jfreechart example source code file (JDBCXYDataset.java)
The jfreechart JDBCXYDataset.java source code
/* ===========================================================
* JFreeChart : a free chart library for the Java(tm) platform
* ===========================================================
*
* (C) Copyright 2000-2008, by Object Refinery Limited and Contributors.
*
* Project Info: http://www.jfree.org/jfreechart/index.html
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library 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 Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
* USA.
*
* [Java is a trademark or registered trademark of Sun Microsystems, Inc.
* in the United States and other countries.]
*
* ------------------
* JDBCXYDataset.java
* ------------------
* (C) Copyright 2002-2008, by Bryan Scott and Contributors.
*
* Original Author: Bryan Scott;
* Contributor(s): David Gilbert (for Object Refinery Limited);
* Eric Alexander;
*
*
* Changes
* -------
* 14-Mar-2002 : Version 1 contributed by Bryan Scott (DG);
* 19-Apr-2002 : Updated executeQuery, to close cursors and to improve support
* for types.
* 26-Apr-2002 : Renamed JdbcXYDataset to better fit in with the existing data
* source conventions.
* 26-Apr-2002 : Changed to extend AbstractDataset.
* 13-Aug-2002 : Updated Javadoc comments and imports (DG);
* 18-Sep-2002 : Updated to support BIGINT (BS);
* 21-Jan-2003 : Renamed JdbcXYDataset --> JDBCXYDataset (DG);
* 01-Jul-2003 : Added support to query whether a timeseries (BS);
* 30-Jul-2003 : Added empty contructor and executeQuery(connection,string)
* method (BS);
* 24-Sep-2003 : Added a check to ensure at least two valid columns are
* returned by the query in executeQuery as suggest in online
* forum by anonymous (BS);
* 02-Dec-2003 : Throwing exceptions allows to handle errors, removed default
* constructor, as without a connection, a query can never be
* executed.
* 16-Mar-2004 : Added check for null values (EA);
* 05-May-2004 : Now extends AbstractXYDataset (DG);
* 21-May-2004 : Implemented TableXYDataset, added support for SMALLINT and
* fixed bug in code that determines the min and max values (see
* bug id 938138) (DG);
* 15-Jul-2004 : Switched getX() with getXValue() and getY() with
* getYValue() (DG);
* 18-Nov-2004 : Updated for changes in RangeInfo interface (DG);
* 11-Jan-2005 : Removed deprecated code in preparation for the 1.0.0
* release (DG);
* ------------- JFREECHART 1.0.x ---------------------------------------------
* 17-Oct-2006 : Deprecated unused methods - see bug 1578293 (DG);
*
*/
package org.jfree.data.jdbc;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.Types;
import java.util.ArrayList;
import java.util.Date;
import org.jfree.data.Range;
import org.jfree.data.RangeInfo;
import org.jfree.data.general.Dataset;
import org.jfree.data.xy.AbstractXYDataset;
import org.jfree.data.xy.TableXYDataset;
import org.jfree.data.xy.XYDataset;
import org.jfree.util.Log;
/**
* This class provides an {@link XYDataset} implementation over a database
* JDBC result set. The dataset is populated via a call to executeQuery with
* the string sql query. The sql query must return at least two columns.
* The first column will be the x-axis and remaining columns y-axis values.
* executeQuery can be called a number of times.
*
* The database connection is read-only and no write back facility exists.
*/
public class JDBCXYDataset extends AbstractXYDataset
implements XYDataset, TableXYDataset, RangeInfo {
/** The database connection. */
private transient Connection connection;
/** Column names. */
private String[] columnNames = {};
/** Rows. */
private ArrayList rows;
/** The maximum y value of the returned result set */
private double maxValue = 0.0;
/** The minimum y value of the returned result set */
private double minValue = 0.0;
/** Is this dataset a timeseries ? */
private boolean isTimeSeries = false;
/**
* Creates a new JDBCXYDataset (initially empty) with no database
* connection.
*/
private JDBCXYDataset() {
this.rows = new ArrayList();
}
/**
* Creates a new dataset (initially empty) and establishes a new database
* connection.
*
* @param url URL of the database connection.
* @param driverName the database driver class name.
* @param user the database user.
* @param password the database user's password.
*
* @throws ClassNotFoundException if the driver cannot be found.
* @throws SQLException if there is a problem connecting to the database.
*/
public JDBCXYDataset(String url,
String driverName,
String user,
String password)
throws SQLException, ClassNotFoundException {
this();
Class.forName(driverName);
this.connection = DriverManager.getConnection(url, user, password);
}
/**
* Creates a new dataset (initially empty) using the specified database
* connection.
*
* @param con the database connection.
*
* @throws SQLException if there is a problem connecting to the database.
