SpringMVC7-RESTful

标签：springframework id org employee import RESTful public SpringMVC7

RESTful简介

资源

资源的表述

状态转移

RESTful的实现

案例

RESTful简介

REST：Representational State Transfer，表现层资源状态转移

资源

资源是一种看待服务器的方式，即，将服务器看作是由很多离散的资源组成。每个资源是服务器上一个可命名的抽象概念。因为资源是一个抽象的概念，所以它不仅仅能代表服务器文件系统中的一个文件、数据库中的一张表等等具体的东西，可以将资源设计的要多抽象有多抽象，只要想象力允许而且客户端应用开发者能够理解。

与面向对象设计类似，资源是以名词为核心来组织的，首先关注的是名词。一个资源可以由一个或多个URI来标识。URI既是资源的名称，也是资源在Web上的地址。对某个资源感兴趣的客户端应用，可以通过资源的URI与其进行交互。

资源的表述

资源的表述是一段对于资源在某个特定时刻的状态的描述。可以在客户端-服务器端之间转移（交换）。资源的表述可以有多种格式，例如HTML/XML/JSON/纯文本/图片/视频/音频等等。资源的表述格式可以通过协商机制来确定。请求-响应方向的表述通常使用不同的格式。

状态转移

状态转移说的是：在客户端和服务器端之间转移（transfer）代表资源状态的表述。通过转移和操作资源的表述，来间接实现操作资源的目的。

RESTful的实现

具体说，就是 HTTP 协议里面，四个表示操作方式的动词：GET、POST、PUT、DELETE

它们分别对应四种基本操作：GET 用来获取资源，POST 用来新建资源，PUT 用来更新资源，DELETE用来删除资源

REST 风格提倡 URL 地址使用统一的风格设计，从前到后各个单词使用斜杠分开，不使用问号键值对方式携带请求参数，而是将要发送给服务器的数据作为 URL 地址的一部分，以保证整体风格的一致性

操作	传统方式	REST风格
查询操作	getUserById?id=1	user/1-->get请求方式
保存操作	saveUser	user-->post请求方式
删除操作	deleteUser?id=1	user/1-->delete请求方式
更新操作	updateUser	user-->put请求方式

案例：

1.查询所有用户信息：

package com.qcby.mvc.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

@Controller
public class UserController {
    /**
     * 使用RESTful模拟用户资源的增删改查
     */

    /**
     * 查询所有用户信息
     * GET
     * /user
     */
    @RequestMapping(value = "/user",method = RequestMethod.GET)
    public String getAllUser(){
        System.out.println("查询所有用户信息");
        return "success";
    }


}

test_rest.html：

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<a th:href="@{/user}">查询所有用户信息</a>
</body>
</html>

springMVC.xml：

<mvc:view-controller path="/test_rest" view-name="test_rest"></mvc:view-controller>

2.根据id查询用户信息

package com.qcby.mvc.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

@Controller
public class UserController {
    /**
     * 使用RESTful模拟用户资源的增删改查
     */

    /**
     * 根据用户id查询用户信息
     * GET
     * /user/1
     */
    @RequestMapping(value = "/user/{id}",method = RequestMethod.GET)
    public String getUserById(){
        System.out.println("根据id查询用户信息");
        return "success";
    }

}

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<a th:href="@{/user/1}">根据id查询用户信息</a><br>
</body>
</html>

3.添加用户信息

package com.qcby.mvc.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

@Controller
public class UserController {
    /**
     * 使用RESTful模拟用户资源的增删改查
     */

    /**
     * 添加用户信息
     * POST
     * /user
     */
    @RequestMapping(value = "/user",method = RequestMethod.POST)
    public String insertUser(String username,String password){
        System.out.println("添加用户信息："+username+","+password);
        return "success";
    }


}

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<form th:action="@{/user}" method="post">
    用户名：<input type="text" name="username"><br>
    密码：<input type="password" name="password"><br>
   <input type="submit" value="添加"><br>
</form>
</body>
</html>

4. 修改用户信息

web.xml：

  <!--配置HiddenHttpMethodFilter-->
  <filter>
    <filter-name>HiddenHttpMethodFilter</filter-name>
    <filter-class>org.springframework.web.filter.HiddenHttpMethodFilter</filter-class>
  </filter>
  <filter-mapping>
    <filter-name>HiddenHttpMethodFilter</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>

package com.qcby.mvc.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

@Controller
public class UserController {
    /**
     * 使用RESTful模拟用户资源的增删改查
     */

    /**
     * 修改用户信息
     * PUT
     * /user
     */
    @RequestMapping(value = "/user",method = RequestMethod.PUT)
    public String updateUser(String username,String password){
        System.out.println("修改用户信息："+username+","+password);
        return "success";
    }

}

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<form th:action="@{/user}" method="post">
    <input type="hidden" name="_method" value="PUT">
    用户名：<input type="text" name="username"><br>
    密码：<input type="password" name="password"><br>
    <input type="submit" value="修改"><br>
</form>
</body>
</html>

