Hbase之原子性更新数据
import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.hbase.HBaseConfiguration; import org.apache.hadoop.hbase.TableName; import org.apache.hadoop.hbase.client.*; import org.apache.hadoop.hbase.filter.CompareFilter; import org.apache.hadoop.hbase.util.Bytes; import java.io.IOException; /** * 修改数据实现原子性 * * 重点: * checkAndMutate */ public class UpdateDataWithAtomic { public static void main(String[] args) throws IOException{ Configuration configuration = HBaseConfiguration.create(); Connection connection = ConnectionFactory.createConnection(configuration); //建立表的连接 Table table = connection.getTable(TableName.valueOf("testtable")); //获取put实例 Put put = new Put(Bytes.toBytes("10086")); put.addColumn(Bytes.toBytes("colfam1"),Bytes.toBytes("qual7"),4,Bytes.toBytes("UpdateDataWithAtomic")); put.addColumn(Bytes.toBytes("colfam1"),Bytes.toBytes("qual8"),4,Bytes.toBytes("UpdateDataWithAtomicTest")); //删除 Delete delete = new Delete(Bytes.toBytes("10086")); delete.addColumn(Bytes.toBytes("colfam1"),Bytes.toBytes("qual1")); //更新实例 RowMutations mutations = new RowMutations(Bytes.toBytes("10086")); mutations.add(put); mutations.add(delete); //Mutate 1 successful: false //checkAndMutate (行键,列族,列分隔) =>比对操作<= (期望值) ====> T mutations F not mutations //(china mobile 1)<(val1) 为假没有进行更新 boolean res1 = table.checkAndMutate(Bytes.toBytes("10086"), Bytes.toBytes("colfam1"), Bytes.toBytes("qual1"), CompareFilter.CompareOp.LESS, Bytes.toBytes("val1"), mutations); System.out.println("Mutate 1 successful: " + res1); //这儿插入了一行数据会导致10086-colfam1-qual1的val2比期望的val1大 Put put2 = new Put(Bytes.toBytes("10086")); put2.addColumn(Bytes.toBytes("colfam1"), Bytes.toBytes("qual1"), 4, Bytes.toBytes("val2")); table.put(put2); //Mutate 2 successful: true //(val2)>(val1) 为真 进行了跟新 boolean res2 = table.checkAndMutate(Bytes.toBytes("10086"), Bytes.toBytes("colfam1"), Bytes.toBytes("qual1"), CompareFilter.CompareOp.LESS, Bytes.toBytes("val1"), mutations); System.out.println("Mutate 2 successful: " + res2); } } //olddata /** 10086 column=colfam1:qual1, timestamp=4, value=china mobile 1 10086 column=colfam1:qual4, timestamp=4, value=china mobile 4 */ //newdata /** 10086 column=colfam1:qual4, timestamp=4, value=china mobile 4 10086 column=colfam1:qual7, timestamp=4, value=UpdateDataWithAtomic 10086 column=colfam1:qual8, timestamp=4, value=UpdateDataWithAtomicTest **/