软工概论课堂测试一添加新课程

1. 设计思想

（1）创建新的动态网站项目后，先在WebContent->WEB-INF->lib文件夹里导入jstl-1.2.jar和mysql-connector-java-5.1.38-bin.jar两个jar包。

（2）写课程类加入基本的set(),get()函数，写课程接口类，课程实现类实现课程接口类（实现增删改查）。

（3）在数据库中创建新表。

（4）编写数据库操作类。

    连接数据库6步：

　　1.加载驱动 2.创建链接对象 3.创建语句传输对象 4.接收结果集对象（主要针对查询） 5.遍历 6.关闭资源

（5）在WebContent目录下新建一个文件夹，在里面编写增加课程的操作文件addInput.jsp和add.jsp。

 在课程添加界面输入要添加的课程名称、任课教师、上课地点，然后接收客户端传递过来的参数用set()方法分别设置lesson属性；

先判断输入的任课教师是否与规定教师相匹配，如不匹配，设置错误信息的参数，页面跳转回增加课程界面，并输出错误信息；

再判断输入的上课地点是否以规定的上课地点开头，如果不符合，同上；

若前两条都通过，调用add方法，该方法里加入查重验证，若输入的课程名称已经存在，则会设置一个错误信息，页面跳转回增加课程界面，输出错误信息；

若前三条都通过，那么可以成功添加新课程，add方法会将输入数据传入数据库保存，并且页面跳转，显示已成功添加课程，并可选择继续添加，或查看课程列表。

 

　　2. 源程序代码

Lesson.java

package com.jaovo.msg.model;

public class Lesson {
    private int id;
    private String lessonname;
    private String lessonteacher;
    private String lessonplace;
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getLessonname() {
        return lessonname;
    }
    public void setLessonname(String lessonname) {
        this.lessonname = lessonname;
    }
    public String getLessonteacher() {
        return lessonteacher;
    }
    public void setLessonteacher(String lessonteacher) {
        this.lessonteacher = lessonteacher;
    }
    public String getLessonplace() {
        return lessonplace;
    }
    public void setLessonplace(String lessonplace) {
        this.lessonplace = lessonplace;
    }
}

ILessonDao.java

package com.jaovo.msg.dao;

import java.util.List;

import com.jaovo.msg.model.Lesson;

public interface ILessonDao {
    public void add(Lesson lesson);
    public void delete(int id);
    public void update(Lesson lesson);
    public Lesson load(int id);
    public Lesson load(String lessonname);
    public List<Lesson> load();
}

LessonDaoImpl.java

package com.jaovo.msg.dao;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import com.jaovo.msg.Util.DBUtil;
import com.jaovo.msg.Util.LessonException;
import com.jaovo.msg.model.Lesson;

import sun.net.www.content.text.plain;

public class LessonDaoImpl implements ILessonDao{

    @Override
    public void add(Lesson lesson) {
        //获得链接对象
        Connection connection = DBUtil.getConnection();
        //准备sql语句
        String sql="select count(*) from t_lesson where lessonname = ?";
        //创建语句传输对象
        PreparedStatement preparedStatement=null;
        ResultSet resultSet=null;
        try {
            preparedStatement=connection.prepareStatement(sql);
            preparedStatement.setString(1, lesson.getLessonname());
            //接收结果集
            resultSet=preparedStatement.executeQuery();
            //遍历结果集
            while(resultSet.next())
            {
                if(resultSet.getInt(1)>0)//>0说明数据库中已存在该用户
                {
                    throw new LessonException("课程已存在");
                }
            }
            sql="insert into t_lesson(lessonname,lessonteacher,lessonplace) value (?,?,?)";
            preparedStatement=connection.prepareStatement(sql);
            preparedStatement.setString(1, lesson.getLessonname());
            preparedStatement.setString(2, lesson.getLessonteacher());
            preparedStatement.setString(3, lesson.getLessonplace());
            preparedStatement.executeUpdate();//更改
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally {
            DBUtil.close(resultSet);
            DBUtil.close(preparedStatement);
            DBUtil.close(connection);
        }
        
