第四章:(5)Web开发 之 Restful 实验


一、默认访问首页

  1、在 controller 中添加一个方法来进行映射处理

    @RequestMapping(value = {"/", "/index.html"}, method = RequestMethod.GET)
    public String login() {
        return "login";
    }

  2、在配置类中添加视图映射 view-controller

@Configuration
public class MyMvcConfig extends WebMvcConfigurerAdapter {

    @Override
    public void addViewControllers(ViewControllerRegistry registry) {
        // super.addViewControllers(registry);
        //浏览器发送 /njf 请求来到 success
        registry.addViewController("/njf").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 WebMvcConfigurerAdapter webMvcConfigurerAdapter(){
        WebMvcConfigurerAdapter adapter = new WebMvcConfigurerAdapter() {
            @Override
            public void addViewControllers(ViewControllerRegistry registry) {
                registry.addViewController("/").setViewName("login");
                registry.addViewController("/index.html").setViewName("login");
            }
        };
        return adapter;
    }

}

二、国际化

  SpringMVC 国际化:

  (1)编写国际化配置文件;

  (2)使用ResourceBundleMessageSource管理国际化资源文件;

  (3)在页面使用fmt:message取出国际化内容;

  1、编写国际化配置文件,编写国际化配置文件,抽取页面需要显示的国际化消息

    login.properties

login.btn=登陆
login.password=密码
login.remember=记住我
login.tip=请登陆
login.username=用户名

   login_zh_CN.properties

login.btn=登陆
login.password=密码
login.remember=记住我
login.tip=请登陆
login.username=用户名

   login_en_US.properties

login.btn=Sign in
login.password=Password
login.remember=Remember me
login.tip=Please sign in
login.username=Username

  2、SpringBoot自动配置好了管理国际化资源文件的组件;

@ConfigurationProperties(prefix = "spring.messages")
public class MessageSourceAutoConfiguration {
    
    /**
     * Comma-separated list of basenames (essentially a fully-qualified classpath
     * location), each following the ResourceBundle convention with relaxed support for
     * slash based locations. If it doesn't contain a package qualifier (such as
     * "org.mypackage"), it will be resolved from the classpath root.
     */
    private String basename = "messages";  
    //我们的配置文件可以直接放在类路径下叫 messages.properties;
    
    @Bean
    public MessageSource messageSource() {
        ResourceBundleMessageSource messageSource = new ResourceBundleMessageSource();
        if (StringUtils.hasText(this.basename)) {
            //设置国际化资源文件的基础名(去掉语言国家代码的)
            messageSource.setBasenames(StringUtils.commaDelimitedListToStringArray(
                    StringUtils.trimAllWhitespace(this.basename)));
        }
        if (this.encoding != null) {
            messageSource.setDefaultEncoding(this.encoding.name());
        }
        messageSource.setFallbackToSystemLocale(this.fallbackToSystemLocale);
        messageSource.setCacheSeconds(this.cacheSeconds);
        messageSource.setAlwaysUseMessageFormat(this.alwaysUseMessageFormat);
        return messageSource;
    }
}

    去配置文件中指定basename:

#https://blog.csdn.net/weixin_44606513/article/details/105962383
spring.messages.basename=i18n/login

  3、去页面获取国际化的值;

DOCTYPE html>
<html lang="en"  xmlns:th="http://www.thymeleaf.org">
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
        <meta name="description" content="">
        <meta name="author" content="">
        <title>Signin Template for Bootstraptitle>
        
        <link href="asserts/css/bootstrap.min.css" th:href="@{/webjars/bootstrap/4.0.0/css/bootstrap.css}" rel="stylesheet">
        
        <link href="asserts/css/signin.css" th:href="@{/asserts/css/signin.css}" rel="stylesheet">
    head>

