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.hadoop.fs; import java.io.IOException; import java.util.Set; import org.apache.hadoop.classification.InterfaceAudience; import org.apache.hadoop.classification.InterfaceStability; import org.apache.hadoop.fs.permission.FsPermission; /** * This class defines a FileStatus that includes a file's block locations. */ @InterfaceAudience.Public @InterfaceStability.Evolving public class LocatedFileStatus extends FileStatus { private static final long serialVersionUID = 0x17339920; private BlockLocation[] locations; public LocatedFileStatus() { super(); } /** * Constructor * @param stat a file status * @param locations a file's block locations */ public LocatedFileStatus(FileStatus stat, BlockLocation[] locations) { this(stat.getLen(), stat.isDirectory(), stat.getReplication(), stat.getBlockSize(), stat.getModificationTime(), stat.getAccessTime(), stat.getPermission(), stat.getOwner(), stat.getGroup(), null, stat.getPath(), stat.hasAcl(), stat.isEncrypted(), stat.isErasureCoded(), locations); if (stat.isSymlink()) { try { setSymlink(stat.getSymlink()); } catch (IOException e) { throw new RuntimeException("Unexpected exception", e); } } } /** * Constructor * * @param length a file's length * @param isdir if the path is a directory * @param block_replication the file's replication factor * @param blocksize a file's block size * @param modification_time a file's modification time * @param access_time a file's access time * @param permission a file's permission * @param owner a file's owner * @param group a file's group * @param symlink symlink if the path is a symbolic link * @param path the path's qualified name * @param locations a file's block locations */ @Deprecated public LocatedFileStatus(long length, boolean isdir, int block_replication, long blocksize, long modification_time, long access_time, FsPermission permission, String owner, String group, Path symlink, Path path, BlockLocation[] locations) { this(length, isdir, block_replication, blocksize, modification_time, access_time, permission, owner, group, symlink, path, permission == null ? false : permission.getAclBit(), permission == null ? false : permission.getEncryptedBit(), permission == null ? false : permission.getErasureCodedBit(), locations); } /** * Constructor. * * @param length a file's length * @param isdir if the path is a directory * @param block_replication the file's replication factor * @param blocksize a file's block size * @param modification_time a file's modification time * @param access_time a file's access time * @param permission a file's permission * @param owner a file's owner * @param group a file's group * @param symlink symlink if the path is a symbolic link * @param path the path's qualified name * @param hasAcl entity has associated ACLs * @param isEncrypted entity is encrypted * @param isErasureCoded entity is erasure coded * @param locations a file's block locations */ public LocatedFileStatus(long length, boolean isdir, int block_replication, long blocksize, long modification_time, long access_time, FsPermission permission, String owner, String group, Path symlink, Path path, boolean hasAcl, boolean isEncrypted, boolean isErasureCoded, BlockLocation[] locations) { this(length, isdir, block_replication, blocksize, modification_time, access_time, permission, owner, group, symlink, path, attributes(hasAcl, isEncrypted, isErasureCoded, false), locations); this.locations = locations; } /** * Constructor. * * @param length a file's length * @param isdir if the path is a directory * @param block_replication the file's replication factor * @param blocksize a file's block size * @param modification_time a file's modification time * @param access_time a file's access time * @param permission a file's permission * @param owner a file's owner * @param group a file's group * @param symlink symlink if the path is a symbolic link * @param path the path's qualified name * @param attr Attribute flags (See {@link FileStatus.AttrFlags}). * @param locations a file's block locations */ public LocatedFileStatus(long length, boolean isdir, int block_replication, long blocksize, long modification_time, long access_time, FsPermission permission, String owner, String group, Path symlink, Path path, Set<AttrFlags> attr, BlockLocation[] locations) { super(length, isdir, block_replication, blocksize, modification_time, access_time, permission, owner, group, symlink, path, attr); this.locations = locations; } /** * Get the file's block locations * * In HDFS, the returned BlockLocation will have different formats for * replicated and erasure coded file. * Please refer to * {@link FileSystem#getFileBlockLocations(FileStatus, long, long)} * for more details. * * @return the file's block locations */ public BlockLocation[] getBlockLocations() { return locations; } /** * Hook for subclasses to lazily set block locations. The {@link #locations} * field should be null before this is called. * @param locations Block locations for this instance. */ protected void setBlockLocations(BlockLocation[] locations) { this.locations = locations; } /** * Compare this FileStatus to another FileStatus * @param o the FileStatus to be compared. * @return a negative integer, zero, or a positive integer as this object * is less than, equal to, or greater than the specified object. */ @Override public int compareTo(FileStatus o) { return super.compareTo(o); } /** Compare if this object is equal to another object * @param o the object to be compared. * @return true if two file status has the same path name; false if not. */ @Override public boolean equals(Object o) { return super.equals(o); } /** * Returns a hash code value for the object, which is defined as * the hash code of the path name. * * @return a hash code value for the path name. */ @Override public int hashCode() { return super.hashCode(); } }