    }

    @Override
    public void delete(int id) {
        Connection connection=DBUtil.getConnection();
        String sql="delete from t_lesson where id = ?";
        PreparedStatement preparedStatement=null;
        try {
            preparedStatement=connection.prepareStatement(sql);
            preparedStatement.setInt(1,id);
            preparedStatement.executeUpdate();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally {
            DBUtil.close(preparedStatement);
            DBUtil.close(connection);
        }
        
    }

    @Override
    public void update(Lesson lesson) {
        //获得链接对象
        Connection connection = DBUtil.getConnection();
        //准备sql语句
        String sql="update t_lesson set lessonname = ? , lessonteacher = ? , set lessonplace = ? , where id = ?";
        //创建语句传输对象
        PreparedStatement preparedStatement=null;
        try {
            preparedStatement=connection.prepareStatement(sql);
            preparedStatement.setString(1,lesson.getLessonname());
            preparedStatement.setString(2, lesson.getLessonteacher());
            preparedStatement.setString(3, lesson.getLessonplace());
            preparedStatement.setInt(4, lesson.getId());
            preparedStatement.executeUpdate();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally {
            DBUtil.close(preparedStatement);
            DBUtil.close(connection);
        }
    
    }

    @Override
    public Lesson load(int id) {
        //获得链接对象
        Connection connection = DBUtil.getConnection();
        //准备sql语句
        String sql="select * from t_lesson where id = ?";
        //创建语句传输对象
        PreparedStatement preparedStatement=null;    
        ResultSet resultSet=null;
        Lesson lesson=null;
        try {
            preparedStatement=connection.prepareStatement(sql);
            preparedStatement.setInt(1,id);
            resultSet=preparedStatement.executeQuery();
            while(resultSet.next()) {
                lesson=new Lesson();
                lesson.setId(id);
                lesson.setLessonname(resultSet.getString("lessonname"));
                lesson.setLessonteacher(resultSet.getString("lessonteacher"));
                lesson.setLessonplace(resultSet.getString("lessonplace"));

            }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally {
            DBUtil.close(resultSet);
            DBUtil.close(preparedStatement);
            DBUtil.close(connection);
        }
        
        return lesson;
    }

    @Override
    public Lesson load(String lessonname) {
        //获得链接对象
        Connection connection = DBUtil.getConnection();
        //准备sql语句
        String sql="select * from t_lesson where lessonname = ?";
        //创建语句传输对象
        PreparedStatement preparedStatement=null;    
        ResultSet resultSet=null;
        Lesson lesson=null;
        try {
            preparedStatement=connection.prepareStatement(sql);
            preparedStatement.setString(1,lessonname);
            resultSet=preparedStatement.executeQuery();
            while(resultSet.next()) {
                lesson=new Lesson();
                lesson.setId(resultSet.getInt("id"));
                lesson.setLessonname(lessonname);
                lesson.setLessonteacher(resultSet.getString("lessonteacher"));
                lesson.setLessonplace(resultSet.getString("lessonplace"));

            }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally {
            DBUtil.close(resultSet);
            DBUtil.close(preparedStatement);
            DBUtil.close(connection);
                }
                
                return lesson;
    }

    @Override
    public List<Lesson> load() {
        //获得链接对象
        Connection connection = DBUtil.getConnection();
        //准备sql语句
        String sql="select * from t_lesson";
        //创建语句传输对象
        PreparedStatement preparedStatement=null;    
        ResultSet resultSet=null;
        //集合中只能放入user对象
        List<Lesson>lessons=new ArrayList<Lesson>();
        Lesson lesson=null;
        try {
            preparedStatement=connection.prepareStatement(sql);
            resultSet=preparedStatement.executeQuery();
            while(resultSet.next()) {
                lesson=new Lesson();
                lesson.setId(resultSet.getInt("id"));
                lesson.setLessonname(resultSet.getString("lessonname"));
                lesson.setLessonteacher(resultSet.getString("lessonteacher"));
                lesson.setLessonplace(resultSet.getString("lessonplace"));
                lessons.add(lesson);
            }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally {
            DBUtil.close(resultSet);
            DBUtil.close(preparedStatement);
            DBUtil.close(connection);
        }
                
        return lessons;
    }
}

DBUtil.java

package com.jaovo.msg.Util;

