Hbase 的API調用

Hbase API 類和數據模型之間的對應關係

HBaseAdmin

HBaseAdmin提供了一個接口來管理 HBase 數據庫的表信息。它提供的方法包括：創建表，刪 除表，列出表項，使表有效或無效，以及添加或刪除表列族成員等。

HBaseConfiguration

HBaseConfiguration的作用：對 HBase 進行配置。

HTableDescriptor

HTableDescriptor作用：包含了表的名字極其對應表的列族。

HColumnDescriptor

HColumnDescriptor作用：維護着關於列族的信息，例如版本號，壓縮設置等。它通常在創建表或者爲表添 加列族的時候使用。列族被創建後不能直接修改，只能通過刪除然後重新創建的方式。列族被刪除的時候，列族裏面的數據也會同時被刪除。

其他的可以去參考官網API文檔

Java代碼示例

package hbase;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.*;
import org.apache.hadoop.hbase.client.*;
import org.apache.hadoop.hbase.filter.*;
import org.apache.hadoop.hbase.util.Bytes;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

public class HbaseTest {

    private HBaseAdmin admin;
    HConnection connection;

    /**
     * 執行Test之前執行的代碼塊
     */
    @Before
    public void init() {
        Configuration conf = new Configuration();
        conf.set("hbase.zookeeper.quorum", "master:2181,node1:2181,node2:2181");
        try {
            /**
             * 創建admin對象，和HMaster建立連接，執行創建，刪除，修改表的操作
             *
             */
            admin = new HBaseAdmin(conf);

            //創建zookeeper連接
            connection = HConnectionManager.createConnection(conf);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }


    @Test
    public void createTable() {
        try {
            //創建表的描述對象
            HTableDescriptor tableDescriptor = new HTableDescriptor("student");
            //增加列簇
            HColumnDescriptor columnDescriptor = new HColumnDescriptor("info");
            //設置列簇的版本數量
            columnDescriptor.setMaxVersions(5);
            tableDescriptor.addFamily(columnDescriptor);
            //判斷表是否存在
            if (admin.tableExists("student")) {
                System.out.println("表已存在");
                return;
            }
            //執行建表操作
            admin.createTable(tableDescriptor);

            //判斷表是否存在
            if (admin.tableExists("student")) {
                System.out.println("建表成功");
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }


    @Test
    public void deleteTable() {
        try {

            //獲取表的描述信息
            HTableDescriptor tableDescriptor = admin.getTableDescriptor(TableName.valueOf("student"));
            HColumnDescriptor[] columnFamilies = tableDescriptor.getColumnFamilies();
            for (HColumnDescriptor columnFamily : columnFamilies) {
                //獲取列簇的名稱
                //Bytes  hbase提供的把字節數組轉換成具體類型的工具
                String name = Bytes.toString(columnFamily.getName());
                System.out.println("列簇名：" + name);
                int maxVersions = columnFamily.getMaxVersions();
                System.out.println("版本數：" + maxVersions);
            }

            /**
             * 刪除表之前先進行disable
             *
             */
            admin.disableTable("student");
            //刪除表
            admin.deleteTable("student");

            if (!admin.tableExists("student")) {
                System.out.println("表以刪除");
            }

        } catch (IOException e) {
            e.printStackTrace();
        }
    }


    /**
     * 插入一條數據
     */
    @Test
    public void insert() {
        HTableInterface table = null;
        try {
            //獲取表對象
            table = connection.getTable("student");
            //創建put對象指向rowkey
            Put put = new Put("001".getBytes());
            put.add("info".getBytes(), "name".getBytes(), "張三".getBytes());
            put.add("info".getBytes(), "age".getBytes(), Bytes.toBytes(23));
            put.add("info".getBytes(), "clazz".getBytes(), "文科一班".getBytes());
            put.add("info".getBytes(), "clazz".getBytes(), "文科一班".getBytes());
            put.add("info".getBytes(), "gender".getBytes(), "男".getBytes());

