基于 Servlet 的 smbms（含静态资源及源码）

*资源在文末

1 环境简介

环境：

JDK 1.8apache-tomcat-9.0.59apache-maven-3.8.4IntelliJ IDEA 2021.1.2 x64 2 初始配置 2.1 web.xml 初始配置

2.2 pow.xml 依赖

        
        
            javax.servlet
            javax.servlet-api
            4.0.1
            provided
        

        
        
            javax.servlet.jsp
            javax.servlet.jsp-api
            2.3.3
            provided
        

        
          mysql
          mysql-connector-java
          5.1.49
        

        
          javax.servlet.jsp.jstl
          jstl-api
          1.2
        

        
          taglibs
          standard
          1.1.2
        

        
        
            com.alibaba
            fastjson
            1.2.79

2.3 tomcat 配置 3 实体类

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User 实体类

package com.bailugansan.pojo;

import java.util.Date;


public class User {
    private Integer id;
    private String userCode;
    private String userName;
    private String userPassword;
    private Integer gender;
    private Date birthday;
    private String phone;
    private String address;
    private Integer userRole;
    private Integer createdBy;
    private Date creationDate;
    private Integer modifyBy;
    private Date modifyDate;

    public User() {
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getUserCode() {
        return userCode;
    }

    public void setUserCode(String userCode) {
        this.userCode = userCode;
    }

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    public String getUserPassword() {
        return userPassword;
    }

    public void setUserPassword(String userPassword) {
        this.userPassword = userPassword;
    }

    public Integer getGender() {
        return gender;
    }

    public void setGender(Integer gender) {
        this.gender = gender;
    }

    public Date getBirthday() {
        return birthday;
    }

    public void setBirthday(Date birthday) {
        this.birthday = birthday;
    }

    public String getPhone() {
        return phone;
    }

    public void setPhone(String phone) {
        this.phone = phone;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    public Integer getUserRole() {
        return userRole;
    }

    public void setUserRole(Integer userRole) {
        this.userRole = userRole;
    }

    public Integer getCreatedBy() {
        return createdBy;
    }

    public void setCreatedBy(Integer createdBy) {
        this.createdBy = createdBy;
    }

    public Date getCreationDate() {
        return creationDate;
    }

    public void setCreationDate(Date creationDate) {
        this.creationDate = creationDate;
    }

    public Integer getModifyBy() {
        return modifyBy;
    }

    public void setModifyBy(Integer modifyBy) {
        this.modifyBy = modifyBy;
    }

    public Date getModifyDate() {
        return modifyDate;
    }

    public void setModifyDate(Date modifyDate) {
        this.modifyDate = modifyDate;
    }
}

4 基础公共类 4.1 数据库配置文件

driver=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/smbms?userUnicode=true&characterEncoding=utf-8
username=root
password=

4.2 数据库基础公共类

package com.bailugansan.util;

import java.io.IOException;
import java.io.InputStream;
import java.sql.*;
import java.util.Properties;



// 数据库基础公共类
public class DbUtil {
    private static String driver;
    private static String url;
    private static String username;
    private static String password;

    // 静态代码块，类加载的时候在连接阶段就初始化了
    static{
        Properties properties = new Properties();
        // 获取类加载器
        ClassLoader classLoader = DbUtil.class.getClassLoader();
        // 获取数据库配置文件的输入流
        InputStream resourceAsStream = classLoader.getResourceAsStream("db.properties");

        try {
            properties.load(resourceAsStream);
        } catch (IOException e) {
            e.printStackTrace();
        }

        driver = properties.getProperty("driver");
        url = properties.getProperty("url");
        username = properties.getProperty("username");
        password = properties.getProperty("password");
    }

    // 获取数据库连接
    public static Connection getConn(){
        Connection connection = null;
        try {
            // 加载驱动
            Class.forName(driver);
            // 获取连接
            connection = DriverManager.getConnection(url, username, password);
        } catch (ClassNotFoundException | SQLException e) {
            e.printStackTrace();
        }
        return connection;
    }

    // 查询公共方法
    // 参数全部提取出来方便统一关闭
    public static ResultSet execute(Connection conn, String sql, Object[] params, ResultSet resultSet, PreparedStatement preparedStatement){
        try {
            // 获取预编语句
            preparedStatement = conn.prepareStatement(sql);
            // 填充占位符
            for (int i = 0; i < params.length; i++) {
                // 占位符从 1 开始
                preparedStatement.setObject(i+1, params[i]);
            }
            // 执行
            resultSet = preparedStatement.executeQuery(sql);
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return resultSet;
    }

    // 增删改公共方法
    public static int update(Connection conn, String sql, Object[] params, int result, PreparedStatement preparedStatement){
        try {
            preparedStatement = conn.prepareStatement(sql);
            // 填充占位符
            for (int i = 0; i < params.length; i++) {
                // 占位符从 1 开始
                preparedStatement.setObject(i+1, params[i]);
            }
            result = preparedStatement.executeUpdate(sql);
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return result;
    }

