HTablePool的替代者HConnection.getTable(String)

你的名字 2022-08-27 15:59 143阅读 0赞

HBase社区从0.94版本开始，已经在筹划弃用HTablePool了，并且决定在0.99中正式弃用（可见HBASE-6580和HBASE-9117等）。在0.94.16 API中，已经可以看到：Deprecated. Use HConnection.getTable(String) instead.

HConnection.getTable的用法示例如下：

public class HConnectionTest {
    	private HConnection conn = null;
    	private Configuration conf = null;
    
    	/**
    	 * creating connection object for HBase, the pool size is 256 by default.
    	 */
    	public QueryUtility() {
    		this.conf = HBaseConfiguration.create();
    		this.conf.set("hbase.zookeeper.quorum", "zk1,zk2,zk3");
    		this.conf.set("hbase.zookeeper.property.clientPort", "2181");
    		
    		try {
    			this.conn = HConnectionManager.createConnection(this.conf);
    		} catch (IOException e) {
    			System.out.println("connection failed, process will exit");
    			e.printStackTrace();
    			System.exit(1);
    		}
    	}
    
    	public void release()
    	{
    		try {
    			this.conn.close();
    		} catch (IOException e) {
    			e.printStackTrace();
    		}
    	}
    	
    	public void queryOneRecord(String strRowkey)
    	{
    		try {
    			/**
    			 * the HTable object can also be set the class member.
    			 */
    			HTable table = (HTable)this.conn.getTable("testtable");
    			
    	        Get get = new Get(strRowkey.getBytes());
    	        Result rs = table.get(get);
    	        
    	        String strRes = "this row " + strRowkey + " has " + rs.size()+ " versions";
    	        System.out.println(strRes);
    	        
    	        table.close();
    		} catch (IOException e) {
    			e.printStackTrace();
    		}
    	}
    }

实验发现：也可将HTable设置为类成员变量，这样在构造函数中添加语句：this.table=(HTable)this.conn.getTable("testtable")，然后queryOneRecord方法中就无需再调用getTable方法了。当然，这样需要在release方法中调用this.table.close().