Report NULL pointer exception

　　

|| When the left is true, the expression on the right is not run | When the left is true, the expression on the right is calculated && the expression on the right is not calculated when the left side is false & the left side is false, or the expression on the right is calculated//add by Zengzhiwei December 26, 2015 23:56:19 beginpublic Boolean CHECKPK (String billpk) throws Businessexception {string Sql=new string (""); sql= "Select GUID from Mid_payinfo where billpk= '" +billpk+ ""; Map map = (map) Getbasedao (). ExecuteQuery (SQL, New Mapprocessor ()); if (map! = NULL | | MAP.SIZE>0)//The correct wording should be  (map! =null&&map.size>0) {return true;} Elsereturn false;} Add by Zengzhiwei December 26, 2015 23:56:29 end

　　

Report NULL pointer exception