Initialize the DbManager.
     * 
     * @param driver
     *            the driver.
     * @param database
     *            the database name.
     * @param login
     *            the login.
     * @param passwd
     *            the password.
     * @param stmtsSize
     *            the max number of Statement instances.
     * @param rstsSize
     *            the max number of ResultSet instances.
     */
    public DbManager(String driver, String database, String login, String passwd, int stmtsSize, int rstsSize) {
        dbManager(driver, database, login, passwd, stmtsSize, 0, rstsSize);
    }

    /**
     * Provide the PreparedStatement, given a query.
     * 
     * @param query
     *            the query.
     * @return the PreparedStatement based on the query.
     */
    public PreparedStatement prepareStatement(String query) {
        try {
            pstmt = con.prepareStatement(query, ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_UPDATABLE);
            return pstmt;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * Shortcut for hsqldb driver name.
     * 
     * @param driver
     *            the driver.
     * @param database
     *            the database name.
     */
    private void longNames(String driver, String database) {
        if (driver.equals("hsqldb")) {
            driverName = "org.hsqldb.jdbcDriver";
            dbName = "jdbc:hsqldb:" + database;
        } else {
            driverName = driver;
            dbName = database;
        }
    }

    /**
     * Initialize the database.
     * 
     * @param driver
     *            the driver.
     * @param database
     *            the database name.
     * @param login
     *            the login.
     * @param passwd
     *            the password.
     */
    private void initDb(String driver, String database, String login, String passwd) {
        try {
            longNames(driver, database);
            Class.forName(driverName);
            con = DriverManager.getConnection(dbName, login, passwd);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * Close the single instance of ResultSet, PreparedStatement, Statement and
     * Connection.
     */
    private void closeSingle() {
        try {
            if (rst != null) {
                rst.close();
            }
            if (pstmt != null) {
                pstmt.close();
            }
            stmt.close();
            con.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * Close the array.
     */
    private void closeArray() {
        try {
            for (int i = 0; i < rstsSize; i++) {
                if (rsts[i] != null) {
                    rsts[i].close();
                }
            }
            for (int i = 0; i < stmtsSize; i++) {
                if (stmts[i] != null) {
                    stmts[i].close();
                }
            }
            for (int i = 0; i < pstmtsSize; i++) {
                if (pstmts[i] != null) {
                    pstmts[i].close();
                }
            }
            con.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * Close the array or the single instance.
     */
    public void close() {
        if (dbArray) {
            closeArray();
        } else {
            closeSingle();
        }
    }

    /**
     * Close the ResultSet
     * 
     * @param rst
     *            the ResultSet
     */
    public void close(ResultSet rst) {
        try {
            rst.close();
            closeSingle();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

}