Apache HBase 2.x JavaAPI操作（上）

Hbase 1.x版本和2.x版本，虽然进行了大量的重构和优化，一些API也已经能抛弃，单核心API没有改多少。

本处：HBASE 2.0.5版本

1.测试准备

1）获取HBASE配置对象

Configuration conf = HBaseConfiguration.create();
conf.set("hbase.zookeeper.quorum","mycat01,mycat02,mycat03");
conf.set("hbase.zookeeper.property.clientPort", "2181");

2）创建连接

Connect cnn=ConnectionFactory.createConnection(conf);

3）创建2大对象

① Admin对象 ----命名空间与管理表DDL

Admin admin=cnn.getAdmin();

② Table 获取DML 表记录的增删改查对象

Table mk=cnn.getTable(TableName.valueOf("test"));

2.命名空间的创建

public static void createNameSpace(Admin admin) throws IOException {
    NamespaceDescriptor mkNameSpace = NamespaceDescriptor.create("mktest").build();
    admin.createNamespace(mkNameSpace);
}

结果：

2.4.1 :036 > list_namespace
NAMESPACE                           
default                              
hbase
mktest                                                                                 3 row(s)
Took 0.4493 seconds                                                                     

3.表相关API

1）单列簇表的创建

public static void createOneColumnFamilyTable(Admin admin) throws IOException {
    TableDescriptorBuilder mk = TableDescriptorBuilder.newBuilder(TableName.valueOf("mk1"));
    ColumnFamilyDescriptorBuilder columnBuilder = ColumnFamilyDescriptorBuilder.newBuilder(Bytes.toBytes("user"));
    ColumnFamilyDescriptor familyDescriptor = columnBuilder.build();
    mk.setColumnFamily(familyDescriptor);
    admin.createTable(mk.build());
}

结果如下

2.4.1 :042 > list 'mktest:.*'
TABLE                                                                                   mktest:mk1                                                                             1 row(s)
Took 0.0219 seconds                                                                      => ["mktest:mk1"] 

2）多列簇表的创建

public static void createMultiPartColumnFamily(Admin admin) throws IOException {
    TableDescriptorBuilder mk = TableDescriptorBuilder.newBuilder(TableName.valueOf("mktest:mk2"));
    ColumnFamilyDescriptorBuilder columnBuilder = ColumnFamilyDescriptorBuilder.newBuilder(Bytes.toBytes("user"));
    ColumnFamilyDescriptorBuilder columnBuilder2 = ColumnFamilyDescriptorBuilder.newBuilder(Bytes.toBytes("socre"));
    List<ColumnFamilyDescriptor> columnFamilyDescriptors=new ArrayList<>();
    columnFamilyDescriptors.add(columnBuilder.build());
    columnFamilyDescriptors.add(columnBuilder2.build());
    mk.setColumnFamilies(columnFamilyDescriptors);
    admin.createTable(mk.build());
}

结果如下：

2.4.1 :043 > list 'mktest:.*'
TABLE                                     
mktest:mk1                                  
mktest:mk2                                      
2 row(s)
Took 0.0448 seconds                                      
 => ["mktest:mk1", "mktest:mk2"] 

3）列出所有命名空间下的的表

public static void listTables(Admin admin) throws IOException {
    TableName[] tableNames = admin.listTableNames();
    for (TableName tableName : tableNames) {
        System.out.println(tableName);
    }
}

结果如下

mktest:mk1
mktest:mk2
test_mk
test_mk2

4）列出某一命名空间下的所有表

public static void listTablesByNameSpace(Admin admin) throws IOException {
    TableName[] tableNames = admin.listTableNamesByNamespace("mktest");
    for (TableName tableName : tableNames) {
        System.out.println(tableName);
    }
}

结果如下

mktest:mk1
mktest:mk2

4.行操作

1）全表扫描

public static void scanWholeTable(Table table) throws IOException {
    Scan scan=new Scan();
    ResultScanner scanner = table.getScanner(scan);
    for (Result rs : scanner) {
        System.out.println("-------------------------------");
        System.out.println("rowKey:"+Bytes.toString(rs.getRow()));
        Cell[] cells = rs.rawCells();
        for (Cell c : cells) {
            String columnName = Bytes.toString(c.getQualifierArray(), c.getQualifierOffset(), c.getQualifierLength());
            String columnValue=null;
            if(columnName.equals("income")||columnName.equals("age")){
                int result=Bytes.toInt(c.getValueArray());
                columnValue=Integer.toString(result);
            }else{
                columnValue = Bytes.toString(c.getValueArray(), c.getValueOffset(), c.getValueLength());
            }
            System.out.println(columnName +":"+columnValue);
        }
    }
}

结果如下

-------------------------------
rowKey:rk001
name:cm
-------------------------------
rowKey:rk002
age:25
income:28
name:tom
sex:female
-------------------------------
rowKey:rk003
age:25
income:28
name:sam
sex:female

