2 * Copyright (C) 2015 Roland Haeder
4 * This program is free software: you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation, either version 3 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program. If not, see <http://www.gnu.org/licenses/>.
17 package org.mxchange.addressbook.database.backend.mysql;
19 import java.io.IOException;
20 import java.sql.Connection;
21 import java.sql.DriverManager;
22 import java.sql.PreparedStatement;
23 import java.sql.ResultSet;
24 import java.sql.SQLException;
25 import java.text.MessageFormat;
26 import java.util.Iterator;
27 import org.mxchange.addressbook.contact.Contact;
28 import org.mxchange.addressbook.database.backend.BaseDatabaseBackend;
29 import org.mxchange.addressbook.database.backend.DatabaseBackend;
30 import org.mxchange.addressbook.database.storage.Storeable;
31 import org.mxchange.addressbook.exceptions.BadTokenException;
32 import org.mxchange.addressbook.exceptions.UnsupportedDatabaseDriverException;
35 * A backend class for MySQL connections
37 * @author Roland Haeder
39 public class MySqlDatabaseBackend extends BaseDatabaseBackend implements DatabaseBackend {
41 * An instance of a datbase connection
43 private static Connection connection;
46 * Prepared statement for full row count
48 private PreparedStatement totalRowCount;
51 * Constructor with table name
53 * @param tableName Table to access
54 * @throws org.mxchange.addressbook.exceptions.UnsupportedDatabaseDriverException
56 public MySqlDatabaseBackend (final String tableName) throws UnsupportedDatabaseDriverException {
58 this.validateDriver("mysql"); //NOI18N
60 // Now that the driver is there, set the table name
61 this.setTableName(tableName);
65 public void connectToDatabase () throws SQLException {
67 this.getLogger().trace("CALLED!"); //NOI18N
69 // Is the connection already there?
70 if (MySqlDatabaseBackend.connection instanceof Connection) {
72 this.getLogger().debug("Connection is already established."); //NOI18N
78 // Generate connection string
79 String connect = String.format("jdbc:mysql://%s/%s", //NOI18N
80 this.getProperty("database.mysql.host"), //NOI18N
81 this.getProperty("database.mysql.dbname") //NOI18N
85 this.getLogger().debug(MessageFormat.format("Attempting to connect to {0} ...", connect)); //NOI18N
87 // Now get a connection instance back
88 MySqlDatabaseBackend.connection = DriverManager.getConnection(
90 this.getProperty("database.mysql.login"), //NOI18N
91 this.getProperty("database.mysql.password") //NOI18N
94 // Is the connection really up?
95 if (MySqlDatabaseBackend.connection.isClosed()) {
96 // Connection is closed again
97 throw new SQLException("Connection is closed."); //NOI18N
101 this.getLogger().debug("Connection is up, preparing some statements ..."); //NOI18N
103 // Here, the connection is established, so prepare some statements
104 this.totalRowCount = MySqlDatabaseBackend.connection.prepareStatement(String.format("SELECT COUNT(`id`) AS `cnt` FROM `%s` LIMIT 1", this.getTableName())); //NOI18N
107 this.getLogger().trace("EXIT!"); //NOI18N
112 public Iterator<Contact> contactIterator () throws BadTokenException {
113 throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
117 public void doShutdown () {
118 // This should not happen:
119 assert(MySqlDatabaseBackend.connection instanceof Connection) : MessageFormat.format("connection is not valid: {0}", MySqlDatabaseBackend.connection); //NOI18N
122 // Close down database connection
123 MySqlDatabaseBackend.connection.close();
124 } catch (final SQLException ex) {
125 // Something happened during close()
126 this.abortProgramWithException(ex);
131 public int getTotalCount () throws SQLException {
133 this.getLogger().trace(MessageFormat.format("tableName={0} - CALLED!", this.getTableName())); //NOI18N
135 // Nothing counted by default
138 // Prepared statements are cool ...
139 if (this.totalRowCount.execute()) {
140 // Did fully work, so get result set
141 ResultSet set = this.totalRowCount.getResultSet();
144 assert(set.last()) : ": last() failed"; //NOI18N
146 // Get integer from 'cnt' alias (see statement)
147 count = set.getInt("cnt"); //NOI18N
150 this.getLogger().debug(MessageFormat.format("count={0}", count)); //NOI18N
152 // Go back to beginning
156 this.getLogger().warn(MessageFormat.format("COUNT() query didn't return any result on table {0}.", this.getTableName())); //NOI18N
160 this.getLogger().trace(MessageFormat.format("count={0} - EXIT!", count)); //NOI18N
167 * Checks whether at least one row is found with given boolean value.
169 * @param columnName Column to check for boolean value
170 * @param bool Boolean value to check
171 * @return Whether boolean value is found and returns at least one row
174 public boolean isRowFound (final String columnName, final boolean bool) throws SQLException {
175 // Is at least one entry found?
176 if (this.getTotalCount() == 0) {
177 // No entry found at all
180 throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
184 public long length () {
185 throw new UnsupportedOperationException("Not implemented for this backend."); //NOI18N
189 public void rewind () {
190 throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
194 public void store (final Storeable object) throws IOException {
195 throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.