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1: /* =========================================================== 2: * JFreeChart : a free chart library for the Java(tm) platform 3: * =========================================================== 4: * 5: * (C) Copyright 2000-2007, by Object Refinery Limited and Contributors. 6: * 7: * Project Info: http://www.jfree.org/jfreechart/index.html 8: * 9: * This library is free software; you can redistribute it and/or modify it 10: * under the terms of the GNU Lesser General Public License as published by 11: * the Free Software Foundation; either version 2.1 of the License, or 12: * (at your option) any later version. 13: * 14: * This library is distributed in the hope that it will be useful, but 15: * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 16: * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 17: * License for more details. 18: * 19: * You should have received a copy of the GNU Lesser General Public 20: * License along with this library; if not, write to the Free Software 21: * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, 22: * USA. 23: * 24: * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 25: * in the United States and other countries.] 26: * 27: * ------------------- 28: * JDBCPieDataset.java 29: * ------------------- 30: * (C) Copyright 2002-2007, by Bryan Scott and Contributors. 31: * 32: * Original Author: Bryan Scott; Andy 33: * Contributor(s): David Gilbert (for Object Refinery Limited); 34: * Thomas Morgner; 35: * 36: * $Id: JDBCPieDataset.java,v 1.3.2.2 2007/02/02 15:03:18 mungady Exp $ 37: * 38: * Changes 39: * ------- 40: * 26-Apr-2002 : Creation based on JdbcXYDataSet, but extending 41: * DefaultPieDataset (BS); 42: * 24-Jun-2002 : Removed unnecessary import and local variable (DG); 43: * 13-Aug-2002 : Updated Javadoc comments and imports, removed default 44: * constructor (DG); 45: * 18-Sep-2002 : Updated to support BIGINT (BS); 46: * 21-Jan-2003 : Renamed JdbcPieDataset --> JDBCPieDataset (DG); 47: * 03-Feb-2003 : Added Types.DECIMAL (see bug report 677814) (DG); 48: * 05-Jun-2003 : Updated to support TIME, optimised executeQuery method (BS); 49: * 30-Jul-2003 : Added empty contructor and executeQuery(connection,string) 50: * method (BS); 51: * 02-Dec-2003 : Throwing exceptions allows to handle errors, removed default 52: * constructor, as without a connection, a query can never be 53: * executed (TM); 54: * 04-Dec-2003 : Added missing Javadocs (DG); 55: * ------------- JFREECHART 1.0.x --------------------------------------------- 56: * 02-Feb-2007 : Removed author tags all over JFreeChart sources (DG); 57: * 58: */ 59: 60: package org.jfree.data.jdbc; 61: 62: import java.sql.Connection; 63: import java.sql.DriverManager; 64: import java.sql.SQLException; 65: import java.sql.Timestamp; 66: import java.sql.Types; 67: import java.sql.ResultSet; 68: import java.sql.ResultSetMetaData; 69: import java.sql.Statement; 70: 71: import org.jfree.data.general.DefaultPieDataset; 72: import org.jfree.data.general.PieDataset; 73: 74: /** 75: * A {@link PieDataset} that reads data from a database via JDBC. 76: * <P> 77: * A query should be supplied that returns data in two columns, the first 78: * containing VARCHAR data, and the second containing numerical data. The 79: * data is cached in-memory and can be refreshed at any time. 80: */ 81: public class JDBCPieDataset extends DefaultPieDataset { 82: 83: /** The database connection. */ 84: private transient Connection connection; 85: 86: /** 87: * Creates a new JDBCPieDataset and establishes a new database connection. 88: * 89: * @param url the URL of the database connection. 90: * @param driverName the database driver class name. 91: * @param user the database user. 92: * @param password the database users password. 93: * 94: * @throws ClassNotFoundException if the driver cannot be found. 95: * @throws SQLException if there is a problem obtaining a database 96: * connection. 