SpringBoot项目复盘

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发布于 2024-05-30 17:22:56

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SpringBoot项目复盘

项目起始

确定数据库中的表、主键、各个字段及其代表的含义；确立好表与表之间的关联关系； （规范好字段的命名规则）**
按照数据库中表及其字段创建实体类及其属性；规范好命名规则
前端确定好页面长什么样，数据以什么格式交互
导入需要的各种依赖，以及做好自定义配置
准备好自己的后台模板，开始实现功能

实现各个功能

登录实现

在form表单中实现对账号、密码的输入。通过th:action="@{/user/login}"将表单数据提交至controller层中
在controller层通过匹配方法上的请求映射为@RequestMapping("/user/login")的方法。
在该方法中实现好对password的判断、是否username为空、username输入有误如何提示、数据如何回显至index页面….

@RequestMapping("/user/login")
public String login(Model model, HttpSession session,
                    @RequestParam("username") String username ,
                    @RequestParam("password") String password){
    if(username !=null && "123456".equals(password)){
        System.out.println("username= " + username);
        System.out.println("密码：" + password);
        //将值（用户名）传进来
        session.setAttribute("loginUser", username);    
        return "redirect:/main.html";
    }else{
        model.addAttribute("msg","用户名或密码错误！");
        return "index";
    }
}

后台实现数据回显的操作

<p style="color: red" th:text="${msg}" th:if="${not #strings.isEmpty(msg)}"></p>

如果后端数据判断显示为null或者密码错误。通过上述的语法就可以实现将数据回显出来，而不是一开始就显示数据

其中输入框提示的信息我们使用国际化的技术，能够实现页面的语言自由切换

<form class="form-signin" th:action="@{/user/login}">
    <img class="mb-4" src="https://getbootstrap.com/docs/4.0/assets/brand/bootstrap-solid.svg" alt="" width="72" height="72">
    <h1 class="h3 mb-3 font-weight-normal" th:text="#{login.tip}">Please sign in</h1>
    <!--消息回显，登录失败的情况
如果msg的值为空才显示
-->
    <p style="color: red" th:text="${msg}" th:if="${not #strings.isEmpty(msg)}"></p>
    <label for="inputEmail" class="sr-only">[#{login.username}]</label>
    <input type="email" id="inputEmail" class="form-control" th:name="username" th:placeholder="#{login.username}" required autofocus>
    <label for="inputPassword" class="sr-only">[#{login.password}]</label>
    <input type="password" id="inputPassword" th:name="password"  class="form-control" th:placeholder="#{login.password}" required>
    <div class="checkbox mb-3">
        <label>
            <input type="checkbox" value="remember-me"  th:text="#{login.remeber}">
        </label>
    </div>
    <button class="btn btn-lg btn-primary btn-block" type="submit" th:text="#{login.tip}"></button>
    <p class="mt-5 mb-3 text-muted">&copy; 2022-2023</p>
    <a class="btn btn-sm" th:href="@{/index.html(l='zh_CN')}">中文</a>
    <a class="btn btn-sm" th:href="@{/index.html(l='en_US')}">English</a>
</form>

通过<label for="inputEmail" class="sr-only">[#{login.username}]</label>显示提示语。

在配置中开启国际化

在application.properties配置文件中，通过spring.messages.basename=i18n.login开启我们配置的国际化配置
在自定义配置类中开启国际化方法

//往容器中注入组件
//自定义的国际化组件就会生效
@Bean
public LocaleResolver localeResolver(){
    return new MyLocaleResolver();
}

在config包下创建MyLocaleResolver类实现国际化的接口

public class MyLocaleResolver implements LocaleResolver {
    //解析请求
    @Override
    public Locale resolveLocale(HttpServletRequest httpServletRequest) {
        //获取请求的语言参数
        String language = httpServletRequest.getParameter("l");
        Locale locale = Locale.getDefault(); //如果没有就使用
        //如果请求的链接携带了国际化的参数
        if(!StringUtils.isEmpty(language)){
            //zh_CN
            String[] split = language.split("_");
            //国家 ，地区
           locale = new Locale(split[0], split[1]);
        }
        return locale;
    }

    @Override
    public void setLocale(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Locale locale) {
    }
}

在resources文件夹下创建资源包login.properties、 login_en_US.properties 、 login_zh_CN.properties从而实现国际化的要求