            //插入一行數據數據
            table.put(put);

        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (table != null) {
                try {
                    table.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }


    /**
     * 一次插入多行數據
     */
    @Test
    public void insertAll() {

        HTableInterface table = null;
        try {
            table = connection.getTable("student");
            //加載磁盤上的數據
            ArrayList<Student> students = DataUtil.load("E:\\bigdata\\bigdata\\data\\students.txt", Student.class);

            ArrayList<Put> puts = new ArrayList<Put>();

            for (Student student : students) {
                byte[] rowkey = student.getId().getBytes();

                Put put = new Put(rowkey);
                put.add("info".getBytes(), "age".getBytes(), Bytes.toBytes(student.getAge()));
                put.add("info".getBytes(), "name".getBytes(), Bytes.toBytes(student.getName()));
                put.add("info".getBytes(), "clazz".getBytes(), Bytes.toBytes(student.getClazz()));
                put.add("info".getBytes(), "gender".getBytes(), Bytes.toBytes(student.getGender()));
                puts.add(put);
            }

            //插入多行數據
            table.put(puts);


        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (table != null) {
                try {
                    table.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }

    }


    @Test
    public void query() {
        HTableInterface table = null;
        try {
            table = connection.getTable("student");
            Get get = new Get("1500100007".getBytes());
            //執行查詢返回結果
            Result result = table.get(get);
            //獲取所有列
            List<Cell> cells = result.listCells();

            //遍歷每一個單元格
            for (Cell cell : cells) {
                String qualifier = Bytes.toString(CellUtil.cloneQualifier(cell));

                if ("age".equals(qualifier)) {
                    Integer value = Bytes.toInt(CellUtil.cloneValue(cell));
                    System.out.println(qualifier + ":" + value);
                } else {
                    String value = Bytes.toString(CellUtil.cloneValue(cell));
                    System.out.println(qualifier + ":" + value);
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (table != null) {
                try {
                    table.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }


    @Test
    public void scanner() {
        HTableInterface table = null;
        try {
            table = connection.getTable("student");

            //創建掃描器對象
            Scan scan = new Scan();

            //指定列簇掃描
            scan.addFamily("info".getBytes());

            //執行送秒操作，返回多行結果
            ResultScanner results = table.getScanner(scan);

            Result line;
            //迭代結果集合
            while ((line = results.next()) != null) {
                //獲取這一行的所有列
                List<Cell> cells = line.listCells();
                //遍歷每一個單元格
                for (Cell cell : cells) {

                    //獲取rowkey
                    String rowkey = Bytes.toString(CellUtil.cloneRow(cell));
                    System.out.print(rowkey+"\t");
                    String qualifier = Bytes.toString(CellUtil.cloneQualifier(cell));
                    if ("age".equals(qualifier)) {
                        Integer value = Bytes.toInt(CellUtil.cloneValue(cell));
                        System.out.print(qualifier + ":" + value + "\t");
                    } else {
                        String value = Bytes.toString(CellUtil.cloneValue(cell));
                        System.out.print(qualifier + ":" + value + "\t");
                    }
                }

                System.out.println();
            }


        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (table != null) {
                try {
                    table.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }


    @Test
    /**
     * 查詢文科班的所有學生
     *
     */
    public void queryWenke(){
        HTableInterface table = null;
        try {
            table = connection.getTable("student");

            //創建掃描器對象
            Scan scan = new Scan();

            //指定列簇掃描
            scan.addFamily("info".getBytes());


            //增加過濾器，過濾文科班的學生
            RegexStringComparator regexStringComparator = new RegexStringComparator("文科");
            SingleColumnValueFilter columnValueFilter = new SingleColumnValueFilter("info".getBytes(), "clazz".getBytes(), CompareFilter.CompareOp.EQUAL, regexStringComparator);