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

public class DBUtil {
    
    public  static  Connection getConnection() {
        try {
            //1 加载驱动
            Class.forName("com.mysql.jdbc.Driver").newInstance();
        } catch (InstantiationException | IllegalAccessException | ClassNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        String user = "root";
        String password = "root";
        String url = "jdbc:mysql://localhost:3306/test";
        Connection connection = null;
        try {
            //2 创建链接对象connection
             connection = DriverManager.getConnection(url,user,password);
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return connection;
    }
    
    //关闭资源的方法
    public static void close(Connection connection ) {
        try {
            if (connection != null) {
                connection.close();
            }
            
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
    public static void close(PreparedStatement preparedStatement ) {
        try {
            if (preparedStatement != null) {
                preparedStatement.close();
            }
            
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
    public static void close(ResultSet resultSet ) {
        try {
            if (resultSet != null) {
                resultSet.close();
            }
            
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
    
}

LessonException.java

package com.jaovo.msg.Util;

public class LessonException extends RuntimeException{

    public LessonException() {
        super();
        // TODO Auto-generated constructor stub
    }

    public LessonException(String message, Throwable cause, boolean enableSuppression, boolean writableStackTrace) {
        super(message, cause, enableSuppression, writableStackTrace);
        // TODO Auto-generated constructor stub
    }

    public LessonException(String message, Throwable cause) {
        super(message, cause);
        // TODO Auto-generated constructor stub
    }

    public LessonException(String message) {
        super(message);
        // TODO Auto-generated constructor stub
    }

    public LessonException(Throwable cause) {
        super(cause);
        // TODO Auto-generated constructor stub
    }
    
}

DaoFactory.java

package com.jaovo.msg.Util;

import com.jaovo.msg.dao.LessonDaoImpl;

public class DaoFactory {
    public static LessonDaoImpl getDaoImpl()
    {
        return new LessonDaoImpl();
    }
}

ValidateUtil.java

//用于验证输入信息是否为空
package com.jaovo.msg.Util;

import java.util.HashMap;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;

import com.jaovo.msg.dao.LessonDaoImpl;
import com.jaovo.msg.model.Lesson;

public class ValidateUtil {
    public static boolean validateNull(HttpServletRequest request,String[] fileds)
    {
        boolean validate=true;
        //map对象用来装载不同的错误信息
        Map<String,String> errorMsg = new HashMap();
        for(String filed : fileds)
        {
            String value=request.getParameter(filed);
            if(value==null||"".equals(value.trim()))
            {
                validate=false;
                errorMsg.put(filed, filed+"不能为空");
            }
            
            if(!validate)
            {
                request.setAttribute("errorMsg", errorMsg);//设置errorMsg属性,属性值为errorMsg,即"filed不能为空"
            }
        }
        return validate;
    }
    
    public static String showError(HttpServletRequest request,String filed)
    {
        Map<String,String> errorMsg = (Map<String,String>)request.getAttribute("errorMsg");
        if(errorMsg==null)
        {
            return "";
        }
        String msg = errorMsg.get(filed);
        if(msg == null)
        {
            return "";
        }
        return msg;
    }
    
}

addInput.jsp

<%@ page import="com.jaovo.msg.Util.ValidateUtil"%>
    <%@page import="java.util.Map" %>
<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>课程添加界面</title>
</head>
<body>
<%-- Map<String,String> errorMsg = (Map<String,String>)request.getAttribute("errorMsg"); --%>
<%
    String lessonError = (String)request.getAttribute("lessonError");
    if(lessonError == null){
        lessonError = "";
    }
%>
    <%=lessonError %><br>
    <form action="add.jsp" method="get">
            <tr>
                <td>课程名称 &nbsp; &nbsp;</td>
                <td>
                    <input type="text" name="lessonname" />
                    <%=ValidateUtil.showError(request,"lessonname") %>
                </td>
            </tr><br><br>
            <tr>
                <td>任课教师 &nbsp; &nbsp;</td>
                <td>
                    <input type="text" name="lessonteacher"/>
                    <%=ValidateUtil.showError(request,"lessonteacher") %>
                </td>
            </tr><br><br>
            <tr>
                <td>上课地点 &nbsp; &nbsp;</td>
                <td>
                    <input type="text" name="lessonplace" />
                    <%=ValidateUtil.showError(request,"lessonplace") %>
                </td>
            </tr><br><br>
            <tr align="center">
                <td colspan="2">
                    <input type="submit" value="保存" />
                    <input type="reset" name="重置" />
                </td>
            </tr>    
    </form>
</body>
</html>