登录开启拦截器

为了防止恶意的跳转，我们需要在用户未登录时自动拦截页面，使其跳转到登录页面，从而防止用户未登录就操作

首先在config包下的myConfig类中添加拦截器配置

//添加拦截器配置
@Override
public void addInterceptors(InterceptorRegistry registry) {
    //添加拦截器
    //登录拦截器 ，拦截哪些选择 ，排除哪些选择
    registry.addInterceptor(new LoginHandlerInterceptor()).addPathPatterns("/**").excludePathPatterns("/index.html",
                                                                                                      "/user/login","/","/css/**","/dist/**","/docs.4.0/**","/js/**","/img/**"
                                                                                                      ,"/index.html(l='zh_CN')","/index.html(l='en_US')","/user/LogOut");
}

在config包下同样创建LoginHandlerInterceptor类，使其实现拦截器接口。从而实现preHandle方法

public class LoginHandlerInterceptor implements HandlerInterceptor {
    //登录成功之后将用户的信息session传过来
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        //登录成功，获取用过户的session
        Object loginUser = request.getSession().getAttribute("loginUser");
        if(loginUser == null) {
            request.setAttribute("msg", "没有权限，请登录");
            request.getRequestDispatcher("/index.html").forward(request, response);
            return false;
        }
        return true;
    }
}

首页实现

<!doctype html >
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
    <meta name="description" content="">
    <meta name="author" content="">
    <link rel="icon" th:href="@{/docs/4.0/assets/img/favicons/favicon.icof}">

    <title>Dashboard Template for Bootstrap</title>

    <link rel="canonical" href="https://getbootstrap.com/docs/4.0/examples/dashboard/">

    <!-- Bootstrap core CSS -->
    <link th:href="@{/dist/css/bootstrap.min.css}" rel="stylesheet">

    <!-- Custom styles for this template -->
    <link th:href="@{/docs/4.0/examples/dashboard/dashboard.css}" rel="stylesheet">
</head>

<body>
<!--顶部导航栏-->
    <div th:insert="~{common/common::topbar}"></div>
<!--侧边栏-->
<div class="container-fluid">
    <div class="row">
        <!--侧边栏-->
        <div th:insert="~{common/common::sidebar(active='main.html')}"></div>

        <main role="main" class="col-md-9 ml-sm-auto col-lg-10 pt-3 px-4">
            <div class="d-flex justify-content-between flex-wrap flex-md-nowrap align-items-center pb-2 mb-3 border-bottom">
                <h1 class="h2">Dashboard</h1>
                <div class="btn-toolbar mb-2 mb-md-0">
                    <div class="btn-group mr-2">
                        <button class="btn btn-sm btn-outline-secondary">Share</button>
                        <button class="btn btn-sm btn-outline-secondary">Export</button>
                    </div>
                    <button class="btn btn-sm btn-outline-secondary dropdown-toggle">
                        <span data-feather="calendar"></span>
                        This week
                    </button>
                </div>
            </div>

            <canvas class="my-4" id="myChart" width="900" height="380"></canvas>
        </main>
    </div>
</div>

<!-- Bootstrap core JavaScript
================================================== -->
<!-- Placed at the end of the document so the pages load faster -->
<script src="https://code.jquery.com/jquery-3.2.1.slim.min.js" integrity="sha384-KJ3o2DKtIkvYIK3UENzmM7KCkRr/rE9/Qpg6aAZGJwFDMVNA/GpGFF93hXpG5KkN" crossorigin="anonymous"></script>
<script>window.jQuery || document.write('<script src="../static/js/vendor/jquery-slim.min.js"></script>')</script>
<script src="../static/js/vendor/popper.min.js"></script>
<script src="../static/dist/js/bootstrap.min.js"></script>

<!-- Icons -->
<script src="https://unpkg.com/feather-icons/dist/feather.min.js"></script>
<script>
    feather.replace()
</script>

<!-- Graphs -->
<script src="https://cdn.jsdelivr.net/npm/chart.js@2.7.1/dist/Chart.min.js"></script>
<script>
    var ctx = document.getElementById("myChart");
    var myChart = new Chart(ctx, {
        type: 'line',
        data: {
            labels: ["Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"],
            datasets: [{
                data: [15339, 21345, 18483, 24003, 23489, 24092, 12034],
                lineTension: 0,
                backgroundColor: 'transparent',
                borderColor: '#007bff',
                borderWidth: 4,
                pointBackgroundColor: '#007bff'
            }]
        },
        options: {
            scales: {
                yAxes: [{
                    ticks: {
                        beginAtZero: false
                    }
                }]
            },
            legend: {
                display: false,
            }
        }
    });
</script>
</body>
</html>

