[转载] JDBC+Servlet+JSP整合开发之-JSP项目实战

–Servlet 的优势与弊端
–JSP 的优势与弊端
–MVC 设计模式
–实例
?使用MVC实现学生信息的添加、显示
-----------------------------START-----------------------------------
? Servlet 的优势与弊端
–优势
?功能强大，可以调用任意的Java JDK API
?能够实现很多高级特征
?成熟
–弊端
?逻辑处理和内容展示很难分离
?开发效率低
–out.println(“”);
?维护成本高
? JSP 的优势与弊端
–优势
?可以直接嵌入静态HTML
?可以直接写代码
?开发效率高
–弊端
?如果直接在JSP页面中写代码
–程序可读性差
–维护困难
? MVC设计模式
–MVC设计模式早在面向对象语言Smalltalk-80中就被提出并在此后得到业界的广泛接受
–它包括三类对象
?模型（Model）对象
–是应用程序的主体部分
?视图（View）对象
–是应用程序中负责生成用户界面的部分
?控制器（Control）对象
–是根据用户的输入，控制用户界面数据显示及更新Model对象状态的部分
–MVC设计模式的好处
? MVC模式不仅实现了功能模块和显示模块的分离
?同时它还提高了应用系统的
–可维护性
–可扩展性
–可移植性
–组件的可复用性
–JSP 的两种实现模式


–具体实现

? 实例
–使用MVC实现学生信息的添加、显示
Datebase

StudentDao.java

StudentDaoImpl.java
package com.michael.dao.impl;   

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

import com.michael.dao.StudentDao;   
import com.michael.util.ConnectionUtil;   
import com.michael.util.SQLConstants;   
import com.michael.vo.Student;   

public class StudentDaoImpl implements StudentDao,SQLConstants {   

        public void add(Student stu) {   
                Connection conn = new ConnectionUtil().openConnection();   
                //String sql = "insert into StudentTbl(name,age,email) values(?,?,?)";   
                try {   
                        PreparedStatement pstmt = conn.prepareStatement(ADD_STUDENT_SQL);   
                        pstmt.setString(1, stu.getName());   
                        pstmt.setInt(2, stu.getAge());   
                        pstmt.setString(3, stu.getEmail());   
                        pstmt.executeUpdate();   
                } catch (SQLException e) {   
                        e.printStackTrace();   
                }finally{   
                        try {   
                                conn.close();   
                        } catch (SQLException e) {   
                                e.printStackTrace();   
                        }   
                }   
        }   

        public List listStudent() {   
                Connection conn = new ConnectionUtil().openConnection();   
                //String sql = "insert into StudentTbl(name,age,email) values(?,?,?)";   
                try {   
                        Statement stmt = conn.createStatement();   
                        ResultSet rs = stmt.executeQuery(QUERY_STUDENT_SQL);   
                        List list = new ArrayList();   
                        while(rs.next()){   
                                int id = rs.getInt(1);   
                                String name = rs.getString(2);   
                                int age = rs.getInt(3);   
                                String email = rs.getString(4);   
                                Student stu = new Student();   
                                stu.setId(id);   
                                stu.setName(name);   
                                stu.setAge(age);   
                                stu.setEmail(email);   
                                list.add(stu);   
                        }   
                        return list;   
                } catch (SQLException e) {   
                        e.printStackTrace();   
                }finally{   
                        try {   
                                conn.close();   
                        } catch (SQLException e) {   
                                e.printStackTrace();   
                        }   
                }   
                return null;   
        }   

}
ConnectionUtil.java
package com.michael.util;   

import java.sql.Connection;   
import java.sql.DriverManager;   
import java.util.Properties;   

public class ConnectionUtil {   

        /**   
         * @param args   
         */   
        public static void main(String[] args) {   
                ConnectionUtil cu = new ConnectionUtil();   
                System.out.println(cu.openConnection());   
        }   
        public Connection openConnection() {   
                String url = "";   
                String driver = "";   
                String user = "";   
                String password = "";   
                Properties prop = new Properties();   
                try {   
                        prop.load(this.getClass().getClassLoader().getResourceAsStream("DBConfig.properties"));   
                        driver = prop.getProperty("driver");   
                        url = prop.getProperty("url");   
                        user = prop.getProperty("user");   
                        password = prop.getProperty("password");   
                        Class.forName(driver);   
                        Connection conn = DriverManager.getConnection(   
                                        url, user, password);   
                        return conn;   
                } catch (Exception e) {   
                        e.printStackTrace();   
                }   
                return null;   
        }   
        public Connection getConnection(String driver, String url, String user,   
                        String password) {   
                // Class.forName()   
                try {   
                        Class.forName(driver);   
                        // DriverManager get connection   
                        Connection conn = DriverManager.getConnection(url, user, password);   
                        return conn;   
                } catch (Exception e) {   
                        e.printStackTrace();   
                }   
                return null;   
        }   

        public Connection getConnection() {   
                // Class.forName()   
                try {   
                        Class.forName("com.mysql.jdbc.Driver");   
                        // DriverManager get connection   
                        Connection conn = DriverManager.getConnection(   
                                        "jdbc:mysql://localhost:3306/jsp_db", "root", "963963");   
                        return conn;   
                } catch (Exception e) {   
                        e.printStackTrace();   
                }   
                return null;   
        }   

