Java Scan類代碼示例

import org.apache.hadoop.hbase.client.Scan; //導入依賴的package包/類
protected void wipeOutMeta() throws IOException {
  // Mess it up by blowing up meta.
  Admin admin = TEST_UTIL.getHBaseAdmin();
  Scan s = new Scan();
  Table meta = new HTable(conf, TableName.META_TABLE_NAME);
  ResultScanner scanner = meta.getScanner(s);
  List<Delete> dels = new ArrayList<Delete>();
  for (Result r : scanner) {
    HRegionInfo info =
        HRegionInfo.getHRegionInfo(r);
    if(info != null && !info.getTable().getNamespaceAsString()
        .equals(NamespaceDescriptor.SYSTEM_NAMESPACE_NAME_STR)) {
      Delete d = new Delete(r.getRow());
      dels.add(d);
      admin.unassign(r.getRow(), true);
    }
  }
  meta.delete(dels);
  scanner.close();
  meta.close();
}
 

import org.apache.hadoop.hbase.client.Scan; //導入依賴的package包/類
/**
 * This will test the row count with startrow = endrow and they will be
 * non-null. The result should be 0, as it assumes a non-get query.
 * @throws Throwable
 */
@Test (timeout=300000)
public void testRowCountWithInvalidRange2() {
  AggregationClient aClient = new AggregationClient(conf);
  Scan scan = new Scan();
  scan.setStartRow(ROWS[5]);
  scan.setStopRow(ROWS[5]);

  final ColumnInterpreter<Long, Long, EmptyMsg, LongMsg, LongMsg> ci =
      new LongColumnInterpreter();
  long rowCount = -1;
  try {
    rowCount = aClient.rowCount(TEST_TABLE, ci, scan);
  } catch (Throwable e) {
    rowCount = 0;
  }
  assertEquals(0, rowCount);
}
 

import org.apache.hadoop.hbase.client.Scan; //導入依賴的package包/類
@Test(timeout = 60 * 1000)
public void testVisibilityLabelsOnRSRestart() throws Exception {
  final TableName tableName = TableName.valueOf(TEST_NAME.getMethodName());
  List<RegionServerThread> regionServerThreads = TEST_UTIL.getHBaseCluster()
      .getRegionServerThreads();
  for (RegionServerThread rsThread : regionServerThreads) {
    rsThread.getRegionServer().abort("Aborting ");
  }
  // Start one new RS
  RegionServerThread rs = TEST_UTIL.getHBaseCluster().startRegionServer();
  waitForLabelsRegionAvailability(rs.getRegionServer());
  try (Table table = createTableAndWriteDataWithLabels(tableName, "(" + SECRET + "|" + CONFIDENTIAL
      + ")", PRIVATE);) {
    Scan s = new Scan();
    s.setAuthorizations(new Authorizations(SECRET));
    ResultScanner scanner = table.getScanner(s);
    Result[] next = scanner.next(3);
    assertTrue(next.length == 1);
  }
}
 

import org.apache.hadoop.hbase.client.Scan; //導入依賴的package包/類
/**
 * Checks that all columns have the expected value and that there is the
 * expected number of rows.
 * @throws IOException
 */
void assertExpectedTable(final Connection connection, TableName table, int count, int value)
throws IOException {
  HTableDescriptor [] htds = util.getHBaseAdmin().listTables(table.getNameAsString());
  assertEquals(htds.length, 1);
  Table t = null;
  try {
    t = connection.getTable(table);
    Scan s = new Scan();
    ResultScanner sr = t.getScanner(s);
    int i = 0;
    for (Result r : sr) {
      i++;
      for (NavigableMap<byte[], byte[]> nm : r.getNoVersionMap().values()) {
        for (byte[] val : nm.values()) {
          assertTrue(Bytes.equals(val, value(value)));
        }
      }
    }
    assertEquals(count, i);
  } catch (IOException e) {
    fail("Failed due to exception");
  } finally {
    if (t != null) t.close();
  }
}
 

import org.apache.hadoop.hbase.client.Scan; //導入依賴的package包/類
@Test(timeout = 300000)
public void testSumWithInvalidRange() {
  AggregationClient aClient = new AggregationClient(conf);
  Scan scan = new Scan();
  scan.addFamily(TEST_FAMILY);
  scan.setStartRow(ROWS[6]);
  scan.setStopRow(ROWS[2]);
  final ColumnInterpreter<Double, Double, EmptyMsg, DoubleMsg, DoubleMsg> ci = 
      new DoubleColumnInterpreter();
  Double sum = null;
  try {
    sum = aClient.sum(TEST_TABLE, ci, scan);
  } catch (Throwable e) {
  }
  assertEquals(null, sum);// control should go to the catch block
}
 

