org.apache.flink.streaming.api.functions.source.FileReadFunction 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.flink.streaming.api.functions.source;
import org.apache.flink.annotation.Internal;
import org.apache.flink.api.common.functions.FlatMapFunction;
import org.apache.flink.api.java.tuple.Tuple3;
import org.apache.flink.core.fs.FSDataInputStream;
import org.apache.flink.core.fs.FileSystem;
import org.apache.flink.core.fs.Path;
import org.apache.flink.util.Collector;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.URI;
/**
* This is used together with {@link FileMonitoringFunction} to read from files that the
* monitoring functions discovers.
*
* @deprecated Internal class deprecated in favour of {@link ContinuousFileMonitoringFunction}.
*/
@Internal
@Deprecated
public class FileReadFunction implements FlatMapFunction, String> {
private static final long serialVersionUID = 1L;
@Override
public void flatMap(Tuple3 value, Collector out) throws Exception {
FSDataInputStream stream = FileSystem.get(new URI(value.f0)).open(new Path(value.f0));
stream.seek(value.f1);
BufferedReader reader = new BufferedReader(new InputStreamReader(stream));
String line;
try {
while ((line = reader.readLine()) != null && (value.f2 == -1L || stream.getPos() <= value.f2)) {
out.collect(line);
}
} finally {
reader.close();
}
}
}