Java tutorial
/* * @(#)$Id$ * * Copyright 2006-2008 Makoto YUI * * Licensed 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. * * Contributors: * Makoto YUI - initial implementation */ package gridool.util.xfer; import gridool.util.collections.SoftHashMap; import gridool.util.datetime.StopWatch; import gridool.util.io.FileUtils; import gridool.util.io.IOUtils; import gridool.util.nio.NIOUtils; import java.io.DataInputStream; import java.io.DataOutputStream; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.net.Socket; import java.net.SocketAddress; import java.nio.channels.FileChannel; import java.nio.channels.SocketChannel; import java.util.Map; import java.util.concurrent.locks.ReadWriteLock; import java.util.concurrent.locks.ReentrantReadWriteLock; import javax.annotation.Nonnull; import javax.annotation.Nullable; import javax.annotation.concurrent.GuardedBy; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; /** * * <DIV lang="en"></DIV> * <DIV lang="ja"></DIV> * * @author Makoto YUI (yuin405@gmail.com) */ public class RecievedFileWriter implements TransferRequestListener { private static final Log LOG = LogFactory.getLog(RecievedFileWriter.class); @Nonnull private final File baseDir; @GuardedBy("locks") private final Map<String, ReadWriteLock> locks; public RecievedFileWriter(@Nonnull String baseDirPath) { this(new File(baseDirPath)); } public RecievedFileWriter(@Nonnull File baseDir) { if (!baseDir.exists()) { throw new IllegalArgumentException("Directory not found: " + baseDir.getAbsolutePath()); } if (!baseDir.isDirectory()) { throw new IllegalArgumentException(baseDir.getAbsolutePath() + " is not directory"); } if (!baseDir.canWrite()) { throw new IllegalArgumentException(baseDir.getAbsolutePath() + " is not writable"); } this.baseDir = baseDir; this.locks = new SoftHashMap<String, ReadWriteLock>(32); } public final void handleRequest(@Nonnull final SocketChannel inChannel, @Nonnull final Socket socket) throws IOException { final StopWatch sw = new StopWatch(); if (!inChannel.isBlocking()) { inChannel.configureBlocking(true); } InputStream in = socket.getInputStream(); DataInputStream dis = new DataInputStream(in); String fname = IOUtils.readString(dis); String dirPath = IOUtils.readString(dis); long len = dis.readLong(); boolean append = dis.readBoolean(); boolean ackRequired = dis.readBoolean(); boolean hasAdditionalHeader = dis.readBoolean(); if (hasAdditionalHeader) { readAdditionalHeader(dis, fname, dirPath, len, append, ackRequired); } final File file; if (dirPath == null) { file = new File(baseDir, fname); } else { File dir = FileUtils.resolvePath(baseDir, dirPath); file = new File(dir, fname); } preFileAppend(file, append); final FileOutputStream dst = new FileOutputStream(file, append); final String fp = file.getAbsolutePath(); final ReadWriteLock filelock = accquireLock(fp, locks); final FileChannel fileCh = dst.getChannel(); final long startPos = file.length(); try { NIOUtils.transferFully(inChannel, 0, len, fileCh); // REVIEWME really an atomic operation? } finally { IOUtils.closeQuietly(fileCh, dst); releaseLock(fp, filelock, locks); postFileAppend(file, startPos, len); } if (ackRequired) { OutputStream out = socket.getOutputStream(); DataOutputStream dos = new DataOutputStream(out); dos.writeLong(len); postAck(file, startPos, len); } if (LOG.isDebugEnabled()) { SocketAddress remoteAddr = socket.getRemoteSocketAddress(); LOG.debug("Received a " + (append ? "part of file '" : "file '") + file.getAbsolutePath() + "' of " + len + " bytes from " + remoteAddr + " in " + sw.toString()); } } protected void readAdditionalHeader(@Nonnull DataInputStream in, @Nonnull String fname, @Nullable String dirPath, long len, boolean append, boolean sync) throws IOException { } protected void preFileAppend(@Nonnull File file, boolean append) throws IOException { } protected void postFileAppend(@Nonnull File file, long startPos, long len) throws IOException { } protected void postAck(@Nonnull File file, long startPos, long len) throws IOException { } private static ReadWriteLock accquireLock(final String key, final Map<String, ReadWriteLock> locks) { ReadWriteLock lock; synchronized (locks) { lock = locks.get(key); if (lock == null) { lock = new ReentrantReadWriteLock(); locks.put(key, lock); } } lock.writeLock().lock(); return lock; } private static void releaseLock(final String key, final ReadWriteLock lock, final Map<String, ReadWriteLock> locks) { lock.writeLock().unlock(); } }