/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.jena.jdbc.results;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.SQLFeatureNotSupportedException;
import org.apache.jena.jdbc.results.metadata.AskResultsMetadata;
import org.apache.jena.jdbc.statements.JenaStatement;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.hp.hpl.jena.datatypes.xsd.XSDDatatype;
import com.hp.hpl.jena.graph.Node;
import com.hp.hpl.jena.graph.NodeFactory;
/**
* Represents an ASK result
*
*/
public class AskResults extends JenaResultSet {
private static final Logger LOGGER = LoggerFactory.getLogger(AskResults.class);
private boolean result, closed = false;
private int currRow = 0;
private boolean needsCommit = false;
private AskResultsMetadata metadata;
private String columnLabel;
/**
* Creates a new ASK result
* @param statement Statement
* @param result Boolean result
* @param commit Whether a commit is required when the results are closed
* @throws SQLException Thrown if the arguments are invalid
*/
public AskResults(JenaStatement statement, boolean result, boolean commit) throws SQLException {
super(statement);
this.result = result;
this.needsCommit = commit;
this.metadata = statement.getJenaConnection().applyPostProcessors(new AskResultsMetadata(this));
this.columnLabel = this.metadata.getColumnLabel(AskResultsMetadata.COLUMN_INDEX_ASK);
}
public boolean absolute(int row) throws SQLException {
// We can move backwards and forwards in an ASK result but there
// is only ever a single row
if (this.isClosed()) {
throw new SQLException("Cannot move to a row after the result set has been closed");
} else if (row == 1) {
return this.first();
} else if (row == -1) {
return this.last();
} else if (row == 0) {
return true;
} else {
throw new SQLException("Moving the requested number of rows would be outside the allowable range of rows");
}
}
public void afterLast() throws SQLException {
this.currRow = 2;
}
public void beforeFirst() throws SQLException {
this.currRow = 0;
}
public void close() throws SQLException {
if (this.closed) return;
this.closed = true;
if (this.needsCommit) {
LOGGER.info("Result Set associated with an auto-committing transaction, performing a commit now");
this.getStatement().getConnection().commit();
}
}
public int findColumn(String columnLabel) throws SQLException {
if (this.columnLabel.equals(columnLabel)) return 1;
throw new SQLException("The given column does not exist in this result set");
}
public boolean first() throws SQLException {
if (this.isClosed()) throw new SQLException("Cannot move to a row after the result set has been closed");
this.currRow = 1;
return true;
}
public int getFetchDirection() throws SQLException {
return ResultSet.FETCH_FORWARD;
}
public int getFetchSize() throws SQLException {
return 1;
}
public int getRow() throws SQLException {
return this.currRow;
}
public int getType() throws SQLException {
return ResultSet.TYPE_SCROLL_INSENSITIVE;
}
public boolean isAfterLast() throws SQLException {
if (this.isClosed()) throw new SQLException("Result Set is closed");
return this.currRow == 2;
}
public boolean isBeforeFirst() throws SQLException {
if (this.isClosed()) throw new SQLException("Result Set is closed");
return this.currRow == 0;
}
public boolean isClosed() throws SQLException {
return this.closed;
}
public boolean isFirst() throws SQLException {
if (this.isClosed()) throw new SQLException("Result Set is closed");
return this.currRow == 1;
}
public boolean isLast() throws SQLException {
if (this.isClosed()) throw new SQLException("Result Set is closed");
return this.currRow == 1;
}
public boolean last() throws SQLException {
if (this.isClosed()) throw new SQLException("Cannot move to a row after the result set has been closed");
this.currRow = 1;
return true;
}
public boolean next() throws SQLException {
if (this.isClosed()) throw new SQLException("Cannot move to a row after the result set has been closed");
if (this.currRow < 2) {
this.currRow++;
}
return this.currRow == 1;
}
public boolean relative(int rows) throws SQLException {
if (this.isClosed()) {
throw new SQLException("Cannot move to a row after the result set has been closed");
} else if (this.currRow == 0 && (rows >= 0 && rows <= 2)) {
this.currRow += rows;
return true;
} else if (this.currRow == 1 && (rows >= -1 && rows <= 1)) {
this.currRow += rows;
return true;
} else if (this.currRow == 2 && (rows >= -2 && rows <= 0)) {
this.currRow += rows;
return true;
} else {
throw new SQLException("Moving the requested number of rows would be outside the allowable range of rows");
}
}
public void setFetchDirection(int direction) throws SQLException {
if (direction != ResultSet.FETCH_FORWARD) throw new SQLFeatureNotSupportedException("Jena JDBC Result Sets only support forward fetch");
}
public void setFetchSize(int rows) throws SQLException {
throw new SQLFeatureNotSupportedException("Fetch Size is not relevant for ASK results");
}
@Override
public ResultSetMetaData getMetaData() throws SQLException {
return this.metadata;
}
@Override
protected String findColumnLabel(int columnIndex) throws SQLException {
if (columnIndex == AskResultsMetadata.COLUMN_INDEX_ASK) return this.columnLabel;
throw new SQLException("Column Index is out of bounds");
}
@Override
protected Node getNode(String columnLabel) throws SQLException {
if (this.isClosed()) throw new SQLException("Result Set is closed");
if (this.currRow != 1) throw new SQLException("Not currently at a row");
if (this.columnLabel.equals(columnLabel)) {
return NodeFactory.createLiteral(Boolean.toString(this.result), XSDDatatype.XSDboolean);
} else {
throw new SQLException("The given column does not exist in the result set");
}
}
@Override
public boolean getBoolean(String columnLabel) throws SQLException {
if (this.isClosed()) throw new SQLException("Result Set is closed");
if (this.currRow != 1) throw new SQLException("Not currently at a row");
if (this.columnLabel.equals(columnLabel)) {
this.setNull(false);
return this.result;
} else {
throw new SQLException("The given column does not exist in the result set");
}
}
}