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