1idea-new-project-spring initializr
2.选中web功能。然后next默认创建工程
所有 /webjars/** ,都去 classpath:/META-INF/resources/webjars/ 找资源;==webjars:以jar包的方式引入静态资源(可能复制的代码格式有问题导致pom报错,出现这种情况建议官网直接复制相关代码即可)
<!-- 引入jquery-webjar在访问的时候只需要写webjars下面资源的名称即可
https://mvnrepository.com/artifact/org.webjars/jquery –>-->
<dependency>
<groupId>org.webjars</groupId>
<artifactId>jquery</artifactId>
<version>3.3.1</version>
</dependency>
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4."/**" 访问当前项目的任何资源,都去(静态资源的文件夹)找映射==
"classpath:/META-INF/resources/",
"classpath:/resources/",
"classpath:/static/",
"classpath:/public/"
"/":当前项目的根路径
5.模板引擎:使用SpringBoot推荐的Thymeleaf;
6.实现用户登录功能:
(1)html页面的的form表单中设置action属性:例如:<form class="form-signin" action="dashboard.html" th:action="@{/user/login}" method="post"> 中的 th:action="@{/user/login}"
<form class="form-signin" action="dashboard.html" th:action="@{/user/login}" method="post">
(2)在controller包中新建一个logincontroller.java,并在类方法前添加@Controller注解
import org.springframework.stereotype.Controller;
import org.springframework.util.StringUtils;
import org.springframework.web.bind.annotation.*;
import javax.servlet.http.HttpSession;
import java.util.Map;
@Controller
public class LoginController {
// @DeleteMapping
// @PutMapping
// @GetMapping
//@RequestMapping(value = "/user/login",method = RequestMethod.POST)
@PostMapping(value = "/user/login")
public String login(@RequestParam("username") String username,
@RequestParam("password") String password,
Map<String,Object> map, HttpSession session){
if(!StringUtils.isEmpty(username) && "123456".equals(password)){
//登陆成功,防止表单重复提交,可以重定向到主页
session.setAttribute("loginUser",username);
return "dashboard";
}else{
//登陆失败
map.put("msg","用户名密码错误");
return "login";
}
}
}
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(3)如果登录显示400错误:HTML中的用户名input出中的name属性没写:如下照片的:name="username"
<input type="text" name="username" class="form-control" placeholder="Username" th:placeholder="#{login.username}" required="" autofocus="">
同理,密码同样处理
<input type="password" name="password" class="form-control" placeholder="Password" th:placeholder="#{login.password}" required="">
(4)禁用缓存后,页面会实时生效,方便处理,在src/main/resources/application.properties中设置,页面修改完成以后ctrl+f9:重新编译
# 禁用缓存
spring.thymeleaf.cache=false
(5)实现显示登录错误信息效果,在如下处插入一个P标签 <p style="color: red" th:text="${msg}" th:if="${not #strings.isEmpty(msg)}"></p>
<h1 class="h3 mb-3 font-weight-normal" th:text="#{login.tip}">Please sign in</h1>
<!--判断-->
<p style="color: red" th:text="${msg}" th:if="${not #strings.isEmpty(msg)}"></p>
<label class="sr-only" th:text="#{login.username}">Username</label>
(6)重定向的使用,在 src/main/java/com/azuma/springboot/config/MyMvcConfig.java中的addViewControllers方法添加一个识图解释器:registry.addViewController("/main.html").setViewName("dashboard")
@Override
public void addViewControllers(ViewControllerRegistry registry) {
registry.addViewController("/").setViewName("login");
registry.addViewController("/index.html").setViewName("login");
//添加视图解释器
registry.addViewController("/main.html").setViewName("dashboard");
}
(7)然后在src/main/java/com/azuma/springboot/controller/LoginController.java中的login方法中,在登录成功处进行重定向
@PostMapping(value = "/user/login")
public String login(@RequestParam("username") String username,
@RequestParam("password") String password,