    <body class="text-center">
        <form class="form-signin" action="dashboard.html">
            <img class="mb-4" th:src="@{/asserts/img/bootstrap-solid.svg}" src="asserts/img/bootstrap-solid.svg" alt="" width="72" height="72">
            <h1 class="h3 mb-3 font-weight-normal" th:text="#{login.tip}">Please sign inh1>
            <label class="sr-only" th:text="#{login.username}">Usernamelabel>
            <input type="text" class="form-control" placeholder="Username" th:placeholder="#{login.username}" required="" autofocus="">
            <label class="sr-only" th:text="#{login.password}">Passwordlabel>
            <input type="password" class="form-control" placeholder="Password" th:placeholder="#{login.password}" required="">
            <div class="checkbox mb-3">
                <label>
                  <input type="checkbox" value="remember-me"/> [[#{login.remember}]]
        label>
            div>
            <button class="btn btn-lg btn-primary btn-block" type="submit" th:text="#{login.btn}">Sign inbutton>
            <p class="mt-5 mb-3 text-muted">? 2017-2018p>
            <a class="btn btn-sm">中文a>
            <a class="btn btn-sm">Englisha>
        form>

    body>

html>

    效果:根据浏览器语言设置的信息切换了国际化;

    原理:国际化Locale(区域信息对象);LocaleResolver(获取区域信息对象);

        @Bean
        @ConditionalOnMissingBean
        @ConditionalOnProperty(prefix = "spring.mvc", name = "locale")
        public LocaleResolver localeResolver() {
            if (this.mvcProperties
                    .getLocaleResolver() == WebMvcProperties.LocaleResolver.FIXED) {
                return new FixedLocaleResolver(this.mvcProperties.getLocale());
            }
             //默认的就是根据请求头带来的区域信息获取Locale进行国际化
            AcceptHeaderLocaleResolver localeResolver = new AcceptHeaderLocaleResolver();
            localeResolver.setDefaultLocale(this.mvcProperties.getLocale());
            return localeResolver;
        }

  4、点击链接切换国际化

    通过页面传递参数:

<a class="btn btn-sm" th:href="@{/index.html(l='zh_CN')}">中文a>
<a class="btn btn-sm" th:href="@{/index.html(l='en_US')}">Englisha>

    自定义一个国际化解析器,并加入到容器中:

/**
 * 可以在连接上携带区域信息
 */
public class MyLocaleResolver implements LocaleResolver {
    
    @Override
    public Locale resolveLocale(HttpServletRequest request) {
        String l = request.getParameter("l");
        Locale locale = Locale.getDefault();
        if(!StringUtils.isEmpty(l)){
            String[] split = l.split("_");
            locale = new Locale(split[0],split[1]);
        }
        return locale;
    }

    @Override
    public void setLocale(HttpServletRequest request, HttpServletResponse response, Locale locale) {

    }
}

//自定义区域化解析器
@Bean
public LocaleResolver localeResolver(){
  return new MyLocaleResolver();
}

三、登录

  1、登录表单

    <form class="form-signin" action="dashboard.html" th:action="@{/user/login}" method="post">
            <img class="mb-4" th:src="@{/asserts/img/bootstrap-solid.svg}" src="asserts/img/bootstrap-solid.svg" alt="" width="72" height="72">
            <h1 class="h3 mb-3 font-weight-normal" th:text="#{login.tip}">Please sign inh1>
            
            <p style="color: red" th:text="${msg}" th:if="${not #strings.isEmpty(msg)}">p>
            <label class="sr-only" th:text="#{login.username}">Usernamelabel>
            <input type="text" class="form-control" name="username" th:placeholder="#{login.username}" placeholder="Username" required="" autofocus="">
            <label class="sr-only" th:text="#{login.password}">Passwordlabel>
            <input type="password" class="form-control" name="password" th:placeholder="#{login.password}" placeholder="Password" required="">
            <div class="checkbox mb-3">
                <label>
            <input type="checkbox" value="remember-me"> [[#{login.remember}]]
        label>
            div>
            <button class="btn btn-lg btn-primary btn-block" type="submit" th:text="#{login.btn}">Sign inbutton>
            <p class="mt-5 mb-3 text-muted">? 2017-2018p>
            <a class="btn btn-sm" th:href="@{/index.html(l='zh_CN')}">中文a>
            <a class="btn btn-sm" th:href="@{/index.html(l='en_US')}">Englisha>
        form>

