Package org.jfree.data

Class JDBCPieDataset

java.lang.Object

org.jfree.data.AbstractDataset

org.jfree.data.DefaultPieDataset

org.jfree.data.JDBCPieDataset

All Implemented Interfaces:

ObjectInputValidation, Serializable, Cloneable, Dataset, KeyedValues, PieDataset, Values

public class JDBCPieDataset
extends DefaultPieDataset

A PieDataset 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

Constructors

Constructor	Description
JDBCPieDataset(String url, String driverName, String user, String password)	Creates a new JDBCPieDataset and establishes a new database connection.
JDBCPieDataset(Connection con)	Creates a new JDBCPieDataset using a pre-existing database connection.
JDBCPieDataset(Connection con, String query)	Creates a new JDBCPieDataset using a pre-existing database connection.

Method Summary

Modifier and Type	Method	Description
void	close()	Close the database connection
void	executeQuery(String query)	ExecuteQuery will attempt execute the query passed to it against the existing database connection.
void	executeQuery(Connection con, String query)	ExecuteQuery will attempt execute the query passed to it against the existing database connection.

Methods inherited from class org.jfree.data.DefaultPieDataset

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

Methods inherited from class org.jfree.data.AbstractDataset

addChangeListener, getGroup, removeChangeListener, setGroup, validateObject

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.jfree.data.Dataset

addChangeListener, getGroup, removeChangeListener, setGroup

Constructor Details

JDBCPieDataset

public JDBCPieDataset(String url,
String driverName,
String user,
String password)
               throws SQLException,
ClassNotFoundException

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.

password - the database users password.

Throws:

ClassNotFoundException - if the driver cannot be found.

SQLException - if there is a problem obtaining a database connection.

JDBCPieDataset

public JDBCPieDataset(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(Connection con,
String query)
               throws SQLException

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.

Throws:

SQLException - if there is a problem executing the query.

Method Details

executeQuery

public void executeQuery(String query)
                  throws SQLException

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.

Throws:

SQLException - if there is a problem executing the query.

executeQuery

public void executeQuery(Connection con,
String query)
                  throws SQLException

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

con - the connection the query is to be executed against

Throws:

SQLException - if there is a problem executing the query.

close

public void close()

Close the database connection