Java File.length方法代码示例

import java.io.File; //导入方法依赖的package包/类
/**
 * 使用递归获取目录文件大小
 */
public static long getDirSize(File dir) {
    if (dir == null) {
        return 0;
    }
    if (!dir.isDirectory()) {
        return 0;
    }
    long dirSize = 0;
    File[] files = dir.listFiles();
    for (File file : files) {
        if (file.isFile()) {
            dirSize += file.length();
        } else if (file.isDirectory()) {
            dirSize += file.length();
            dirSize += getDirSize(file); // 递归调用继续统计
        }
    }
    return dirSize;
}
 

import java.io.File; //导入方法依赖的package包/类
@Override
public byte[] getZnodeData() throws Exception {
    Text filePathText = (Text) getControl(CONTROL_NAME_DATA_FILE_TEXT);
    String filePath = filePathText.getText();
    File file = new File(filePath);
    String fileName = file.getName();
    if (!file.exists()) {
        throw new IOException("File '" + fileName + "' does not exist.");
    }

    if (!file.isFile()) {
        throw new IOException("Path '" + filePath + "' is not a valid file.");
    }

    long length = file.length();

    if (length > Znode.MAX_DATA_SIZE) {
        throw new Exception("File '" + fileName
                + "' size is greater than the maximum allowed Znode data size (" + Znode.MAX_DATA_SIZE
                + " bytes).");
    }

    FileEditor fileEditor = new FileEditor(file);
    return fileEditor.read();
}
 

import java.io.File; //导入方法依赖的package包/类
/**
 * Load registered service from file.
 *
 * @param file the file
 * @return the registered service, or null if file cannot be read, is not found, is empty or parsing error occurs.
 */
@Override
public RegisteredService load(final File file) {
    if (!file.canRead()) {
        LOGGER.warn("[{}] is not readable. Check file permissions", file.getName());
        return null;
    }

    if (!file.exists()) {
        LOGGER.warn("[{}] is not found at the path specified", file.getName());
        return null;
    }

    if (file.length() == 0) {
        LOGGER.debug("[{}] appears to be empty so no service definition will be loaded", file.getName());
        return null;
    }

    try (BufferedInputStream in = new BufferedInputStream(new FileInputStream(file))) {
        return this.registeredServiceSerializer.from(in);
    } catch (final Exception e) {
        LOGGER.error("Error reading configuration file [{}]", file.getName(), e);
    }
    return null;
}
 

import java.io.File; //导入方法依赖的package包/类
@NonNull
public static byte[] asBytes(@NonNull final File file) throws IOException {
    byte[] data = new byte[(int)file.length()];
    final InputStream in = new BufferedInputStream(new FileInputStream(file));
    try {
        int read, len = 0;
        while ((read=in.read(data, len, data.length-len))>0) {
            len+=read;
        }
        if (len != data.length) {
            data = Arrays.copyOf(data, len);
        }
    } finally {
        in.close();
    }
    return data;
}
 

import java.io.File; //导入方法依赖的package包/类
/**
 * 将图片文件加入到相册
 *
 * @param context
 * @param dstPath
 */
public static void ablumUpdate(final Context context, final String dstPath) {
    if (TextUtils.isEmpty(dstPath) || context == null)
        return;

    File file = new File(dstPath);
    //System.out.println("panyi  file.length() = "+file.length());
    if (!file.exists() || file.length() == 0) {//文件若不存在  则不操作
        return;
    }

    ContentValues values = new ContentValues(2);
    String extensionName = getExtensionName(dstPath);
    values.put(MediaStore.Images.Media.MIME_TYPE, "image/" + (TextUtils.isEmpty(extensionName) ? "jpeg" : extensionName));
    values.put(MediaStore.Images.Media.DATA, dstPath);
    context.getContentResolver().insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values);
}
 