  2、登录的控制器

@Controller
public class LoginController {


    //@RequestMapping(value = "/user/login", method = RequestMethod.POST)
    @PostMapping(value = "/user/login")
    public String login(@RequestParam("username") String username,
                        @RequestParam("password") String password,
                        Map map) {

        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
            return "redirect:/main.html";
        } else {
            //登陆失败
            map.put("msg", "用户名或密码错误!");
            return "login";
        }
    }
}

    添加到主页的视图映射

@Configuration
public class MyMvcConfig extends WebMvcConfigurerAdapter {

    @Override
    public void addViewControllers(ViewControllerRegistry registry) {
        // super.addViewControllers(registry);
        //浏览器发送 /njf 请求来到 success
        registry.addViewController("/njf").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 WebMvcConfigurerAdapter webMvcConfigurerAdapter(){
        WebMvcConfigurerAdapter adapter = new WebMvcConfigurerAdapter() {
            @Override
            public void addViewControllers(ViewControllerRegistry registry) {
                registry.addViewController("/").setViewName("login");
                registry.addViewController("/index.html").setViewName("login");
                registry.addViewController("/main.html").setViewName("dashboard");
            }
        };
        return adapter;
    }
}

  3、禁用模板引擎的缓存

# 禁用缓存
spring.thymeleaf.cache=false 

  4、登陆错误消息的显示

四、拦截器进行登陆检查

  1、修改登录控制器方法

@Controller
public class LoginController {


    //@RequestMapping(value = "/user/login", method = RequestMethod.POST)
    @PostMapping(value = "/user/login")
    public String login(@RequestParam("username") String username,
                        @RequestParam("password") String password,
                        Map map, HttpSession session) {

        if (!StringUtils.isEmpty(username) && "123456".equals(password)) {
            session.setAttribute("loginUser", username);
            //登陆成功,防止表单重复提交,可以重定向到主页
            return "redirect:/main.html";
        } else {
            //登陆失败
            map.put("msg", "用户名或密码错误!");
            return "login";
        }
    }
}

  2、新增登录拦截器

/**
 * 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 loginUser = request.getSession().getAttribute("loginUser");
        if (loginUser == null) {
            //未登录,返回登陆页面
            //转发到登录页面
            request.setAttribute("msg", "没有权限请先登录");
            request.getRequestDispatcher("/").forward(request, response);
            return false;
        } else {
            //已登录,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、把拦截器添加到容器中

@Configuration
public class MyMvcConfig extends WebMvcConfigurerAdapter {

    @Override
    public void addViewControllers(ViewControllerRegistry registry) {
        // super.addViewControllers(registry);
        //浏览器发送 /njf 请求来到 success
        registry.addViewController("/njf").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 WebMvcConfigurerAdapter webMvcConfigurerAdapter(){
        WebMvcConfigurerAdapter adapter = new WebMvcConfigurerAdapter() {
            @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
            @Override
            public void addInterceptors(InterceptorRegistry registry) {
                //super.addInterceptors(registry);
                //静态资源;  *.css , *.js
                //SpringBoot已经做好了静态资源映射
                registry.addInterceptor(new LoginHandlerInterceptor()).addPathPatterns("/**")
                        .excludePathPatterns("/index.html", "/", "/user/login");
            }
        };

        return adapter;
    }

    //区域化解析器
    @Bean
    public LocaleResolver localeResolver(){
        return new MyLocaleResolver();
    }


}

五、

六、