code: public Block getBlock(String sqlquery, Collection queryParams, int startIndex, int count) {
  		Debug.logVerbose("[JdonFramework]enter getBlock .. ", module);
  		if ((count > this.blockLength) || (count <= 0)) { // every query max
  			// length must be
  			// little than
  			// blockLength
  			count = this.blockLength;
  		}
  		QueryConditonDatakey qcdk = new QueryConditonDatakey(sqlquery, queryParams, startIndex, count, this.blockLength);
  		Block block = getBlock(qcdk);
  		if (block.getCount() > 0) {
  			Debug.logVerbose("[JdonFramework]got a Block" + block.getCount(), module);
  			return block;
  		} else {
  			Debug.logVerbose("[JdonFramework]not found the block!", module);
  			return null;
  		}
  	}
docs: get a data block by the sql sentence.
  
  @param sqlqueryAllCount
  @param sqlquery
  @return if not found, return null;