RESTful案例

一 . 准备工作

和传统 CRUD 一样，实现对员工信息的增删改查。

搭建环境

1 . 准备实体类

package com.atguigu.pojo;
public class Employee {

    private Integer id;
    private String lastName;

    private String email;
    //1 male, 0 female
    private Integer gender;

    public Integer getId() {
        return id;
    }

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

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public Integer getGender() {
        return gender;
    }

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

    public Employee(Integer id, String lastName, String email, Integer gender) {
        super();
        this.id = id;
        this.lastName = lastName;
        this.email = email;
        this.gender = gender;
    }

    public Employee() {
    }

}

2 .准备dao模拟数据

package com.atguigu.dao;

import com.atguigu.pojo.Employee;
import org.springframework.stereotype.Repository;

import java.util.Collection;
import java.util.HashMap;
import java.util.Map;

@Repository
public class EmployeeDao {

    private static Map<Integer, Employee> employees = null;

    static{
        employees = new HashMap<Integer, Employee>();

        employees.put(1001, new Employee(1001, "E-AA", "aa@163.com", 1));
        employees.put(1002, new Employee(1002, "E-BB", "bb@163.com", 1));
        employees.put(1003, new Employee(1003, "E-CC", "cc@163.com", 0));
        employees.put(1004, new Employee(1004, "E-DD", "dd@163.com", 0));
        employees.put(1005, new Employee(1005, "E-EE", "ee@163.com", 1));
    }

    private static Integer initId = 1006;

    public void save(Employee employee){
        if(employee.getId() == null){
            employee.setId(initId++);
        }
        employees.put(employee.getId(), employee);
    }

    public Collection<Employee> getAll(){
        return employees.values();
    }

    public Employee get(Integer id){
        return employees.get(id);
    }

    public void delete(Integer id){
        employees.remove(id);
    }

}

3. 创建控制层EmployeeController

package com.atguigu.controller;
import org.springframework.stereotype.Controller;

@Controller
public class EmployeeController {

    
}

二功能清单

三 . 具体功能：查询所有员工数据

①控制器方法

package com.atguigu.controller;

/**
 * 查询所有的员工信息-->/employee-->get
 * 跳转到添加页面-->/to/add-->get
 * 新增员工信息-->/employee-->post
 * 跳转到修改页面-->/employee/1-->get
 * 修改员工信息-->/employee-->put
 * 删除员工信息-->/employee/1-->delete
 */
@Controller
public class EmployeeController {
    @Autowired
    private EmployeeDao employeeDao;

    @RequestMapping(value = "/employee", method = RequestMethod.GET)
    public String getAllEmployee(Model model){
        //获取所有的员工信息
        Collection<Employee> allEmployee = employeeDao.getAll();
        //将所有的员工信息在请求域中共享
        model.addAttribute("allEmployee", allEmployee);
        //跳转到列表页面
        return "employee_list";
    }

}

②创建employee_list.html

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>employee list</title>
    <link rel="stylesheet" th:href="@{/static/css/index_work.css}">
</head>
<body>
    <table>
        <tr>
            <th colspan="5">employee list</th>
        </tr>
        <tr>
            <th>id</th>
            <th>lastName</th>
            <th>email</th>
            <th>gender</th>
            <th>options</th>
        </tr>
        <tr th:each="employee : ${allEmployee}">
            <td th:text="${employee.id}"></td>
            <td th:text="${employee.lastName}"></td>
            <td th:text="${employee.email}"></td>
            <td th:text="${employee.gender}"></td>
            <td>
               <a href="">delete</a>
                <a href="">update</a>
            </td>
        </tr>
    </table>
</body>
</html>

如果这个报红就把错误警告取消

不过我们建议把它给选择上因为如果不选择上以后就算有错误也不在提醒

③ index.html

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>首页</title>
</head>
<body>
<h1>index.html</h1>
<a th:href="@{/user}">查询所有的用户信息</a><br>
<a th:href="@{/user/1}">查询id为1的用户信息</a><br>
<form th:action="@{/user}" method="post">
    <input type="submit" value="添加用户信息">
</form>
<form th:action="@{/user}" method="post">
    <input type="hidden" name="_method" value="put">
    <input type="submit" value="修改用户信息">
</form>
<form th:action="@{/user/5}" method="post">
    <input type="hidden" name="_method" value="delete">
    <input type="submit" value="删除用户信息">
</form>
<hr>
<a th:href="@{/employee}">查询所有的员工信息</a>
</body>
</html>

④ 测试

⑤ 处理静态资源样式

把静态资源复制过来然后在clean一下然后在重新打包

   <link rel="stylesheet" th:href="@{/static/css/index_work.css}">

报404

解决办法：配置默认的servlet处理静态资源

    <!--
        配置默认的servlet处理静态资源
        当前工程的web.xml配置的前端控制器DispatcherServlet的url-pattern是/
        tomcat的web.xml配置的DefaultServlet的url-pattern也是/
        此时，浏览器发送的请求会优先被DispatcherServlet进行处理，但是DispatcherServlet无法处理静态资源
        若配置了<mvc:default-servlet-handler />，此时浏览器发送的所有请求都会被DefaultServlet处理
        若配置了<mvc:default-servlet-handler />和<mvc:annotation-driven />
        浏览器发送的请求会先被DispatcherServlet处理，无法处理在交给DefaultServlet处理
    -->
    <mvc:default-servlet-handler />

    <!--开启mvc的注解驱动-->
    <mvc:annotation-driven />