jsp 增删改查

其他 2018-05-11 16:02:02 阅读次数: 1
使用Idea创建项目
1.新建web application项目 Idea 选择 Java Enterprise -> web application
2.新版本没有web-inf文件夹 解决方法 进入project structure ->facets->点击小加号，添加web.xml
3.在web/WEB-INF目录下新建两个文件夹，classes用于存放servlet的字节码文件（.class），lib用于存放项目引用的包。
4.进入Project Structure，进入Modules（IDEA的工程）选项卡，将Paths的两个输出路径均改成第2步新建的classes。
5.然后点击Dependencies，选择右边＋号，新建JARS路径，选择第2步创建的lib文件夹 - >Jar Directory
6.进入Artifacts选项卡，将输出目录定为Tomcat安装位置的webapps下新建的该工程文件夹
7.Run->Edit Configurations配置Tomcat，设置tomcat端口等信息。
8.设置默认启动路径 http://localhost:9999/web/ 或手动输入
 
导入servlet.jar包
file->project structure ->libraries->加号->tomcat下的lib 即可。
 
数据结构 
CREATE TABLE `david2018_db`.`User` (
`UserId` INT NOT NULL AUTO_INCREMENT,
`UserName` NVARCHAR(30) NULL,
`PassWord` NVARCHAR(30) NULL,
`Age` INT NULL,
`Sex` NVARCHAR(30) NULL,
PRIMARY KEY (`UserId`));
 
测试数据 
insert into david2018_db.User (UserName,PassWord,Age,Sex) values ('武大郎','123456',35,'男');
insert into david2018_db.User (UserName,PassWord,Age,Sex) values ('潘金莲','123456',18,'女');
insert into david2018_db.User (UserName,PassWord,Age,Sex) values ('西门庆','123456',24,'男');
insert into david2018_db.User (UserName,PassWord,Age,Sex) values ('武松','123456',22,'男');
insert into david2018_db.User (UserName,PassWord,Age,Sex) values ('鲁智深','123456',30,'男');
insert into david2018_db.User (UserName,PassWord,Age,Sex) values ('林冲','123456',32,'男');
 
创建项目结构
src/com.david.dao 数据访问层
src/com.david.domain 模型层
src/com.david.service 服务层
src/com.david.utils 工具层
src/com.david.web servlet层
 
创建数据库配置文件src新建 database.properties
driverName=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/david2018_db
user=root
password=1234
 
连接池的jar包 dbcp、pool、logging
 
如果报错，java.lang.NoClassDefFoundError: org/apache/commons/dbutils/ResultSetHandler
Artifacts->点击右下角fix即可
 
编写domain 实体类 
public class User {
    private int UserId;
    private String UserName;
    private String PassWord;
    private int Age;
    private String Sex;


    public int getUserId() {
        return UserId;
    }
    public void setUserId(int UserId) {
        this.UserId = UserId;
    }
    public String getUserName() {
        return UserName;
    }
    public void setUserName(String UserName) {
        this.UserName = UserName;
    }
    public String getPassWord() {
        return PassWord;
    }
    public void setPassWord(String PassWord) {
        this.PassWord = PassWord;
    }
    public int getAge() {
        return Age;
    }
    public void setAge(int Age) {
        this.Age = Age;
    }
    public String getSex() {
        return Sex;
    }
    public void setSex(String Sex) {
        this.Sex = Sex;
    }
}

编写工具类 获得数据库连接 utils包下创建DBUtil类

public class DBUtil {
    public static BasicDataSource dataSource = new BasicDataSource();

    static {
        try {
            Properties pp = new Properties();
            InputStream is = DBUtil.class.getClassLoader().getResourceAsStream("database.properties");
            pp.load(is);
            String driver = pp.getProperty("driverName");
            String url = pp.getProperty("url");
            String username = pp.getProperty("user");
            String password = pp.getProperty("password");

            dataSource.setDriverClassName(driver);
            dataSource.setUrl(url);
            dataSource.setUsername(username);
            dataSource.setPassword(password);
            dataSource.setInitialSize(10);//初始化连接数
            dataSource.setMaxIdle(5); //最大空闲
            dataSource.setMinIdle(1); //最小空闲

        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static BasicDataSource GetDataSource(){
        return dataSource;
    }


}
编写获得User列表接口 dao创建UserDao类 
//获取全部列表
public List<User> GetAllUser() throws SQLException {
    String sql = "select * from User";
    QueryRunner qr = new QueryRunner(DBUtil.GetDataSource());
    List<User> users = qr.query(sql,new BeanListHandler<User>(User.class));
    return users;
}
编写User服务 调用dao中的 GetAllUser方法 
public List<User> GetAllService() throws SQLException {
    UserDao dao = new UserDao();
    return dao.GetAllUser();
}
编写Servlet 将列表数据转发到jsp页面 
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    UserService service = new UserService();
    List<User> userList = null;
    try {
        userList = service.GetAllService();

