| /* |
| * 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 org.apache.pig.EvalFunc; |
| import org.apache.pig.PigException; |
| import org.apache.pig.backend.executionengine.ExecException; |
| import org.apache.pig.data.DataType; |
| import org.apache.pig.data.Tuple; |
| import org.apache.pig.impl.logicalLayer.schema.Schema; |
| |
| |
| /** |
| * This method should never be used directly, use {@link CONCAT}. |
| */ |
| public class StringConcat extends EvalFunc<String> { |
| |
| @Override |
| public String exec(Tuple input) throws IOException { |
| try{ |
| if (input == null || input.size() == 0) |
| return null; |
| |
| StringBuilder sb = new StringBuilder(); |
| for (int i = 0; i < input.size(); i++){ |
| if (input.get(i)==null) |
| return null; |
| sb.append(String.valueOf(input.get(i))); |
| } |
| return sb.toString(); |
| } catch (ExecException exp) { |
| throw exp; |
| } catch (Exception e) { |
| int errCode = 2106; |
| String msg = "Error while computing concat in " + this.getClass().getSimpleName(); |
| throw new ExecException(msg, errCode, PigException.BUG, e); |
| } |
| } |
| |
| @Override |
| public Schema outputSchema(Schema input) { |
| return new Schema(new Schema.FieldSchema(null, DataType.CHARARRAY)); |
| } |
| |
| @Override |
| public SchemaType getSchemaType() { |
| return SchemaType.VARARG; |
| } |
| |
| @Override |
| public boolean allowCompileTimeCalculation() { |
| return true; |
| } |
| } |