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POGetting Null value from attribute
 

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  1. POGetting Null value from attribute
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    <p>In the Dynamic web application I facing some issues,so I'm posting my code:</p> <p>Here is my controller(servlet):</p> <pre><code> String select = request.getParameter("select"); // getting proper value String search = request.getParameter("search"); // getting proper value request.setAttribute("select", select); request.setAttribute("search", search); System.out.println("Select : "+select+" Search : "+search); int page = 1; int recordsPerPage = 20; if(request.getParameter("page") != null) page = Integer.parseInt(request.getParameter("page")); SearchDAO searchDAO=new SearchDAO(); List&lt;User&gt; list=searchDAO.searchAllUsers((page-1)*recordsPerPage,recordsPerPage,select,search); int noOfRecords = searchDAO.getNoOfRecords(); System.out.println("4&gt; NoOfRecords : "+noOfRecords); int noOfPages = (int) Math.ceil(noOfRecords * 1.0 / recordsPerPage); System.out.println("5&gt; NoOfPages : "+noOfPages); request.setAttribute("searchList", list); System.out.println("6&gt; List : "+list); request.setAttribute("noOfPages", noOfPages); // Getting null value, 0 request.setAttribute("currentPage", page); // Getting null value, 0 RequestDispatcher view = request.getRequestDispatcher("/jsp/Securex_Anti_Theft_SearchUserList.jsp"); view.forward(request, response); </code></pre> <p>And here is my DAO (simple java class):</p> <pre><code>public class SearchDAO { private int noOfRecords; Connection connection; Statement stmt; public List&lt;User&gt; searchAllUsers(int offset ,int noOfRecords,String select,String search){ private static Connection getConnection() throws SQLException,ClassNotFoundException{ Connection con = ConnectionFactory.getInstance().getConnection(); return con; //ConnectionFactory is class for making the connection to DB. } String query="select SQL_CALC_FOUND_ROWS * from info where '"+select+ "' like '%"+search+"%' order by serialNo asc limit " + offset + " , " + noOfRecords; List&lt;User&gt; list1 = new ArrayList&lt;User&gt;(); User user1=null; try { connection = getConnection(); stmt = connection.createStatement(); ResultSet rs=stmt.executeQuery(query); System.out.println("1&gt; :"+rs); while(rs.next()){ user1=new User(); user1.setSerial(rs.getInt(1)); System.out.println("I'm inside a loop"); user1.setName(rs.getString(2)); user1.setEmail(rs.getString(3)); list1.add(user1); } rs.close(); rs = stmt.executeQuery("SELECT FOUND_ROWS()"); System.out.println("2&gt; :" +rs); if(rs.next()) this.noOfRecords = rs.getInt(1); System.out.println("3&gt; :" +this.noOfRecords); } catch (SQLException e) { e.printStackTrace(); } catch (ClassNotFoundException e) { e.printStackTrace(); }finally { try { if(stmt != null) stmt.close(); if(connection != null) connection.close(); } catch (SQLException e) { e.printStackTrace(); } } return list1; } public int getNoOfRecords() { return noOfRecords; } } </code></pre> <p>And the Output is : </p> <pre><code>1&gt; :com.mysql.jdbc.JDBC4ResultSet@1af8502 2&gt; :com.mysql.jdbc.JDBC4ResultSet@455aa8 3&gt; :0 4&gt; NoOfRecords : 0 5&gt; NoOfPages : 0 6&gt; List : [] </code></pre> <p>I have same same servlet and class for select all users,and that's working properly,bbut getting null value from here.Even ResultSet returns value i.e. com.mysql.jdbc.JDBC4ResultSet@88d319,but unable fetch the value from DAO to servlet.</p> <p>Getting null value from <code>//</code> attributes,To me everything should be going fine but still getting null value,feel free to point out my mistake,If I have done anything</p>
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    1. COAre you sure, that your DAO returns not empty result?
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    2. COResultSet returns value i.e. com.mysql.jdbc.JDBC4ResultSet@88d319,but unable fetch the value from DAO to servlet
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    3. COin your Dao class, why the method `searchAllUsers` and `getConnection` are nested?
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