    } catch (SQLException e) {
        e.printStackTrace();
    }
    request.setAttribute("userList", userList);
    request.getRequestDispatcher("userList.jsp").forward(request,response);
}
配置web.xml文件 
<servlet>
    <servlet-name>UserList</servlet-name>
    <servlet-class>com.david.web.UserList</servlet-class>
</servlet>
<servlet-mapping>
    <servlet-name>UserList</servlet-name>
    <url-pattern>/userList</url-pattern>
</servlet-mapping>
编写userList.jsp 渲染页面 
<%@ page import="com.david.domain.User" %>
<%@ page import="java.util.List" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>用户列表</title>
</head>
<body>
<a href="AddUser.jsp">添加用户</a>
<table>
    <tr>
        <th>用户ID</th>
        <th>用户名</th>
        <th>用户密码</th>
        <th>用户年龄</th>
        <th>用户性别</th>
        <th>操作</th>
    </tr>
    <%
        if (request.getAttribute("userList") != null) {
    %>
    <%for (User u : (List<User>) request.getAttribute("userList")) {%>
    <tr>
        <td><%=u.getUserId()%>
        </td>
        <td><%=u.getUserName()%>
        </td>
        <td><%=u.getPassWord()%>
        </td>
        <td><%=u.getAge()%>
        </td>
        <td><%=u.getSex()%>
        </td>
        <td>
            <a href="GetUserById?userId=<%=u.getUserId()%>">修改</a>
            <a href="DeleteUser?userId=<%=u.getUserId()%>">删除</a>
        </td>
    </tr>
    <%}%>
    <%}%>
</table>
</body>
</html>
页面中可以使用el jstl语法 我就不写了
列表完成，下面编写添加用户方法
UserDao输入如下方法 
//添加用户
public boolean AddUser(User user) throws SQLException {
    String sql = "insert into User (UserName,PassWord,Age,Sex) values (?,?,?,?)";
    QueryRunner qr = new QueryRunner(DBUtil.GetDataSource());
    Object[] params = {user.getUserName(),user.getPassWord(),user.getAge(),user.getSex()};
    int result = qr.update(sql,params);
    return result > 0;
}
UserService 
public boolean AddUser(User user) throws SQLException {
    UserDao dao = new UserDao();
    return dao.AddUser(user);
}
servlet 
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    request.setCharacterEncoding("UTF-8");
    String userName = request.getParameter("userName");
    String passWord = request.getParameter("passWord");
    String age = request.getParameter("age");
    String sex = request.getParameter("sex");

    User u = new User();
    u.setUserName(userName);
    u.setPassWord(passWord);
    u.setAge(Integer.parseInt(age));
    u.setSex(sex);

    UserService users = new UserService();
    try {
        boolean result  = users.AddUser(u);
        if(result){
            response.sendRedirect("userList");
        }else{

        }
    } catch (SQLException e) {
        e.printStackTrace();
    }
}
AddUser.jsp页面如下 
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>添加用户</title>
</head>
<body>
<form method="post" action="AddUser">
    <p>用户名:<input name="userName"></p>
    <p>密码：<input name="passWord"></p>
    <p>性别：
        <input type="radio" checked value="男" name="sex">男
        <input type="radio" value="女" name="sex">女
    </p>
    <p>年龄：<select name="age">
        <%for (int i = 18; i < 50; i++) {%>
        <option value="<%=i%>"><%=i%></option>
        <%}%>
    </select></p>
    <p>
        <button type="submit">添加</button>
    </p>
    <a href="userList">用户列表</a>
</form>

</body>
</html>
 
xml文件 
<servlet>
    <servlet-name>AddUser</servlet-name>
    <servlet-class>com.david.web.AddUser</servlet-class>
</servlet>
<servlet-mapping>
    <servlet-name>AddUser</servlet-name>
    <url-pattern>/AddUser</url-pattern>
</servlet-mapping>
 
