作业7 Hbase操作与编程使用

1.任务：

• 列出HBase所有的表的相关信息，例如表名；
• 在终端打印出指定的表的所有记录数据；
• 向已经创建好的表添加和删除指定的列族或列；
• 清空指定的表的所有记录数据；
• 统计表的行数。

 

 

 

 

 

 

 

 

 

 

 

 2.关系型数据库中的表和数据（教材P92上)，要求将其转换为适合于HBase存储的表并插入数据。

 

 

 

 

 

 

 

 

 

 

 

 

编程完成以下指定功能（教材P92下)：

3.1. createTable(String tableName, String[] fields)创建表。

public static void createTable(String tableName,String[] fields) throws IOException {
 
        init();
        TableName tablename = TableName.valueOf(tableName);
 
        if(admin.tableExists(tablename)){
            System.out.println("table is exists!");
            admin.disableTable(tablename);
            admin.deleteTable(tablename);//删除原来的表
        }
 
        TableDescriptorBuilder tableDescriptor = TableDescriptorBuilder.newBuilder(tablename);
        for(String str : fields){
            tableDescriptor.setColumnFamily(ColumnFamilyDescriptorBuilder.newBuilder(Bytes.toBytes(str)).build());
            admin.createTable(tableDescriptor.build());
        }
        close();
    }

3.2. addRecord(String tableName, String row, String[] fields, String[] values)

public static void addRecord(String tableName,String row,String[] fields,String[] values) throws IOException {
        init();
        Table table = connection.getTable(TableName.valueOf(tableName));
        for(int i = 0;i != fields.length;i++){
            Put put = new Put(row.getBytes());
            String[] cols = fields[i].split(":");
            put.addColumn(cols[0].getBytes(), cols[1].getBytes(), values[i].getBytes());
            table.put(put);
        }
        table.close();
        close();
    }

3.3. scanColumn(String tableName, String column)

public static void scanColumn(String tableName,String column)throws  IOException{
        init();
        Table table = connection.getTable(TableName.valueOf(tableName));
        Scan scan = new Scan();
        scan.addFamily(Bytes.toBytes(column));
        ResultScanner scanner = table.getScanner(scan);
        for (Result result = scanner.next(); result != null; result = scanner.next()){
            showCell(result);
        }
        table.close();
        close();
    }
    //格式化输出
    public static void showCell(Result result){
        Cell[] cells = result.rawCells();
        for(Cell cell:cells){
            System.out.println("RowName:"+new String(Bytes.toString(cell.getRowArray(),cell.getRowOffset(), cell.getRowLength()))+" ");
            System.out.println("Timetamp:"+cell.getTimestamp()+" ");
            System.out.println("column Family:"+new String(Bytes.toString(cell.getFamilyArray(),cell.getFamilyOffset(), cell.getFamilyLength()))+" ");
            System.out.println("row Name:"+new String(Bytes.toString(cell.getQualifierArray(),cell.getQualifierOffset(), cell.getQualifierLength()))+" ");
            System.out.println("value:"+new String(Bytes.toString(cell.getValueArray(),cell.getValueOffset(), cell.getValueLength()))+" ");           
        }
    }

3.4. modifyData(String tableName, String row, String column)

public static void modifyData(String tableName,String row,String column,String val)throws IOException{
    init();
    Table table = connection.getTable(TableName.valueOf(tableName));
    Put put = new Put(row.getBytes());
    put.addColumn(column.getBytes(),null,val.getBytes());
    table.put(put);
    table.close();
    close();
}

3.5. deleteRow(String tableName, String row)

public static void deleteRow(String tableName,String row)throws IOException{
        init();
        Table table = connection.getTable(TableName.valueOf(tableName));
        Delete delete = new Delete(row.getBytes());        
        table.delete(delete);
        table.close();
        close();
    }