大数据开发进阶笔记——HBase的常用原子操作Java代码

HBase的常用原子操作Java代码：

 

Append:追加，类似于put操作。

Configurationconf =HBaseConfiguration.create();

conf.set(“hbase.zookeeper.quorum”,”192.168.1.149”);

conf.set(“hbase.zookeeper.property.clientport”,”2181”);

HConnection conn=HConnectionManager.createConnection(conf);

HTableInterfacetable = conn.getTable(“创建的表名”);

Append append = newAppend(Bytes.toBytes(“r1”));

append.add(Bytes.toBytes(“d”), Bytes.toBytes(“a”),Bytes.toBytes(“abcd”));

table.append(append);

table.close();

conn.close();

 

checkAndPut:检查是否存在参数描述的记录，如果存在，则不写入数据，如果不存在就写入数据。注意：是对某一个row_key的原子操作，不能跨row_key。

Configurationconf =HBaseConfiguration.create();

conf.set(“hbase.zookeeper.quorum”,”192.168.1.149”);

conf.set(“hbase.zookeeper.property.clientport”,”2181”);

HConnection conn=HConnectionManager.createConnection(conf);

HTableInterfacetable = conn.getTable(“创建的表名”);

Put put = new Put(Bytes.toBytes(“r1”));

put.add(Bytes.toBytes(“d”), Bytes.toBytes(“b”),Bytes.toBytes(“bbbb”));

//不会写入，因为之前追加过有记录

table.checkAndPut(Bytes.toBytes(“r1”), Bytes.toBytes(“d”),Bytes.toBytes(“a”), Bytes.toBytes(“abcd”),put);// 参数：row_key,family,column,row_value

//会写入

table.checkAndPut(Bytes.toBytes(“r1”), Bytes.toBytes(“d”),Bytes.toBytes(“a”), Bytes.toBytes(“ad”),put);

table.close();

conn.close();

 

 

checkAndDelete：

Configurationconf =HBaseConfiguration.create();

conf.set(“hbase.zookeeper.quorum”,”192.168.1.149”);

conf.set(“hbase.zookeeper.property.clientport”,”2181”);

HConnection conn=HConnectionManager.createConnection(conf);

HTableInterfacetable = conn.getTable(“创建的表名”);

Delete delete = newDelete(Bytes.toBytes(“r1”));

delete.deleteColumns(Bytes.toBytes(“d”), Bytes.toBytes(“a”));

//不会被删

table.checkAndDelete(Bytes.toBytes(“r1”), Bytes.toBytes(“d”),Bytes.toBytes(“a”), Bytes.toBytes(“b”),delete);//参数：是否有row_key，是否有column，是否有row_value，删除对象

//会被删

table.checkAndDelete(Bytes.toBytes(“r1”), Bytes.toBytes(“d”),Bytes.toBytes(“a”), Bytes.toBytes(“bbbb”),delete);

table.close();

conn.close();

 

计数器

Configurationconf = HBaseConfiguration.create();

conf.set(“hbase.zookeeper.quorum”,”192.168.1.149”);

conf.set(“hbase.zookeeper.property.clientport”,”2181”);

HConnection conn=HConnectionManager.createConnection(conf);

HTableInterfacetable = conn.getTable(“创建的表名”);

lone result = table.incrementColumnValue(Bytes.toBytes(“r1”),Bytes.toBytes(“d”), Bytes.toBytes(“b”), 10);//10是追加计数的值

lone result =table.incrementColumnValue(Bytes.toBytes(“r1”), Bytes.toBytes(“d”), Bytes.toBytes(“b”),0);// 0是追加计数的值

lone result = table.incrementColumnValue(Bytes.toBytes(“r1”),Bytes.toBytes(“d”), Bytes.toBytes(“b”), -5);

lone result =table.incrementColumnValue(Bytes.toBytes(“r1”), Bytes.toBytes(“d”), Bytes.toBytes(“b”),+5);

System.out.print(result);

table.close();

conn.close();

 

Hbase重要组件——过滤器

Hbase过滤器：Filter:

在Hbase服务端将客户需要过滤掉数据过滤掉，减少传输到客户端的数据量，减轻负担。

//对row_key进行过滤

Configuration conf =HBaseConfiguration.create();

conf.set(“hbase.zookeeper.quorum”,”192.168.1.149”);

conf.set(“hbase.zookeeper.property.clientport”,”2181”);

