 public void executeQuery(Connection con,
String query) throws SQLException {
Statement statement = null;
ResultSet resultSet = null;
try {
statement = con.createStatement();
resultSet = statement.executeQuery(query);
ResultSetMetaData metaData = resultSet.getMetaData();
int columnCount = metaData.getColumnCount();
if (columnCount < 2) {
throw new SQLException(
"JDBCCategoryDataset.executeQuery() : insufficient columns "
+ "returned from the database.");
}
// Remove any previous old data
int i = getRowCount();
while (--i >= 0) {
removeRow(i);
}
while (resultSet.next()) {
// first column contains the row key...
Comparable rowKey = resultSet.getString(1);
for (int column = 2; column < = columnCount; column++) {
Comparable columnKey = metaData.getColumnName(column);
int columnType = metaData.getColumnType(column);
switch (columnType) {
case Types.TINYINT:
case Types.SMALLINT:
case Types.INTEGER:
case Types.BIGINT:
case Types.FLOAT:
case Types.DOUBLE:
case Types.DECIMAL:
case Types.NUMERIC:
case Types.REAL: {
Number value = (Number) resultSet.getObject(column);
if (this.transpose) {
setValue(value, columnKey, rowKey);
}
else {
setValue(value, rowKey, columnKey);
}
break;
}
case Types.DATE:
case Types.TIME:
case Types.TIMESTAMP: {
Date date = (Date) resultSet.getObject(column);
Number value = new Long(date.getTime());
if (this.transpose) {
setValue(value, columnKey, rowKey);
}
else {
setValue(value, rowKey, columnKey);
}
break;
}
case Types.CHAR:
case Types.VARCHAR:
case Types.LONGVARCHAR: {
String string
= (String) resultSet.getObject(column);
try {
Number value = Double.valueOf(string);
if (this.transpose) {
setValue(value, columnKey, rowKey);
}
else {
setValue(value, rowKey, columnKey);
}
}
catch (NumberFormatException e) {
// suppress (value defaults to null)
}
break;
}
default:
// not a value, can't use it (defaults to null)
break;
}
}
}
fireDatasetChanged();
}
finally {
if (resultSet != null) {
try {
resultSet.close();
}
catch (Exception e) {
// report this?
}
}
if (statement != null) {
try {
statement.close();
}
catch (Exception e) {
// report this?
}
}
}
}
Populates the dataset by executing the supplied query 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. | org.jfree.data.general.AbstractDataset
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