add.jsp

<%@page import="com.jaovo.msg.Util.LessonException"%>
<%@page import="com.jaovo.msg.dao.LessonDaoImpl" %>
<%@page import="com.jaovo.msg.model.Lesson" %>
<%@page import="com.jaovo.msg.Util.ValidateUtil" %>
<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<%
    //接收客户端传递过来的参数
    String lessonname=request.getParameter("lessonname");
    String lessonteacher=request.getParameter("lessonteacher");
    String lessonplace=request.getParameter("lessonplace");
    boolean validate=ValidateUtil.validateNull(request,new String[]{"lessonname","lessonteacher","lessonplace"});
    if(!validate){
%>
    <jsp:forward page="addInput.jsp"></jsp:forward>  
<%    }
    Lesson lesson=new Lesson();
    lesson.setLessonname(lessonname);
    lesson.setLessonteacher(lessonteacher);
    lesson.setLessonplace(lessonplace);
    
    LessonDaoImpl LessonDao=new LessonDaoImpl();

    try
    {
    if(!("王建民".equals(lessonteacher)|| "刘立嘉".equals(lessonteacher)||"刘丹".equals(lessonteacher)||"王辉".equals(lessonteacher)||"杨子光".equals(lessonteacher)))
    {
        request.setAttribute("lessonError","任课教师不存在");
    %>
    <<jsp:forward page="addInput.jsp"></jsp:forward>
    <%
    }
    else if(!(lessonplace.startsWith("一教")||lessonplace.startsWith("二教")||lessonplace.startsWith("三教")||lessonplace.startsWith("基教")))
    {
        request.setAttribute("lessonError","上课地点有误");
        %>
        <<jsp:forward page="addInput.jsp"></jsp:forward>
        <%
    }
    else
        LessonDao.add(lesson);
    %>
        课程添加成功！<br>
        <a href="addInput.jsp">继续添加</a><br>
        <a href="list.jsp">课程列表</a>
    <%
    }catch(LessonException e){
                 //验证出错
                request.setAttribute("lessonError", e.getMessage());
        %>
        <<jsp:forward page="addInput.jsp"></jsp:forward>
    <%
        }
    %>
</html>

list.jsp

<%@page import="com.jaovo.msg.model.Lesson"%>
<%@page import="java.util.List"%>
<%@page import="com.jaovo.msg.dao.LessonDaoImpl"%>
<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>课程展示界面</title>
</head>
<%
    LessonDaoImpl lessonDao=new LessonDaoImpl();
    List<Lesson> lessons=lessonDao.load();
%>
<body>
<h2 align="center">课程展示界面</h2>
<hr width="100%" color="blue"  />
<!--     
    <jsp:include page="inc.jsp" >
        <jsp:param name="op" value="展示" />
    </jsp:include>
     -->
        <table align="center" border="1" width="500">
        <tr>
                <td>课程编号</td>
                <td>课程名称</td>
                <td>任课教师</td>
                <td>上课地点</td>
        </tr>
        <%
            for( Lesson lesson : lessons){
        %>
        <tr>
                <td><%=lesson.getId() %></td>
                <td><%=lesson.getLessonname() %></td>
                <td><%=lesson.getLessonteacher() %></td>
                <td><%=lesson.getLessonplace() %></td>
            <!--      
                <td><a href="delete.jsp?id=<%=lesson.getId() %>" >删除</a></td>
                <td><a href="updateInput.jsp?id=<%=lesson.getId() %>" >更新</a></td>
            -->
        </tr>
        <%
            }
        %>    
        </table>
</body>
</html>

　　

　　3. 运行结果截图