| /* |
| * 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.impl.streaming; |
| |
| import java.util.List; |
| |
| import org.apache.pig.backend.executionengine.ExecException; |
| import org.apache.pig.impl.streaming.StreamingCommand.Handle; |
| import org.apache.pig.impl.streaming.StreamingCommand.HandleSpec; |
| |
| /** |
| * Factory to create an {@link InputHandler} or {@link OutputHandler} |
| * depending on the specification of the {@link StreamingCommand}. |
| */ |
| public class HandlerFactory { |
| |
| /** |
| * Create an <code>InputHandler</code> for the given input specification |
| * of the <code>StreamingCommand</code>. |
| * |
| * @param command <code>StreamingCommand</code> |
| * @return <code>InputHandler</code> for the given input specification |
| * @throws ExecException |
| */ |
| public static InputHandler createInputHandler(StreamingCommand command) |
| throws ExecException { |
| List<HandleSpec> inputSpecs = command.getHandleSpecs(Handle.INPUT); |
| |
| HandleSpec in = null; |
| if (inputSpecs == null || (in = inputSpecs.get(0)) == null) { |
| return new DefaultInputHandler(); |
| } |
| |
| return (in.name.equals("stdin")) ? new DefaultInputHandler(in) : |
| new FileInputHandler(in); |
| } |
| |
| /** |
| * Create an <code>OutputHandler</code> for the given output specification |
| * of the <code>StreamingCommand</code>. |
| * |
| * @param command <code>StreamingCommand</code> |
| * @return <code>OutputHandler</code> for the given output specification |
| * @throws ExecException |
| */ |
| public static OutputHandler createOutputHandler(StreamingCommand command) |
| throws ExecException { |
| List<HandleSpec> outputSpecs = command.getHandleSpecs(Handle.OUTPUT); |
| |
| HandleSpec out = null; |
| if (outputSpecs == null || (out = outputSpecs.get(0)) == null) { |
| return new DefaultOutputHandler(); |
| } |
| |
| return (out.name.equals("stdout")) ? new DefaultOutputHandler(out) : |
| new FileOutputHandler(out); |
| } |
| } |