解释

通过后端登录成功将数据return "redirect:/main.html";重定向main.html，但是main.html这个地址是我们虚构的首页地址，以防止登录成功将用户信息传入导致用户信息泄露。

只需要在自定义配置中配置即可

@Configuration
public class MyConfig implements WebMvcConfigurer {
    /*
        配置根目录下的东西可以在这里配置
     */
    @Override
    public void addViewControllers(ViewControllerRegistry registry) {
        registry.addViewController("/").setViewName("index");
        registry.addViewController("/index.html").setViewName("index");
        /*将/main.html作为一个跳板，放置用户信息被揭密，*/
        registry.addViewController("/main.html").setViewName("dashboard");
    }
}

通过registry.addViewController("/main.html").setViewName("dashboard");调用main.html就可以跳转至dashboard首页

list页面实现

list页面作为数据显示的页面，它可以将我们后台传过来的数据通过Thymeleaf语法，将数据显示到后台

<main role="main" class="col-md-9 ml-sm-auto col-lg-10 pt-3 px-4">
  <h2>Section title</h2>
  <a class="btn btn-sm btn-success" th:href="@{/to/add}">添加员工</a>
  <div class="table-responsive">
    <table class="table table-striped table-sm">
      <thead>
        <tr>
          <th>id</th>
          <th>lastName</th>
          <th>Email</th>
          <th>gender</th>
          <th>department</th>
          <th>birth</th>
          <th>操作</th>
        </tr>
      </thead>
      <tbody>
        <tr th:each="li : ${list}">
          <td th:text="${li.getId()}"></td>
          <td th:text="${li.getLastName()}"></td>
          <td th:text="${li.getEmail()}"></td>
          <td th:text="${li.getGender() == 0 ? '女' : '男'}" ></td>
          <td th:text="${li.getDepartment().getDepartmentName()}"></td>
          <td th:text="${#dates.format(li.getBirth(),'yyyy-MM-dd HH:mm:ss')}"></td>
          <td>
            <a class="btn btn-sm btn-primary" th:href="@{'/updateEmp/'+${li.getId()}}">修改</a>
            <a class="btn btn-sm btn-danger" th:href="@{'/deleteEmp/'+${li.getId()}}">删除</a>
          </td>
        </tr>

      </tbody>
    </table>
  </div>
</main>

后端通过用户点击员工管理

<li class="nav-item">
    <a th:class="${active=='list.html' ? 'nav-link active' :'nav-link'}" th:href="@{/list}">
        <span data-feather="users"></span>
        员工管理
    </a>
</li>

，请求就会跳转至controller匹配相应的请求映射

@Autowired
private EmployeeDao employeeDao;
@Autowired
private DepartmentDao departmentDao;
@RequestMapping("/list")
public String list(Model model){
    Collection<Employee> list = employeeDao.getAllEmployee();
    model.addAttribute("list",list);
    return "list";
}

后端通过Model将数据回显给list页面

在list页面。通过Thymeleaf语法<tr th:each="li : ${list}">将数据显示出来

<td th:text="${li.getId()}"></td>
  <td th:text="${li.getLastName()}"></td>
  <td th:text="${li.getEmail()}"></td>
  <td th:text="${li.getGender() == 0 ? '女' : '男'}" ></td>
  <td th:text="${li.getDepartment().getDepartmentName()}"></td>
  <td th:text="${#dates.format(li.getBirth(),'yyyy-MM-dd HH:mm:ss')}"></td>
  <td>
    <a class="btn btn-sm btn-primary" th:href="@{'/updateEmp/'+${li.getId()}}">修改</a>
    <a class="btn btn-sm btn-danger" th:href="@{'/deleteEmp/'+${li.getId()}}">删除</a>
  </td>
</tr>

这样，我们请求就能转发过来，用户就能看到数据

同时在list页面，我们也会有实现curd的跳转键

实现delete 和 update功能

对于delete功能，这里没什么好说的，仅仅通过点击用户后面对应的标签，将要删除的员工的id作为请求参数传到后端即可th:href="@{'/updateEmp/'+${li.getId()}}"后端通过匹配请求映射将功能实现

@RequestMapping("/deleteEmp/{id}")
public String deleteEmp(@PathVariable("id")Integer id){
    employeeDao.deleteEmp(id);
    return "redirect:/list";
}