Map<String,Object> map, HttpSession session){
if(!StringUtils.isEmpty(username) && "123456".equals(password)){
//登陆成功,防止表单重复提交,可以重定向到主页
session.setAttribute("loginUser",username);
return "redirect:/main.html";
}else{
//登陆失败
map.put("msg","用户名密码错误");
return "login";
}
}
(8)启动浏览器,输入http://localhost:8080/crud/ 进行登录测试
7.添加用户登录拦截功能
(1)在src/main/java/com/azuma/springboot/controller/LoginController.java的login方法中添加一个session(上面已经添加过了)
session.setAttribute("loginUser",username);
(2)添加一个拦截器的类:src/main/java/com/azuma/springboot/component/LoginHandlerInterceptor.java
package com.azuma.springboot.component;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* 登陆检查,
*/
public class LoginHandlerInterceptor implements HandlerInterceptor {
//目标方法执行之前
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
Object user = request.getSession().getAttribute("loginUser");
if(user == null){
//未登陆,返回登陆页面
request.setAttribute("msg","没有权限请先登陆");
request.getRequestDispatcher("/index.html").forward(request,response);
return false;
}else{
//已登陆,放行请求
return true;
}
}
@Override
public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
}
@Override
public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
}
}
(3)拦截器类写好后要记得在src/main/java/com/azuma/springboot/config/MyMvcConfig.java中进行配置(注意在Spring 5.0 中,已经将 WebMvcConfigurerAdapter 抽象类加上 @Deprecated 注解 记为过时)所以src/main/java/com/azuma/springboot/config/MyMvcConfig.java中的WebMvcConfigurerAdapter被划掉了
解决方法:
spring5以上版本不建议使用,所以把原来的继承 WebMvcConfigurerAdapter改为
public class CustomWebConigurer implements WebMvcConfigurer
可以实现相同的功能。
是1.8以后接口中可以不必实现接口的抽象方法才变化的。
WebMvcConfigurerAdapter 其实也是实现了 WebMvcConfigurer接口的
(4)由上可知,修改:src/main/java/com/azuma/springboot/config/MyMvcConfig.java中的extend WebMvcConfigurerAdapter修改成implements WebMvcConfigurer
package com.azuma.springboot.config;
import com.azuma.springboot.component.LoginHandlerInterceptor;
import com.azuma.springboot.component.MyLocaleResolver;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.LocaleResolver;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.ViewControllerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
//使用WebMvcConfigurerAdapter可以来扩展SpringMVC的功能
//@EnableWebMvc 不要接管SpringMVC
@Configuration
public class MyMvcConfig implements WebMvcConfigurer {
@Override
public void addViewControllers(ViewControllerRegistry registry) {
// super.addViewControllers(registry);
//浏览器发送 /atguigu 请求来到 success
registry.addViewController("/azuma").setViewName("success");
}
//所有的WebMvcConfigurerAdapter组件都会一起起作用
@Bean //将组件注册在容器
public WebMvcConfigurer WebMvcConfigurer(){
WebMvcConfigurer adapter = new WebMvcConfigurer() {
@Override
public void addViewControllers(ViewControllerRegistry registry) {
registry.addViewController("/").setViewName("login");
registry.addViewController("/index.html").setViewName("login");
registry.addViewController("/main.html").setViewName("dashboard");
}
//注册拦截器,配置过滤静态资源
//静态资源; *.css , *.js
//SpringBoot已经做好了静态资源映射
@Override
public void addInterceptors(InterceptorRegistry registry) {
registry.addInterceptor(new LoginHandlerInterceptor())
.addPathPatterns("/**")
.excludePathPatterns("/index.html","/","/user/login","/static/**", "/webjars/**", "/asserts/**");
}
};
return adapter;
}
@Bean
public LocaleResolver localeResolver(){
return new MyLocaleResolver();
}
}