org.jfree.data
Class JDBCPieDataset

java.lang.Object
  |
  +--org.jfree.data.AbstractDataset
        |
        +--org.jfree.data.DefaultPieDataset
              |
              +--org.jfree.data.JDBCPieDataset

All Implemented Interfaces:

Dataset, KeyedValues, PieDataset, java.io.Serializable, Values

public class JDBCPieDataset

extends DefaultPieDataset

A pie dataset that reads data from a database via JDBC.

A query should be supplied that returns data in two columns, the first containing VARCHAR data, and the second containing numerical data. The data is cached in-memory and can be refreshed at any time.

Author:

Bryan Scott.

See Also:

Serialized Form

Constructor Summary

JDBCPieDataset(java.sql.Connection con)
Creates a new JDBCPieDataset using a pre-existing database connection.

JDBCPieDataset(java.sql.Connection con, java.lang.String query)
Creates a new JDBCPieDataset using a pre-existing database connection.

JDBCPieDataset(java.lang.String url, java.lang.String driverName, java.lang.String user, java.lang.String passwd)
Creates a new JDBCPieDataset and establishes a new database connection.

Method Summary

void	executeQuery(java.lang.String query) ExecuteQuery will attempt execute the query passed to it against the existing database connection.

Methods inherited from class org.jfree.data.DefaultPieDataset

equals, getIndex, getItemCount, getKey, getKeys, getValue, getValue, setValue, setValue

Methods inherited from class org.jfree.data.AbstractDataset

addChangeListener, fireDatasetChanged, getGroup, notifyListeners, removeChangeListener, setGroup

Methods inherited from class java.lang.Object

clone, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.jfree.data.Dataset

addChangeListener, getGroup, removeChangeListener, setGroup

Constructor Detail

JDBCPieDataset

public JDBCPieDataset(java.lang.String url,
                      java.lang.String driverName,
                      java.lang.String user,
                      java.lang.String passwd)

Creates a new JDBCPieDataset and establishes a new database connection.

Parameters:

url - the URL of the database connection.

driverName - The database driver class name.

user - The database user.

passwd - The database users password.

JDBCPieDataset

public JDBCPieDataset(java.sql.Connection con)

Creates a new JDBCPieDataset using a pre-existing database connection.

The dataset is initially empty, since no query has been supplied yet.

Parameters:

con - the database connection.

JDBCPieDataset

public JDBCPieDataset(java.sql.Connection con,
                      java.lang.String query)

Creates a new JDBCPieDataset using a pre-existing database connection.

The dataset is initialised with the supplied query.

Parameters:

con - the database connection.

query - the database connection.

Method Detail

executeQuery

public void executeQuery(java.lang.String query)

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.

Parameters:

query - The query to be executed