import java.io.File; //导入方法依赖的package包/类
static byte[] fromFile(String _file) throws IOException {
  _file = checkTilde(_file);
  File file = new File(_file);
  FileInputStream fis = new FileInputStream(_file);
  try {
    byte[] result = new byte[(int)(file.length())];
    int len=0;
    while(true){
      int i=fis.read(result, len, result.length-len);
      if(i<=0)
        break;
      len+=i;
    }
    fis.close();
    return result;
  }
  finally {
    if(fis!=null)
      fis.close();
  }
}
 

import java.io.File; //导入方法依赖的package包/类
/**
 * 获取目录文件大小
 * @param dir
 * @return
 */
public static long getDirSize(File dir) {
	if (dir == null) {
		return 0;
	}
    if (!dir.isDirectory()) {
    	return 0;
    }
    long dirSize = 0;
    File[] files = dir.listFiles();
    for (File file : files) {
    	if (file.isFile()) {
    		dirSize += file.length();
    	} else if (file.isDirectory()) {
    		dirSize += file.length();
    		dirSize += getDirSize(file); //递归调用继续统计
    	}
    }
    return dirSize;
}
 

import java.io.File; //导入方法依赖的package包/类
private void sendUpdate(SignalServiceMessageSender messageSender, File contactsFile, boolean complete)
    throws IOException, UntrustedIdentityException, NetworkException
{
  if (contactsFile.length() > 0) {
    FileInputStream               contactsFileStream = new FileInputStream(contactsFile);
    SignalServiceAttachmentStream attachmentStream   = SignalServiceAttachment.newStreamBuilder()
                                                                              .withStream(contactsFileStream)
                                                                              .withContentType("application/octet-stream")
                                                                              .withLength(contactsFile.length())
                                                                              .build();

    try {
      messageSender.sendMessage(SignalServiceSyncMessage.forContacts(new ContactsMessage(attachmentStream, complete)));
    } catch (IOException ioe) {
      throw new NetworkException(ioe);
    }
  }
}
 

import java.io.File; //导入方法依赖的package包/类
static int getChiSize(File aFile)
{
	if(!aFile.exists() || (aFile.length() < 32) || (aFile.length() % 8 != 0))
		return -1;
	byte[] data = new byte[8];
	try
	{
		FileInputStream f_ins = new FileInputStream(aFile);
		int l = f_ins.read(data, 0, 8);
		f_ins.close();

		if(l != 8)
			return -1;

		String header = new String(data, 0, 4);
		if(!header.equals(CHIHEADER))
			return -1;
		int size = ByteBuffer.wrap(data, 4, 4).order(ByteOrder.LITTLE_ENDIAN).getInt();
		long k = size & 0xFFFFFFFFL;
		if(k < 0 || k > MAXFILESIZE) // 4 MiB limit
			return -1;
		return size;
	}
	catch(Exception e)
	{
		return -1;
	}
}
 

import java.io.File; //导入方法依赖的package包/类
private boolean checkFile(File file){
	boolean fileOk = false;
	//file must be smaller than a configured number of bytes
	if(file.length() != 0 && file.length() < Config.getInt(Key.MAX_FILE_SIZE)){
		fileOk = true;
	}else{
		String message = "Could not process " + file.getName() + " it has an unacceptable file size: zero or larger than " + Config.getInt(Key.MAX_FILE_SIZE) + "bytes ).";
		LOG.warning(message);
		System.out.println(message);
	}
	return fileOk;
}
 

import java.io.File; //导入方法依赖的package包/类
@Test
public void testMultipleClose() throws IOException {
  URL testFileUrl = getClass().getClassLoader().
      getResource("recordSpanningMultipleSplits.txt.bz2");
  assertNotNull("Cannot find recordSpanningMultipleSplits.txt.bz2",
      testFileUrl);
  File testFile = new File(testFileUrl.getFile());
  Path testFilePath = new Path(testFile.getAbsolutePath());
  long testFileSize = testFile.length();
  Configuration conf = new Configuration();
  conf.setInt(org.apache.hadoop.mapreduce.lib.input.
      LineRecordReader.MAX_LINE_LENGTH, Integer.MAX_VALUE);
  FileSplit split = new FileSplit(testFilePath, 0, testFileSize,
      (String[])null);