实现update功能相较于delete功能是比较麻烦的

同样需要将要修改的员工id作为请求参数传入后端th:href="@{'/updateEmp/'+${li.getId()}}",然后后端通过查询，获取该员工的所有信息，然后通过Model将数据共享至update页面

@RequestMapping("/updateEmp/{id}")
public String update(Model model,@PathVariable("id") Integer id){
    System.out.println("id==" + id);
    Employee employee = employeeDao.getEmployeeById(id);
    System.out.println("emp == " + employee);
    model.addAttribute("emp",employee);
    Collection<Department> departments = departmentDao.getDepartments();
    model.addAttribute("departments",departments);
    return "/updateEmp";
}

在updateEmp页面，需要将数据回显出来

<!--表单提交-->
<form class="form-horizontal" role="form" th:action="@{/updateSucc}" method="post" >
    <input type="hidden" name="id" th:value="${emp.getId()}">
    <div class="form-group">
        <label for="lastName" class="col-sm-2 control-label">名字</label>
        <div class="col-sm-10">
            <input th:value="${emp.getLastName()}" type="text" class="form-control" id="lastName" name="lastName"
                   placeholder="请输入名字">
        </div>
    </div>
    <div class="form-group">
        <label for="lastname" class="col-sm-2 control-label">Email</label>
        <div class="col-sm-10">
            <input th:value="${emp.getEmail()}" type="text" class="form-control" id="Email" name="Email"
                   placeholder="请输入邮箱">
        </div>
    </div>

    <div class="form-group">
        <label for="gender">性别</label>
        <div class="form-check form-check-inline">
            <input th:checked="${emp.getGender()==1}" type="radio" class="form-check-input" name="gender" value="1" >
            <label class="form-check-label">男</label>
        </div>
        <div class="form-check form-check-inline">
            <input th:checked="${emp.getGender()==0}" type="radio" class="form-check-input" name="gender" value="0" >
            <label class="form-check-label">女</label>
        </div>
    </div>
    <div class="form-group">
        <label>Department</label>
        <select class="form-control" name="department.id">
            <option th:selected="${dept.getId()==emp.getDepartment().getId()}" th:each="dept:${departments}" th:text="${dept.getDepartmentName()}" th:value="${dept.getId()}"></option>
        </select>
    </div>

    <div class="form-group">
        <label for="birth" class="col-sm-2 control-label">birth</label>
        <div class="col-sm-10">
            <input th:value="${#dates.format(emp.getBirth(),'yyyy-MM-dd HH:mm')}" type="text" class="form-control" id="birth"  name="birth"
                   placeholder="请输入生日">
        </div>
    </div>

    <div class="form-group">
        <div class="col-sm-offset-2 col-sm-10">
            <div class="checkbox">
                <label>
                    <input type="checkbox"> 请记住我
                </label>
            </div>
        </div>
    </div>
    <div class="form-group">
        <div class="col-sm-offset-2 col-sm-10">
            <button type="submit" class="btn btn-default">登录</button>
        </div>
    </div>
</form>

通过隐藏域<input type="hidden" name="id" th:value="${emp.getId()}">可以将后端传入的信息获取到

因为我们共享数据时是通过model.addAttribute("emp",employee);，所以在获取，然后在<input th:value="

对于复杂的比如department

<select class="form-control" name="department.id">
            <option th:selected="${dept.getId()==emp.getDepartment().getId()}" th:each="dept:${departments}" th:text="${dept.getDepartmentName()}" th:value="${dept.getId()}"></option>
</select>

可以先通过deparment.id获取全部的信息，然后通过匹配emp.getDepartment().getId()获取将表单展示出来。通过th:value="${dept.getId()}"将我们需要的数据显示到页面

然后通过请求form表单的th:action="@{/updateSucc}"提交表单至后端.

后端通过请求映射匹配到相应的请求方法

@PostMapping("/updateSucc")
public String updateSuccess(Employee employee){
    employeeDao.save(employee);
    return "redirect:/list";
}

然后进行修改，最后通过重定向将请求跳转至原来的页面

add功能实现

用户通过点击添加员工将请求发送到后端，后端通过请求映射匹配到相应的请求方法，实现添加功能

<a class="btn btn-sm btn-success" th:href="@{/to/add}">添加员工</a>

@GetMapping("/to/add")
public String addEmp(Model model){
    Collection<Department> departments = departmentDao.getDepartments();
    model.addAttribute("departments",departments);
    return "addEmp";
}

后台页面与update页面类似