import org.apache.hadoop.hbase.snapshot.ExportSnapshot; //导入依赖的package包/类
/**
 * @param args
 * @throws Throwable
 */
public static void main(String[] args) throws Throwable {
  ProgramDriver pgd = new ProgramDriver();

  pgd.addClass(RowCounter.NAME, RowCounter.class,
    "Count rows in HBase table.");
  pgd.addClass(CellCounter.NAME, CellCounter.class,
    "Count cells in HBase table.");
  pgd.addClass(Export.NAME, Export.class, "Write table data to HDFS.");
  pgd.addClass(Import.NAME, Import.class, "Import data written by Export.");
  pgd.addClass(ImportTsv.NAME, ImportTsv.class, "Import data in TSV format.");
  pgd.addClass(LoadIncrementalHFiles.NAME, LoadIncrementalHFiles.class,
               "Complete a bulk data load.");
  pgd.addClass(CopyTable.NAME, CopyTable.class,
      "Export a table from local cluster to peer cluster.");
  pgd.addClass(VerifyReplication.NAME, VerifyReplication.class, "Compare" +
      " the data from tables in two different clusters. WARNING: It" +
      " doesn't work for incrementColumnValues'd cells since the" +
      " timestamp is changed after being appended to the log.");
  pgd.addClass(WALPlayer.NAME, WALPlayer.class, "Replay WAL files.");
  pgd.addClass(ExportSnapshot.NAME, ExportSnapshot.class, "Export" +
      " the specific snapshot to a given FileSystem.");

  ProgramDriver.class.getMethod("driver", new Class [] {String[].class}).
    invoke(pgd, new Object[]{args});
}
 

import org.apache.hadoop.hbase.snapshot.ExportSnapshot; //导入依赖的package包/类
/**
 * @param args
 * @throws Throwable
 */
public static void main(String[] args) throws Throwable {
  ProgramDriver pgd = new ProgramDriver();

  pgd.addClass(RowCounter.NAME, RowCounter.class,
    "Count rows in HBase table.");
  pgd.addClass(CellCounter.NAME, CellCounter.class,
    "Count cells in HBase table.");
  pgd.addClass(Export.NAME, Export.class, "Write table data to HDFS.");
  pgd.addClass(Import.NAME, Import.class, "Import data written by Export.");
  pgd.addClass(ImportTsv.NAME, ImportTsv.class, "Import data in TSV format.");
  pgd.addClass(LoadIncrementalHFiles.NAME, LoadIncrementalHFiles.class,
               "Complete a bulk data load.");
  pgd.addClass(CopyTable.NAME, CopyTable.class,
      "Export a table from local cluster to peer cluster.");
  pgd.addClass(VerifyReplication.NAME, VerifyReplication.class, "Compare" +
      " data from tables in two different clusters. It" +
      " doesn't work for incrementColumnValues'd cells since" +
      " timestamp is changed after appending to WAL.");
  pgd.addClass(WALPlayer.NAME, WALPlayer.class, "Replay WAL files.");
  pgd.addClass(ExportSnapshot.NAME, ExportSnapshot.class, "Export" +
      " the specific snapshot to a given FileSystem.");

  ProgramDriver.class.getMethod("driver", new Class [] {String[].class}).
    invoke(pgd, new Object[]{args});
}
 

import org.apache.hadoop.hbase.snapshot.ExportSnapshot; //导入依赖的package包/类
/**
 * Verfy the result of getBalanceSplits() method.
 * The result are groups of files, used as input list for the "export" mappers.
 * All the groups should have similar amount of data.
 *
 * The input list is a pair of file path and length.
 * The getBalanceSplits() function sort it by length,
 * and assign to each group a file, going back and forth through the groups.
 */
@Test
public void testBalanceSplit() throws Exception {
  // Create a list of files
  List<Pair<Path, Long>> files = new ArrayList<Pair<Path, Long>>();
  for (long i = 0; i <= 20; i++) {
    files.add(new Pair<Path, Long>(new Path("file-" + i), i));
  }

  // Create 5 groups (total size 210)
  //    group 0: 20, 11, 10,  1 (total size: 42)
  //    group 1: 19, 12,  9,  2 (total size: 42)
  //    group 2: 18, 13,  8,  3 (total size: 42)
  //    group 3: 17, 12,  7,  4 (total size: 42)
  //    group 4: 16, 11,  6,  5 (total size: 42)
  List<List<Path>> splits = ExportSnapshot.getBalancedSplits(files, 5);
  assertEquals(5, splits.size());
  assertEquals(Arrays.asList(new Path("file-20"), new Path("file-11"),
    new Path("file-10"), new Path("file-1"), new Path("file-0")), splits.get(0));
  assertEquals(Arrays.asList(new Path("file-19"), new Path("file-12"),
    new Path("file-9"), new Path("file-2")), splits.get(1));
  assertEquals(Arrays.asList(new Path("file-18"), new Path("file-13"),
    new Path("file-8"), new Path("file-3")), splits.get(2));
  assertEquals(Arrays.asList(new Path("file-17"), new Path("file-14"),
    new Path("file-7"), new Path("file-4")), splits.get(3));
  assertEquals(Arrays.asList(new Path("file-16"), new Path("file-15"),
    new Path("file-6"), new Path("file-5")), splits.get(4));
}
 

import org.apache.hadoop.hbase.snapshot.ExportSnapshot; //导入依赖的package包/类
/**
 * Test ExportSnapshot
 */
private void testExportFileSystemState(final byte[] tableName, final byte[] snapshotName,
    int filesExpected) throws Exception {
  Path copyDir = TEST_UTIL.getDataTestDir("export-" + System.currentTimeMillis());
  URI hdfsUri = FileSystem.get(TEST_UTIL.getConfiguration()).getUri();
  FileSystem fs = FileSystem.get(copyDir.toUri(), new Configuration());
  copyDir = copyDir.makeQualified(fs);

  // Export Snapshot
  int res = ExportSnapshot.innerMain(TEST_UTIL.getConfiguration(), new String[] {
    "-snapshot", Bytes.toString(snapshotName),
    "-copy-to", copyDir.toString()
  });
  assertEquals(0, res);

  // Verify File-System state
  FileStatus[] rootFiles = fs.listStatus(copyDir);
  assertEquals(filesExpected, rootFiles.length);
  for (FileStatus fileStatus: rootFiles) {
    String name = fileStatus.getPath().getName();
    assertTrue(fileStatus.isDir());
    assertTrue(name.equals(HConstants.SNAPSHOT_DIR_NAME) || name.equals(".archive"));
  }

  // compare the snapshot metadata and verify the hfiles
  final FileSystem hdfs = FileSystem.get(hdfsUri, TEST_UTIL.getConfiguration());
  final Path snapshotDir = new Path(HConstants.SNAPSHOT_DIR_NAME, Bytes.toString(snapshotName));
  verifySnapshot(hdfs, new Path(TEST_UTIL.getDefaultRootDirPath(), snapshotDir),
      fs, new Path(copyDir, snapshotDir));
  verifyArchive(fs, copyDir, tableName, Bytes.toString(snapshotName));
  FSUtils.logFileSystemState(hdfs, snapshotDir, LOG);

  // Remove the exported dir
  fs.delete(copyDir, true);
}