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.rocketmq.remoting.netty; import io.netty.buffer.ByteBuf; import io.netty.channel.DefaultFileRegion; import io.netty.channel.FileRegion; import io.netty.channel.embedded.EmbeddedChannel; import java.io.BufferedOutputStream; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.util.Random; import java.util.UUID; import org.junit.Assert; import org.junit.Test; public class FileRegionEncoderTest { /** * This unit test case ensures that {@link FileRegionEncoder} indeed wraps {@link FileRegion} to * {@link ByteBuf}. * @throws IOException if there is an error. */ @Test public void testEncode() throws IOException { FileRegionEncoder fileRegionEncoder = new FileRegionEncoder(); EmbeddedChannel channel = new EmbeddedChannel(fileRegionEncoder); File file = File.createTempFile(UUID.randomUUID().toString(), ".data"); file.deleteOnExit(); Random random = new Random(System.currentTimeMillis()); int dataLength = 1 << 10; byte[] data = new byte[dataLength]; random.nextBytes(data); write(file, data); FileRegion fileRegion = new DefaultFileRegion(file, 0, dataLength); Assert.assertEquals(0, fileRegion.transfered()); Assert.assertEquals(dataLength, fileRegion.count()); Assert.assertTrue(channel.writeOutbound(fileRegion)); ByteBuf out = (ByteBuf) channel.readOutbound(); byte[] arr = new byte[out.readableBytes()]; out.getBytes(0, arr); Assert.assertArrayEquals("Data should be identical", data, arr); } /** * Write byte array to the specified file. * * @param file File to write to. * @param data byte array to write. * @throws IOException in case there is an exception. */ private static void write(File file, byte[] data) throws IOException { BufferedOutputStream bufferedOutputStream = null; try { bufferedOutputStream = new BufferedOutputStream(new FileOutputStream(file, false)); bufferedOutputStream.write(data); bufferedOutputStream.flush(); } finally { if (null != bufferedOutputStream) { bufferedOutputStream.close(); } } } }