java.lang.NullPointerException in JSP code

Question

after my wits end i am posting question here. i am getting "java.lang.NullPointerException" error while developing a small JSP web application. Please help me to fix it.

Here below i mention my code:

<body>
    <%!
        public class Actor{
        String URL = "jdbc:mysql://localhost:3306/henry_books";
        String USERNAME = "root";
        String PASSWORD = "adminroot";

        Connection connection = null;
        PreparedStatement selectActors = null;
        ResultSet resultSet = null;
        public Actor(){
        try{
            connection = DriverManager.getConnection(URL, USERNAME, PASSWORD);
            selectActors = connection.prepareStatement("SELECT * FROM author");

            }catch(SQLException e){
                e.printStackTrace();
            }
        }
        public ResultSet getActors(){
            try{
                resultSet = selectActors.executeQuery();
            }catch(SQLException e){
                e.printStackTrace();
            }
            return resultSet;
         }
        }
    %>
    <%
        Actor actor = new Actor();
        ResultSet actors = actor.getActors();
        while(actors.next()){
            %>
            <span><%= actors.getInt("authorNum")%></span>  
        <% }
    %>
</body>

Getting Error on ResultSet actors = actor.getActors(); line Error:

  org.apache.jasper.JasperException:

An exception occurred processing JSP page /book_app/web/index.jsp at line 48

45:         %>
46:         <%
47:             Actor actor = new Actor();
48:             ResultSet actors = actor.getActors();
49:             while(actors.next()){
50:                 %>
51:                 <span><%= actors.getInt("authorNum")%></span>  


Stacktrace:    
root cause

java.lang.NullPointerException
org.apache.jsp.book_005fapp.web.index_jsp$Actor.getActors(index_jsp.java:39)
org.apache.jsp.book_005fapp.web.index_jsp._jspService(index_jsp.java:109)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:432)

Answer 1

Add Driver class before establishing connection and also make sure you have added mysql-connector.jar file in your lib folder.

public Actor(){
    try{
        Class.forName("com.mysql.jdbc.Driver");  //Add this line
        connection = DriverManager.getConnection(URL, USERNAME, PASSWORD);
        selectActors = connection.prepareStatement("SELECT * FROM author");

        }catch(SQLException e){
            e.printStackTrace();
        }
    }

Refer this for details

java.lang.NullPointerException in JSP code

Question

1 answers

solution1
0 2017-04-18 05:40:32

java.lang.NullPointerException in JSP code

Question

1 answers

solution1 0 2017-04-18 05:40:32

solution1
0 2017-04-18 05:40:32