97: */ 98: public JDBCPieDataset(String url, 99: String driverName, 100: String user, 101: String password) 102: throws SQLException, ClassNotFoundException { 103: 104: Class.forName(driverName); 105: this.connection = DriverManager.getConnection(url, user, password); 106: } 107: 108: /** 109: * Creates a new JDBCPieDataset using a pre-existing database connection. 110: * <P> 111: * The dataset is initially empty, since no query has been supplied yet. 112: * 113: * @param con the database connection. 114: */ 115: public JDBCPieDataset(Connection con) { 116: if (con == null) { 117: throw new NullPointerException("A connection must be supplied."); 118: } 119: this.connection = con; 120: } 121: 122: 123: /** 124: * Creates a new JDBCPieDataset using a pre-existing database connection. 125: * <P> 126: * The dataset is initialised with the supplied query. 127: * 128: * @param con the database connection. 129: * @param query the database connection. 130: * 131: * @throws SQLException if there is a problem executing the query. 132: */ 133: public JDBCPieDataset(Connection con, String query) throws SQLException { 134: this(con); 135: executeQuery(query); 136: } 137: 138: /** 139: * ExecuteQuery will attempt execute the query passed to it against the 140: * existing database connection. If no connection exists then no action 141: * is taken. 142: * The results from the query are extracted and cached locally, thus 143: * applying an upper limit on how many rows can be retrieved successfully. 144: * 145: * @param query the query to be executed. 146: * 147: * @throws SQLException if there is a problem executing the query. 148: */ 149: public void executeQuery(String query) throws SQLException { 150: executeQuery(this.connection, query); 151: } 152: 153: /** 154: * ExecuteQuery will attempt execute the query passed to it against the 155: * existing database connection. If no connection exists then no action 156: * is taken. 157: * The results from the query are extracted and cached locally, thus 158: * applying an upper limit on how many rows can be retrieved successfully. 159: * 160: * @param query the query to be executed 161: * @param con the connection the query is to be executed against 162: * 163: * @throws SQLException if there is a problem executing the query. 164: */ 165: public void executeQuery(Connection con, String query) throws SQLException { 166: 167: Statement statement = null; 168: ResultSet resultSet = null; 169: 170: try { 171: statement = con.createStatement(); 172: resultSet = statement.executeQuery(query); 173: ResultSetMetaData metaData = resultSet.getMetaData(); 174: 175: int columnCount = metaData.getColumnCount(); 176: if (columnCount != 2) { 177: throw new SQLException( 178: "Invalid sql generated. PieDataSet requires 2 columns only" 179: ); 180: } 181: 182: int columnType = metaData.getColumnType(2); 183: double value = Double.NaN; 184: while (resultSet.next()) { 185: Comparable key = resultSet.getString(1); 186: switch (columnType) { 187: case Types.NUMERIC: 188: case Types.REAL: 189: case Types.INTEGER: 190: case Types.DOUBLE: 191: case Types.FLOAT: 192: case Types.DECIMAL: 193: case Types.BIGINT: 194: value = resultSet.getDouble(2); 195: setValue(key, value); 196: break; 197: 198: case Types.DATE: 199: case Types.TIME: 200: case Types.TIMESTAMP: 201: Timestamp date = resultSet.getTimestamp(2); 202: value = date.getTime(); 203: setValue(key, value); 204: break; 205: 206: default: 207: System.err.println( 208: "JDBCPieDataset - unknown data type" 209: ); 210: break; 211: } 212: } 213: 214: fireDatasetChanged(); 215: 216: } 217: finally { 218: if (resultSet != null) { 219: try { 220: resultSet.close(); 221: } 222: catch (Exception e) { 223: System.err.println("JDBCPieDataset: swallowing exception."); 224: } 225: } 226: if (statement != null) { 227: try { 228: statement.close(); 229: } 230: catch (Exception e) { 231: System.err.println("JDBCPieDataset: swallowing exception."); 232: } 233: } 234: } 235: } 236: 237: 238: /** 239: * Close the database connection 240: */ 241: public void close() { 242: try { 243: this.connection.close(); 244: } 245: catch (Exception e) { 246: System.err.println("JdbcXYDataset: swallowing exception."); 247: } 248: } 249: }