java api操作

java api操作 导入开发包 将hbase安装包中lib下包导入java项目  创建表  Configuration conf = HBaseConfiguration.create(); conf.set(“hbase.zookeeper.quorum”, “CentOS01:2181,CentOS02:2181,CentOS03:2181”);  HBaseAdmin admin = new HBaseAdmin(conf);  HTableDescriptor htd = new HTableDescriptor(TableName.valueOf(“tabe”)); HColumnDescriptor hcd_fam1 = new HColumnDescriptor(“fam1”); hcd_fam1.setMaxVersions(3); HColumnDescriptor hcd_fam2 = new HColumnDescriptor(“fam2”); htd.addFamily(hcd_fam1); htd.addFamily(hcd_fam2);  admin.createTable(htd);  admin.close();   插入数据 Configuration conf = HBaseConfiguration.create(); conf.set(“hbase.zookeeper.quorum”,”CentOS01:2181,CentOS02:2181,CentOS03:2181″);  HTable table = new HTable(conf,”tabe”); Put put = new Put(Bytes.toBytes(“row1”)); put.add(Bytes.toBytes(“fam1”),Bytes.toBytes(“col1”),Bytes.toBytes(“val1”)); put.add(Bytes.toBytes(“fam1”),Bytes.toBytes(“col2”),Bytes.toBytes(“val2”)); put.add(Bytes.toBytes(“fam2”),Bytes.toBytes(“col3”),Bytes.toBytes(“val3″)); table.put(put);  table.close();    **javaapi操作hbase时，入口类为HTable，此对象创建时需要扫描.META表，以及其他操作，这非常耗时，所以，应该将该对象设置为单例，复用该对象，如果需要多个HTable对象，应该使用HTable Pool,通过对象池复用对象。 HTablePool pool = new HTablePool(conf,10);//不知道为什么过时了？ **hbase所有修改数据的操作都保证了行级别的原子性，  试验：一次插入100万条数据 HTable table = new HTable(conf,”tabx”); List<Put> puts = new ArrayList<Put>(); for(int i=1;i<=1000000;i++){ Put put = new Put(Bytes.toBytes(“row”+i)); put.add(Bytes.toBytes(“fam1”),Bytes.toBytes(“col1”),Bytes.toBytes(“val”+i)) puts.add(put);  if(i % 10000 == 0){ table.put(puts); puts = new ArrayList<Put>(); } } table.put(puts); table.close();   获取数据 Configuration conf = HBaseConfiguration.create(); conf.set(“hbase.zookeeper.quorum”,”CentOS01:2181,CentOS02:2181,CentOS03:2181″);  HTable table = new HTable(conf,”tabe”); Get get = new Get(Bytes.toBytes(“row1”)); Result result = table.get(get); byte [] bs = result.getValue(Bytes.toBytes(“fam1”),Bytes.toBytes(“col1”)); String str = Bytes.toString(bs); System.out.println(str);  table.close();   获取数据集 Configuration conf = HBaseConfiguration.create(); conf.set(“hbase.zookeeper.quorum”,”CentOS01:2181,CentOS02:2181,CentOS03:2181″);  HTable table = new HTable(conf,”tabe”); Scan scan = new Scan(Bytes.toBytes(“row1”)); ResultScanner scanner = table.getScanner(scan); Iterator it = scanner.iterator(); while(it.hasNext()){ Result result = (Result) it.next(); byte [] bs = result.getValue(Bytes.toBytes(“fam1”),Bytes.toBytes(“col1”)); String str = Bytes.toString(bs); System.out.println(str); } table.close();   删除数据 Configuration conf = HBaseConfiguration.create(); conf.set(“hbase.zookeeper.quorum”,”CentOS01:2181,CentOS02:2181,CentOS03:2181″);  HTable table = new HTable(conf,”tabe”); Delete delete = new Delete(Bytes.toBytes(“row1”)); table.delete(delete); table.close();   删除表  //1.创建配置对象 HBaseConfiguration conf = new HBaseConfiguration(); conf.set(“hbase.zookeeper.quorum”, “CentOS01”); //2.创建HBaseAdmin对象 HBaseAdmin admin = new HBaseAdmin(conf); //3.删除表 admin.disableTable(Bytes.toBytes(“tab1”)); admin.deleteTable(Bytes.toBytes(“tab1”)); //4.关闭连接 admin.close();