HConnection conn= HConnectionManager.createConnection(conf);

HTableInterfacetable = conn.getTable(“创建的表名”);

Scan scan = new Scan();

Scan.setCacheBlocks(flase);//产生的数据不会放到Blockcache 里

//Filter filter = newRowFilter(CompareFilter.CompareOp.EQUAL,new BinaryComparator(Bytes.toBytes(“abc”)));//过滤出row_key

//Filter filter = newRowFilter(CompareFilter.CompareOp.EQUAL,newBinaryPrefixComparator(Bytes.toBytes( “ab”)));//过滤出row_key前缀包含ab的

Filter filter = newRowFilter(CompareFilter.CompareOp.EQUAL,new SubstringComparator ( “b”));//row_key包含b的被过滤出来

scan.setFilter(filter);

ResultScannerscanner = table.getScanner(scan);

for(Result result: scanner){

List<Cell> cell = result.listCells();

for(Cell cell:cells){

   String rowkey = newString(CellUnit.cloneRow(cell));

   String family = newString(CellUnit.cloneFamily(cell));

   String column = newString(CellUnit.clonecolumn(cell));

   String value = newString(CellUnit.clonecolumn(cell));

   System.out.println(rowkey+””+family+” ”+column+” ”+value);

 

}

}

scanner.close();

table.close();

conn.close();

 

//对column进行过滤

Configuration conf =HBaseConfiguration.create();

conf.set(“hbase.zookeeper.quorum”,”192.168.1.149”);

conf.set(“hbase.zookeeper.property.clientport”,”2181”);

HConnection conn=HConnectionManager.createConnection(conf);

HTableInterfacetable = conn.getTable(“创建的表名”);

Scan scan = new Scan();

Scan.setCacheBlocks(flase);//产生的数据不会放到Blockcache 里

Filter filter =new QualiFilter(CompareFilter.CompareOp.EQUAL,newBinaryComparator(Bytes.toBytes( “abc”)));//过滤出column为abc的

scan.setFilter(filter);

ResultScannerscanner = table.getScanner(scan);

for(Result result: scanner){

List<Cell> cell = result.listCells();

for(Cell cell:cells){

   String rowkey = newString(CellUnit.cloneRow(cell));

   String family = newString(CellUnit.cloneFamily(cell));

   String column = newString(CellUnit.clonecolumn(cell));

   String value = newString(CellUnit.clonecolumn(cell));

   System.out.println(rowkey+””+family+” ”+column+” ”+value);

 

}

}

scanner.close();

table.close();

conn.close();

 

//FilterList

Configuration conf = HBaseConfiguration.create();

conf.set(“hbase.zookeeper.quorum”,”192.168.1.149”);

conf.set(“hbase.zookeeper.property.clientport”,”2181”);

HConnection conn=HConnectionManager.createConnection(conf);

HTableInterfacetable = conn.getTable(“创建的表名”);

Scan scan = new Scan();

Scan.setCacheBlocks(flase);//产生的数据不会放到Blockcache 里

SingleColumnValueFilterfilter1 = new SingleColumnValueFilter (Bytes.toBytes( “d”),

Bytes.toBytes(“b”),

CompareFilter.CompareOp.EQUAL,

newBinaryPrefixComparator(Bytes.toBytes(“abc”)));//column_family,column,比较符,column_value

filter1.setFilterIfMissing(true);

 

SingleColumnValueFilterfilter2 = new SingleColumnValueFilter (Bytes.toBytes( “d”),

Bytes.toBytes(“c”),

CompareFilter.CompareOp.EQUAL,

newRegexStringComparator(“1|2|3”));//正则：要么为1要么为2要么为3

filter2.setFilterIfMissing(true);

List<Filter>filters = new ArrayList<Filter>();

filters.add(filter1);

filters.add(filter2);

FilterListfilterlist = new FilterList(filters);

scan.setFilter(filterlist);

ResultScannerscanner = table.getScanner(scan);

for(Result result: scanner){

List<Cell> cell = result.listCells();

for(Cell cell:cells){

   String rowkey = newString(CellUnit.cloneRow(cell));

   String family = newString(CellUnit.cloneFamily(cell));

   String column = newString(CellUnit.clonecolumn(cell));

   String value = newString(CellUnit.clonecolumn(cell));

   System.out.println(rowkey+””+family+” ”+column+” ”+value);

 

}

}

scanner.close();

table.close();

conn.close();