零、前提
使用工具：idea、MySQL
使用技术：JDBC、servlet
一、数据库
Database - test1 # 数据库：test1
CREATE TABLE `student` (
`id` int(3) NOT NULL auto_increment,
`name` varchar(10) default NULL,
`age` int(3) default NULL,
`classes` varchar(10) default NULL,
PRIMARY KEY (`id`),
UNIQUE KEY `index_1` (`name`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8; # 表：studentinsert into `student`(`id`,`name`,`age`,`classes`) values (7,'李让',28,'毕业'),(8,'张三',20,'大二'),(9,'张四',10,'三年级'),(11,'小张',10,'三年级'),(12,'张丹',17,'高二'),(13,'小暇',19,'大一'),(14,'小兰',19,'大一'),(15,'李杯狐',12,'五年级'); #表中的内容
二、项目框架
2-1 domain-Student 实体类
public class Student { private int id; private String name; private int age; private String classes; public Student() { } public Student(String name, int age, String classes) { this.name = name; this.age = age; this.classes = classes; } public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } public String getClasses() { return classes; } public void setClasses(String classes) { this.classes = classes; }}2-2 util-JdbcUtils 工具类
public class JdbcUtils { private final static String url = "jdbc:mysql://localhost:3306/test1?useUnicode=true&characterEncoding=utf8"; private final static String user = "root"; private final static String psw = "mysql"; public static Connection getConn() { Connection conn = null; try { Class.forName("com.mysql.jdbc.Driver"); conn = DriverManager.getConnection(url, user, psw); } catch (Exception e) { e.printStackTrace(); } return conn; }}2-3 dao-StudentDao接口
public interface StudentDao { public List<Student> findAll() throws SQLException, ClassNotFoundException; public Student findById(int id) throws SQLException, ClassNotFoundException; public int add(Student s) throws SQLException, ClassNotFoundException; public int delete(int id) throws SQLException, ClassNotFoundException; public int modify(int id ,Student s) throws SQLException, ClassNotFoundException;}2-4 dao-impl-StudentDaoImpl 接口实现
public class StudentDaoImpl implements StudentDao { private Connection conn = null; private PreparedStatement ps = null; private ResultSet rs = null; @Override public List<Student> findAll() throws SQLException, ClassNotFoundException { conn= JdbcUtils.getConn(); String sql = "select * from student"; ps = conn.prepareStatement(sql); rs = ps.executeQuery(); List<Student> list = new ArrayList<Student>(); while(rs.next()){ Student s = new Student(); s.setId(rs.getInt("id")); s.setAge(rs.getInt("age")); s.setClasses(rs.getString("classes")); s.setName(rs.getString("name")); list.add(s); } return list; } @Override public Student findById(int id) throws SQLException, ClassNotFoundException { conn= JdbcUtils.getConn(); String sql = "select * from student where id = ?"; ps = conn.prepareStatement(sql); ps.setInt(1,id); rs = ps.executeQuery(); Student s = new Student(); while(rs.next()){ s.setId(rs.getInt("id")); s.setAge(rs.getInt("age")); s.setClasses(rs.getString("classes")); s.setName(rs.getString("name")); } return s; } @Override public int add(Student s) throws SQLException, ClassNotFoundException { conn= JdbcUtils.getConn(); String sql = "insert into student(name,age,classes) values(?,?,?)"; ps = conn.prepareStatement(sql); ps.setString(1,s.getName()); ps.setInt(2,s.getAge()); ps.setString(3,s.getClasses()); int i = ps.executeUpdate(); return i; } @Override public int delete(int id) throws SQLException, ClassNotFoundException { conn= JdbcUtils.getConn(); String sql = "delete from student where id = ?"; ps = conn.prepareStatement(sql); ps.setInt(1,id); int i = ps.executeUpdate(); return i; } @Override public int modify(int id, Student s) throws SQLException, ClassNotFoundException { conn= JdbcUtils.getConn(); String sql = "update student set name=?,age=?,classes=? where id=?"; ps = conn.prepareStatement(sql); ps.setString(1,s.getName()); ps.setInt(2,s.getAge()); ps.setString(3,s.getClasses()); ps.setInt(4,id); int i = ps.executeUpdate(); return i; }}2-5 servle-StudentServlet
public class StudentServlet extends HttpServlet { StudentDao studentDao = new StudentDaoImpl(); public List<Student> findAll() throws SQLException, ClassNotFoundException { return studentDao.findAll(); } public int modify(int id ,Student s) throws SQLException, ClassNotFoundException { return studentDao.modify(id,s); } public Student findById(int id) throws SQLException, ClassNotFoundException { return studentDao.findById(id); } public int add(Student s) throws SQLException, ClassNotFoundException{ return studentDao.add(s); } public int delete(int id) throws SQLException, ClassNotFoundException{ return studentDao.delete(id); }} 2-5 servle-StudentServletAdd
