/**
* 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.pig.builtin;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import org.apache.pig.EvalFunc;
import org.apache.pig.FuncSpec;
import org.apache.pig.data.DataType;
import org.apache.pig.data.Tuple;
import org.apache.pig.impl.logicalLayer.FrontendException;
import org.apache.pig.impl.logicalLayer.schema.Schema;
import org.joda.time.format.DateTimeFormat;
import org.joda.time.format.DateTimeFormatter;
/**
*
* <p>ToString converts the DateTime object of the ISO or the customized string.</p>
*
*/
public class ToString extends EvalFunc<String> {
public String exec(Tuple input) throws IOException {
if (input == null || input.size() < 1 || input.get(0) == null) {
return null;
}
if (input.size() == 1) {
return DataType.toDateTime(input.get(0)).toString();
} else if (input.size() == 2) {
DateTimeFormatter dtf = DateTimeFormat.forPattern(DataType.toString(input.get(1)));
return DataType.toDateTime(input.get(0)).toString(dtf);
} else {
return null;
}
}
@Override
public Schema outputSchema(Schema input) {
return new Schema(new Schema.FieldSchema(getSchemaName(this.getClass().getName().toLowerCase(), input), DataType.CHARARRAY));
}
@Override
public List<FuncSpec> getArgToFuncMapping() throws FrontendException {
List<FuncSpec> funcList = new ArrayList<FuncSpec>();
Schema s = new Schema();
s.add(new Schema.FieldSchema(null, DataType.DATETIME));
funcList.add(new FuncSpec(this.getClass().getName(), s));
s = new Schema();
s.add(new Schema.FieldSchema(null, DataType.DATETIME));
s.add(new Schema.FieldSchema(null, DataType.CHARARRAY));
funcList.add(new FuncSpec(this.getClass().getName(), s));
return funcList;
}
@Override
public boolean allowCompileTimeCalculation() {
return true;
}
}