/**
* 检查文件是否上锁
*
* @return
* @throws IOException
*/
public boolean validateFile() throws IOException {
fileUrl = System.getProperty("user.dir") + "/SpiderRun.lock";
File myfilelock = new File(fileUrl);
RandomAccessFile raf = null;
FileChannel fc = null;
if (!myfilelock.exists()) {
// 不存在，则新增文件，然后加锁
raf = new RandomAccessFile(myfilelock, "rw");
fc = raf.getChannel();
FileLock fl = fc.tryLock();
if (fl != null && fl.isValid()) {
// System.err.println(fileUrl + "文件被创建且被锁！");
return false;
}
} else {
// 存在，判断是否被锁
raf = new RandomAccessFile(myfilelock, "rw");
fc = raf.getChannel();
FileLock fl = fc.tryLock();
if (fl != null && fl.isValid()) {
// 被锁
System.err.println(fileUrl + "文件已被锁，请删除后，再启动该进程！");
return true;
}
}
return false;
}
@Test
public void testLockNegative() throws IOException {
FileChannel channel = channel(regularFile(0), READ, WRITE);
try {
channel.lock(-1, 10, true);
fail();
} catch (IllegalArgumentException expected) {
}
try {
channel.lock(0, -1, true);
fail();
} catch (IllegalArgumentException expected) {
}
try {
channel.tryLock(-1, 10, true);
fail();
} catch (IllegalArgumentException expected) {
}
try {
channel.tryLock(0, -1, true);
fail();
} catch (IllegalArgumentException expected) {
}
}
/**
* Try to open the file.
*
* @param fileName the file name
* @param readOnly whether the file should only be opened in read-only mode, even if the file is
* writable
* @param encryptionKey the encryption key, or null if encryption is not used
*/
public void open(String fileName, boolean readOnly, char[] encryptionKey) {
if (file != null) {
return;
}
if (fileName != null) {
FilePath p = FilePath.get(fileName);
// if no explicit scheme was specified, NIO is used
if (p instanceof FilePathDisk && !fileName.startsWith(p.getScheme() + ":")) {
// ensure the NIO file system is registered
FilePathNio.class.getName();
fileName = "nio:" + fileName;
}
}
this.fileName = fileName;
FilePath f = FilePath.get(fileName);
FilePath parent = f.getParent();
if (parent != null && !parent.exists()) {
throw DataUtils.newIllegalArgumentException("Directory does not exist: {0}", parent);
}
if (f.exists() && !f.canWrite()) {
readOnly = true;
}
this.readOnly = readOnly;
try {
file = f.open(readOnly ? "r" : "rw");
if (encryptionKey != null) {
byte[] key = FilePathEncrypt.getPasswordBytes(encryptionKey);
encryptedFile = file;
file = new FilePathEncrypt.FileEncrypt(fileName, key, file);
}
file = FilePathCache.wrap(file);
try {
if (readOnly) {
fileLock = file.tryLock(0, Long.MAX_VALUE, true);
} else {
fileLock = file.tryLock();
}
} catch (OverlappingFileLockException e) {
throw DataUtils.newIllegalStateException(
DataUtils.ERROR_FILE_LOCKED, "The file is locked: {0}", fileName, e);
}
if (fileLock == null) {
throw DataUtils.newIllegalStateException(
DataUtils.ERROR_FILE_LOCKED, "The file is locked: {0}", fileName);
}
fileSize = file.size();
} catch (IOException e) {
throw DataUtils.newIllegalStateException(
DataUtils.ERROR_READING_FAILED, "Could not open file {0}", fileName, e);
}
}
private boolean lock(int flg) {
try {
if (fc != null) {
if (flg == TRY_LOCK_FLG) {
fl = fc.tryLock();
} else if (flg == LOCK_FLG) {
fl = fc.lock();
}
if (fl == null) {
return false;
}
return true;
} else {
return false;
}
} catch (IOException e) {
e.printStackTrace();
try {
fl.release();
} catch (IOException ex) {
ex.printStackTrace();
}
return false;
}
}
public boolean isLocked() {
try {
channel = new RandomAccessFile(file, "rw").getChannel();
try {
lock = channel.tryLock();