@WebServlet("/stu_add")public class StudentServletAdd extends HttpServlet { @Override protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { this.doPost(req, resp); } @Override protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { req.setCharacterEncoding("utf8"); //解决乱码 StudentServlet ss = new StudentServlet(); String name = req.getParameter("name"); String age = req.getParameter("age"); String classes = req.getParameter("classes"); Student s = new Student(name,Integer.parseInt(age),classes); try { ss.add(s); } catch (SQLException throwables) { throwables.printStackTrace(); } catch (ClassNotFoundException e) { e.printStackTrace(); } resp.sendRedirect("/five/stu_list.jsp"); }}2-6 web-stu_list.jsp
<%@ page import="cn.my.sms.servlet.StudentServlet" %><%@ page import="cn.my.sms.domain.Student" %><%@ page import="java.util.List" %><%@ page contentType="text/html;charset=UTF-8" language="java" %><html><head> <title>学生界面</title></head><body> <h2 align="center">学生系统管理</h2> <p align="center">欢迎你：XX <a href="login.html">安全退出</a></p> <hr/> <p align="center"><a href="stu_add.jsp">添加学生</a></p> <form action="#" method="post"> <table align="center" border="1px" width="80%"> <tr> <td>学号</td> <td>姓名</td> <td>年龄</td> <td>班级</td> <td>操作</td> </tr> <% StudentServlet ss = new StudentServlet(); List<Student> list = ss.findAll(); for(Student s:list){ %> <tr> <td><%= s.getId() %></td> <td><%= s.getName() %></td> <td><%= s.getAge() %></td> <td><%= s.getClasses() %></td> <td> <a href="stu_delete?id=<%= s.getId() %>" onclick="return confirm('真的要删除该学生吗？')">删除</a>| <a href="stu_modify.jsp?id=<%= s.getId() %>">修改</a> </td> </tr> <% } %> </table> </form></body></html>2-6 web-stu_add.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %><html><head> <title>添加学生界面</title></head><body><form action="stu_add" method="post"> <table align="center" border="1px"> <tr> <td>姓名</td> <td><input type="text" name="name"></td> </tr> <tr> <td>年龄</td> <td><input type="text" name="age"></td> </tr> <tr> <td>班级</td> <td><input type="text" name="classes"> </td> </tr> <tr> <td align="center" colspan="2"><input type="submit" value="添加学生"></td> </tr> </table></form></body></html>2-7 servlet-StudentServletDelete
@WebServlet("/stu_delete")public class StudentServletDelete extends HttpServlet { StudentServlet ss = new StudentServlet(); @Override protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { this.doPost(req, resp); } @Override protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { String id = req.getParameter("id"); System.out.println("id = " + id); int i = 0; try { i = ss.delete(Integer.parseInt(id)); } catch (Exception e) { e.printStackTrace(); } resp.sendRedirect("/five/stu_list.jsp"); }}2-8 servlet-StudentServletModify
@WebServlet("/stu_modify")public class StudentServletModify extends HttpServlet { @Override protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { this.doPost(req, resp); } @Override protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { req.setCharacterEncoding("utf8"); String id = req.getParameter("id"); String name = req.getParameter("name"); String age = req.getParameter("age"); String classes = req.getParameter("classes"); Student s = new Student(name,Integer.parseInt(age),classes); StudentServlet ss = new StudentServlet(); try { ss.modify(Integer.parseInt(id),s); } catch (Exception throwables) { throwables.printStackTrace(); } resp.sendRedirect("stu_list.jsp"); }}2-9 web-stu_modify.jsp
<%@ page import="cn.my.sms.servlet.StudentServlet" %><%@ page import="cn.my.sms.domain.Student" %><%@ page contentType="text/html;charset=UTF-8" language="java" %><html><head> <title>修改学生</title></head><body><form action="stu_modify" method="post"> <% String id = request.getParameter("id"); StudentServlet ss = new StudentServlet(); Student s = ss.findById(Integer.parseInt(id)); %> <input type="hidden" name="id" value="<%= s.getId() %>"> <table align="center" border="1px"> <tr> <td>姓名</td> <td><input type="text" name="name" value="<%= s.getName() %>"></td> </tr> <tr> <td>年龄</td> <td><input type="text" name="age" value="<%= s.getAge() %>"></td> </tr> <tr> <td>班级</td> <td><input type="text" name="classes" value="<%= s.getClasses() %>"> </td> </tr> <tr> <td align="center" colspan="2"><input type="submit" value="修改学生"></td> </tr> </table></form></body></html>三、总结
3-1 根据数据库创建实体类；
3-2 写工具类，获得 conn对象；
3-3 在StudentDao接口中写用到的方法，并在StudentDaoImpl类中实现所有的方法；
3-4 创建servlet包，在StudentServlet中调用所有的StudentDao接口中的方法（目的：方便管理、纠错、隔离）；
3-5 创建主界面、新增学生界面、修改学生界面等三个页面；
3-6 在servlet包下创建类（StudentServletAdd、StudentServletDelete、StudentServletModify），三个类继承 HTTPServlet ，与三个页面结合实现新增、删除、修改等操作；
3-7 没有写登录页面。