2）扫描表—设置起始位置（不包含末位置）

public static void scanTableBetween(Table table) throws IOException {
    Scan scan=new Scan();
    scan.withStartRow(Bytes.toBytes("rk002"));
    // scan.withStopRow(Bytes.toBytes("rk004")); // 本处数据不够，没有测试---不包含结束行
    ResultScanner scanner = table.getScanner(scan);
    for (Result rs : scanner) {
        System.out.println("-------------------------------");
        System.out.println("rowKey:"+Bytes.toString(rs.getRow()));
        Cell[] cells = rs.rawCells();
        for (Cell c : cells) {
            String columnName = Bytes.toString(c.getQualifierArray(), c.getQualifierOffset(), c.getQualifierLength());
            String columnValue=null;
            if(columnName.equals("income")||columnName.equals("age")){
                int result=Bytes.toInt(c.getValueArray());
                columnValue=Integer.toString(result);
            }else{
                columnValue = Bytes.toString(c.getValueArray(), c.getValueOffset(), c.getValueLength());
            }
            System.out.println(columnName +":"+columnValue);
        }
    }
}

3）获取单行数据–get

public static void getRowData(Table table) throws IOException {
    Get get=new Get(Bytes.toBytes("rk002"));
    Result rs = table.get(get);
    Cell[] cells = rs.rawCells();
    for (Cell c : cells) {
        String columnName = Bytes.toString(c.getQualifierArray(), c.getQualifierOffset(), c.getQualifierLength());
        String columnValue=null;
        if(columnName.equals("income")||columnName.equals("age")){
            int result=Bytes.toInt(c.getValueArray());
            columnValue=Integer.toString(result);
        }else{
            columnValue = Bytes.toString(c.getValueArray(), c.getValueOffset(), c.getValueLength());
        }
        System.out.println(columnName +":"+columnValue);
    }
}

结果如下

age:25
income:28
name:tom
sex:female

4）获取多行数据–get

public static void getRowDataList(Table table) throws IOException {
    List<Get> gets=new ArrayList<>();
    gets.add(new Get(Bytes.toBytes("rk001")));
    gets.add(new Get(Bytes.toBytes("rk002")));
    gets.add(new Get(Bytes.toBytes("rk003")));
    gets.add(new Get(Bytes.toBytes("rk004")));
    Result[] rs = table.get(gets);
    for (Result r : rs) {
        Cell[] cells = r.rawCells();
        for (Cell c : cells) {
            String columnName = Bytes.toString(c.getQualifierArray(), c.getQualifierOffset(), c.getQualifierLength());
            String columnValue=null;
            if(columnName.equals("income")||columnName.equals("age")){
                int result=Bytes.toInt(c.getValueArray());
                columnValue=Integer.toString(result);
            }else{
                columnValue = Bytes.toString(c.getValueArray(), c.getValueOffset(), c.getValueLength());
            }
            System.out.println(columnName +":"+columnValue);
         }
     }
 }

结果如下

name:cm
age:25
income:28
name:tom
sex:female
age:25
income:28
name:sam
sex:female

5）删除行

public static void deleteRowData(Table table) throws IOException {
    Delete delete=new Delete("rk004".getBytes());
    table.delete(delete);
    System.out.println("删除数据！rk004");
}

结果如下

删除数据！rk004

6）添加行数据----事先已全部清空表test_mk2

public static void putRowData(Table table) throws IOException {
    Put put=new Put(Bytes.toBytes("rk002"));
    put.addColumn(Bytes.toBytes("info2"),Bytes.toBytes("name") , Bytes.toBytes("tom"));
    put.addColumn(Bytes.toBytes("info2"), Bytes.toBytes("age"), Bytes.toBytes(24));
    put.addColumn(Bytes.toBytes("info2"), Bytes.toBytes("sex"),Bytes.toBytes("female"));
    put.addColumn(Bytes.toBytes("info2"), Bytes.toBytes("income"), Bytes.toBytes(2000.0));

    Put put2=new Put(Bytes.toBytes("rk003"));
    put2.addColumn(Bytes.toBytes("info2"),Bytes.toBytes("name") , Bytes.toBytes("sam"));
    put2.addColumn(Bytes.toBytes("info2"), Bytes.toBytes("age"), Bytes.toBytes(34));
    put2.addColumn(Bytes.toBytes("info2"), Bytes.toBytes("sex"),Bytes.toBytes("female"));
    put2.addColumn(Bytes.toBytes("info2"), Bytes.toBytes("income"), Bytes.toBytes(3400.0));

    List<Put> puts=new ArrayList<>();
    puts.add(put);
    puts.add(put2);
    table.put(puts);
    table.close();
}

结果如下

2.4.1 :055 > scan 'test_mk2'
ROW                              COLUMN+CELL                                                                                   
 rk001                           column=info2:name, timestamp=1554120098856, value=cm                                          
 rk002                           column=info2:age, timestamp=1554121338856, value=\x00\x00\x00\x18                             
 rk002                           column=info2:income, timestamp=1554121338856, value=@\x9F@\x00\x00\x00\x00\x00                
 rk002                           column=info2:name, timestamp=1554121338856, value=tom                                         
 rk002                           column=info2:sex, timestamp=1554121338856, value=female                                       
 rk003                           column=info2:age, timestamp=1554121338856, value=\x00\x00\x00"                                
 rk003                           column=info2:income, timestamp=1554121338856, value=@\xAA\x90\x00\x00\x00\x00\x00             
 rk003                           column=info2:name, timestamp=1554121338856, value=sam                                         
 rk003                           column=info2:sex, timestamp=1554121338856, value=female                                       
3 row(s)