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- The original author of this article: Brother Gu’s younger brother
- Author blog address: http://blog.csdn.net/lfdfhl
In this tutorial, we implement the function of deleting students. When you click delete in the student list, you can delete a student and reload the student list. So, the operation actually consists of two steps:
- 1. Delete students
- 2. Refresh the student list
DeleteStudentServlet
Please create DeleteStudentServlet under the servlet package to realize the function of deleting students, the code is as follows:
package com.cn.servlet;
import com.cn.util.C3P0Utils;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.sql.Connection;
import java.sql.PreparedStatement;
@WebServlet(name = "DeleteStudentServlet", urlPatterns = "/DeleteStudentServlet")
public class DeleteStudentServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
int id = Integer.parseInt(request.getParameter("id"));
Connection connection = null;
PreparedStatement preparedStatement = null;
try {
connection = C3P0Utils.getConnection();
String sql = "delete from student where id=?";
preparedStatement = connection.prepareStatement(sql);
preparedStatement.setInt(1, id);
int result = preparedStatement.executeUpdate();
if (result > 0){
System.out.println("success");
} else{
System.out.println("error");
}
} catch (Exception e) {
e.printStackTrace();
} finally {
C3P0Utils.release(connection, preparedStatement, null);
}
String contextPath = request.getContextPath();
response.sendRedirect( contextPath+"/ShowStudentServlet");
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}
The diagram is as follows:
