1、RESTFul
1、RESTful简介
2、RESTful的实现
3、HiddenHttpMethodFilter
l2、RESTful案例
1、准备工作
2、功能清单
3、具体功能:访问首页
4、具体功能:查询所有员工数据
5、具体功能:删除
6、具体功能:跳转到添加数据页面
7、具体功能:执行保存
8、具体功能:跳转到更新数据页面
9、具体功能:执行更新
web.xml存在的两个位置:
在tomcat服务器中的web.xml针对服务器中所有项目。
JspServlet、DefaultServlet
在每个项目中的web.xml只针对该项目有效。
当url-pattern冲突时,以就近原则即当前项目优先,即先通过DispatcherServlet处理。DispatcherServlet处理不了时,交给DefaultServlet处理,DefaultServlet处理不了时报404。
前提是有两个标签
<mvc:default-servlet-handler/>
<mvc:annotation-driven>
REST:Representational State Transfer,表现层资源状态转移。
a>资源
b>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。
c>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。
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 |
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-4.1.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-4.1.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc-4.1.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-4.1.xsd">
<context:component-scan base-package="com.crane.mvc.controller"></context:component-scan>
<!-- 配置Thymeleaf视图解析器 -->
<bean id="viewResolver" class="org.thymeleaf.spring5.view.ThymeleafViewResolver">
<!-- 视图解析器优先级 -->
<property name="order" value="1"/>
<property name="characterEncoding" value="UTF-8"/>
<property name="templateEngine">
<bean class="org.thymeleaf.spring5.SpringTemplateEngine">
<property name="templateResolver">
<bean class="org.thymeleaf.spring5.templateresolver.SpringResourceTemplateResolver">
<!-- 视图前缀 -->
<property name="prefix" value="/WEB-INF/templates/"/>
<!-- 视图后缀 -->
<property name="suffix" value=".html"/>
<property name="templateMode" value="HTML5"/>
<property name="characterEncoding" value="UTF-8" />
</bean>
</property>
</bean>
</property>
</bean>
<mvc:view-controller path="/" view-name="index"/>
<mvc:view-controller path="/test_rest" view-name="test_rest"/>
<!-- 开启mvc注解驱动 -->
<mvc:annotation-driven/>
</beans>
<!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>
<a th:href="@{/user/1}">根据用户id查询用户信息</a>
<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>
@Controller
public class UserController {
/**
* 使用restful,模拟用户资源增删改查
* /user GET 查询所有用户信息
* /user/1 GET 根据用户id查询用户信息
* /user POST 添加用户信息
* /user/1 DELETE 删除用户信息
* /user PUT 更新用户信息
*/
@RequestMapping(value = "/user", method = RequestMethod.GET)
public String getAllUser(){
System.out.println("查询所有用户信息");
return "success";
}
@RequestMapping(value = "/user/{id}", method = RequestMethod.GET)
public String getUserById(){
System.out.println("根据用户id查询用户信息");
return "success";
}
@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";
}
}
访问:http://localhost:8080/SpringMVC/test_rest
3、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:
a>当前请求的请求方式必须为post
b>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>
注意:
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);
SpringMVC.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-4.1.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-4.1.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc-4.1.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-4.1.xsd">
<context:component-scan base-package="com.crane.mvc.controller"></context:component-scan>
<!-- 配置Thymeleaf视图解析器 -->
<bean id="viewResolver" class="org.thymeleaf.spring5.view.ThymeleafViewResolver">
<!-- 视图解析器优先级 -->
<property name="order" value="1"/>
<property name="characterEncoding" value="UTF-8"/>
<property name="templateEngine">
<bean class="org.thymeleaf.spring5.SpringTemplateEngine">
<property name="templateResolver">
<bean class="org.thymeleaf.spring5.templateresolver.SpringResourceTemplateResolver">
<!-- 视图前缀 -->
<property name="prefix" value="/WEB-INF/templates/"/>
<!-- 视图后缀 -->
<property name="suffix" value=".html"/>
<property name="templateMode" value="HTML5"/>
<property name="characterEncoding" value="UTF-8" />
</bean>
</property>
</bean>
</property>
</bean>
<mvc:view-controller path="/" view-name="index"/>