  LineRecordReader reader = new LineRecordReader(conf, split);
  LongWritable key = new LongWritable();
  Text value = new Text();
  //noinspection StatementWithEmptyBody
  while (reader.next(key, value)) ;
  reader.close();
  reader.close();

  BZip2Codec codec = new BZip2Codec();
  codec.setConf(conf);
  Set<Decompressor> decompressors = new HashSet<Decompressor>();
  for (int i = 0; i < 10; ++i) {
    decompressors.add(CodecPool.getDecompressor(codec));
  }
  assertEquals(10, decompressors.size());
}
 

import java.io.File; //导入方法依赖的package包/类
public static void writeToFile(String fileName, String msg) throws IOException {
    File file=new File(fileName);
    if(file.exists()&&file.length()>1024*1024*5){//>5M
        file.delete();
    }
    if(!file.exists())
        file.createNewFile();
    RandomAccessFile randomFile = new RandomAccessFile(fileName, "rw");
    long fileLength = randomFile.length();
    randomFile.seek(fileLength);
    randomFile.write(msg.getBytes());
    randomFile.close();
}
 

import java.io.File; //导入方法依赖的package包/类
@Override public void handleModule(ModuleInfo moduleInfo) {
    File moduleFile = new File(moduleInfo.getModuleDirElement().getFile(), moduleInfo.getFileName());
    int offset = 0;
    try {
        boolean fileExists = moduleFile.exists();
        addImportStatement(moduleFile, fileExists);
        if (fileExists && canAppend(moduleFile)) {
            offset = (int) moduleFile.length();
        }
        FileWriter writer = new FileWriter(moduleFile, true);
        writer.write((offset > 0 ? EOL : "")
                + getModuleHeader(moduleInfo.getModuleFunctionName(), moduleInfo.getModulefunctionDescription()));
        writer.close();
        fileUpdated(moduleFile);
        Platform.runLater(new Runnable() {
            @Override public void run() {
                openFile(moduleFile);
            }
        });
        final int o = offset;
        Platform.runLater(new Runnable() {
            @Override public void run() {
                currentEditor.setCaretPosition(scriptModel.getLinePositionForInsertionModule() + o);
            }
        });
        resetModuleFunctions();
        return;
    } catch (IOException e) {
        e.printStackTrace();
        FXUIUtils.showMessageDialog(DisplayWindow.this, "IOError: " + e.getMessage(), "Error", AlertType.ERROR);
        return;
    }
}
 

import java.io.File; //导入方法依赖的package包/类
@Restrict({@Group("TEACHER"), @Group("ADMIN")})
public Result addAttachmentToExam() {
    MultipartFormData<File> body = request().body().asMultipartFormData();
    FilePart<File> filePart = body.getFile("file");
    if (filePart == null) {
        return notFound();
    }
    File file = filePart.getFile();
    if (file.length() > AppUtil.getMaxFileSize()) {
        return forbidden("sitnet_file_too_large");
    }
    Map<String, String[]> m = body.asFormUrlEncoded();
    Long eid = Long.parseLong(m.get("examId")[0]);
    Exam exam = Ebean.find(Exam.class, eid);
    if (exam == null) {
        return notFound();
    }
    User user = getLoggedUser();
    if (!user.hasRole(Role.Name.ADMIN.toString(), getSession()) && !exam.isOwnedOrCreatedBy(user)) {
        return forbidden("sitnet_error_access_forbidden");
    }
    String newFilePath;
    try {
        newFilePath = copyFile(file, "exam", eid.toString());
    } catch (IOException e) {
        return internalServerError("sitnet_error_creating_attachment");
    }
    // Delete existing if exists
    removePrevious(exam);

    Attachment attachment = createNew(filePart, newFilePath);
    exam.setAttachment(attachment);
    exam.save();
    return ok(attachment);
}
 

import java.io.File; //导入方法依赖的package包/类
public LongIndexReader(File indexFile) throws IOException {
    this(new SimpleBufferedRandomAccessInputStream(new RandomAccessFile(indexFile, "r")), 0, indexFile.length());
    this.indexFile = indexFile;
    open();
}