            SubstringComparator comp = new SubstringComparator("男");
            SingleColumnValueFilter columnValueFilter1 = new SingleColumnValueFilter("info".getBytes(), "gender".getBytes(), CompareFilter.CompareOp.EQUAL, comp);

            //過濾器集合
            FilterList fl = new FilterList(FilterList.Operator.MUST_PASS_ALL);

            //前綴過濾
            BinaryPrefixComparator prefixComparator = new BinaryPrefixComparator(Bytes.toBytes("呂"));

            SingleColumnValueFilter filter = new SingleColumnValueFilter(Bytes.toBytes("info"), Bytes.toBytes("name"),CompareFilter.CompareOp.EQUAL, prefixComparator);

            //過濾文科班的學生
            fl.addFilter(columnValueFilter);

            //過濾性別爲男的學生
            fl.addFilter(columnValueFilter1);

            //增加前綴過濾
            fl.addFilter(filter);

            scan.setFilter(fl);
            //執行送秒操作，返回多行結果
            ResultScanner results = table.getScanner(scan);

            Result line;
            //迭代結果集合
            while ((line = results.next()) != null) {
                //獲取這一行的所有列
                List<Cell> cells = line.listCells();
                //遍歷每一個單元格
                for (Cell cell : cells) {
                    //獲取rowkey
                    String rowkey = Bytes.toString(CellUtil.cloneRow(cell));
                    System.out.print(rowkey+"\t");
                    String qualifier = Bytes.toString(CellUtil.cloneQualifier(cell));
                    if ("age".equals(qualifier)) {
                        Integer value = Bytes.toInt(CellUtil.cloneValue(cell));
                        System.out.print(qualifier + ":" + value + "\t");
                    } else {
                        String value = Bytes.toString(CellUtil.cloneValue(cell));
                        System.out.print(qualifier + ":" + value + "\t");
                    }
                }
                System.out.println();
            }

        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (table != null) {
                try {
                    table.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }


    /**
     * 行鍵過濾器
     *
     */
    @Test
    public void rowFilter() {
        HTableInterface table = null;
        try {
            table = connection.getTable("student");

            //創建掃描器對象
            Scan scan = new Scan();

            //指定列簇掃描
            scan.addFamily("info".getBytes());


            /**
             * 設置開始key 和結束key
             *
             */
            /*scan.setStartRow("1500100199".getBytes());
            scan.setStopRow("1500100253".getBytes());*/


            /**
             * rowkey前綴過濾
             *
             */
            BinaryPrefixComparator binaryPrefixComparator = new BinaryPrefixComparator("15001002".getBytes());
            RowFilter rowFilter = new RowFilter(CompareFilter.CompareOp.EQUAL, binaryPrefixComparator);

            scan.setFilter(rowFilter);

            //執行送秒操作，返回多行結果
            ResultScanner results = table.getScanner(scan);

            Result line;
            //迭代結果集合
            while ((line = results.next()) != null) {
                //獲取這一行的所有列
                List<Cell> cells = line.listCells();
                //遍歷每一個單元格
                for (Cell cell : cells) {
                    //獲取rowkey
                    String rowkey = Bytes.toString(CellUtil.cloneRow(cell));
                    System.out.print(rowkey + "\t");
                    String qualifier = Bytes.toString(CellUtil.cloneQualifier(cell));
                    if ("age".equals(qualifier)) {
                        Integer value = Bytes.toInt(CellUtil.cloneValue(cell));
                        System.out.print(qualifier + ":" + value + "\t");
                    } else {
                        String value = Bytes.toString(CellUtil.cloneValue(cell));
                        System.out.print(qualifier + ":" + value + "\t");
                    }
                }
                System.out.println();
            }

        }catch (Exception e){
            e.printStackTrace();
        }
    }



            /**
             * 最後執行
             */

    @After
    public void close() {
        System.out.println("回收資源");
        if (admin != null) {
            try {
                admin.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        if (connection != null) {
            try {
                connection.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }


}