Hbase计数器可以用于统计用户数，点击量等信息
基本操作
可以使用incr操作计数器，incr语法格式如下：
incr '<table>', '<row>', '<column>', |<increment-value>|
然后使用get_counter可以获取对应的计数器的值
不用初始化计数器，第一次使用计数器时，计数器被自动设置为0
eg：
对于wishTest1表
incr 'wishTest1','2','score:Math',1 incr 'wishTest1','2','score:Math',1 get_counter 'wishTest1','2','score:Math'
结果如下：
hbase(main):004:0> incr 'wishTest1','2','score:Math',1
COUNTER VALUE = 1 hbase(main):005:0> incr 'wishTest1','2','score:Math',1
COUNTER VALUE = 2 hbase(main):007:0> get_counter 'wishTest1','2','score:Math'
COUNTER VALUE = 2 hbase(main):008:0>
增大计数的递增值：
hbase(main):001:0> incr 'wishTest1','2','score:Math',10
COUNTER VALUE = 12 hbase(main):002:0> incr 'wishTest1','2','score:Math',10
COUNTER VALUE = 22 hbase(main):003:0> get_counter 'wishTest1','2','score:Math'
COUNTER VALUE = 22
使用API操作计数器
使用table.incrementColumnValue()
eg:
String tableName = "wishTest1";
HTablePool pool = new HTablePool(cfg, 1000);
try {
long count1 = pool.getTable(tableName).incrementColumnValue(Bytes.toBytes("2"),Bytes.toBytes("score"),Bytes.toBytes("Math"),1);
long count2 = pool.getTable(tableName).incrementColumnValue(Bytes.toBytes("2"),Bytes.toBytes("score"),Bytes.toBytes("Math"),1);
long currentCount = pool.getTable(tableName).incrementColumnValue(Bytes.toBytes("2"),Bytes.toBytes("score"),Bytes.toBytes("Math"),0);
System.out.println("count1: "+count1);
System.out.println("count2: "+count2);
System.out.println("currentCount: "+currentCount);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
输出：
count1: 23
count2: 24
currentCount: 24