Query MySQL using JSP and Servlet POST method - mysql

Question

I'm not sure if I'm trying to "print" my result correctly. What I'm trying to do is use JSP to take in the variable and then pass it to the servlet where it will query the database and then display the result. I tested querying my database in a different java file and I had no trouble with that. Any advice would be greatly appreciated!
JSP file:
<form method="post" action="HelloServlet"/>
Enter your name:<input name = "exName"/><br>
<input type = "submit" />
</form>
JAVA file (servlet):
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws
ServletException, IOException {
//response.setContentType("text/html; charset=ISO-8859-1");
PrintWriter out = response.getWriter();
java.sql.Connection con = null;
java.sql.PreparedStatement pst = null;
ResultSet rs = null;
String url = "jdbc:mysql://localhost:3306/masters";
String user = "christine";
String password = "password";
try{
String exName = request.getParameter("exName");
con = DriverManager.getConnection(url, user, password);
pst = con.prepareStatement("SELECT * FROM exercise WHERE exercise_name ='"+exName+"';");
rs = pst.executeQuery();
while (rs.next()){
String name = rs.getString("description_txt");
out.print(exName);
out.print(name);
}
}catch(SQLException ex){
}finally {
try {
if (rs != null){
rs.close();
}
if (pst != null){
pst.close();
}
if (con != null){
con.close();
}
}catch(SQLException ex){
}
}
}

Answer 1

There are few things you need to change in your code.
As #BalusC mentioned do not suppress exception. Write exception to browser using out.println(ex); or throw new ServletException(ex). This will help you in finding the cause of problem.
Add Class.forName("com.mysql.jdbc.Driver"); before DriverManager.getConnection().
As you are already using PreparedStatement use
pst = con.prepareStatement("SELECT * FROM exercise WHERE exercise_name =?");
pst.setString(1, exName);
rs = pst.executeQuery();