} catch (OverlappingFileLockException e) {
close();
return true;
}
if (lock == null) {
close();
return true;
}
hook =
new Thread() {
@Override
public void run() {
close();
deleteFile();
}
};
Runtime.getRuntime().addShutdownHook(hook);
return false;
} catch (Exception e) {
close();
return true;
}
}
public static boolean isAppActive() {
try {
file = new File(System.getProperty("user.home"), appName + ".tmp");
channel = new RandomAccessFile(file, "rw").getChannel();
try {
lock = channel.tryLock();
} catch (OverlappingFileLockException e) {
// already locked
closeLock();
return true;
}
if (lock == null) {
closeLock();
return true;
}
Runtime.getRuntime()
.addShutdownHook(
new Thread() {
// destroy the lock when the JVM is closing
public void run() {
closeLock();
deleteFile();
}
});
return false;
} catch (Exception e) {
closeLock();
return true;
}
}
public StorageRootFile(String dbPath, String options, int pageSize, FreeSpaceManager fsm) {
this.fsm = fsm;
PAGE_SIZE = pageSize;
File file = new File(dbPath);
if (!file.exists()) {
throw DBLogger.newUser("DB file does not exist: " + dbPath);
}
try {
raf = new RandomAccessFile(file, options);
fc = raf.getChannel();
try {
// tryLock is supposed to return null, but it throws an Exception
fileLock = fc.tryLock();
if (fileLock == null) {
fc.close();
raf.close();
throw DBLogger.newUser("This file is in use by another process: " + dbPath);
}
} catch (OverlappingFileLockException e) {
fc.close();
raf.close();
throw DBLogger.newUser("This file is in use by another PersistenceManager: " + dbPath);
}
if (ZooDebug.isTesting()) {
ZooDebug.registerFile(fc);
}
} catch (IOException e) {
throw DBLogger.newFatal("Error opening database: " + dbPath, e);
}
}
public OneInstanceGuard(String lockFileName) {
lockFile = new File(lockFileName);
if (lockFile.exists()) {
lockFile.delete();
}
try {
channel = new RandomAccessFile(lockFile, "rw").getChannel();
} catch (FileNotFoundException e) {
// Not running
LOG.info("File not found: " + e);
return;
}
try {
lock = channel.tryLock();
if (lock == null) {
// File is lock by other application
channel.close();
throw new IOException("Instance already active");
}
} catch (IOException e) {
// Running
LOG.info("Instance already running");
alreadyRunning = true;
return;
}
ShutdownHook shutdownHook = new ShutdownHook(this);
Runtime.getRuntime().addShutdownHook(shutdownHook);
}
/** Reply a specific WAL. */
private void replayLog(Path logPath) throws KevaDBException {
// Now look at the disk.
if (logPath != null) {
// Get a list of the sstables already in place.
Map<String, Integer> manifest =
db.getDiskService().getDataManifests(db, 0, SSTableService.MAX_LEVELS);
FileLock fileLock = null;
try {
// Must open in "rw" mode so that we can use filelock.
FileChannel fc =
FileChannel.open(logPath, StandardOpenOption.READ, StandardOpenOption.WRITE);
MappedByteBuffer in = fc.map(FileChannel.MapMode.READ_ONLY, 0, (int) fc.size());
fileLock = fc.tryLock();
if (fileLock != null) {
for (; ; ) {
if (!unroll(in, manifest)) {
break;
}
}
}
if (fileLock != null) {
fileLock.release();
}
fc.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
/**
* @param directory
* @return
* @throws IOException
*/
FileLock acquireLock(File directory) throws IOException {
// Get a file channel for the file
File file = new File(directory, LOCK_FILE);
FileChannel channel = new RandomAccessFile(file, "rw").getChannel();
// Use the file channel to create a lock on the file.
// This method blocks until it can retrieve the lock.
