JSP＋Servlet项目案例

项目目录结构

首先本项目使用到的软件环境有：eclipse jee neon， Tomcat8.5，JDK1.8数据库：mysql。

补充：本项目需要mysql连接jdbc的jar包，以及jstl的jar包。

jstl.jar

mysql-connector-java-5.1.45-bin.jar

standard-1.1.2.jar

数据库，可以直接运行即可

CREATE TABLE users(id INT PRIMARY KEY AUTO_INCREMENT, NAME VARCHAR(20), age INT);

INSERT INTO users(NAME, age) VALUES('蕾姆', 17);

INSERT INTO users(NAME, age) VALUES('艾米莉亚', 17);

1、BaseDao.java

package com.dao;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.sql.SQLException;

public class BaseDao {

// 数据库驱动类

// 数据库地址

public static final String URL = "jdbc:mysql://localhost:3306/thh";

// 用户名

public static final String USER = "root";

// 密码

public static final String PASSWORD = "tanghh";

Connection conn = null;

PreparedStatement pstmt = null;

ResultSet rs = null;

// 获得数据库连接

public void getConnection() {

try {

Class.forName(DRIVER);

conn = DriverManager.getConnection(URL, USER, PASSWORD);

} catch (ClassNotFoundException e) {

e.printStackTrace();

} catch (SQLException e) {

e.printStackTrace();

}

}

// 更新数据

public int executeUpdate(String sql, Object... obj) {

int num = 0;

getConnection();

try {

pstmt = conn.prepareStatement(sql);

for (int i = 0; i

pstmt.setObject(i + 1, obj[i]);

}

num = pstmt.executeUpdate();

} catch (SQLException e) {

e.printStackTrace();

} finally {

closeAll();

}

return num;

}

// 查询数据

public ResultSet executeQuery(String sql, Object... obj) {

getConnection();

try {

pstmt = conn.prepareStatement(sql);

for (int i = 0; i

pstmt.setObject(i + 1, obj[i]);

}

rs = pstmt.executeQuery();

} catch (SQLException e) {

e.printStackTrace();

}

return rs;

}

// 关闭资源

public void closeAll() {

try {

rs.close();

} catch (SQLException e) {

e.printStackTrace();

}

try {

pstmt.close();

} catch (SQLException e) {

e.printStackTrace();

}

try {

conn.close();

} catch (SQLException e) {

e.printStackTrace();

}

}

}

2、UsersDao.java

package com.dao;

import java.util.List;

import com.entity.Users;

public interface UsersDao {

public int addUser(Users u);

public int delUser(int id);

public int updateUser(Users u);

public Users findUserById(int id);

public List getAllUsers();

}

3、UserDaoImpl.java

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.dao.BaseDao;

import com.dao.UsersDao;

import com.entity.Users;

public class UsersDaoImpl extends BaseDao implements UsersDao {

Connection conn = null;

PreparedStatement pstmt = null;

ResultSet rs = null;

// 添加用户

@Override

public int addUser(Users u) {

int num = 0;

String sql = "insert into users(name,age) values(?,?)";

try {

num = executeUpdate(sql, u.getName(), u.getAge());

} catch (Exception e) {

e.printStackTrace();

}

return num;

}

// 删除用户

@Override

public int delUser(int id) {

int num = 0;

String sql = "delete from users where id=?";

try {

num = executeUpdate(sql, id);

} catch (Exception e) {

e.printStackTrace();

}

return num;

}

// 更新用户

@Override

public int updateUser(Users u) {

int num = 0;

String sql = "update users set name=?,age=? where id=?";

try {

num = executeUpdate(sql, u.getName(), u.getAge(), u.getId());

} catch (Exception e) {

e.printStackTrace();

}

return num;

}

// 根据id查找

@Override

public Users findUserById(int id) {

Users u = null;

