Hbase惯用shell及API

Hbase常用shell及API
  在项目中使用到了HBASE,我也只是用到了其中一点API,更深层的东西了解不多,还需要以后继续学习和研究.
1.Hbase Shell常用命令
(1)创建表:create '表名称', 'family','列名称1','列名称2'
以student表为例,创建以下表结构:

create 'student','name','fistname','lastname'

(2)查看表结构: describe '表名'
查看student表:

	describe 'student'

         (3)表中增加记录:put '表名','rowkey','family:column','值' 
往student表中新增一条记录:

put 'student','111','name:firstname','kim'   

(4)查看某记录:get '表名','rowkey'
查看刚才插入的一条记录:

get 'student','111'

(5)查看所有记录: scan '表名'
如:scan 'student',数据如下:

ROW                                COLUMN+CELL                                                                                                                                            
  111                                                column=name:firstname, timestamp=1323844528158, value=kim    

(6)查看多个version的数据:
get 'student','111',{COLUMN=>'name:firstname',VERSIONS=>10},数据如下:

COLUMN                                   CELL                                                                                                                             

        name:firstname                                     timestamp=1323845067789, value=kim4                                                                    	
        name:firstname                                     timestamp=1323845064974, value=kim3                                                                       
	 name:firstname                                     timestamp=1323845062682, value=kim2    

 

(7)删除一张表:
先disable '表名',然后再drop '表名'即可.


2.Hbase Client相关API使用

  别的不多说,这是一个访问HBASE数据类.代码如下:

public class HbaseManagerImpl implements HbaseManager {

    private static final Logger logger        = LoggerFactory
                                                  .getLogger(HbaseManagerImpl.class);

    private final static String SEPARATE_CHAR = ":";
    private HTablePool          hTablePool    = null;


    public HbaseManagerImpl() {

        try {

            Configration configration = ConfigrationFactory.getConfigration();
            Configuration hbaseConfiguration = HBaseConfiguration.create();
            hTablePool = new HTablePool(hbaseConfiguration, 100);

        } catch (Exception e) {
            logger.error("HbaseManager启动失败", e);
        }

    }
      /**
     * 根据表名,rowKey,family及时间戳[startTs,endTs)查询相关数据.
     * 
     */
    public Map<String, Map<Long, String>> queryMultiVersions(String tableName, String rowKey,
                                                             String family, long startTS, long endTS) {
        //返回结果
        Map<String, Map<Long, String>> resultMap = new HashMap<String, Map<Long, String>>();

        if (startTS > endTS) {
            logger.warn("rowKey[" + rowKey + "],开始时间戳大于结束时间戳");
            return resultMap;
        }

        HTableInterface hTable = null;

        try {
            hTable = hTablePool.getTable(Bytes.toBytes(tableName));

            Get get = new Get(Bytes.toBytes(rowKey));
            get.setMaxVersions();
            get.setTimeRange(startTS, endTS);

            Result result = hTable.get(get);

            NavigableMap<byte[], NavigableMap<byte[], NavigableMap<Long, byte[]>>> map = result
                .getMap();

            if (map == null) {
                return resultMap;
            }

            //取得指定family下的数据
            NavigableMap<byte[], NavigableMap<Long, byte[]>> familyMap = map.get(Bytes
                .toBytes(family));
            if (familyMap == null) {
                return resultMap;
            }

            Set<byte[]> familyMapSet = familyMap.keySet();

            for (Iterator<byte[]> familyIt = familyMapSet.iterator(); familyIt.hasNext();) {
                byte[] keyColumn = (byte[]) familyIt.next();
                NavigableMap<Long, byte[]> columnMap = familyMap.get(keyColumn);

                Map<Long, String> mapColumn = new HashMap<Long, String>();

                Set<Long> columnMapSet = columnMap.keySet();
                for (Iterator<Long> columnIt = columnMapSet.iterator(); columnIt.hasNext();) {
                    Long columnKey = (Long) columnIt.next();
                    String columnValue = new String(columnMap.get(columnKey));
                    mapColumn.put(columnKey, columnValue);
                }

                resultMap.put(new String(keyColumn), mapColumn);
            }

        } catch (Exception e) {
            logger.error("查询HBASE出错,rowKey[" + rowKey + "]", e);
           
        } finally {
            if (hTable != null) {
                hTablePool.putTable(hTable);
            }
        }
        return resultMap;
    }
    
    /**
     * HBASE中存入数据.
     */
    public boolean save(String tableName, String family, String rowkey, String column,
                        String value, long timestamp) {

        boolean result = false;
        HTableInterface hTable = null;


        try {
            hTable = hTablePool.getTable(Bytes.toBytes(tableName));
            final Put put = new Put(Bytes.toBytes(rowkey));

            byte[] familyBytes = Bytes.toBytes(family);
            byte[] qualifier = Bytes.toBytes(column);
            byte[] valueBytes = value.getBytes();
            put.add(familyBytes, qualifier, timestamp, valueBytes);
            hTable.put(put);
            result = true;
        } catch (Exception e) {
            logger.error("保存HBASE出错,rowKey[" + rowkey + "],timestamp[" + timestamp + "],value["
                         + value + "]", e);
          
        } finally {
            if (hTable != null) {
                hTablePool.putTable(hTable);
            }
        }

        return result;
    }

     /**
     * 删除指定表名的rowKey下某时间戳的数据。
     */   
    public boolean delete(String tableName, String rowKey, long timestamp) {
        boolean result = false;
        HTableInterface hTable = null;
        try {
            hTable = hTablePool.getTable(Bytes.toBytes(tableName));

            if (hTable == null) {
                return result;
            }

            byte[] rowKeys = Bytes.toBytes(rowKey);
            Delete delete = new Delete(rowKeys, timestamp, null);
            hTable.delete(delete);
            result = true;
        } catch (Exception e) {
            logger.error("delete(),rowKey[" + rowKey + "],ts[" + timestamp + "].", e);
            
        } finally {
            if (hTable != null) {
                hTablePool.putTable(hTable);
            }
        }

        return result;
    }
   
}