FileLock lock = channel.lock();
// Try acquiring the lock without blocking. This method returns
// null or throws an exception if the file is already locked.
while (!lock.isValid()) {
try {
lock = channel.tryLock();
} catch (OverlappingFileLockException e) {
// File is already locked in this thread or virtual machine
}
// wait for the other process to unlock it, should take a couple of seconds
try {
Thread.sleep(500);
} catch (InterruptedException e) {
// someone waked us earlier, no problem
}
}
return lock;
}
@Test
public void testLock() throws IOException {
FileChannel channel = channel(regularFile(10), READ, WRITE);
assertNotNull(channel.lock());
assertNotNull(channel.lock(0, 10, false));
assertNotNull(channel.lock(0, 10, true));
assertNotNull(channel.tryLock());
assertNotNull(channel.tryLock(0, 10, false));
assertNotNull(channel.tryLock(0, 10, true));
FileLock lock = channel.lock();
assertTrue(lock.isValid());
lock.release();
assertFalse(lock.isValid());
}
public static FileLock getFileLock(FileChannel fileChannel) {
try {
return fileChannel.tryLock();
} catch (Exception e) {
_logger.error(e.getMessage(), e);
return null;
}
}
public static void main(String[] args) {
try {
String filename = "fileToLock.dat";
File file = new File(filename);
file.createNewFile();
// Creates a random access file stream to read from, and optionally
// to write to
FileChannel channel = new RandomAccessFile(file, "rw").getChannel();
DataOutputStream out2 =
new DataOutputStream(new BufferedOutputStream(new FileOutputStream(filename)));
out2.writeDouble(3.14159);
out2.writeChars("That was pi\n");
out2.writeBytes("That was pi\n");
out2.close();
// Acquire an exclusive lock on this channel's file ( block until
// the region can be
// locked, this channel is closed, or the invoking thread is
// interrupted)
FileLock lock = channel.lock(0, Long.MAX_VALUE, false);
System.out.print("Press any key...");
System.in.read();
// Attempts to acquire an exclusive lock on this channel's file
// (does not block, an
// invocation always returns immediately, either having acquired a
// lock on the requested
// region or having failed to do so.
try {
lock = channel.tryLock(0, Long.MAX_VALUE, true);
} catch (OverlappingFileLockException e) {
// thrown when an attempt is made to acquire a lock on a a file
// that overlaps
// a region already locked by the same JVM or when another
// thread is already
// waiting to lock an overlapping region of the same file
System.out.println("Overlapping File Lock Error: " + e.getMessage());
}
// tells whether this lock is shared
boolean isShared = lock.isShared();
// release the lock
lock.release();
// close the channel
channel.close();
} catch (IOException e) {
System.out.println("I/O Error: " + e.getMessage());
}
}
@Override
public synchronized FileLock tryLock(long position, long size, boolean shared)
throws IOException {
FileLock l = channel.tryLock(position, size, shared);
if (l == null) {
return null;
}
lock = new FileLockRetry(l, this);
return lock;
}
/* Get a FileLock with retry. */
private static FileLock getLockWithReTry(FileChannel channel, long position, long size)
throws Exception {
int retries = 0;
FileLock lock = channel.tryLock(position, size, false);
while (lock == null && retries <= MAX_RETRIES) {
Thread.sleep(1000);
lock = channel.tryLock(position, size, false);
retries++;
}
if (lock == null) {
System.err.println("Can't get a FileLock during " + MAX_RETRIES + " seconds.");
System.exit(6);
}
return lock;
}
/**
* Creates and initializes an SPV block store. Will create the given file if it's missing. This
* operation will block on disk.
*/
public SPVBlockStore(NetworkParameters params, File file) throws BlockStoreException {
checkNotNull(file);
this.params = checkNotNull(params);
try {
this.numHeaders = DEFAULT_NUM_HEADERS;
boolean exists = file.exists();
// Set up the backing file.
randomAccessFile = new RandomAccessFile(file, "rw");
long fileSize = getFileSize();
if (!exists) {
log.info("Creating new SPV block chain file " + file);
randomAccessFile.setLength(fileSize);
} else if (randomAccessFile.length() != fileSize) {
throw new BlockStoreException(
"File size on disk does not match expected size: "
+ randomAccessFile.length()
+ " vs "
+ fileSize);
}
FileChannel channel = randomAccessFile.getChannel();
fileLock = channel.tryLock();
if (fileLock == null)
throw new BlockStoreException("Store file is already locked by another process");
// Map it into memory read/write. The kernel will take care of flushing writes to disk at the
// most
// efficient times, which may mean that until the map is deallocated the data on disk is
// randomly
// inconsistent. However the only process accessing it is us, via this mapping, so our own
// view will
// always be correct. Once we establish the mmap the underlying file and channel can go away.
