/*
* Copyright © 2014 Cask Data, Inc.
*
* Licensed 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 co.cask.cdap.explore.jdbc;
import co.cask.cdap.common.utils.ImmutablePair;
import co.cask.cdap.proto.ColumnDesc;
import com.google.common.collect.ImmutableList;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.List;
/**
* Static result set where the schema is set and the results are empty.
*/
public class StaticEmptyExploreResultSet extends BaseExploreResultSet {
private final List<ImmutablePair<String, String>> schema;
public StaticEmptyExploreResultSet(List<ImmutablePair<String, String>> schema) {
this.schema = schema;
}
@Override
public boolean next() throws SQLException {
if (isClosed()) {
throw new SQLException("Resultset is closed");
}
return false;
}
@Override
public void close() throws SQLException {
setIsClosed(true);
}
@Override
public ResultSetMetaData getMetaData() throws SQLException {
if (isClosed()) {
throw new SQLException("Resultset is closed");
}
ImmutableList.Builder builder = ImmutableList.builder();
for (int i = 0; i < schema.size(); i++) {
ImmutablePair<String, String> pair = schema.get(i);
builder.add(new ColumnDesc(pair.getFirst(), pair.getSecond(), i + 1, ""));
}
return new ExploreResultSetMetaData(builder.build());
}
@Override
public Object getObject(int i) throws SQLException {
if (isClosed()) {
throw new SQLException("Resultset is closed");
}
return null;
}
@Override
public int findColumn(String name) throws SQLException {
if (isClosed()) {
throw new SQLException("Resultset is closed");
}
for (int i = 0; i < schema.size(); i++) {
if (schema.get(i).getFirst().equals(name)) {
return i + 1;
}
}
throw new SQLException("Could not find column with name: " + name);
}
}