import org.apache.hadoop.hbase.client.Scan; //導入依賴的package包/類
/**
 * create scan on IFile
 */
private Scan createScanOnIFile(Scan rawScan, ScanRange primaryRange,
    ScanRange.ScanRangeList allRangeList) throws IOException {
  ScanRange.ScanRangeList copy = new ScanRange.ScanRangeList();
  for (ScanRange r : allRangeList.getRanges()) {
    if (r != primaryRange) {
      copy.addScanRange(r);
    }
  }
  Scan scan = new Scan();
  scan.setStartRow(primaryRange.getStart());
  scan.setStopRow(primaryRange.getStop());
  if (!copy.getRanges().isEmpty()) {
    scan.setFilter(copy.toFilterList());
  }
  scan.setCacheBlocks(false);
  return scan;
}
 

import org.apache.hadoop.hbase.client.Scan; //導入依賴的package包/類
@Test
public void testMultiRowRangeFilterWithoutRangeOverlap() throws IOException {
  tableName = Bytes.toBytes("testMultiRowRangeFilterWithoutRangeOverlap");
  HTable ht = TEST_UTIL.createTable(tableName, family, Integer.MAX_VALUE);
  generateRows(numRows, ht, family, qf, value);

  Scan scan = new Scan();
  scan.setMaxVersions();

  List<RowRange> ranges = new ArrayList<RowRange>();
  ranges.add(new RowRange(Bytes.toBytes(30), true, Bytes.toBytes(40), false));
  ranges.add(new RowRange(Bytes.toBytes(10), true, Bytes.toBytes(20), false));
  ranges.add(new RowRange(Bytes.toBytes(60), true, Bytes.toBytes(70), false));

  MultiRowRangeFilter filter = new MultiRowRangeFilter(ranges);
  scan.setFilter(filter);
  int resultsSize = getResultsSize(ht, scan);
  LOG.info("found " + resultsSize + " results");
  List<Cell> results1 = getScanResult(Bytes.toBytes(10), Bytes.toBytes(20), ht);
  List<Cell> results2 = getScanResult(Bytes.toBytes(30), Bytes.toBytes(40), ht);
  List<Cell> results3 = getScanResult(Bytes.toBytes(60), Bytes.toBytes(70), ht);

  assertEquals(results1.size() + results2.size() + results3.size(), resultsSize);

  ht.close();
}
 

import org.apache.hadoop.hbase.client.Scan; //導入依賴的package包/類
private int countRows(final HRegion r) throws IOException {
  int rowcount = 0;
  InternalScanner scanner = r.getScanner(new Scan());
  try {
    List<Cell> kvs = new ArrayList<Cell>();
    boolean hasNext = true;
    while (hasNext) {
      hasNext = scanner.next(kvs);
      if (!kvs.isEmpty())
        rowcount++;
    }
  } finally {
    scanner.close();
  }
  return rowcount;
}
 

import org.apache.hadoop.hbase.client.Scan; //導入依賴的package包/類
public Result getRowOrBefore(Table table, byte[] row, byte[] family) throws IOException {
  long start = System.currentTimeMillis();
  Scan scan = new Scan();
  scan.addFamily(family);
  scan.setReversed(true);
  scan.setStartRow(row);
  scan.setCacheBlocks(false);
  scan.setCaching(1);
  scan.setSmall(true);
  ResultScanner scanner = table.getScanner(scan);
  Result ret = scanner.next();
  scanner.close();
  prevRowTotalTime += System.currentTimeMillis() - start;
  prevRowTotalCount++;
  return ret;
}
 

import org.apache.hadoop.hbase.client.Scan; //導入依賴的package包/類
public void testSkipColumn() throws IOException {
  List<KeyValueScanner> scanners = scanFixture(kvs);
  StoreScanner scan = new StoreScanner(new Scan(), scanInfo, scanType,
      getCols("a", "d"), scanners);