// Note that
// the details of mmapping vary between platforms.
buffer = channel.map(FileChannel.MapMode.READ_WRITE, 0, fileSize);
// Check or initialize the header bytes to ensure we don't try to open some random file.
byte[] header;
if (exists) {
header = new byte[4];
buffer.get(header);
if (!new String(header, "US-ASCII").equals(HEADER_MAGIC))
throw new BlockStoreException("Header bytes do not equal " + HEADER_MAGIC);
} else {
initNewStore(params);
}
} catch (Exception e) {
try {
if (randomAccessFile != null) randomAccessFile.close();
} catch (IOException e2) {
throw new BlockStoreException(e2);
}
throw new BlockStoreException(e);
}
}
public boolean tryLock() {
try {
lockRandomAccessFile = new RandomAccessFile(lockFilePath.toFile(), "rw");
lockChannel = lockRandomAccessFile.getChannel();
lockFile = lockChannel.tryLock(0, 1024, false);
return lockFile != null;
} catch (IOException e) {
throw new IllegalStateException("Failed to create lock in " + lockFilePath.toString(), e);
}
}
public static void test() throws IOException, InterruptedException {
FileOutputStream out = new FileOutputStream("tt.txt");
FileChannel fileChannel = out.getChannel();
FileLock lock = fileChannel.tryLock();
System.out.println(lock);
for (int i = 0; i < 10; i++) {
out.write("fjsdlfjsdlf".getBytes());
out.write("\n".getBytes());
}
out.flush();
out.close();
Thread.sleep(10000);
}
private void reLock() throws IOException {
if (lock == null) {
return;
}
try {
lock.base.release();
} catch (IOException e) {
// ignore
}
FileLock l2 = channel.tryLock(lock.position(), lock.size(), lock.isShared());
if (l2 == null) {
throw new IOException("Re-locking failed");
}
lock.base = l2;
}
/**
* Unlockes file
*
* @param file target File
*/
@SuppressWarnings("resource")
public static void unlock(File file) {
try {
FileChannel channel = new RandomAccessFile(file, "rw").getChannel();
FileLock lock = channel.lock();
try {
lock = channel.tryLock();
file.setWritable(true);
} catch (OverlappingFileLockException e) {
}
lock.release();
channel.close();
} catch (Exception e) {
}
}
public DbLock(File lockFile) throws IOException {
Preconditions.checkNotNull(lockFile, "lockFile is null");
this.lockFile = lockFile;
// open and lock the file
channel = new RandomAccessFile(lockFile, "rw").getChannel();
try {
lock = channel.tryLock();
} catch (IOException e) {
Closeables.closeQuietly(channel);
throw e;
}
if (lock == null) {
throw new IOException(format("Unable to acquire lock on '%s'", lockFile.getAbsolutePath()));
}
}
/**
* Check system exec only one pro <br>
* Created on: Nov 23, 2012 11:23:15 AM
*
* @param fileName
* @return
*/
public static boolean tryLock(String fileName) {
/** A token representing a lock on a region of a file. */
FileLock lock = null;
/** A channel for reading, writing, mapping, and manipulating a file. */
FileChannel channel = null;
/** Instances of this class support both reading and writing to a random access file. */
RandomAccessFile randomAccessFile = null;
try {
randomAccessFile = new RandomAccessFile(fileName, "rw");
if (null != randomAccessFile) {
channel = randomAccessFile.getChannel();
}
if (null != channel) {
lock = channel.tryLock();
}
return (null != lock && lock.isValid());
} catch (FileNotFoundException e) {
System.out.println(" Project lock file [" + fileName + "] error ! PORGRAMME EXIT.");
System.out.println(
"MASSAGE : "
+ e.getMessage()
+ "\nCAUSE : "
+ e.getCause()
+ "\nCLASS : "
+ e.getClass());
System.exit(1);
} catch (IOException e) {
System.out.println(" Project lock file [" + fileName + "] error ! PORGRAMME EXIT.");
System.out.println(
