1idea-new-project-spring initializr
2.選中web功能。然后next默認創建工程
3.所有 /webjars/** ，都去 classpath:/META-INF/resources/webjars/ 找資源；==
<!-- 引入jquery-webjar在訪問的時候只需要寫webjars下面資源的名稱即可 https://mvnrepository.com/artifact/org.webjars/jquery –>--> <dependency> <groupId>org.webjars</groupId> <artifactId>jquery</artifactId> <version>3.3.1</version> </dependency>
4."/**" 訪問當前項目的任何資源，都去（靜態資源的文件夾）找映射==
"classpath:/META-INF/resources/",
"classpath:/resources/",
"classpath:/static/",
"classpath:/public/"
"/"：當前項目的根路徑
5.模板引擎：使用SpringBoot推薦的Thymeleaf；
6.實現用戶登錄功能：
（1）html頁面的的form表單中設置action屬性：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包中新建一個logincontroller.java，並在類方法前添加@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)){ //登陸成功，防止表單重復提交，可以重定向到主頁 session.setAttribute("loginUser",username); return "dashboard"; }else{ //登陸失敗 map.put("msg","用戶名密碼錯誤"); return "login"; } } }
<input type="text" name="username" class="form-control" placeholder="Username" th:placeholder="#{login.username}" required="" autofocus="">
同理，密碼同樣處理
<input type="password" name="password" class="form-control" placeholder="Password" th:placeholder="#{login.password}" required="">
（4）禁用緩存后，頁面會實時生效，方便處理，在src/main/resources/application.properties中設置，頁面修改完成以后ctrl+f9：重新編譯
# 禁用緩存
spring.thymeleaf.cache=false
（5）實現顯示登錄錯誤信息效果，在如下處插入一個P標簽 <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> <!--判斷--> <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方法添加一個識圖解釋器:registry.addViewController("/main.html").setViewName("dashboard")
@Override public void addViewControllers(ViewControllerRegistry registry) { registry.addViewController("/").setViewName("login"); registry.addViewController("/index.html").setViewName("login"); //添加視圖解釋器 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，在登錄成功處進行重定向
@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)){ //登陸成功，防止表單重復提交，可以重定向到主頁 session.setAttribute("loginUser",username); return "redirect:/main.html"; }else{ //登陸失敗 map.put("msg","用戶名密碼錯誤"); return "login"; } }
（8）啟動瀏覽器，輸入http://localhost:8080/crud/ 進行登錄測試
7.添加用戶登錄攔截功能
（1）在src/main/java/com/azuma/springboot/controller/LoginController.java的login方法中添加一個session（上面已經添加過了）
session.setAttribute("loginUser",username);
（2）添加一個攔截器的類：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; /** * 登陸檢查， */ public class LoginHandlerInterceptor implements HandlerInterceptor { //目標方法執行之前 @Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception { Object user = request.getSession().getAttribute("loginUser"); if(user == null){ //未登陸，返回登陸頁面 request.setAttribute("msg","沒有權限請先登陸"); request.getRequestDispatcher("/index.html").forward(request,response); return false; }else{ //已登陸，放行請求 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）攔截器類寫好后要記得在src/main/java/com/azuma/springboot/config/MyMvcConfig.java中進行配置（注意在Spring 5.0 中，已經將 WebMvcConfigurerAdapter 抽象類加上 @Deprecated 注解 記為過時）所以src/main/java/com/azuma/springboot/config/MyMvcConfig.java中的WebMvcConfigurerAdapter被划掉了
解決方法：
spring5以上版本不建議使用，所以把原來的繼承 WebMvcConfigurerAdapter改為 public class CustomWebConigurer implements WebMvcConfigurer 可以實現相同的功能。 是1.8以后接口中可以不必實現接口的抽象方法才變化的。 WebMvcConfigurerAdapter 其實也是實現了 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可以來擴展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); //瀏覽器發送 /atguigu 請求來到 success registry.addViewController("/azuma").setViewName("success"); } //所有的WebMvcConfigurerAdapter組件都會一起起作用 @Bean //將組件注冊在容器 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"); } //注冊攔截器，配置過濾靜態資源 //靜態資源； *.css , *.js //SpringBoot已經做好了靜態資源映射 @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(); } }