HiddenHttpMethodFilter

由于浏览器只支持发送get和post方式的请求，那么该如何发送put和delete请求呢？

SpringMVC 提供了 HiddenHttpMethodFilter 帮助我们将 POST 请求转换为 DELETE 或 PUT 请求

HiddenHttpMethodFilter 处理put和delete请求的条件：

当前请求的请求方式必须为post
当前请求必须传输请求参数_method

满足以上条件，HiddenHttpMethodFilter 过滤器就会将当前请求的请求方式转换为请求参数_method的值，因此请求参数_method的值才是最终的请求方式

在web.xml中注册HiddenHttpMethodFilter:

<filter>
    <filter-name>HiddenHttpMethodFilter</filter-name>
    <filter-class>org.springframework.web.filter.HiddenHttpMethodFilter</filter-class>
</filter>
<filter-mapping>
    <filter-name>HiddenHttpMethodFilter</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>

注：

目前为止，SpringMVC中提供了两个过滤器：CharacterEncodingFilter和HiddenHttpMethodFilter

在web.xml中注册时，必须先注册CharacterEncodingFilter，再注册HiddenHttpMethodFilter

原因：

在 CharacterEncodingFilter 中通过 request.setCharacterEncoding(encoding) 方法设置字符集的
request.setCharacterEncoding(encoding) 方法要求前面不能有任何获取请求参数的操作
而 HiddenHttpMethodFilter 恰恰有一个获取请求方式的操作：String paramValue = request.getParameter(this.methodParam);

案例

1.准备工作

和传统 CRUD 一样，实现对员工信息的增删改查。

新建模块springMVC-rest

创建实体类：

package com.qcby.rest.bean;

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() {
   }
}

准备dao模拟数据：

package com.qcby.rest.dao;

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

import com.qcby.rest.bean.Employee;
import org.springframework.stereotype.Repository;


@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", "[email protected]", 1));
      employees.put(1002, new Employee(1002, "E-BB", "[email protected]", 1));
      employees.put(1003, new Employee(1003, "E-CC", "[email protected]", 0));
      employees.put(1004, new Employee(1004, "E-DD", "[email protected]", 0));
      employees.put(1005, new Employee(1005, "E-EE", "[email protected]", 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);
   }
}

2.功能清单

功能	URL 地址	请求方式
访问首页√	/	GET
查询全部数据√	/employee	GET
删除√	/employee/2	DELETE
跳转到添加数据页面√	/toAdd	GET
执行保存√	/employee	POST
跳转到更新数据页面√	/employee/2	GET
执行更新√	/employee	PUT

3.具体功能：访问首页

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>首页</h1>
<a th:href="@{/employee}">查看员工信息</a>
</body>
</html>

springMVC.xml：

    <mvc:view-controller path="/" view-name="index"></mvc:view-controller>

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

4.具体功能：查询所有员工数据

package com.qcby.rest.controller;

import com.qcby.rest.bean.Employee;
import com.qcby.rest.dao.EmployeeDao;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;

import java.util.Collection;

@Controller
public class EmployeeController {
    @Autowired
    private EmployeeDao employeeDao;

    @RequestMapping(value = "/employee")
    public String getEmployee(Model model){
        Collection<Employee> employeeList = employeeDao.getAll();
        model.addAttribute("employeeList",employeeList);
        return "employee_list";
    }
}

employee_list.html：

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>Employee Info</title>
</head>
<body>
    <table border="1" cellspacing="0" cellpadding="0" style="text-align: center">
        <tr>
            <th colspan="5">Employee Info</th>
        </tr>
        <tr>
            <th>id</th>
            <th>lastName</th>
            <th>email</th>
            <th>gender</th>
            <th>options</th>
        </tr>
        <tr th:each="employee : ${employeeList}">
            <td th:text="${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>

5.具体功能：删除

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>Employee Info</title>
</head>
<body>
<table id="dataTable" border="1" cellspacing="0" cellpadding="0" style="text-align: center">
    <tr>
        <th colspan="5">Employee Info</th>
    </tr>
    <tr>
        <th>id</th>
        <th>lastName</th>
        <th>email</th>
        <th>gender</th>
        <th>options</th>
    </tr>
    <tr th:each="employee : ${employeeList}">
        <td th:text="${employee.id}"></td>
        <td th:text="${employee.lastName}"></td>
        <td th:text="${employee.email}"></td>
        <td th:text="${employee.gender}"></td>
        <td>
            <a @click.prevent="deleteEmployee" th:href="@{|/employee/${employee.id}|}">delete</a>
            <a href="">update</a>
        </td>
    </tr>
</table>

<form id="deleteForm" method="post" th:action="@{/employee}">
    <input type="hidden" name="_method" value="delete">
</form>

