我使用Netbeans开发了一个基本表单来获取客户意见。我有一个index.jsp文件，它包含所有的html代码，一个从表单获取值的servlet和一个用于建立数据库连接并填充数据库的java类。我在tomcat服务器上运行它，但是我收到HTTP 500错误。
这是index.jsp
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Feedback Form for Personal Account Users</title>
</head>
<body>
<form name = "FeedbackForm" action="SubmitUser" method ="post">
<p id="Questions">Your Comments: </p>
<textarea id="selection" rows="4" cols="100" name="comment">
</textarea>
<br>
<br>
<input type = "submit" name ="sub" value="Submit">
</form>
</body>
</html>
具有数据库连接的Java类
package feedback;
package feedback;
import java.sql.*;
import java.util.logging.Level;
import java.util.logging.Logger;
public class DbConnection {
private String driver = "com.mysql.jdbc.Driver";
private String url = "jdbc:mysql://localhost:3306/online_feedback";
private Connection con;
private Statement st;
private int i;
public void connectDB(){
try {
Class.forName(driver);
con = DriverManager.getConnection(url, "root", "");
} catch (ClassNotFoundException ex) {
Logger.getLogger(DbConnection.class.getName()).log(Level.SEVERE, null, ex);
} catch (SQLException ex) {
Logger.getLogger(DbConnection.class.getName()).log(Level.SEVERE, null, ex);
}
}
public int insertValues(String sql){
try {
connectDB();
Statement st = con.createStatement();
i = st.executeUpdate(sql);
return i;
} catch (SQLException ex) {
Logger.getLogger(DbConnection.class.getName()).log(Level.SEVERE, null, ex);
}
return i;
}
public void main (String []args){
DbConnection db = new DbConnection();
db.connectDB();
}
}
以下是Servlet（SubmitUser）从表单
获取值package feedback;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class SubmitUser extends HttpServlet {
private DbConnection db = new DbConnection();
protected void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
String comment = request.getParameter("comment");
String sql = "INSERT INTO test values('comment' )";
int i = db.insertValues(sql);
if (i==0){
out.println("<html>");
out.println("<head>");
out.println("<title>Servlet SubmitUser</title>");
out.println("</head>");
out.println("<body>");
out.println("<h1>You have missed</h1>");
out.println("</body>");
out.println("</html>");
}
else{
out.println("<html>");
out.println("<head>");
out.println("<title>Servlet SubmitUser</title>");
out.println("</head>");
out.println("<body>");
out.println("<h1>Successfully Submmited</h1>");
out.println("</body>");
out.println("</html>");
}
}
}
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}
/**
* Handles the HTTP <code>POST</code> method.
*
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}
/**
* Returns a short description of the servlet.
*
* @return a String containing servlet description
*/
@Override
public String getServletInfo() {
return "Short description";
}// </editor-fold>
}