*/
public JDBCXYDataset(Connection con) throws SQLException {
this();
this.connection = con;
}
/**
* Creates a new dataset using the specified database connection, and
* populates it using data obtained with the supplied query.
*
* @param con the connection.
* @param query the SQL query.
*
* @throws SQLException if there is a problem executing the query.
*/
public JDBCXYDataset(Connection con, String query) throws SQLException {
this(con);
executeQuery(query);
}
/**
* Returns <code>true if the dataset represents time series data,
* and <code>false otherwise.
*
* @return A boolean.
*/
public boolean isTimeSeries() {
return this.isTimeSeries;
}
/**
* Sets a flag that indicates whether or not the data represents a time
* series.
*
* @param timeSeries the new value of the flag.
*/
public void setTimeSeries(boolean timeSeries) {
this.isTimeSeries = timeSeries;
}
/**
* ExecuteQuery will attempt execute the query passed to it against the
* existing database connection. If no connection exists then no action
* is taken.
*
* The results from the query are extracted and cached locally, thus
* applying an upper limit on how many rows can be retrieved successfully.
*
* @param query the query to be executed.
*
* @throws SQLException if there is a problem executing the query.
*/
public void executeQuery(String query) throws SQLException {
executeQuery(this.connection, query);
}
/**
* ExecuteQuery will attempt execute the query passed to it against the
* provided database connection. If connection is null then no action is
* taken.
*
* The results from the query are extracted and cached locally, thus
* applying an upper limit on how many rows can be retrieved successfully.
*
* @param query the query to be executed.
* @param con the connection the query is to be executed against.
*
* @throws SQLException if there is a problem executing the query.
*/
public void executeQuery(Connection con, String query)
throws SQLException {
if (con == null) {
throw new SQLException(
"There is no database to execute the query."
);
}
ResultSet resultSet = null;
Statement statement = null;
try {
statement = con.createStatement();
resultSet = statement.executeQuery(query);
ResultSetMetaData metaData = resultSet.getMetaData();
int numberOfColumns = metaData.getColumnCount();
int numberOfValidColumns = 0;
int [] columnTypes = new int[numberOfColumns];
for (int column = 0; column < numberOfColumns; column++) {
try {
int type = metaData.getColumnType(column + 1);
switch (type) {
case Types.NUMERIC:
case Types.REAL:
case Types.INTEGER:
case Types.DOUBLE:
case Types.FLOAT:
case Types.DECIMAL:
case Types.BIT:
case Types.DATE:
case Types.TIME:
case Types.TIMESTAMP:
case Types.BIGINT:
case Types.SMALLINT:
++numberOfValidColumns;
columnTypes[column] = type;
break;
default:
Log.warn(
"Unable to load column "
+ column + " (" + type + ","
+ metaData.getColumnClassName(column + 1)
+ ")"
);
columnTypes[column] = Types.NULL;
break;
}
}
catch (SQLException e) {
columnTypes[column] = Types.NULL;
throw e;
}
}
if (numberOfValidColumns <= 1) {
throw new SQLException(
"Not enough valid columns where generated by query."
);
}
/// First column is X data
this.columnNames = new String[numberOfValidColumns - 1];
/// Get the column names and cache them.
int currentColumn = 0;
for (int column = 1; column < numberOfColumns; column++) {
if (columnTypes[column] != Types.NULL) {
this.columnNames[currentColumn]
= metaData.getColumnLabel(column + 1);
++currentColumn;
}
}
// Might need to add, to free memory from any previous result sets
if (this.rows != null) {
for (int column = 0; column < this.rows.size(); column++) {
ArrayList row = (ArrayList) this.rows.get(column);
row.clear();
}
this.rows.clear();
}
// Are we working with a time series.
switch (columnTypes[0]) {
case Types.DATE:
case Types.TIME:
case Types.TIMESTAMP:
this.isTimeSeries = true;
break;
default :
this.isTimeSeries = false;
break;
}
// Get all rows.
// rows = new ArrayList();
while (resultSet.next()) {
ArrayList newRow = new ArrayList();
for (int column = 0; column < numberOfColumns; column++) {
Object xObject = resultSet.getObject(column + 1);
switch (columnTypes[column]) {
case Types.NUMERIC:
case Types.REAL:
case Types.INTEGER:
case Types.DOUBLE:
case Types.FLOAT:
case Types.DECIMAL:
case Types.BIGINT:
case Types.SMALLINT:
newRow.add(xObject);
break;
case Types.DATE:
case Types.TIME:
case Types.TIMESTAMP:
newRow.add(new Long(((Date) xObject).getTime()));
break;
case Types.NULL:
break;
default:
System.err.println("Unknown data");
columnTypes[column] = Types.NULL;
break;
}
}
this.rows.add(newRow);
}
/// a kludge to make everything work when no rows returned
if (this.rows.size() == 0) {
ArrayList newRow = new ArrayList();
for (int column = 0; column < numberOfColumns; column++) {
if (columnTypes[column] != Types.NULL) {
newRow.add(new Integer(0));
}
}
this.rows.add(newRow);
}
/// Determine max and min values.
