RESTful风格
（一）什么是RESTful
（1）RESTful不是一套标准，只是一套开发方式，构架思想
（2）url更加简洁
（3）有利于不同系统之间的资源共享
（二）概述
RESTful具体来讲就是HTTP协议的四种形式，四种基本操作
GET:获取资源
POST：新建资源
PUT：修改资源
DELETE：删除资源
（三）实例
（1）功能
1.数据的增删改查
2.controller层的应用
3.HTTP四种基本操作的应用
（2）代码实现
1.pom.xml
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.11</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>5.1.3.RELEASE</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jstl</artifactId>
<version>1.2</version>
</dependency>
</dependencies>
2.web.xml
<web-app>
<display-name>Archetype Created Web Application</display-name>
<servlet>
<servlet-name>SpringMVC</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:springmvc.xml</param-value>
</init-param>
</servlet>
<servlet-mapping>
<servlet-name>SpringMVC</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
<!--过滤器，将请求转换为标准的http方法，使得支持GET,POST,PUT,DELETE请求-->
<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>
</web-app>
3.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:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
<!--包扫描-->
<context:component-scan base-package="controller,dao"></context:component-scan>
<!--视图解析器-->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<!--前缀-->
<property name="prefix" value="/"></property>
<!--后缀-->
<property name="suffix" value=".jsp"></property>
</bean>
</beans>
4.User.java
package entiry;
public class User {
private int id;
private String name;
private String password;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
@Override
public String toString() {
return "User{" +
"id=" + id +
", name='" + name + '\'' +
", password='" + password + '\'' +
'}';
}
}
5.UserDao.java
package dao;
import entiry.User;
import org.springframework.stereotype.Repository;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
@Repository
public class UserDao {
private Map<Integer, User> map=new HashMap<Integer, User>();
/**
* 增加
* @param user
*/
public void add(User user){
map.put(user.getId(),user);
}
/**
* 查询所有
* @return
*/
public Collection<User> selectAll(){
return map.values();
}
/**
* 通过id查询
* @param id
* @return
*/
public User select(int id){
return map.get(id);
}
/**
* 修改
* @param user
*/
public void update(User user){
map.put(user.getId(),user);
}
/**
* 删除
* @param id
*/
public void delete(int id){
map.remove(id);
}
}
6.UserController.java
package controller;
import dao.UserDao;
import entiry.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.servlet.ModelAndView;
@Controller
public class UserController {
@Autowired
private UserDao userDao;
@PostMapping("/add")
public String add(User user){
userDao.add(user);
//重定向到selectAll
return "redirect:/selectAll";
}
@GetMapping("/selectAll")
public ModelAndView selectAll(){
ModelAndView modelAndView=new ModelAndView();
modelAndView.addObject("users",userDao.selectAll());
modelAndView.setViewName("select");
for(User user:userDao.selectAll()){
System.out.println(user);
}
return modelAndView;
}
@GetMapping("/select/{id}")
public ModelAndView select(@PathVariable(value="id") int id){
ModelAndView modelAndView=new ModelAndView();
modelAndView.setViewName("update");
modelAndView.addObject("user",userDao.select(id));
return modelAndView;
}
@PutMapping("/update")
public String update(User user){
userDao.update(user);
return "redirect:/selectAll";
}
@DeleteMapping("/delete/{id}")
public String delete(@PathVariable(value="id")int id){
userDao.delete(id);
return "redirect:/selectAll";
}
}
7.add.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<form action="${pageContext.request.contextPath}/add" method="post">
id:<input type="text" name="id"><br>
用户名：<input type="text" name="name"><br>
密码：<input type="text" name="password"><br>
<input type="submit">
</form>
</body>
</html>
8.select.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@page isELIgnored="false" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<html>
<head>
<title>Title</title>
</head>
<body>
<table>
<tr>
<td>id</td>
<td>用户名</td>
<td>密码</td>
<td></td>
<td></td>
</tr>
<c:forEach items="${users}" var="user">
<tr>
<td>${user.id}</td>
<td>${user.name}</td>
<td>${user.password}</td>
<td>
<form action="${pageContext.request.contextPath}/select/${user.id}"method="get">
<button type="submit">修改</button>
</form>
</td>
<td>
<form action="${pageContext.request.contextPath}/delete/${user.id}" method="post">
<!--将请求的方式设为DELETE-->
<input type="hidden" name="_method" value="DELETE">
<button type="submit" >删除</button>
</form>
</td>
</tr>
</c:forEach>
</table>
</body>
</html>
9.update.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<form action="${pageContext.request.contextPath}/update" method="post">
<table>
<tr>
<td>id</td>
<td><input type="text" name="id" value="${user.id}" readonly="readonly"></td>
</tr>
<tr>
<td>用户名</td>
<td><input type="text" name="name" value="${user.name}"></td>
</tr>
<tr>
<td>密码</td>
<td><input type="text" name="password" value="${user.password}"></td>
</tr>
</table>
<!--将请求的方式设为PUT-->
<input type="hidden" name="_method" value="PUT">
<input type="submit">
</form>
</body>
</html>