String sql = "select * from users where id=?";

rs = executeQuery(sql, id);

try {

if (rs.next()) {

u = new Users(rs.getInt(1), rs.getString(2), rs.getInt(3));

}

} catch (SQLException e) {

e.printStackTrace();

}

return u;

}

// 查询所有用户

@Override

public List getAllUsers() {

List ulist = new ArrayList();

String sql = "select * from users";

rs = executeQuery(sql);

try {

while (rs.next()) {

Users u = new Users(rs.getInt(1), rs.getString(2), rs.getInt(3));

ulist.add(u);

}

} catch (SQLException e) {

e.printStackTrace();

}

return ulist;

}

}

4、Users.java

package com.entity;

/**

* users表所对应的实体类

*/

public class Users {

// 实体类的属性和表的字段名称一一对应

private int id;

private String name;

private int age;

public Users(int id, String name, int age) {

this.id = id;

this.name = name;

this.age = age;

}

public Users() {

}

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;

}

@Override

public String toString() {

return "User [id=" + id + ", name=" + name + ", age=" + age + "]";

}

}

5、UsersServlet.java

package com.servlet;

import java.io.IOException;

import java.io.PrintWriter;

import java.util.List;

import javax.servlet.ServletException;

import com.dao.UsersDao;

import com.entity.Users;

public class UsersServlet extends HttpServlet {

/**

*

*/

private static final long serialVersionUID = 1L;

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

doPost(request, response);

}

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

response.setContentType("text/html;charset=utf-8");

request.setCharacterEncoding("utf-8");

HttpSession session = request.getSession();

PrintWriter out = response.getWriter();

UsersDao ud = new UsersDaoImpl();

String dos = request.getParameter("do");

if (dos == null || dos.equals("")) {

dos = "index";

}

// 主页

if (dos.equals("index")) {

List ulist = ud.getAllUsers();

session.setAttribute("ulist", ulist);

response.sendRedirect("index.jsp");

return;

}

// 添加页

if (dos.equals("add")) {

String name = request.getParameter("name");

String ages = request.getParameter("age");

int age = Integer.parseInt(ages);

Users u = new Users(0, name, age);

ud.addUser(u);

out.print("");

}

if (dos.equals("del")) {

String ids = request.getParameter("id");

int id = Integer.parseInt(ids);

ud.delUser(id);

out.print("");

return;

}

if (dos.equals("editbefore")) {

String ids = request.getParameter("id");

int id = Integer.parseInt(ids);

Users u = ud.findUserById(id);

session.setAttribute("edituser", u);

response.sendRedirect("edit.jsp");

return;

}

if (dos.equals("edit")) {

String ids = request.getParameter("id");

int id = Integer.parseInt(ids);

String name = request.getParameter("name");

String ages = request.getParameter("age");

int age = Integer.parseInt(ages);

Users u = new Users(id, name, age);

ud.updateUser(u);

out.print("");

return;

}

}

}

6、web.xml

xmlns="http://java.sun.com/xml/ns/javaee"

xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"

id="WebApp_ID" version="3.0">

jdbc

UsersServlet

com.servlet.UsersServlet

UsersServlet

/usersservlet

usersservlet

7、add.jsp

String path = request.getContextPath();

String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";

">

My JSP 'add.jsp' starting page

新增页面

姓名：

年龄：

8、edit.jsp

String path = request.getContextPath();

String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";

">

My JSP 'add.jsp' starting page

修改页面

姓名：

年龄：

9、index.jsp

String path = request.getContextPath();

String basePath = request.getScheme() + "://" + request.getServerName() + ":" + request.getServerPort()

+ path + "/";

">

My JSP 'index.jsp' starting page

table {

width: 600px;

height: 300px;

}

td {

text-align: center;

}

主页

id

姓名

年龄

操作

$

$

$

修改

onclick="javascript:return confirm('确认删除吗？');">删除新增

10、运行结果

全部用户

修改用户

删除用户

新添用户

恭喜完成！！！

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