}
SQLConstants.java

DBConfig.properties

Student.java

StudentDaoImplTest.java

下面进行单元测试

数据库添加成功！

下面继续哈~
stu.jsp
   
   
   

   
   
       
        My JSP 'stu.jsp' starting page   
            姓名:   
                       
                年龄:   
                       
                电邮:   
                       
                   
                   
        IDNameAgeEmail${s.id }   
                                ${s.name }   
                                ${s.age }   
                                ${s.email }   
                        
StuServlet.java
package com.michael.servlet;   

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

import javax.servlet.ServletException;   
import javax.servlet.http.HttpServlet;   
import javax.servlet.http.HttpServletRequest;   
import javax.servlet.http.HttpServletResponse;   

import com.michael.dao.StudentDao;   
import com.michael.dao.impl.StudentDaoImpl;   
import com.michael.vo.Student;   

public class StuServlet extends HttpServlet {   

        /**   
         * Constructor of the object.   
         */   
        public StuServlet() {   
                super();   
        }   

        /**   
         * Destruction of the servlet.    
         */   
        public void destroy() {   
                super.destroy(); // Just puts "destroy" string in log   
                // Put your code here   
        }   

        /**   
         * The doGet method of the servlet.    
         *   
         * This method is called when a form has its tag value method equals to get.   
         *   
         * @param request the request send by the client to the server   
         * @param response the response send by the server to the client   
         * @throws ServletException if an error occurred   
         * @throws IOException if an error occurred   
         */   
        public void doGet(HttpServletRequest request, HttpServletResponse response)   
                        throws ServletException, IOException {   

                doPost(request,response);   
        }   

        /**   
         * The doPost method of the servlet.    
         *   
         * This method is called when a form has its tag value method equals to post.   
         *   
         * @param request the request send by the client to the server   
         * @param response the response send by the server to the client   
         * @throws ServletException if an error occurred   
         * @throws IOException if an error occurred   
         */   
        public void doPost(HttpServletRequest request, HttpServletResponse response)   
                        throws ServletException, IOException {   
                String methodName = request.getParameter("methodName");   
                if(methodName!=null&&methodName.equals("add")){   
                        add(request,response);   
                }else{   
                        query(request,response);   
                }   
                /*   
                //响应用户请求   
                String name = request.getParameter("name");   
                String age = request.getParameter("age");   
                String email = request.getParameter("email");   
                //调用后台逻辑   
                StudentDao dao = new StudentDaoImpl();   
                Student stu = new Student();   
                stu.setName(name);   
                stu.setAge(new Integer(age));   
                stu.setEmail(email);   
                dao.add(stu);   
                List list = dao.listStudent();   
                request.setAttribute("StuList", list);   
                //数据处理后跳转   
                request.getRequestDispatcher("/stu.jsp").forward(request,response);   
                */   
        }   
        public void add(HttpServletRequest request, HttpServletResponse response)   
                        throws ServletException, IOException {   
                //响应用户请求   
                String name = request.getParameter("name");   
                String age = request.getParameter("age");   
                String email = request.getParameter("email");   
                //调用后台逻辑   
                StudentDao dao = new StudentDaoImpl();   
                Student stu = new Student();   
                stu.setName(name);   
                stu.setAge(new Integer(age));   
                stu.setEmail(email);   
                dao.add(stu);   
                query(request,response);   
        }   

        public void query(HttpServletRequest request, HttpServletResponse response)   
                        throws ServletException, IOException {   

                //调用后台逻辑   
                StudentDao dao = new StudentDaoImpl();   
                List list = dao.listStudent();   
                request.setAttribute("StuList", list);   
                // 跳转   
                request.getRequestDispatcher("/stu.jsp").forward(request, response);   
        }   
        /**   
         * Initialization of the servlet.    
         *   
         * @throws ServletException if an error occurs   
         */   
        public void init() throws ServletException {   
                // Put your code here   
        }   

}

原文 《JDBC+Servlet+JSP整合开发之30-JDBC、Servlet、JSP的MVC》
http://redking.blog.51cto.com/27212/316441/