课堂作业

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
<style>
    .a{
        margin-top: 20px;
    }
    .b{
        font-size: 20px;
        width: 160px;
        color: white;
        background-color: greenyellow;
    }
</style>
</head>
<body>
    <%
         Object message = request.getAttribute("message");
         if(message!=null && !"".equals(message)){
     
    %>
         <script type="text/javascript">
              alert("<%=request.getAttribute("message")%>");
         </script>
    <%} %>
    <div align="center">
        <h1 style="color: red;">公文录入</h1>
        <a href="index.jsp">返回主页</a>
        <form action="CourseServlet?method=add" method="post" onsubmit="return check()">
            <div class="a">
                公文标题<input type="text" id="title" name="title"/>
            </div>
            <div class="a">
                部门名称<input type="text" id="workname" name="workname" />
            </div>
            <div class="a">
                起草人<input type="text" id="man" name="man" />
            </div>
            <div class="a">
                <button type="submit" class="b">保&nbsp;&nbsp;&nbsp;存</button>
            </div>
        </form>
    </div>
    <script type="text/javascript">
        function check() {
            var title = document.getElementById("title");;
            var workname = document.getElementById("workname");
            var man = document.getElementById("man");
            
            //非空
            if(title.value == '') {
                alert('公文为空');
                name.focus();
                return false;
            }
            if(workname.value == '') {
                alert('部门为空');
                teacher.focus();
                return false;
            }
            if(man.value == '') {
                alert('起草人');
                classroom.focus();
                return false;
            }
            
        
        }
    </script>
</body>
</html>

package dao;
//对数据库的操作
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

import entity.Course;
import util.DBUtil;

/**
 * 课程Dao
 * Dao层操作数据
 * @author Zheng
 *
 */
public class CourseDao {

    /**
     * 添加 增
     * @param course
     * @return
     */
    public boolean add(Course course) {
        String sql = "insert into course(title, workname, man) values('" + course.getTitle() + "','" + course.getWorkname() + "','" + course.getMan() + "')";
        Connection conn = DBUtil.getConn();
        Statement state = null;
        boolean f = false;
        int a = 0;
        
        try {
            state = conn.createStatement();
            state.executeUpdate(sql);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            DBUtil.close(state, conn);
        }
        
        if (a > 0) {
            f = true;
        }
        return f;
    }
    
    public boolean title(String title) {
        boolean flag = false;
        String sql = "select name from course where name = '" + title + "'";
        Connection conn = DBUtil.getConn();
        Statement state = null;
        ResultSet rs = null;
        
        try {
            state = conn.createStatement();
            rs = state.executeQuery(sql);
            while (rs.next()) {
                flag = true;
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            DBUtil.close(rs, state, conn);
        }
        return flag;
    }
}

package service;

import java.util.List;

import dao.CourseDao;
import entity.Course;

/**
 * CourseService
 * 服务层
 * @author Zheng
 *
 */
@SuppressWarnings("unused")
public class CourseService {

    CourseDao cDao = new CourseDao();
    
    /**
     * 添加
     * @param course
     * @return
     */
    public boolean add(Course course) {
        boolean f = false;
        if(!cDao.title(course.getTitle())) {
            cDao.add(course);
            f = true;
        }
        return f;
    }}

package entity;

public class Course {

    
    private String title;
    private String workname;
    private String man;
    

    public String getTitle() {
        return title;
    }
    public void setTitle(String title) {
        this.title = title;
    }
    public String getWorkname() {
        return workname;
    }
    public void setWorkname(String workname) {
        this.workname = workname;
    }
    public String getMan() {
        return man;
    }
    public void setMan(String man) {
        this.man = man;
    }
    
    public Course() {}
    //*构造方法

    
    public Course(String title, String workname, String man) {
        this.title = title;
        this.workname = workname;
        this.man = man;
    }
}

package servlet;

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 entity.Course;
import service.CourseService;

@SuppressWarnings("unused")
@WebServlet("/CourseServlet")
public class CourseServlet extends HttpServlet {
    
    private static final long serialVersionUID = 1L;

    CourseService service = new CourseService();
    
    /**
     * 方法选择
     */
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        req.setCharacterEncoding("utf-8");
        String method = req.getParameter("method");
        if ("add".equals(method)) {
            add(req, resp);
        }
    }

    /**
     * 添加
     * @param req
     * @param resp
     * @throws IOException 
     * @throws ServletException 
     */
    private void add(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException {
        req.setCharacterEncoding("utf-8");
        String title = req.getParameter("title");
        String workname = req.getParameter("workname");
        String man = req.getParameter("man");
        Course course = new Course(title,workname,man);
        
        //添加后消息显示
        if(service.add(course)) {
            req.setAttribute("message", "添加成功");
            req.getRequestDispatcher("add.jsp").forward(req,resp);
        } else {
            req.setAttribute("message", "课程名称重复，请重新录入");
            req.getRequestDispatcher("add.jsp").forward(req,resp);
        }
    }}

package util;
//数据库连接
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

/**
 * 数据库连接工具
 * @author Zheng
 *
 */
public class DBUtil {
    
    public static String db_url = "jdbc:mysql://localhost:3306/mysql?useUnicode=true&characterEncoding=GB18030&useSSL=false&serverTimezone=GMT&allowPublicKeyRetrieval=true";
    public static String db_user = "root";
    public static String db_pass = "1234";
    
    public static Connection getConn () {
        Connection conn = null;
        
        try {
            Class.forName("com.mysql.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();
            }
        }
    }

}

posted @ 2019-12-09 17:31 kai_kaikai 阅读(163) 评论(0) 收藏举报

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