如何解决 Exception::java.security.AccessControlException: access denied in HttpServlet

Question

I have created one Servlet class and I am trying to retrieve one record from Oracle 11g and also I am trying to use MySQL database but getting this exception: error ouput image

I am using below stuff:

WebServer: Tomcat9
JRE: 1.8
Databases: Oracle 11g,MySQL

Here is my servlet class:

public class EmployeeSearchApp extends HttpServlet{

    private static final String EMP_SEARCH_DETAILS = "SELECT EMPMO,ENAME,JOB,SAL,EMPNO FROM EMP WHERE EMPNO=?";

      private static final String url="jdbc:oracle:thin:@localhost:1521:orcl";
      private static final String userName = "scott"; 
      private static final String password = "tiger";
    /*
     * private static final String url="jdbc:mysql://localhost:3306/world"; private
     * static final String userName = "ram"; private static final String password =
     * "padma";
     */

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {
        PrintWriter pw=null;
        int eno=0;
        Connection con=null;
        PreparedStatement ps=null;
        ResultSet rs=null;
        try {
            //Getting the print Writer Object 
            pw=res.getWriter();

            //Setting the content type
            res.setContentType("text/html");

            //getting the parameter value
            eno=Integer.parseInt(req.getParameter("eno"));

            //JDBC code

            //Registering JDBC driver
            Class.forName("oracle.jdbc.driver.OracleDriver");
            //Class.forName("com.mysql.jdbc.Driver");

            //Establishing the db connection
            con=DriverManager.getConnection(url,userName,password);

            //Preparing the Prepared Statement object
            ps=con.prepareStatement(EMP_SEARCH_DETAILS);

            //set the value into query param
            ps.setInt(1, eno);

            //execute the sql query
            rs=ps.executeQuery();

            //process the result set object
            if(rs.next()) {
                pw.println("<h1>EMPLOYEE DETAILS</h1>");
                pw.println("<h1>Employee ID:"+rs.getInt(1)+"</h1>");
                pw.println("<h1>Employee Name:"+rs.getString(2)+"</h1>");
                pw.println("<h1>Employee Job:"+rs.getString(3)+"</h1>");
                pw.println("<h1>Employee Sal:"+rs.getDouble(4)+"</h1>");
                pw.println("<h1>Employee Dept NO:"+rs.getInt(5)+"</h1>");
            }

        }catch (SQLException se) {
            se.printStackTrace();
            pw.println("<h1 style='color:red;'>Internal Database problem</h1>");
        } 
        catch (ClassNotFoundException cnf) { 
            cnf.printStackTrace();
            pw.println("<h1 style='color:red;'>Internal problem</h1>"); 
        }

        catch (Exception e) {
            e.printStackTrace();
            pw.println("<h1 style='color:red;'>Internal problem</h1>");
        }finally {
            rs.close();
            ps.close();
            con.close();
        }
    }   
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {
        doGet(req, res);
    }
}

and the exception on console is as follows

Exception::java.security.AccessControlException: access denied

What could be the possible scenarios when one may get this exception? And how do I resolve this?

Answer 1

Stack-trace shows that a security manager (ie: java policies ) is enabled, and restraining you from accessing system properties. That means that your JVM/Tomcat has been configured to restrain web application privileges and actions. Only the administrator of the target platform can help you with that (either add sufficient authorizations in running policies, or give you an alternative method for what you aim for).