Java tutorial
/* * 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.backend.local.executionengine; import java.io.OutputStream; import java.io.InputStream; import java.util.Iterator; import java.util.Map; import java.util.Properties; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.pig.backend.executionengine.ExecException; import org.apache.pig.backend.executionengine.ExecJob; import org.apache.pig.data.Tuple; import org.apache.pig.impl.PigContext; import org.apache.pig.impl.io.FileSpec; import org.apache.pig.LoadFunc; import org.apache.pig.impl.io.FileLocalizer; import org.apache.pig.impl.io.BufferedPositionedInputStream; import org.apache.pig.tools.pigstats.PigStats; public class LocalJob implements ExecJob { private final Log log = LogFactory.getLog(getClass()); protected JOB_STATUS status; protected PigContext pigContext; protected FileSpec outFileSpec; private PigStats stats; public LocalJob(JOB_STATUS status, PigContext pigContext, FileSpec outFileSpec) { this.status = status; this.pigContext = pigContext; this.outFileSpec = outFileSpec; } public LocalJob(JOB_STATUS status, PigContext pigContext, FileSpec outFileSpec, PigStats stats) { this.status = status; this.pigContext = pigContext; this.outFileSpec = outFileSpec; this.stats = stats; } public JOB_STATUS getStatus() { return status; } public boolean hasCompleted() throws ExecException { return true; } public Iterator<Tuple> getResults() throws ExecException { final LoadFunc p; try { p = (LoadFunc) PigContext.instantiateFuncFromSpec(outFileSpec.getFuncSpec()); InputStream is = FileLocalizer.open(outFileSpec.getFileName(), pigContext); p.bindTo(outFileSpec.getFileName(), new BufferedPositionedInputStream(is), 0, Long.MAX_VALUE); } catch (Exception e) { throw new ExecException("Unable to get results for " + outFileSpec, e); } return new Iterator<Tuple>() { Tuple t; boolean atEnd; public boolean hasNext() { if (atEnd) return false; try { if (t == null) t = p.getNext(); if (t == null) atEnd = true; } catch (Exception e) { log.error(e); t = null; atEnd = true; } return !atEnd; } public Tuple next() { Tuple next = t; if (next != null) { t = null; return next; } try { next = p.getNext(); } catch (Exception e) { log.error(e); } if (next == null) atEnd = true; return next; } public void remove() { throw new RuntimeException("Removal not supported"); } }; } public Properties getContiguration() { Properties props = new Properties(); return props; } public PigStats getStatistics() { //throw new UnsupportedOperationException(); return stats; } public void completionNotification(Object cookie) { throw new UnsupportedOperationException(); } public void kill() throws ExecException { throw new UnsupportedOperationException(); } public void getLogs(OutputStream log) throws ExecException { throw new UnsupportedOperationException(); } public void getSTDOut(OutputStream out) throws ExecException { throw new UnsupportedOperationException(); } public void getSTDError(OutputStream error) throws ExecException { throw new UnsupportedOperationException(); } public Exception getException() { return null; } }