<mvc:view-controller path="/test_rest" view-name="test_rest"/>
<!-- 开启mvc注解驱动 -->
<mvc:annotation-driven/>
</beans>
test_rest.xml
<!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>
@RequestMapping(value = "/user", method = RequestMethod.PUT)
public String updateUser(String username, String password){
System.out.println(" 更新用户信息:" + username + ":" + password);
return "success";
}
和传统 CRUD 一样,实现对员工信息的增删改查。
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() {
}
}
@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);
}
}
注意:删除是不能直接通过超链接访问,需要使用超链接控制表单使用_method来处理。
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 |
代码流程:
1、访问首页:http://localhost:8080/SpringMVC_war_exploded/
2、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>
<a th:href="@{/employee}">查看全部员工信息</a>
</body>
</html>
3、获取全部员工信息:经过controller获取信息逻辑、employee_list.html渲染数据视图,返回:
@Controller
public class EmployeeController {
@Autowired
private EmployeeDao employeeDao;
@GetMapping(value = "/employee")
public String getAllEmployee(Model model){
Collection<Employee> employeeList = employeeDao.getAll();
model.addAttribute("employeeList", employeeList);
return "employee_list";
}
}
4、视图employee_list.html
<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="UTF-8">
<title>Title</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="deleteEmployee" th:href="@{'/employee/' + ${employee.id}}">delete</a>
<!-- <a th:href="@{/employee/}+ ${employee.id}">delete</a>-->
<a href="">update</a>
</td>
</tr>
</table>
<!-- vue: 通过超链接控制表单提交 -->
<form id="deleteForm" method="post">
<input type="hidden" name="_method" value="delete">
</form>
<!-- 此时:点击删除的超链接时,会取消其默认行为,会提交表单,经过过滤器处理。 -->
<script type="text/javascript" th:src="@{/static/js/vue.js}"/>
<script type="text/javascript">
var vue = new Vue({
el:"#dataTable",
methods:{
deleteEmployee:function(event){
//根据id获取表单元素
var deleteEmployee = 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();
//取消超链接的默认行为
event.preventDefault();
}
}
});
</script>
</body>
</html>
5、删除:注意删除是不能直接通过删除超链接处理的,
需要在点击删除的超链接时,取消其默认的跳转行为,让其提交表单,然后在经过过滤器处理。
6、添加:请求添加----控制器----返回添加页面,表单请求添加---控制器----返回表单页面
<tr>
<th>id</th>
<th>lastname</th>
<th>email</th>
<th>gender</th>
<th>options(<a th:href="@{/toAdd}">add</a> )</th>
</tr>
<mvc:view-controller path="/toAdd" view-name="employee_add"/>
<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="UTF-8">
<title>Title</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">mail
<input type="radio" name="gender" value="0">femail<br/>
<input type="submit" value="add">
</form>
</body>
</html>
@GetMapping(value = "/employee")
public String getAllEmployee(Model model){
Collection<Employee> employeeList = employeeDao.getAll();
model.addAttribute("employeeList", employeeList);
return "employee_list";
}
<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="UTF-8">
<title>Title</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(<a th:href="@{/toAdd}">add</a> )</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="deleteEmployee" th:href="@{'/employee/' + ${employee.id}}">delete</a>
<!-- <a th:href="@{/employee/}+ ${employee.id}">delete</a>-->
<a href="">update</a>
</td>
</tr>
</table>
<!-- vue: 通过超链接控制表单提交 -->
<form id="deleteForm" method="post">
<input type="hidden" name="_method" value="delete">
</form>
<!-- 此时:点击删除的超链接时,会取消其默认行为,会提交表单,经过过滤器处理。 -->
<script type="text/javascript" th:src="@{/static/js/vue.js}"/>
<script type="text/javascript">
var vue = new Vue({
el:"#dataTable",
methods:{
deleteEmployee:function(event){
//根据id获取表单元素
var deleteEmployee = 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();
//取消超链接的默认行为
event.preventDefault();
}
}
});
</script>
</body>
</html>
6、修改:请求更新----控制器获取数据-----数据回显到update页面,更新页面提交请求----控制器----返回表单页面。
a>配置view-controller
<mvc:view-controller path="/" view-name="index"/>
b>创建页面
<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="UTF-8" >
<title>Title</title>
</head>
<body>
