Hbase的JavaAPI

package dashuju19.hbase; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.hbase.Cell; import org.apache.hadoop.hbase.CompareOperator; import org.apache.hadoop.hbase.HBaseConfiguration; import org.apache.hadoop.hbase.TableName; import org.apache.hadoop.hbase.client.*; import org.apache.hadoop.hbase.filter.FilterList; import org.apache.hadoop.hbase.filter.SingleColumnValueFilter; import org.apache.hadoop.hbase.util.Bytes; import java.io.IOException; import java.util.List; public class HbaseJavaScan { public static void main(String[] args) throws IOException { Admin admin = getAdmin(); // 查询6月份的数据 queryDate(admin.getConnection(), "WATER_BILL","C1","RECORD_DATE", "2020-06-01","2020-06-30"); //关闭admin admin.close(); } public static Admin getAdmin() { //1.创建hbase的配置 Configuration configuration = HBaseConfiguration.create(); //2.创建hbase的连接 Connection connection = null; Admin admin = null; try { //通过工厂模式，根据配置创造连接 connection = ConnectionFactory.createConnection(configuration); System.out.println(connection); //3.创建admin对象 admin = connection.getAdmin(); } catch (IOException e) { e.printStackTrace(); } return admin; } /** * @description: 查询某列某个日期范围的数据 * @param connection * @param tablename * @param columnFamily * @param column * @param startValue * @param endValue * @throws IOException */ public static void queryDate(Connection connection, String tablename, String columnFamily,String column,String startValue,String endValue) throws IOException { // 1.获取Htable Table table = connection.getTable(TableName.valueOf(tablename)); // 2.构建scan对象 Scan scan = new Scan(); // 3.构建2个过滤器 // 3.1 构建日期范围过滤器 // 构建开始日期过滤器 SingleColumnValueFilter startDateFilter = new SingleColumnValueFilter(Bytes.toBytes(columnFamily),Bytes.toBytes(column), CompareOperator.GREATER_OR_EQUAL,Bytes.toBytes(startValue)); // 构建结束日期过滤器 SingleColumnValueFilter endDateFilter = new SingleColumnValueFilter(Bytes.toBytes(columnFamily),Bytes.toBytes(column), CompareOperator.LESS_OR_EQUAL,Bytes.toBytes(endValue)); // 3.2 构建过滤器列表 FilterList filterList = new FilterList(FilterList.Operator.MUST_PASS_ALL,startDateFilter,endDateFilter); // 4.构建扫描器 scan.setFilter(filterList); // 5.执行scan扫描操作 ResultScanner resultScanner = table.getScanner(scan); // 6.迭代打印result for (Result result:resultScanner) { // 6.1 打印rowkey System.out.println("rowkey=>" + Bytes.toString(result.getRow())); System.out.println("-------------------------------------------------"); // 6.2 迭代单元格列表 List<Cell> cells = result.listCells(); for (Cell cell:cells) { // 6.3 打印数据 // 打印列簇名 System.out.print(Bytes.toString(cell.getFamilyArray(),cell.getFamilyOffset(),cell.getFamilyLength())); //打印列名 //System.out.print(":"+Bytes.toString(cell.getQualifierArray(),cell.getQualifierOffset(),cell.getQualifierLength())); //解决数值型数据乱码的问题 String columName = Bytes.toString(cell.getQualifierArray(),cell.getQualifierOffset(),cell.getQualifierLength()); System.out.print(":"+columName); //判断是否为数值型列 if (columName.equals("NUM_CURRENT")||columName.equals("NUM_PREVIOUS")||columName.equals("NUM_USAGE")||columName.equals("TOTAL_MONEY")){ //打印数值型的值 System.out.println("=>"+Bytes.toDouble(cell.getValueArray(),cell.getValueOffset())); }else { //打印字符型的值 System.out.println("=>" + Bytes.toString(cell.getValueArray(),cell.getValueOffset(),cell.getValueLength())); } } System.out.println("------------------------------------------------"); } // 关闭资源 resultScanner.close(); table.close(); } }