JDBC ResultSet no results?

Why aren't there any results for this query? Only "Movies!" is printed when i run this servlet.

import java.io.*;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.sql.*;

public class Service extends HttpServlet {
 private static final long serialVersionUID = 1L;

 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  response.setContentType("text/html");
  PrintWriter out = response.getWriter();
  out.println("Movies!");

  Connection connection = null;
  Statement statement = 开发者_如何转开发null;
  try {
   connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/test");   
   statement = connection.createStatement();
   String query = "SELECT * FROM movies";
   ResultSet rs = statement.executeQuery(query);
   while(rs.next()) {
    out.println("result set");
    out.print(rs.getInt(1));
    out.print(rs.getString(2));
    out.print(rs.getInt(3));
    out.print(rs.getInt(4));
   }
  } catch(SQLException e) {
   e.printStackTrace();
  }
 }
}

Best guess: There are no rows in the table. What's the result when you execute the query manually ?

mysql test # connect to mysql

SELECT * FROM movies;

You're writing exceptions to server log file by e.printStackTrace() instead of throwing it so that it would end up in a nice error page in webbrowser.

Fix it as follows:

throw new ServletException("Querying from DB failed!", e);

Otherwise you've got to dig in the server logs for the exact cause of the problem.

Unrelated to the actual problem, remember to close your resources properly in a finally block. You're leaking them. See also the basic JDBC tutorial.

Update: finally, you got the cause of the problem:

java.sql.SQLException: No suitable driver found

You need to download the JDBC driver, put the JAR file in /WEB-INF/lib folder and load it in your code as follows before you acquire any connection:

Class.forName("com.mysql.jdbc.Driver");

See also:

• Java connectivity with MySQL - mini tutorial

Download MySQL JDBC Driver from

http://dev.mysql.com/downloads/connector/j/

Copy jar into WEB-INF/lib folder

hi before compilation you must put the clsses12.jar or other Ojdc14 jar file put in class path then make compile . some sample code here ResultSet res=statement.executeQuery("SELECT FIRST-NAME FROM FOO"); StringBuffer sb=new StringBuffer(); while(rs.next()) { sb.append("\n"+rs.getString(1)); }

Hi Download MYSQL JDBC driver from http://www.mysql.com/products/connector/ under the like JDBC Driver for MYSQL. place jdbc jar file at location - /WEB-INF/lib - in your application.

In your code following statement is missing

Class.forName("com.mysql.jdbc.Driver");

Place it before your following line of code

connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/test");

And restart the server..Make sure your database service is running...

And check..

I hope you would not get the error again...

~ Priyanjan