<h1>首页</h1>
<a th:href="@{/employee}">访问员工信息</a>
</body>
</html>
a>控制器方法
@RequestMapping(value = "/employee", method = RequestMethod.GET)
public String getEmployeeList(Model model){
Collection<Employee> employeeList = employeeDao.getAll();
model.addAttribute("employeeList", employeeList);
return "employee_list";
}
b>创建employee_list.html
<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="UTF-8">
<title>Employee Info</title>
<script type="text/javascript" th:src="@{/static/js/vue.js}"></script>
</head>
<body>
<table border="1" cellpadding="0" cellspacing="0" style="text-align: center;" id="dataTable">
<tr>
<th colspan="5">Employee Info</th>
</tr>
<tr>
<th>id</th>
<th>lastName</th>
<th>email</th>
<th>gender</th>
<th>options(<a th:href="@{/toAdd}">add</a>)</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="${employee.gender}"></td>
<td>
<a class="deleteA" @click="deleteEmployee" th:href="@{'/employee/'+${employee.id}}">delete</a>
<a th:href="@{'/employee/'+${employee.id}}">update</a>
</td>
</tr>
</table>
</body>
</html>
a>创建处理delete请求方式的表单
<!-- 作用:通过超链接控制表单的提交,将post请求转换为delete请求 -->
<form id="delete_form" method="post">
<!-- HiddenHttpMethodFilter要求:必须传输_method请求参数,并且值为最终的请求方式 -->
<input type="hidden" name="_method" value="delete"/>
</form>
b>删除超链接绑定点击事件
引入vue.js
<script type="text/javascript" th:src="@{/static/js/vue.js}"></script>
删除超链接
<a class="deleteA" @click="deleteEmployee" th:href="@{'/employee/'+${employee.id}}">delete</a>
通过vue处理点击事件
<script type="text/javascript">
var vue = new Vue({
el:"#dataTable",
methods:{
//event表示当前事件
deleteEmployee:function (event) {
//通过id获取表单标签
var delete_form = document.getElementById("delete_form");
//将触发事件的超链接的href属性为表单的action属性赋值
delete_form.action = event.target.href;
//提交表单
delete_form.submit();
//阻止超链接的默认跳转行为
event.preventDefault();
}
}
});
</script>
c>控制器方法
@RequestMapping(value = "/employee/{id}", method = RequestMethod.DELETE)
public String deleteEmployee(@PathVariable("id") Integer id){
employeeDao.delete(id);
return "redirect:/employee";
}
a>配置view-controller
<mvc:view-controller path="/toAdd" view-name="employee_add"></mvc:view-controller>
b>创建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
<input type="radio" name="gender" value="0">female<br>
<input type="submit" value="add"><br>
</form>
</body>
</html>
a>控制器方法
@RequestMapping(value = "/employee", method = RequestMethod.POST)
public String addEmployee(Employee employee){
employeeDao.save(employee);
return "redirect:/employee";
}
a>修改超链接
<a th:href="@{'/employee/'+${employee.id}}">update</a>
b>控制器方法
@RequestMapping(value = "/employee/{id}", method = RequestMethod.GET)
public String getEmployeeById(@PathVariable("id") Integer id, Model model){
Employee employee = employeeDao.get(id);
model.addAttribute("employee", employee);
return "employee_update";
}
c>创建employee_update.html
<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="UTF-8">
<title>Update Employee</title>
</head>
<body>
<form th:action="@{/employee}" method="post">
<input type="hidden" name="_method" value="put">
<input type="hidden" name="id" th:value="${employee.id}">
lastName:<input type="text" name="lastName" th:value="${employee.lastName}"><br>
email:<input type="text" name="email" th:value="${employee.email}"><br>
<!--
th:field="${employee.gender}"可用于单选框或复选框的回显
若单选框的value和employee.gender的值一致,则添加checked="checked"属性
-->
gender:<input type="radio" name="gender" value="1" th:field="${employee.gender}">male
<input type="radio" name="gender" value="0" th:field="${employee.gender}">female<br>
<input type="submit" value="update"><br>
</form>
</body>
</html>
a>控制器方法
@RequestMapping(value = "/employee", method = RequestMethod.PUT)
public String updateEmployee(Employee employee){
employeeDao.save(employee);
return "redirect:/employee";
}
版权说明 : 本文为转载文章, 版权归原作者所有 版权申明
原文链接 : https://blog.csdn.net/mingyuli/article/details/122678273
内容来源于网络,如有侵权,请联系作者删除!