/*
* 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.phoenix.expression.function;
import java.io.*;
import java.sql.SQLException;
import java.text.Format;
import java.text.ParseException;
import java.util.List;
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
import org.apache.hadoop.io.WritableUtils;
import org.apache.phoenix.expression.Expression;
import org.apache.phoenix.parse.*;
import org.apache.phoenix.parse.FunctionParseNode.Argument;
import org.apache.phoenix.parse.FunctionParseNode.BuiltInFunction;
import org.apache.phoenix.schema.PDataType;
import org.apache.phoenix.schema.tuple.Tuple;
import org.apache.phoenix.util.DateUtil;
/**
*
* Implementation of the TO_DATE(<string>,[<format-string>]) built-in function.
* The second argument is optional and defaults to the phoenix.query.dateFormat value
* from the HBase config. If present it must be a constant string.
*
*
* @since 0.1
*/
@BuiltInFunction(name=ToDateFunction.NAME, nodeClass=ToDateParseNode.class, args= {@Argument(allowedTypes={PDataType.VARCHAR}),@Argument(allowedTypes={PDataType.VARCHAR},isConstant=true,defaultValue="null")} )
public class ToDateFunction extends ScalarFunction {
public static final String NAME = "TO_DATE";
private Format dateParser;
private String dateFormat;
public ToDateFunction() {
}
public ToDateFunction(List<Expression> children, String dateFormat, Format dateParser) throws SQLException {
super(children.subList(0, 1));
this.dateFormat = dateFormat;
this.dateParser = dateParser;
}
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + dateFormat.hashCode();
result = prime * result + getExpression().hashCode();
return result;
}
@Override
public boolean equals(Object obj) {
if (this == obj) return true;
if (obj == null) return false;
if (getClass() != obj.getClass()) return false;
ToDateFunction other = (ToDateFunction)obj;
if (!getExpression().equals(other.getExpression())) return false;
if (!dateFormat.equals(other.dateFormat)) return false;
return true;
}
@Override
public boolean evaluate(Tuple tuple, ImmutableBytesWritable ptr) {
Expression expression = getExpression();
if (!expression.evaluate(tuple, ptr) || ptr.getLength() == 0) {
return false;
}
PDataType type = expression.getDataType();
String dateStr = (String)type.toObject(ptr, expression.getSortOrder());
try {
Object value = dateParser.parseObject(dateStr);
byte[] byteValue = getDataType().toBytes(value);
ptr.set(byteValue);
return true;
} catch (ParseException e) {
throw new IllegalStateException("to_date('" + dateStr + ")' did not match expected date format of '" + dateFormat + "'.");
}
}
@Override
public PDataType getDataType() {
return PDataType.DATE;
}
@Override
public boolean isNullable() {
return getExpression().isNullable();
}
@Override
public void readFields(DataInput input) throws IOException {
super.readFields(input);
dateFormat = WritableUtils.readString(input);
dateParser = DateUtil.getDateParser(dateFormat);
}
@Override
public void write(DataOutput output) throws IOException {
super.write(output);
WritableUtils.writeString(output, dateFormat);
}
private Expression getExpression() {
return children.get(0);
}
@Override
public String getName() {
return NAME;
}
}