org.apache.pig.builtin.TOKENIZE Maven / Gradle / Ivy
/*
* 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 java.util.StringTokenizer;
import org.apache.pig.EvalFunc;
import org.apache.pig.PigException;
import org.apache.pig.backend.executionengine.ExecException;
import org.apache.pig.data.BagFactory;
import org.apache.pig.data.DataBag;
import org.apache.pig.data.DataType;
import org.apache.pig.data.Tuple;
import org.apache.pig.data.TupleFactory;
import org.apache.pig.impl.logicalLayer.FrontendException;
import org.apache.pig.impl.logicalLayer.schema.Schema;
import org.apache.pig.FuncSpec;
/**
* Given a chararray as an argument, this method will split the chararray and
* return a bag with a tuple for each chararray that results from the split.
* The string is split on space, double quote, comma, open parend, close parend,
* and asterisk (star).
*/
public class TOKENIZE extends EvalFunc {
TupleFactory mTupleFactory = TupleFactory.getInstance();
BagFactory mBagFactory = BagFactory.getInstance();
@Override
public DataBag exec(Tuple input) throws IOException {
try {
if (input==null)
return null;
if (input.size()==0)
return null;
Object o = input.get(0);
if (o==null)
return null;
DataBag output = mBagFactory.newDefaultBag();
if (!(o instanceof String)) {
int errCode = 2114;
String msg = "Expected input to be chararray, but" +
" got " + o.getClass().getName();
throw new ExecException(msg, errCode, PigException.BUG);
}
StringTokenizer tok = new StringTokenizer((String)o, " \",()*", false);
while (tok.hasMoreTokens()) {
output.add(mTupleFactory.newTuple(tok.nextToken()));
}
return output;
} catch (ExecException ee) {
throw ee;
}
}
@SuppressWarnings("deprecation")
@Override
public Schema outputSchema(Schema input) {
try {
Schema.FieldSchema tokenFs = new Schema.FieldSchema("token",
DataType.CHARARRAY);
Schema tupleSchema = new Schema(tokenFs);
Schema.FieldSchema tupleFs;
tupleFs = new Schema.FieldSchema("tuple_of_tokens", tupleSchema,
DataType.TUPLE);
Schema bagSchema = new Schema(tupleFs);
bagSchema.setTwoLevelAccessRequired(true);
Schema.FieldSchema bagFs = new Schema.FieldSchema(
"bag_of_tokenTuples",bagSchema, DataType.BAG);
return new Schema(bagFs);
} catch (FrontendException e) {
// throwing RTE because
//above schema creation is not expected to throw an exception
// and also because superclass does not throw exception
throw new RuntimeException("Unable to compute TOKENIZE schema.");
}
}
public List getArgToFuncMapping() throws FrontendException {
List funcList = new ArrayList();
Schema s = new Schema();
s.add(new Schema.FieldSchema(null, DataType.CHARARRAY));
funcList.add(new FuncSpec(this.getClass().getName(), s));
return funcList;
}
};