    // 关闭连接,释放资源
    public static boolean closeConn(Connection conn, PreparedStatement prep, ResultSet resu){
        boolean flag = true;
        try {
            if(conn != null){
                conn.close();
                // GC 回收
                conn = null;
            }
            if(prep != null){
                prep.close();
                prep = null;
            }
            if(resu != null){
                resu.close();
                resu = null;
            }
        } catch (SQLException e) {
            e.printStackTrace();
            flag = false;
        }
        return flag;
    }
}

5 过滤器 5.1 字符集过滤器

package com.bailugansan.filter;

import javax.servlet.*;
import java.io.IOException;


public class CharacterEncodingFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        request.setCharacterEncoding("utf-8");
        response.setCharacterEncoding("utf-8");
        response.setContentType("text/html;charset=utf-8");
        chain.doFilter(request, response);
    }

    @Override
    public void destroy() {

    }
}

6 登录模块 6.1 登录功能

public class LoginServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        UserServiceImpl userService = new UserServiceImpl();

        String userCode = req.getParameter("userCode");
        String userPassword = req.getParameter("userPassword");

        User user = userService.login(userCode, userPassword);
        System.out.println(user);
        if(user != null){
            // 给登录成功的用户发放 Session
            req.getSession().setAttribute(Constants.USER_SESSION, user);
            // 重定向，转跳到登录后的页面
            resp.sendRedirect("jsp/frame.jsp");
        } else{
            req.setAttribute("error", "用户名或密码错误");
            req.getRequestDispatcher("login.jsp").forward(req, resp);
        }
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req, resp);
    }
}

6.2 登录注销

public class LoginoutServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // 移除用户 Session
        req.getSession().removeAttribute(Constants.USER_SESSION);

        resp.sendRedirect(req.getContextPath()+"/login.jsp");
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req, resp);
    }
}

6.3 登录拦截

package com.bailugansan.filter;

import com.bailugansan.pojo.User;
import com.bailugansan.util.Constants;

import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;


public class SysFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        HttpServletRequest req = (HttpServletRequest) request;
        HttpServletResponse resp = (HttpServletResponse) response;
        // 获取登录对象中 Session 中存放的 User 对象
        User user = (User)req.getSession().getAttribute(Constants.USER_SESSION);

        if(user == null){
            resp.sendRedirect(req.getContextPath()+"/error.jsp");
        }
        chain.doFilter(request, response);
    }

    @Override
    public void destroy() {
    }
}

7 密码修改 7.1 旧密码验证

public class PwdServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String method = req.getParameter("method");

        // Servlet 复用
        if(method != null && "check".equals(method)){
            checkPwd(req, resp);
        } else {
            pwdModify(req, resp);
        }
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req, resp);
    }

    // 修改密码
    protected void pwdModify(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        Object o = req.getSession().getAttribute(Constants.USER_SESSION);
        String newpassword = req.getParameter("newpassword");

        if(o != null && !StringUtils.isNullOrEmpty(newpassword)){
            UserService userService = new UserServiceImpl();
            boolean updateResult = userService.pwdModify(((User) o).getId(), newpassword);
            if(updateResult){ // 成功则删除 Session 并退出登录
                req.setAttribute("message","修改成功，请重新登录");
                req.getSession().removeAttribute(Constants.USER_SESSION);
                try {
                    resp.sendRedirect(req.getContextPath()+"/login.jsp");
                } catch (IOException e) {
                    e.printStackTrace();
                }
            } else {
                System.out.println(111);
                req.setAttribute("message", "修改失败，请重试");
                resp.sendRedirect(req.getContextPath()+"/jsp/pwdmodify.jsp");
            }
        }
    }

    // 验证旧密码
    protected void checkPwd(HttpServletRequest req, HttpServletResponse resp) throws IOException {
        Object o = req.getSession().getAttribute(Constants.USER_SESSION);
        String oldpassword = req.getParameter("oldpassword");

        Map resultMap = new HashMap();

        if(o == null ){ // Session 失效或者过期
            resultMap.put("result", "sessionerror");
        } else if(StringUtils.isNullOrEmpty(oldpassword)){ // 输入旧密码为空
            resultMap.put("result", "error");
        } else {
            String userPassword = ((User) o).getUserPassword();
            if(userPassword.equals(oldpassword)){ // 校验正确
                resultMap.put("result", "true");
            } else {
                resultMap.put("result", "false");
            }
        }

        resp.setContentType("application/json");
        PrintWriter writer = resp.getWriter();
        writer.write(JSONArray.toJSONString(resultMap));
        writer.flush();
        writer.close();
    }
}

8 用户管理

这里只实现了用户查询

9 部分注意事项 9.1 乱码问题

如果设置了 charset=“utf-8" 无效

或 js 修改无效

可以尝试清除浏览器缓再看看，ctrl + F5

9.2 项目完成度

该项目完成的功能：

Gitee 链接

基于 Servlet 的 smbms（含静态资源及源码）

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