if (this.rows.size() < 1) {
this.maxValue = 0.0;
this.minValue = 0.0;
}
else {
ArrayList row = (ArrayList) this.rows.get(0);
this.maxValue = Double.NEGATIVE_INFINITY;
this.minValue = Double.POSITIVE_INFINITY;
for (int rowNum = 0; rowNum < this.rows.size(); ++rowNum) {
row = (ArrayList) this.rows.get(rowNum);
for (int column = 1; column < numberOfColumns; column++) {
Object testValue = row.get(column);
if (testValue != null) {
double test = ((Number) testValue).doubleValue();
if (test < this.minValue) {
this.minValue = test;
}
if (test > this.maxValue) {
this.maxValue = test;
}
}
}
}
}
fireDatasetChanged(); // Tell the listeners a new table has arrived.
}
finally {
if (resultSet != null) {
try {
resultSet.close();
}
catch (Exception e) {
// TODO: is this a good idea?
}
}
if (statement != null) {
try {
statement.close();
}
catch (Exception e) {
// TODO: is this a good idea?
}
}
}
}
/**
* Returns the x-value for the specified series and item. The
* implementation is responsible for ensuring that the x-values are
* presented in ascending order.
*
* @param seriesIndex the series (zero-based index).
* @param itemIndex the item (zero-based index).
*
* @return The x-value
*
* @see XYDataset
*/
public Number getX(int seriesIndex, int itemIndex) {
ArrayList row = (ArrayList) this.rows.get(itemIndex);
return (Number) row.get(0);
}
/**
* Returns the y-value for the specified series and item.
*
* @param seriesIndex the series (zero-based index).
* @param itemIndex the item (zero-based index).
*
* @return The yValue value
*
* @see XYDataset
*/
public Number getY(int seriesIndex, int itemIndex) {
ArrayList row = (ArrayList) this.rows.get(itemIndex);
return (Number) row.get(seriesIndex + 1);
}
/**
* Returns the number of items in the specified series.
*
* @param seriesIndex the series (zero-based index).
*
* @return The itemCount value
*
* @see XYDataset
*/
public int getItemCount(int seriesIndex) {
return this.rows.size();
}
/**
* Returns the number of items in all series. This method is defined by
* the {@link TableXYDataset} interface.
*
* @return The item count.
*/
public int getItemCount() {
return getItemCount(0);
}
/**
* Returns the number of series in the dataset.
*
* @return The seriesCount value
*
* @see XYDataset
* @see Dataset
*/
public int getSeriesCount() {
return this.columnNames.length;
}
/**
* Returns the key for the specified series.
*
* @param seriesIndex the series (zero-based index).
*
* @return The seriesName value
*
* @see XYDataset
* @see Dataset
*/
public Comparable getSeriesKey(int seriesIndex) {
if ((seriesIndex < this.columnNames.length)
&& (this.columnNames[seriesIndex] != null)) {
return this.columnNames[seriesIndex];
}
else {
return "";
}
}
/**
* Returns the number of items that should be displayed in the legend.
*
* @return The legendItemCount value
*
* @deprecated This method is not used in JFreeChart 1.0.x (it was left in
* the API by mistake and is officially deprecated from version 1.0.3
* onwards).
*/
public int getLegendItemCount() {
return getSeriesCount();
}
/**
* Returns the legend item labels.
*
* @return The legend item labels.
*
* @deprecated This method is not used in JFreeChart 1.0.x (it was left in
* the API by mistake and is officially deprecated from version 1.0.3
* onwards).
*/
public String[] getLegendItemLabels() {
return this.columnNames;
}
/**
* Close the database connection
*/
public void close() {
try {
this.connection.close();
}
catch (Exception e) {
System.err.println("JdbcXYDataset: swallowing exception.");
}
}
/**
* Returns the minimum y-value in the dataset.
*
* @param includeInterval a flag that determines whether or not the
* y-interval is taken into account.
*
* @return The minimum value.
*/
public double getRangeLowerBound(boolean includeInterval) {
return this.minValue;
}
/**
* Returns the maximum y-value in the dataset.
*
* @param includeInterval a flag that determines whether or not the
* y-interval is taken into account.
*
* @return The maximum value.
*/
public double getRangeUpperBound(boolean includeInterval) {
return this.maxValue;
}
/**
* Returns the range of the values in this dataset's range.
*
* @param includeInterval a flag that determines whether or not the
* y-interval is taken into account.
*
* @return The range.
*/
public Range getRangeBounds(boolean includeInterval) {
return new Range(this.minValue, this.maxValue);
}
}
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