HBaseAPI详解
1 HBaseAPI
1.1 获取Configuration对象
public static Configuration conf;
static{
    //使用HBaseConfiguration的单例方法实例化
    conf = ate();
conf.set("keeper.quorum", "192.168.9.102");
conf.set("keeper.property.clientPort", "2181");
}
1.2 判断表是否存在
public static boolean isTableExist(String tableName) throws MasterNotRunningException,
ZooKeeperConnectionException, IOException{
    //在HBase中管理、访问表需要先创建HBaseAdmin对象
//Connection connection = ateConnection(conf);
//HBaseAdmin admin = (HBaseAdmin) Admin();
    HBaseAdmin admin = new HBaseAdmin(conf);
    return admin.tableExists(tableName);
}
1.3 创建表
public static void createTable(String tableName, columnFamily) throws
MasterNotRunningException, ZooKeeperConnectionException, IOException{
    HBaseAdmin admin = new HBaseAdmin(conf);
    //判断表是否存在
    if(isTableExist(tableName)){
        System.out.println("表" + tableName + "已存在");
        //it(0);
    }else{
        //创建表属性对象,表名需要转字节
        HTableDescriptor descriptor = new HTableDescriptor(TableName.valueOf(tableName));
        //创建多个列族
        for(String cf : columnFamily){
            descriptor.addFamily(new HColumnDescriptor(cf));
        }
        //根据对表的配置，创建表
        ateTable(descriptor);
        System.out.println("表" + tableName + "创建成功！");
    }
}
1.4 删除表
public static void dropTable(String tableName) throws MasterNotRunningException,
ZooKeeperConnectionException, IOException{
    HBaseAdmin admin = new HBaseAdmin(conf);
    if(isTableExist(tableName)){
        admin.disableTable(tableName);
        admin.deleteTable(tableName);
        System.out.println("表" + tableName + "删除成功！");
    }else{
        System.out.println("表" + tableName + "不存在！");
    }
}
1.5 向表中插入数据
public static void addRowData(String tableName, String rowKey, String columnFamily, String
column, String value) throws IOException{
    //创建HTable对象
    HTable hTable = new HTable(conf, tableName);
    //向表中插入数据
    Put put = new Bytes(rowKey));
    //向Put对象中组装数据
    put.Bytes(columnFamily), Bytes(column), Bytes(value));
    hTable.put(put);
    hTable.close();
    System.out.println("插入数据成功");
}
1.6 删除多行数据
drop table if exists admin
public static void deleteMultiRow(String tableName, rows) throws IOException{
    HTable hTable = new HTable(conf, tableName);
    List<Delete> deleteList = new ArrayList<Delete>();
    for(String row : rows){
        Delete delete = new Bytes(row));
        deleteList.add(delete);
    }
    hTable.delete(deleteList);
    hTable.close();
}
1.7 获取所有数据
public static void getAllRows(String tableName) throws IOException{
    HTable hTable = new HTable(conf, tableName);
    //得到用于扫描region的对象
    Scan scan = new Scan();
    //使用HTable得到resultcanner实现类的对象
    ResultScanner resultScanner = Scanner(scan);
    for(Result result : resultScanner){
        Cell[] cells = result.rawCells();
        for(Cell cell : cells){
            //得到rowkey
            System.out.println("行键:" + String(CellUtil.cloneRow(cell)));
            //得到列族
            System.out.println("列族" + String(CellUtil.cloneFamily(cell)));
            System.out.println("列:" + String(CellUtil.cloneQualifier(cell)));
            System.out.println("值:" + String(CellUtil.cloneValue(cell)));
        }
    }
}
1.8 获取某一行数据
public static void getRow(String tableName, String rowKey) throws IOException{
    HTable table = new HTable(conf, tableName);
    Get get = new Bytes(rowKey));
    //get.setMaxVersions();显示所有版本
    //get.setTimeStamp();显示指定时间戳的版本
    Result result = (get);
    for(Cell cell : result.rawCells()){
        System.out.println("行键:" + Row()));
        System.out.println("列族" + String(CellUtil.cloneFamily(cell)));
        System.out.println("列:" + String(CellUtil.cloneQualifier(cell)));
        System.out.println("值:" + String(CellUtil.cloneValue(cell)));
        System.out.println("时间戳:" + Timestamp());
    }
}
1.9 获取某一行指定“列族:列”的数据
public static void getRowQualifier(String tableName, String rowKey, String family, String
qualifier) throws IOException{
    HTable table = new HTable(conf, tableName);
    Get get = new Bytes(rowKey));
    get.Bytes(family), Bytes(qualifier));
    Result result = (get);
    for(Cell cell : result.rawCells()){
        System.out.println("行键:" + Row()));
        System.out.println("列族" + String(CellUtil.cloneFamily(cell)));
        System.out.println("列:" + String(CellUtil.cloneQualifier(cell)));
        System.out.println("值:" + String(CellUtil.cloneValue(cell)));
    }
}

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