Java LocalFileSystem.setPermission方法代碼示例

import org.apache.hadoop.fs.LocalFileSystem; //導入方法依賴的package包/類
@Override
public void truncateLogsAsUser(String user, List<Task> allAttempts)
  throws IOException {
  
  Task firstTask = allAttempts.get(0);
  String taskid = firstTask.getTaskID().toString();
  
  LocalDirAllocator ldirAlloc =
      new LocalDirAllocator(JobConf.MAPRED_LOCAL_DIR_PROPERTY);
  String taskRanFile = TaskTracker.TT_LOG_TMP_DIR + Path.SEPARATOR + taskid;
  Configuration conf = getConf();
  
  //write the serialized task information to a file to pass to the truncater
  Path taskRanFilePath = 
    ldirAlloc.getLocalPathForWrite(taskRanFile, conf);
  LocalFileSystem lfs = FileSystem.getLocal(conf);
  FSDataOutputStream out = lfs.create(taskRanFilePath);
  out.writeInt(allAttempts.size());
  for (Task t : allAttempts) {
    out.writeBoolean(t.isMapTask());
    t.write(out);
  }
  out.close();
  lfs.setPermission(taskRanFilePath, 
                    FsPermission.createImmutable((short)0755));
  
  List<String> command = new ArrayList<String>();
  File jvm =                                  // use same jvm as parent
    new File(new File(System.getProperty("java.home"), "bin"), "java");
  command.add(jvm.toString());
  command.add("-Djava.library.path=" + 
              System.getProperty("java.library.path"));
  command.add("-Dhadoop.log.dir=" + TaskLog.getBaseLogDir());
  command.add("-Dhadoop.root.logger=INFO,console");
  command.add("-classpath");
  command.add(System.getProperty("java.class.path"));
  // main of TaskLogsTruncater
  command.add(TaskLogsTruncater.class.getName()); 
  command.add(taskRanFilePath.toString());
  String[] taskControllerCmd = new String[4 + command.size()];
  taskControllerCmd[0] = taskControllerExe;
  taskControllerCmd[1] = user;
  taskControllerCmd[2] = localStorage.getDirsString();
  taskControllerCmd[3] = Integer.toString(
      Commands.RUN_COMMAND_AS_USER.getValue());

  int i = 4;
  for (String cmdArg : command) {
    taskControllerCmd[i++] = cmdArg;
  }
  if (LOG.isDebugEnabled()) {
    for (String cmd : taskControllerCmd) {
      LOG.debug("taskctrl command = " + cmd);
    }
  }
  ShellCommandExecutor shExec = new ShellCommandExecutor(taskControllerCmd);
  try {
    shExec.execute();
  } catch (Exception e) {
    LOG.warn("Exit code from " + taskControllerExe.toString() + " is : "
        + shExec.getExitCode() + " for truncateLogs");
    LOG.warn("Exception thrown by " + taskControllerExe.toString() + " : "
        + StringUtils.stringifyException(e));
    LOG.info("Output from LinuxTaskController's "
             + taskControllerExe.toString() + " follows:");
    logOutput(shExec.getOutput());
    lfs.delete(taskRanFilePath, false);
    throw new IOException(e);
  }
  lfs.delete(taskRanFilePath, false);
  if (LOG.isDebugEnabled()) {
    LOG.info("Output from LinuxTaskController's "
             + taskControllerExe.toString() + " follows:");
    logOutput(shExec.getOutput());
  }
}
 

import org.apache.hadoop.fs.LocalFileSystem; //導入方法依賴的package包/類
/**
 * Create the directory or check permissions if it already exists.
 *
 * The semantics of mkdirsWithExistsAndPermissionCheck method is different
 * from the mkdirs method provided in the Sun's java.io.File class in the
 * following way:
 * While creating the non-existent parent directories, this method checks for
 * the existence of those directories if the mkdir fails at any point (since
 * that directory might have just been created by some other process).
 * If both mkdir() and the exists() check fails for any seemingly
 * non-existent directory, then we signal an error; Sun's mkdir would signal
 * an error (return false) if a directory it is attempting to create already
 * exists or the mkdir fails.
 *
 * @param localFS local filesystem
 * @param dir directory to be created or checked
 * @param expected expected permission
 * @throws IOException
 */
public static void mkdirsWithExistsAndPermissionCheck(
    LocalFileSystem localFS, Path dir, FsPermission expected)
    throws IOException {
  File directory = localFS.pathToFile(dir);
  boolean created = false;

  if (!directory.exists())
    created = mkdirsWithExistsCheck(directory);

  if (created || !localFS.getFileStatus(dir).getPermission().equals(expected))
      localFS.setPermission(dir, expected);
}
 

import org.apache.hadoop.fs.LocalFileSystem; //導入方法依賴的package包/類
/**
 * Create the directory or check permissions if it already exists.
 *
 * The semantics of mkdirsWithExistsAndPermissionCheck method is different
 * from the mkdirs method provided in the Sun's java.io.File class in the
 * following way:
 * While creating the non-existent parent directories, this method checks for
 * the existence of those directories if the mkdir fails at any point (since
 * that directory might have just been created by some other process).
 * If both mkdir() and the exists() check fails for any seemingly
 * non-existent directory, then we signal an error; Sun's mkdir would signal
 * an error (return false) if a directory it is attempting to create already
 * exists or the mkdir fails.
 *
 * @param localFS local filesystem
 * @param dir directory to be created or checked
 * @param expected expected permission
 * @throws IOException
 */
static void mkdirsWithExistsAndPermissionCheck(
    LocalFileSystem localFS, Path dir, FsPermission expected)
    throws IOException {
  File directory = localFS.pathToFile(dir);
  boolean created = false;

  if (!directory.exists())
    created = mkdirsWithExistsCheck(directory);

  if (created || !localFS.getFileStatus(dir).getPermission().equals(expected))
    localFS.setPermission(dir, expected);
}