| /* |
| * 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.beam.runners.apex.examples; |
| |
| import java.io.IOException; |
| import java.io.Serializable; |
| import java.util.Collections; |
| import java.util.List; |
| import java.util.NoSuchElementException; |
| import javax.annotation.Nullable; |
| import org.apache.beam.sdk.coders.Coder; |
| import org.apache.beam.sdk.coders.StringUtf8Coder; |
| import org.apache.beam.sdk.io.UnboundedSource; |
| import org.apache.beam.sdk.options.PipelineOptions; |
| import org.joda.time.Instant; |
| |
| /** |
| * unbounded source that reads from text. |
| */ |
| public class UnboundedTextSource extends UnboundedSource<String, UnboundedSource.CheckpointMark> { |
| private static final long serialVersionUID = 1L; |
| |
| @Override |
| public List<? extends UnboundedSource<String, CheckpointMark>> split( |
| int desiredNumSplits, PipelineOptions options) throws Exception { |
| return Collections.<UnboundedSource<String, CheckpointMark>>singletonList(this); |
| } |
| |
| @Override |
| public UnboundedReader<String> createReader(PipelineOptions options, |
| @Nullable CheckpointMark checkpointMark) { |
| return new UnboundedTextReader(this); |
| } |
| |
| @Nullable |
| @Override |
| public Coder<CheckpointMark> getCheckpointMarkCoder() { |
| return null; |
| } |
| |
| @Override |
| public void validate() { |
| } |
| |
| @Override |
| public Coder<String> getDefaultOutputCoder() { |
| return StringUtf8Coder.of(); |
| } |
| |
| /** |
| * reads from text. |
| */ |
| public static class UnboundedTextReader extends UnboundedReader<String> implements Serializable { |
| |
| private static final long serialVersionUID = 7526472295622776147L; |
| |
| private final UnboundedTextSource source; |
| |
| private final String[] texts = new String[]{"foo foo foo bar bar", "foo foo bar bar bar"}; |
| private long index = 0; |
| |
| private String currentRecord; |
| |
| private Instant currentTimestamp; |
| |
| public UnboundedTextReader(UnboundedTextSource source) { |
| this.source = source; |
| } |
| |
| @Override |
| public boolean start() throws IOException { |
| currentRecord = texts[0]; |
| currentTimestamp = new Instant(0); |
| return true; |
| } |
| |
| @Override |
| public boolean advance() throws IOException { |
| index++; |
| currentRecord = texts[(int) index % (texts.length)]; |
| currentTimestamp = new Instant(index * 1000); |
| try { |
| Thread.sleep(index); // allow for downstream processing to complete |
| } catch (InterruptedException e) { |
| throw new RuntimeException(e); |
| } |
| return true; |
| } |
| |
| @Override |
| public byte[] getCurrentRecordId() throws NoSuchElementException { |
| return new byte[0]; |
| } |
| |
| @Override |
| public String getCurrent() throws NoSuchElementException { |
| return this.currentRecord; |
| } |
| |
| @Override |
| public Instant getCurrentTimestamp() throws NoSuchElementException { |
| return currentTimestamp; |
| } |
| |
| @Override |
| public void close() throws IOException { |
| } |
| |
| @Override |
| public Instant getWatermark() { |
| return currentTimestamp; |
| } |
| |
| @Override |
| public CheckpointMark getCheckpointMark() { |
| return null; |
| } |
| |
| @Override |
| public UnboundedSource<String, ?> getCurrentSource() { |
| return this.source; |
| } |
| } |
| } |