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Editorial Team
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Asked: 2026-06-04T00:39:41+00:00

Anyone know how to fix the following errors unreported exception javax.naming.NamingException; must be caught

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Anyone know how to fix the following errors

unreported exception javax.naming.NamingException; must be caught or declared to be thrown
Context context = new InitialContext();

Auth.java:46: unreported exception java.sql.SQLException; must be caught or declared to be thrown conn = ds.getConnection();

that I get from this java servlet?

import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.*;
import javax.sql.DataSource;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import java.sql.SQLException;
import oracle.jdbc.OracleTypes;

public class ABC extends HttpServlet {

  @Override
  public void init(ServletConfig config) throws ServletException {
    super.init(config);
  }

  protected void doGet(HttpServletRequest req, HttpServletResponse res)
    throws ServletException, IOException {

    Connection conn;
    CallableStatement cs;

    String xy = req.getParameter("xy");
    String zz = req.getParameter("zz");

    // call stored procedure
    Context context = new InitialContext();
    DataSource ds = (DataSource)context.lookup("jdbc/mypool");
    conn = ds.getConnection();
    cs = conn.prepareCall( "{call mysproc (?,?)}" );
    cs.setString(1, xy);
    cs.setString(2, zz);
    cs.execute();

    if ( conn != null ) {
      try { conn.close(); } catch ( Exception ex ) {}
      conn = null;
    }

    // Set the content type (MIME Type) of the response.
    res.setContentType("text/html");

    // Write the HTML to the response
    PrintWriter out = res.getWriter();
    out.println("<html>");
    out.println("<head>");
    out.println("<title>my title</title>");
    out.println("</head>");
    out.println("<body>");
    out.println("<h2>my header</h2>");
    out.println("my body text<br/>");
    out.println("</body>);
    out.println("</html>");
    out.flush();
    out.close();
  }

  public void destroy() {  
  }         
}

If I try to replace

  protected void doGet(HttpServletRequest req, HttpServletResponse res)
    throws ServletException, IOException {

with

  protected void doGet(HttpServletRequest req, HttpServletResponse res)
    throws Exception {

or

  protected void doGet(HttpServletRequest req, HttpServletResponse res)
    throws ServletException, IOException, SQLException, NamingException {

they both produce errors saying I cannot override doGet, as overridden method does not throw Exception, or SQLException, or NamingException.

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1 Answer

  1. Editorial Team

    new InitialContext() throws a checked exception NamingException, which should either be caught or the method where you are using this code should have a throws clause associated with it.

    Since you are extending HttpServlet and overriding doGet method you cannot attach new checked Exception, as it is against the law of overriding in Java.

    Instead place the code inside a try catch block and catch NamingException.

    So instead of

    Context context = new InitialContext();

    replace this by

    Context context = null;
try {
    context = new InitialContext();
} catch(NamingException exp){
    //Handle Exception
}

    Similarly dataSource.getConnection throws a checked exception SQLException which should be caught or rethrown, once again you cannot add new checked exception to your doGet method because of rules of overriding you will have to catch it explicitly.

    try {
    DataSource ds = (DataSource)context.lookup("jdbc/mypool");
    conn = ds.getConnection();
    cs = conn.prepareCall( "{call mysproc (?,?)}" );
    cs.setString(1, xy);
    cs.setString(2, zz);
    cs.execute();

} catch ( SQLException exp ) {
  //Handle your exception
} finally {  
  if (conn != null ) {
      try {
         conn.close(); 
      } catch(SQLException sqlExp){
         // Handle your exception     
      }
      conn = null;
    }
}

    Rules of Overriding in Java:

    Overridden Method

    • Arguments Must not change
    • Return type Can’t change except for covariant (subtype) returns
    • Exceptions Can reduce/eliminate. Must not throw new/broader checked exceptions
    • Access Must not be more restrictive. Can be less restrictive.
    • Invocation Which method to call is based on object type, at runtime time
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