要设置mysql的字符集编码是utf8的 否则会乱码
 
编写删除方法
dao中 
    //删除用户
    public boolean DeleteUser(int userId) throws SQLException {
        String sql = "delete from User where UserId = ?";
        QueryRunner qr = new QueryRunner(DBUtil.GetDataSource());
        return qr.update(sql,userId) > 0;
    }
service 
    public boolean DeleteUser(int userId) throws SQLException {
        UserDao dao = new UserDao();
        return dao.DeleteUser(userId);
    }
servlet 
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String userId = request.getParameter("userId");
        UserService service = new UserService();
        int id = Integer.parseInt(userId);
        try {
            boolean result = service.DeleteUser(id);
            if(result){
                response.sendRedirect("userList");
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
web.xml 
    <servlet>
        <servlet-name>DeleteUser</servlet-name>
        <servlet-class>com.david.web.DeleteUser</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>DeleteUser</servlet-name>
        <url-pattern>/DeleteUser</url-pattern>
    </servlet-mapping>
userList.jsp加入路径即可 
<a href="DeleteUser?userId=<%=u.getUserId()%>">删除</a> 
修改
dao 
    //查找一条User通过UserId
    public User GetUserByUserId(int userId) throws SQLException {
        String sql = "select * from User where UserId = ?";
        QueryRunner qr = new QueryRunner(DBUtil.GetDataSource());
        User user = qr.query(sql, userId, new BeanHandler<User>(User.class));
        return user;
    }
    //修改user
    public boolean UpdateUser(User user) throws SQLException {
        String sql = "update User set UserName = ?,PassWord = ?,Age = ?, Sex = ? where UserId = ?";
        Object [] params = {user.getUserName(),user.getPassWord(),user.getAge(),user.getSex(),user.getUserId()};
        QueryRunner qr = new QueryRunner(DBUtil.GetDataSource());
        int result = qr.update(sql,params);
        return result > 0;
    }
service 
    public User GetUserByUserId(int userId) throws SQLException {
        UserDao dao = new UserDao();
        return dao.GetUserByUserId(userId);
    }
    //修改user
    public boolean UpdateUser(User user) throws SQLException {
        UserDao dao = new UserDao();
        return dao.UpdateUser(user);
    }
servlet
GetUserById 
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String userId = request.getParameter("userId");
        UserService service = new UserService();
        try {
            User u =service.GetUserByUserId(Integer.parseInt(userId));
            request.setAttribute("user",u);
            request.getRequestDispatcher("Update.jsp").forward(request,response);
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
updateUser 
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        request.setCharacterEncoding("UTF-8");
        String userId = request.getParameter("userId");
        String userName = request.getParameter("userName");
        String passWord = request.getParameter("passWord");
        String age = request.getParameter("age");
        String sex = request.getParameter("sex");

        User u = new User();
        u.setUserName(userName);
        u.setPassWord(passWord);
        u.setAge(Integer.parseInt(age));
        u.setSex(sex);
        u.setUserId(Integer.parseInt(userId));

        UserService users = new UserService();
        try {
            boolean result = users.UpdateUser(u);
            if (result) {
                response.sendRedirect("userList");
            } else {

            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
userList.jsp 加入修改入口 
<a href="GetUserById?userId=<%=u.getUserId()%>">修改</a>
updateuser.jsp 
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>修改用户</title>
</head>
<body>
<%
User u = (User)request.getAttribute("user");
%>
<form method="post" action="UpdateUser">
    <p>用户Id：<input name="userId" value="<%=u.getUserId()%>" readonly></p>
    <p>用户名:<input name="userName" value="<%=u.getUserName()%>"></p>
    <p>密码：<input name="passWord" value="<%=u.getPassWord()%>"></p>
    <p>性别：
        <input type="radio" <%if(u.getSex().equals("男")){%> checked <%}%> value="男" name="sex">男
        <input type="radio" <%if(u.getSex().equals("女")){%> checked <%}%> value="女" name="sex">女
    </p>
    <p>年龄：<select name="age">
        <%for (int i = 18; i < 50; i++) {%>
        <option value="<%=i%>"><%=i%></option>
        <%}%>
    </select>
    <script>
        for(var i = 0;i<document.getElementsByTagName("option").length;i++){
            var option = document.getElementsByTagName("option")[i];
            if(option.value == "<%=u.getAge()%>"){
                option.selected = true;
            }
        }
    </script>
    </p>
    <p>
        <button type="submit">确认修改</button>
    </p>
    <a href="userList">用户列表</a>
</form>

</body>
</html>
xml.web 
    <servlet>
        <servlet-name>UpdateUser</servlet-name>
        <servlet-class>com.david.web.UpdateUser</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>UpdateUser</servlet-name>
        <url-pattern>/UpdateUser</url-pattern>
    </servlet-mapping>
    <servlet>
        <servlet-name>GetUserById</servlet-name>
        <servlet-class>com.david.web.GetUserById</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>GetUserById</servlet-name>
        <url-pattern>/GetUserById</url-pattern>
    </servlet-mapping>
 

猜你喜欢

转载自www.cnblogs.com/baidawei/p/9025063.html
今日推荐
《美国对全球网络空间安全与发展的威胁和破坏》报告发布
火速冲上 GitHub 热榜 —— 开源编程语言、框架哪有这么可爱？
北京人形机器人创新中心发布全球首个纯电驱拟人奔跑的全尺寸人形机器人“天工”
LFOSSA 源来如此公开课 | 掌握云原生未来：CNCF 认证全面攻略与备考秘籍
周排行
循环神经网络（rnn）讲解
Tigao教程四：单独的关节运动
金蝶K3WISE15.0-注册套打教程
如何在Mac上配置Kubernetes
Android应用结束自身进程的方法
SpringMVC学习 十三 拦截器栈
中国驻洛杉矶总领馆举行新春招待会
HttpClient get post 发送
11 - three.js 笔记 - 绘制三维字体模型
Mysql递归获取某个父节点下面的所有子节点和子节点上的所有父节点
每日归档
更多
2024-05-01(4)
2024-04-30(1)
2024-04-29(40)
2024-04-28(0)
2024-04-27(56)
2024-04-26(39)
2024-04-25(22)
2024-04-24(36)
2024-04-23(26)
2024-04-22(39)

代码天地 © 2018 codetd.com

境外服务器   最新电视剧2022