  List<Cell> results = new ArrayList<Cell>();
  assertEquals(true, scan.next(results));
  assertEquals(2, results.size());
  assertEquals(kvs[0], results.get(0));
  assertEquals(kvs[3], results.get(1));
  results.clear();

  assertEquals(true, scan.next(results));
  assertEquals(1, results.size());
  assertEquals(kvs[kvs.length-1], results.get(0));

  results.clear();
  assertEquals(false, scan.next(results));
}
 

import org.apache.hadoop.hbase.client.Scan; //導入依賴的package包/類
@Test (timeout=300000)
public void testStdWithInvalidRange() {
  AggregationClient aClient = new AggregationClient(conf);
  Scan scan = new Scan();
  scan.addFamily(TEST_FAMILY);
  scan.setStartRow(ROWS[6]);
  scan.setStopRow(ROWS[1]);
  final ColumnInterpreter<Long, Long, EmptyMsg, LongMsg, LongMsg> ci =
      new LongColumnInterpreter();
  Double std = null;
  try {
    std = aClient.std(TEST_TABLE, ci, scan);
  } catch (Throwable e) {
  }
  assertEquals(null, std);// control should go to the catch block
}
 

import org.apache.hadoop.hbase.client.Scan; //導入依賴的package包/類
@Test
public void testGetScanner_WithNotOkFamilies() throws IOException {
  byte[] fam1 = Bytes.toBytes("fam1");
  byte[] fam2 = Bytes.toBytes("fam2");

  byte[][] families = { fam1 };

  // Setting up region
  String method = this.getName();
  this.region = initHRegion(tableName, method, CONF, families);
  try {
    Scan scan = new Scan();
    scan.addFamily(fam2);
    boolean ok = false;
    try {
      region.getScanner(scan);
    } catch (Exception e) {
      ok = true;
    }
    assertTrue("Families could not be found in Region", ok);
  } finally {
    HRegion.closeHRegion(this.region);
    this.region = null;
  }
}
 

import org.apache.hadoop.hbase.client.Scan; //導入依賴的package包/類
@Test
public void testScanForSuperUserWithFewerLabelAuths() throws Throwable {
  String[] auths = { SECRET };
  String user = "admin";
  try (Connection conn = ConnectionFactory.createConnection(conf)) {
    VisibilityClient.setAuths(conn, auths, user);
  }
  TableName tableName = TableName.valueOf(TEST_NAME.getMethodName());
  final Table table = createTableAndWriteDataWithLabels(tableName, SECRET + "&" + CONFIDENTIAL
      + "&!" + PRIVATE, SECRET + "&!" + PRIVATE);
  PrivilegedExceptionAction<Void> scanAction = new PrivilegedExceptionAction<Void>() {
    public Void run() throws Exception {
      Scan s = new Scan();
      s.setAuthorizations(new Authorizations(SECRET, CONFIDENTIAL));
      try (Connection connection = ConnectionFactory.createConnection(conf);
           Table t = connection.getTable(table.getName())) {
        ResultScanner scanner = t.getScanner(s);
        Result[] result = scanner.next(5);
        assertTrue(result.length == 2);
      }
      return null;
    }
  };
  SUPERUSER.runAs(scanAction);
}
 

import org.apache.hadoop.hbase.client.Scan; //導入依賴的package包/類
private int countDeleteMarkers(Region region) throws IOException {
  Scan s = new Scan();
  s.setRaw(true);
  // use max versions from the store(s)
  s.setMaxVersions(region.getStores().iterator().next().getScanInfo().getMaxVersions());
  InternalScanner scan = region.getScanner(s);
  List<Cell> kvs = new ArrayList<Cell>();
  int res = 0;
  boolean hasMore;
  do {
    hasMore = scan.next(kvs);
    for (Cell kv : kvs) {
      if(CellUtil.isDelete(kv)) res++;
    }
    kvs.clear();
  } while (hasMore);
  scan.close();
  return res;
}
 

import org.apache.hadoop.hbase.client.Scan; //導入依賴的package包/類
public ScanTask(ScanTaskConfig scanTaskConfig, Scan... scans) {
    if (scanTaskConfig == null) {
        throw new NullPointerException("scanTaskConfig must not be null");
    }
    if (scans == null) {
        throw new NullPointerException("scans must not be null");
    }
    if (scans.length == 0) {
        throw new IllegalArgumentException("scans must not be empty");
    }
    this.tableName = scanTaskConfig.getTableName();
    this.tableFactory = scanTaskConfig.getTableFactory();
    this.rowKeyDistributor = scanTaskConfig.getRowKeyDistributor();
    this.scans = scans;
    this.resultQueue = new ArrayBlockingQueue<>(scanTaskConfig.getScanTaskQueueSize());
}