HBase实现分页核心代码

Scan scan = new Scan();
scan.setStartRow(getBytes(startRow));
scan.setStopRow(getBytes(stopRow));
scan.setCaching(1000);
scan.setCacheBlocks(false);
ResultScanner scanner = table.getScanner(scan);
int i = 0;
List<byte[]> rowList = new LinkedList<byte[]>();
// 遍历扫描器对象, 并将需要查询出来的数据row key取出
for (Result result : scanner)
{
	String row = toStr(result.getRow());
	if (i >= firstPage && i < endPage)
	{
		rowList.add(getBytes(row));
	}
	i++;
}
// 获取取出的row key的GET对象
List<Get> getList = getList(rowList);
Result[] results = table.get(getList);
List<Map<String, String>> mapList
// 遍历结果
for (Result result : results)
{
	Map<byte[], byte[]> fmap = packFamilyMap(result);
	Map<String, String> rmap = packRowMap(fmap);
	mapList.add(rmap);
}
List<Get> getList(List<byte[]> rowList)
{
	List<Get> list = new LinkedList<Get>();
	for (byte[] row : rowList)
	{
		Get get = new Get(row);

		get.addColumn(getBytes("family1"), getBytes("column1"));
		get.addColumn(getBytes("family1"), getBytes("column2"));
		get.addColumn(getBytes("family2"), getBytes("column1"));
		list.add(get);
	}
	return list;
}
Map<byte[], byte[]> packFamilyMap(Result result)
{
	Map<byte[], byte[]> dataMap = null;
	dataMap = new LinkedHashMap<byte[], byte[]>();
	dataMap.putAll(result.getFamilyMap(getBytes("family1")));
	dataMap.putAll(result.getFamilyMap(getBytes("family2")));
	return dataMap;
}
Map<byte[], byte[]> packFamilyMap(Result result)
{
	Map<byte[], byte[]> dataMap = null;
	dataMap = new LinkedHashMap<byte[], byte[]>();
	dataMap.putAll(result.getFamilyMap(getBytes("family1")));
	dataMap.putAll(result.getFamilyMap(getBytes("family2")));
	return dataMap;
}

http://www.21edu8.com/pcnet/programming/29943/

猜你喜欢

转载自houshangxiao.iteye.com/blog/2084989
今日推荐