mysql servers实现层拼写SQL

	@Override
	public List<controlresult> getControlresultList(Map<String, Object> params) throws Exception
	{
		Logger log = Logger.getLogger(RemoteControlController.class);
		List<controlresult> resultList = new ArrayList<>();
		Connection conn = null;
        Statement stmt = null;
        ResultSet rs = null;
		try{
			Class.forName("com.mysql.jdbc.Driver");
			 String dbNmae = "logall"+params.get("dbName");
			 String dbIp = ConfigUtil.pro.get("linkLogIp").toString();
			 String linkCloudSql = "jdbc:mysql://"+dbIp+"/"+dbNmae;
			 String linkCloudUsername =ConfigUtil.pro.get("linkLogIpUsername").toString();
			 String linkCloudPassword =ConfigUtil.pro.get("linkLogIpPassword").toString();
			 
			 
			 conn = DriverManager
	                 .getConnection(
	                		 linkCloudSql,linkCloudUsername, linkCloudPassword);
			 stmt = conn.createStatement();
			 PreparedStatement ps=null;
			 
			 StringBuffer buffer = new StringBuffer("SELECT `id`,`idc`,`flag`,`cmdStartTime`,`json`,`cmdEndTime`,`retValue`,`crmId`,CASE WHEN `fName` = '' OR `fName` IS NULL THEN `idsid` ELSE `fName` END `fName`,`insertTime`,TIMESTAMPDIFF(SECOND,cmdstarttime,cmdendtime )  AS duration FROM  log_controlresult  WHERE idc = ? and flag in ('BlueToothControl','carControlNew')");
			 if(params.get("ret") != null && StringUtils.isNoneEmpty(params.get("ret").toString())){
				 buffer.append("and retValue=?");
			 }
			 buffer.append(" order by crmid desc");
			 buffer.append(" LIMIT "+params.get("startIndex")+","+params.get("pageSize"));
			 
			 
			 
			 ps=(PreparedStatement) conn.prepareStatement(buffer.toString());
         	 ps.setString(1, params.get("idc").toString());

         	 
         	 if(params.get("ret") != null && StringUtils.isNoneEmpty(params.get("ret").toString())){
         		ps.setString(2, params.get("ret").toString());
			 }
         	
         	log.info("控制历史sql:"+buffer.toString());
         	 rs = ps.executeQuery();
			 while(rs.next())
			 {
				 controlresult cresult = new controlresult();
				 cresult.setId(rs.getLong("id"));
				 cresult.setIdc(rs.getString("idc"));
				 cresult.setFlag(rs.getString("flag"));
				 cresult.setCmdStartTime(rs.getTimestamp("cmdStartTime"));
				 cresult.setJson(rs.getString("json"));
				 cresult.setCmdEndTime(rs.getTimestamp("cmdEndTime"));
				 cresult.setRetValue(rs.getString("retValue"));
				 cresult.setCrmId(rs.getLong("crmId"));
				 cresult.setfName(rs.getString("fName"));
				 cresult.setInsertTime(rs.getTimestamp("insertTime"));
				 cresult.setDuration(rs.getInt("duration"));
				 cresult.setCmdName(GetSendTypeNameByJson(cresult.getJson()));
				 resultList.add(cresult);
			 }
		}
		finally {
	    	 try {
	                if (!conn.isClosed()) {
	                    conn.close();
	                }
	                if (!stmt.isClosed()) {
	                    stmt.close();
	                }
	                if (!rs.isClosed()) {
	                    rs.close();
	                }
	            } catch (SQLException e) {
	                e.printStackTrace();
	            }
	    }
		
		return resultList;
	}