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.pulsar.io.file; import java.io.File; import java.io.IOException; import java.io.OutputStream; import java.nio.file.Files; import java.nio.file.Path; import java.nio.file.Paths; import java.nio.file.StandardOpenOption; import java.nio.file.attribute.FileAttribute; import java.util.concurrent.BlockingQueue; import org.apache.commons.io.IOUtils; import org.apache.commons.lang3.RandomStringUtils; public class TestFileGenerator extends Thread { // Allows us to communicate back which files we generated private final BlockingQueue<File> producedFiles; private final int numFiles; private final long delay; private final int numLines; private final String prefix; private final String suffix; private final FileAttribute<?>[] attrs; private final Path tempDir; private boolean keepRunning = true; public TestFileGenerator(BlockingQueue<File> producedFiles, int numFiles, long delay, int numLines, String dir, String prefix, String suffix, FileAttribute<?>... attrs) throws IOException { this.numFiles = numFiles; this.delay = delay; this.numLines = numLines; this.producedFiles = producedFiles; this.prefix = prefix; this.suffix = suffix; this.attrs = attrs; tempDir = Files.createDirectories(Paths.get(dir), attrs); } public void run() { int counter = 0; while (keepRunning && (counter++ < numFiles)) { createFile(); try { sleep(delay); } catch (InterruptedException e) { return; } } } public void halt() { keepRunning = false; } private final void createFile() { try { Path path = Files.createTempFile(tempDir, prefix, suffix, attrs); try (OutputStream out = Files.newOutputStream(path, StandardOpenOption.APPEND)) { for (int idx = 0; idx < numLines; idx++) { IOUtils.write(RandomStringUtils.random(50, true, false) + "\n", out, "UTF-8"); } } producedFiles.put(path.toFile()); } catch (IOException | InterruptedException e) { e.printStackTrace(); } } }