"MASSAGE : "
+ e.getMessage()
+ "\nCAUSE : "
+ e.getCause()
+ "\nCLASS : "
+ e.getClass());
System.exit(1);
}
return false;
}
private static void unlockFile(File file) {
try {
RandomAccessFile raf = new RandomAccessFile(file, "rw");
FileChannel channel = raf.getChannel();
try {
if (channel.tryLock() == null) { // File is locked
log.warn("File " + file.getAbsolutePath() + " is locked and couldn't be released");
return;
}
} finally {
channel.close(); // Unlock in either case
}
} catch (IOException e) {
e.printStackTrace();
log.error("Couldn't unlock " + file, e);
}
}
private FileLock obtainLock(FileChannel channel, boolean shared)
throws TimeoutException, IOException {
FileLock lock = null;
int attempts = 0;
try {
/** Using 0x7fffffff in place of Long.MAX_VALUE. Bug # 4719967,4719605 * */
while ((lock = channel.tryLock(0L, 0x7fffffff, shared)) == null && attempts++ < ATTEMPTS) {
Thread.currentThread().sleep(TIMEOUT);
}
} catch (InterruptedException e) {
throw new TimeoutException();
}
if (lock == null) {
throw new TimeoutException();
}
return lock;
}
private void lock() throws IOException, BlockStoreException {
if (!semaphores.tryAcquire(fileName)) {
throw new BlockStoreException("File in use");
}
try {
lock = channel.tryLock();
} catch (OverlappingFileLockException e) {
semaphores.release(fileName);
lock = null;
}
if (lock == null) {
try {
this.file.close();
} finally {
this.file = null;
}
throw new BlockStoreException("Could not lock file");
}
}
/*
* TODO: Finish method.
*/
public static String readBytesFromFile(File filename)
throws IOException, OverlappingFileLockException {
if (!filename.exists()) {
return null;
}
try {
ByteBuffer buffer = ByteBuffer.allocate(((int) filename.getTotalSpace() * 4));
fileReader = new FileInputStream(filename).getChannel();
FileLock lock = fileReader.tryLock();
if (lock != null) {
fileReader.read(buffer);
} else {
throw new OverlappingFileLockException();
}
} finally {
fileWriter.close();
}
return "";
}
public static FileLock tryLock(File file) {
FileLock toReturn = null;
try {
RandomAccessFile raf = new RandomAccessFile(file, "rw");
try {
FileChannel channel = raf.getChannel();
toReturn = channel.tryLock();
raf.writeBytes("lock file for: " + ManagementFactory.getRuntimeMXBean().getName());
} finally {
if (toReturn == null) raf.close();
}
} catch (OverlappingFileLockException e) {
toReturn = null;
} catch (FileNotFoundException e) {
toReturn = null;
} catch (IOException e) {
toReturn = null;
}
return toReturn;
}
/*
* (non-Javadoc)
*
* @see javax.servlet.Filter#doFilter(javax.servlet.ServletRequest,
* javax.servlet.ServletResponse, javax.servlet.FilterChain)
*/
public void doFilter(ServletRequest req, ServletResponse resp, FilterChain filterChain)
throws IOException, ServletException {
if (!(req instanceof HttpServletRequest) || !(resp instanceof HttpServletResponse)) {
filterChain.doFilter(req, resp);
return;
}
HttpServletRequest request = (HttpServletRequest) req;
HttpServletResponse response = (HttpServletResponse) resp;
String servletPath = request.getServletPath();
Page p = pageMappings.get(servletPath);
if (p == null) {
// 不需要静态化的页面
filterChain.doFilter(request, response);
return;
}
String filePath = findStaticPage(request, p);
File file = new File(pagesLocation, filePath);
File etagFile = new File(pagesLocation, filePath + ".etag");
FileOutputStream out = null;
boolean fileLocked = true;
String etagServer = findEtag(etagFile);
String etagClient = request.getHeader("If-None-Match");
boolean fileValid = file.isFile() && file.length() > 0 && etagServer != null;
long expired = 0;
if (p.cronExpression != null) {
