【HBase十一】Java API操作HBase

Java  /  管理员 发布于 2年前   157

Admin类的主要方法注释：

 

1. 创建表

 /**   * Creates a new table. Synchronous operation.   *   * @param desc table descriptor for table   * @throws IllegalArgumentException if the table name is reserved   * @throws MasterNotRunningException if master is not running   * @throws org.apache.hadoop.hbase.TableExistsException if table already exists (If concurrent   * threads, the table may have been created between test-for-existence and attempt-at-creation).   * @throws IOException if a remote or network exception occurs   */  void createTable(HTableDescriptor desc) throws IOException;  /**   * Creates a new table with the specified number of regions.  The start key specified will become   * the end key of the first region of the table, and the end key specified will become the start   * key of the last region of the table (the first region has a null start key and the last region   * has a null end key). BigInteger math will be used to divide the key range specified into enough   * segments to make the required number of total regions. Synchronous operation.   *   * @param desc table descriptor for table   * @param startKey beginning of key range   * @param endKey end of key range   * @param numRegions the total number of regions to create   * @throws IllegalArgumentException if the table name is reserved   * @throws MasterNotRunningException if master is not running   * @throws org.apache.hadoop.hbase.TableExistsException if table already exists (If concurrent   * threads, the table may have been created between test-for-existence and attempt-at-creation).   * @throws IOException   */  void createTable(HTableDescriptor desc, byte[] startKey, byte[] endKey, int numRegions)      throws IOException;  /**   * Creates a new table with an initial set of empty regions defined by the specified split keys.   * The total number of regions created will be the number of split keys plus one. Synchronous   * operation. Note : Avoid passing empty split key.   *   * @param desc table descriptor for table   * @param splitKeys array of split keys for the initial regions of the table   * @throws IllegalArgumentException if the table name is reserved, if the split keys are repeated   * and if the split key has empty byte array.   * @throws MasterNotRunningException if master is not running   * @throws org.apache.hadoop.hbase.TableExistsException if table already exists (If concurrent   * threads, the table may have been created between test-for-existence and attempt-at-creation).   * @throws IOException   */  void createTable(final HTableDescriptor desc, byte[][] splitKeys) throws IOException;  /**   * Creates a new table but does not block and wait for it to come online. Asynchronous operation.   * To check if the table exists, use {@link #isTableAvailable} -- it is not safe to create an   * HTable instance to this table before it is available. Note : Avoid passing empty split key.   *   * @param desc table descriptor for table   * @throws IllegalArgumentException Bad table name, if the split keys are repeated and if the   * split key has empty byte array.   * @throws MasterNotRunningException if master is not running   * @throws org.apache.hadoop.hbase.TableExistsException if table already exists (If concurrent   * threads, the table may have been created between test-for-existence and attempt-at-creation).   * @throws IOException   */  void createTableAsync(final HTableDescriptor desc, final byte[][] splitKeys) throws IOException;