HTablePool简单使用例子

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HTablePool用在经常要创建表关闭表的程序中，可以大大优化性能，提高效率。

HTablePool()
HTablePool(Configuration config, int maxSize)
HTablePool(Configuration config, int maxSize, HTableInterfaceFactory tableFactory)
maxSize并非tablepool可创建的最大数，可以创建远大于设定值的表对象，当putTable()即返回时会与maxSize比较当前空闲数，空闲的已经有maxSize个，则直接释放表，不放入tablePool里
HTableInterface getTable(String tableName)
HTableInterface getTable(byte[] tableName)

void putTable(HTableInterface table)

public static void testTablePool() throws IOException {HTablePool tablePool = new HTablePool(conf, 5);ArrayList<HTableInterface> hts = new ArrayList<HTableInterface>();try {for(int i=0; i <6; i++){HTableInterface hTable =  tablePool.getTable(Bytes.toBytes("testtable"));System.out.println("the number:" + i);hts.add(hTable);}} catch (Exception e) {System.out.println("error!");// TODO: handle exceptione.printStackTrace();}System.out.println("tablepool size: " + hts.size());Scan scan = new Scan();int number = 0;PageFilter filter = new PageFilter(1);scan.setFilter(filter);ResultScanner rs = hts.get(0).getScanner(scan);System.out.println("begin!");int i = 0;for (Result result : rs) {System.out.println("number:" + (++i));number = 0;/*for (KeyValue kv : result.list()) {number++;System.out.println("number: " + number + "  :"+ Bytes.toString(kv.getKey()));System.out.println(Bytes.toString(kv.getValue()));}*///System.out.println("result " + i + result.toString());}rs.close();for (HTableInterface hTable : hts) {tablePool.putTable(hTable);}}

conf 与正常建htable时的配置相同即可。