expired =
p.cronExpression.getNextValidTimeAfter(new Date(file.lastModified())).getTime()
- System.currentTimeMillis();
} else {
if (p.refreshInterval == Long.MAX_VALUE) {
expired = Long.MAX_VALUE;
} else {
expired = System.currentTimeMillis() - file.lastModified();
expired = expired > 0 ? p.refreshInterval - expired : p.refreshInterval;
}
}
fileValid = fileValid && expired > 0;
if (fileValid) {
try {
// 文件已存在,加共享锁,防止读取脏数据,同步块要尽可能的小，提高并发性
out = new FileOutputStream(file, true);
FileChannel fc = out.getChannel();
FileLock fileLock = fc.tryLock(0, Long.MAX_VALUE, false);
fileLocked = (fileLock == null || !fileLock.isValid());
} catch (Exception ex) {
fileLocked = true;
} finally {
if (out != null) {
// 关闭共享锁文件流
try {
out.close();
} catch (Exception ex) {
}
}
}
} else {
try {
// 清除不合法静态文件
if (!file.isFile() || file.delete()) {
file.getParentFile().mkdirs();
file.createNewFile();
// 文件不存在加排他锁,防止重复写入,同步块要尽可能的小，提高并发性
out = new FileOutputStream(file);
try {
FileChannel fc = out.getChannel();
FileLock fileLock = fc.tryLock();
fileLocked = (fileLock == null || !fileLock.isValid());
} catch (Exception ex) {
fileLocked = true;
}
// double check lock
etagServer = findEtag(etagFile);
fileValid = file.isFile() && file.length() > 0 && etagServer != null;
if (p.cronExpression != null) {
expired =
p.cronExpression.getNextValidTimeAfter(new Date(file.lastModified())).getTime()
- System.currentTimeMillis();
} else {
if (p.refreshInterval == Long.MAX_VALUE) {
expired = Long.MAX_VALUE;
} else {
expired = System.currentTimeMillis() - file.lastModified();
expired = expired > 0 ? p.refreshInterval - expired : p.refreshInterval;
}
}
fileValid = fileValid && expired > 0;
} else {
fileLocked = true;
}
} catch (Exception ex) {
fileLocked = true;
} finally {
if (fileLocked && out != null) {
// 关闭排他锁文件流
try {
out.close();
} catch (Exception ex) {
}
}
}
}
if (fileLocked) {
// 静态页面正在写入,跳过静态化
if (expired != Long.MAX_VALUE) {
expired = expired < 0 ? 0 : expired / 1000;
response.setHeader("cache-control", "max-age=" + expired);
}
filterChain.doFilter(request, response);
return;
}
if (fileValid) {
response.setHeader("etag", etagServer);
if (etagServer.equalsIgnoreCase(etagClient)) {
response.setStatus(HttpServletResponse.SC_NOT_MODIFIED);
} else {
// 静态页面合法,直接跳转过去
StringBuilder sb = new StringBuilder();
sb.append(prefix);
sb.append(filePath);
if ("web".equals(xSendFileKey)) {
// 直接使用web容器返回
RequestDispatcher dispatcher = request.getRequestDispatcher(sb.toString());
dispatcher.forward(request, response);
} else {
// 使用http服务器进行加速
response.setHeader(xSendFileKey, sb.toString());
if (expired != Long.MAX_VALUE) {
expired = expired < 0 ? 0 : expired / 1000;
response.setHeader("cache-control", "max-age=" + expired);
}
}
}
} else {
// 静态页面不存在或者已过期
StaticizeResponse res = null;
try {
res = new StaticizeResponse(response, out, file);
if (expired != Long.MAX_VALUE) {
expired = expired < 0 ? 0 : expired / 1000;
response.setHeader("cache-control", "max-age=" + expired);
}
// md5还没生成先写入空值的md5值,下次请求返回正确的md5值
response.setHeader("etag", "d41d8cd98f00b204e9800998ecf8427e");
filterChain.doFilter(request, res);
} finally {
if (res != null) {
try {
res.flushBuffer();
res.close();
} catch (Exception ex) {
}
etagServer = res.getMd5();
saveEtag(etagFile, etagServer);
}
}
}
}
@Override
public FileLock tryLock(long position, long size, boolean shared) throws IOException {
return base.tryLock(position, size, shared);
}
@Override
public synchronized FileLock tryLock(long position, long size, boolean shared)
throws IOException {
return readBase.tryLock(position, size, shared);
}