<script src="https://cdn.jsdelivr.net/npm/vue@2/dist/vue.js"></script>
<script type="text/javascript">
    var vue = new Vue({
        el:"#dataTable",
        methods:{
            deleteEmployee: function (event) {
                // 获取表单元素
                var deleteForm = document.getElementById("deleteForm");
                // 将触发点击事件的超链接 href 属性赋值给表单的 action
                deleteForm.action = event.target.href;
                // 提交表单
                deleteForm.submit();
                // 阻止默认的链接行为（避免 GET 请求）
                event.preventDefault();
            }
        }
    });
</script>
</body>
</html>

package com.qcby.rest.controller;

import com.qcby.rest.bean.Employee;
import com.qcby.rest.dao.EmployeeDao;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.*;

import java.util.Collection;

@Controller
public class EmployeeController {
    @Autowired
    private EmployeeDao employeeDao;

    @RequestMapping(value = "/employee")
    public String getEmployee(Model model){
        Collection<Employee> employeeList = employeeDao.getAll();
        model.addAttribute("employeeList",employeeList);
        return "employee_list";
    }

    @DeleteMapping(value = "/employee/{id}")
    public String deleteEmployee(@PathVariable("id") Integer id){
        employeeDao.delete(id);
        return "redirect:/employee";
    }
}

springMVC.xml：

<!--开放对静态资源的访问-->
<mvc:default-servlet-handler/>

点击id=1005的delete：

6.具体功能：添加数据

employ_list.html：

<th>options( <a th:href="@{/toAdd}">add</a> )</th>

springMVC.xml：

<mvc:view-controller path="/toAdd" view-name="employee_add"></mvc:view-controller>

employee_add.html：

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>add employee</title>
</head>
<body>
<form th:action="@{/employee}" method="post">
    lastName：<input type="text" name="lastName"><br>
    email：<input type="text" name="email"><br>
    gender：<input type="radio" name="gender" value="1">male<br>
    <input type="radio" name="gender" value="0">female<br>
    <input type="submit" value="add"><br>
</form>
</body>
</html>

package com.qcby.rest.controller;

import com.qcby.rest.bean.Employee;
import com.qcby.rest.dao.EmployeeDao;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.*;

import java.util.Collection;

@Controller
public class EmployeeController {
    @Autowired
    private EmployeeDao employeeDao;

    @RequestMapping(value = "/employee")
    public String getEmployee(Model model){
        Collection<Employee> employeeList = employeeDao.getAll();
        model.addAttribute("employeeList",employeeList);
        return "employee_list";
    }


    @RequestMapping(value = "/employee",method = RequestMethod.POST)
    public String addEmployee(Employee employee){
        employeeDao.save(employee);
        return "redirect:/employee";
    }
}

8.具体功能：更新数据

employee_list.html：

<a th:href="@{|/employee/${employee.id}|}">update</a>

employee_update.html：

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>update employee</title>
</head>
<body>
<form th:action="@{/employee}" method="post">
    <input type="hidden" name="_method" value="put">
    <input type="hidden" name="id" th:value="${employee.id}">
    lastName：<input type="text" name="lastName" th:value="${employee.lastName}"><br>
    email：<input type="text" name="email" th:value="${employee.email}"><br>
    gender：<input type="radio" name="gender" value="1" th:field="${employee.gender}">male<br>
    <input type="radio" name="gender" value="0" th:field="${employee.gender}">female<br>
    <input type="submit" value="update"><br>
</form>
</body>
</html>

回显数据：

package com.qcby.rest.controller;

import com.qcby.rest.bean.Employee;
import com.qcby.rest.dao.EmployeeDao;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.*;

import java.util.Collection;

@Controller
public class EmployeeController {
    @Autowired
    private EmployeeDao employeeDao;


    @RequestMapping(value = "/employee/{id}",method = RequestMethod.GET)
    public String getEmployeeById(@PathVariable("id") Integer id,Model model){
        Employee employee = employeeDao.get(id);
        model.addAttribute("employee",employee);
        return "employee_update";

    }
}

package com.qcby.rest.controller;

import com.qcby.rest.bean.Employee;
import com.qcby.rest.dao.EmployeeDao;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.*;

import java.util.Collection;

@Controller
public class EmployeeController {
    @Autowired
    private EmployeeDao employeeDao;

    @RequestMapping(value = "/employee")
    public String getEmployee(Model model){
        Collection<Employee> employeeList = employeeDao.getAll();
        model.addAttribute("employeeList",employeeList);
        return "employee_list";
    }

    @RequestMapping(value = "/employee",method = RequestMethod.PUT)
    public String updateEmployee(Employee employee){
        employeeDao.save(employee);
        return "redirect:/employee";
    }
}

标签：springframework,id,org,employee,import,RESTful,public,SpringMVC7
From： https://blog.csdn.net/m0_73902080/article/details/143188967

RESTful简介

资源

资源的表述

状态转移

RESTful的实现

案例

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