课程添加

建立各包

 

Bean层

package bean;

public class Course {
    int id;
    private String teachername;
    private String place;
    private String classname;
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getTeachername() {
        return teachername;
    }
    public void setTeachername(String teachername) {
        this.teachername = teachername;
    }
    public String getPlace() {
        return place;
    }
    public void setPlace(String place) {
        this.place = place;
    }
    public String getClassname() {
        return classname;
    }
    public void setClassname(String classname) {
        this.classname = classname;
    }
    public Course(int id,String teachername,String place,String classname) {
        this.id=id;
        this.teachername=teachername;
        this.place=place;
        this.classname=classname;
    }
    public Course(String teachername,String place,String classname) {
        this.teachername=teachername;
        this.place=place;
        this.classname=classname;
    }

}

dao层

package dao;

import bean.Course;

import java.beans.Statement;
import java.sql.Connection;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;

import DBUtil.DBUtil;

public class Coursedao {
    
    
    public void courseadd(Course course) {
        String sql = "insert into runoob_db3(teachername,place,classname) values('" + course.getTeachername()+"','"+course.getPlace() + "','"
                +course.getClassname()+ "')";
        //创建数据库链接
        Connection conn = DBUtil.getConn();
        java.sql.Statement state = null;
        boolean f = false;
        int a = 0;

        try {
            state = conn.createStatement();
            state.executeUpdate(sql);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            //关闭连接
            DBUtil.close(state, conn);
        }
    }
    
    public List<Course> findByteachername(String teachername) {
        String sql = "select * from runoob_db3 where teachername ='" + teachername + "'";
        List<Course> list = new ArrayList<>();
        Connection conn = DBUtil.getConn();
        java.sql.Statement state = null;
        ResultSet rs = null;
        
        try {
            state = conn.createStatement();
            rs = state.executeQuery(sql);
            Course bean = null;
            while (rs.next()) { 
                int id=rs.getInt("id");
                String place=rs.getString("place");
                String classname = rs.getString("classname");
                bean =new Course(id,teachername,place,classname);
                list.add(bean);              
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            DBUtil.close(rs, state, conn);
        }
        return list;
    }


}

DBUtil

package DBUtil;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

/**
* 数据库连接工具
*
*/
public class DBUtil {

  public static String db_url = "jdbc:mysql://localhost:3306/runoob?serverTimezone=UTC";
  public static String db_user = "root";
  public static String db_pass = "152486";

  public static Connection getConn() {
      Connection conn = null;

      try {
          Class.forName("com.mysql.cj.jdbc.Driver");//加载驱动
          conn = DriverManager.getConnection(db_url, db_user, db_pass);
      } catch (Exception e) {
          e.printStackTrace();
      }

      return conn;
  }

  /**
   * 关闭连接
   * @param state
   * @param conn
   */
  public static void close (Statement state, Connection conn) {
      if (state != null) {
          try {
              state.close();
          } catch (SQLException e) {
              e.printStackTrace();
          }
      }

      if (conn != null) {
          try {
              conn.close();
          } catch (SQLException e) {
              e.printStackTrace();
          }
      }
  }

  public static void close (ResultSet rs, Statement state, Connection conn) {
      if (rs != null) {
          try {
              rs.close();
          } catch (SQLException e) {
              e.printStackTrace();
          }
      }

      if (state != null) {
          try {
              state.close();
          } catch (SQLException e) {
              e.printStackTrace();
          }
      }

      if (conn != null) {
          try {
              conn.close();
          } catch (SQLException e) {
              e.printStackTrace();
          }
      }
  }
}

servlet层

package servlet;
import java.util.Date; 
import java.text.SimpleDateFormat; 

import java.io.IOException;
import java.util.List;

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 bean.Course;
import dao.Coursedao;

@WebServlet("/CourseServlet")
public class CourseServlet extends HttpServlet{
    
    private static final long serialVersionUID = 1L;
    
    Coursedao dao=new Coursedao();
    
     protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
            req.setCharacterEncoding("utf-8");
            String method = req.getParameter("method");

            if ("courseadd".equals(method)) {
                courseadd(req, resp);
            
                
            } else if("findByteachername".equals(method)) {
                findByteachername(req,resp);
            }
                //else if("chaxun".equals(method)) {
//                chaxun(req,resp);
//            }else if("liulan".equals(method)) {
//                liulan(req,resp);
//            }else if("delete2".equals(method)) {
//                delete2(req,resp);
//            }else if("getByname".equals(method)) {
//                getByname(req,resp);
//            }else if("getByname1".equals(method)) {
//                getByname1(req,resp);
//            }else if("xiugai".equals(method)) {
//                xiugai(req,resp);
//            }
     }
     
     
     private void courseadd(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException {
             req.setCharacterEncoding("utf-8");
            //获取数据
             String teachername=req.getParameter("teachername");
            String place=req.getParameter("place");
            String classname=req.getParameter("classname");
            Course course=new Course(teachername,place,classname);
            dao.courseadd(course);
            req.setAttribute("message", "录入成功");
            req.getRequestDispatcher("add.jsp").forward(req,resp);
     }
     
     private void findByteachername(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException {
             req.setCharacterEncoding("utf-8");
            //获取数据
             String teachername=req.getParameter("teachername");
            List<Course> courses=dao.findByteachername(teachername);
            if(courses == null) {
                req.setAttribute("message", "查无此信息！");
                req.getRequestDispatcher("find.jsp").forward(req,resp);
            } else {
                req.setAttribute("courses", courses);
                req.getRequestDispatcher("list.jsp").forward(req,resp);
            }

     }
}

增加页面

package servlet;
import java.util.Date; 
import java.text.SimpleDateFormat; 

import java.io.IOException;
import java.util.List;

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 bean.Course;
import dao.Coursedao;

@WebServlet("/CourseServlet")
public class CourseServlet extends HttpServlet{
    
    private static final long serialVersionUID = 1L;
    
    Coursedao dao=new Coursedao();
    
     protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
            req.setCharacterEncoding("utf-8");
            String method = req.getParameter("method");

            if ("courseadd".equals(method)) {
                courseadd(req, resp);
            
                
            } else if("findByteachername".equals(method)) {
                findByteachername(req,resp);
            }
                //else if("chaxun".equals(method)) {
//                chaxun(req,resp);
//            }else if("liulan".equals(method)) {
//                liulan(req,resp);
//            }else if("delete2".equals(method)) {
//                delete2(req,resp);
//            }else if("getByname".equals(method)) {
//                getByname(req,resp);
//            }else if("getByname1".equals(method)) {
//                getByname1(req,resp);
//            }else if("xiugai".equals(method)) {
//                xiugai(req,resp);
//            }
     }
     
     
     private void courseadd(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException {
             req.setCharacterEncoding("utf-8");
            //获取数据
             String teachername=req.getParameter("teachername");
            String place=req.getParameter("place");
            String classname=req.getParameter("classname");
            Course course=new Course(teachername,place,classname);
            dao.courseadd(course);
            req.setAttribute("message", "录入成功");
            req.getRequestDispatcher("add.jsp").forward(req,resp);
     }
     
     private void findByteachername(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException {
             req.setCharacterEncoding("utf-8");
            //获取数据
             String teachername=req.getParameter("teachername");
            List<Course> courses=dao.findByteachername(teachername);
            if(courses == null) {
                req.setAttribute("message", "查无此信息！");
                req.getRequestDispatcher("find.jsp").forward(req,resp);
            } else {
                req.setAttribute("courses", courses);
                req.getRequestDispatcher("list.jsp").forward(req,resp);
            }

     }
}