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SpringBoot (五) -crud 国际化 拦截器 thymeleaf公共页面元素抽取

2019-05-17 12:38 726 查看
版权声明:转载请注明出处! https://blog.csdn.net/xiaowei0548/article/details/90291064

5、如何修改SpringBoot的默认配置

模式:

​ 1)、SpringBoot在自动配置很多组件的时候,先看容器中有没有用户自己配置的(@Bean、@Component)如果有就用用户配置的,如果没有,才自动配置;如果有些组件可以有多个(ViewResolver)将用户配置的和自己默认的组合起来;

​ 2)、在SpringBoot中会有非常多的xxxConfigurer帮助我们进行扩展配置

​ 3)、在SpringBoot中会有很多的xxxCustomizer帮助我们进行定制配置

6、RestfulCRUD

1)、默认访问首页

//使用WebMvcConfigurerAdapter可以来扩展SpringMVC的功能
//@EnableWebMvc   不要接管SpringMVC
@Configuration
public class MyMvcConfig extends WebMvcConfigurerAdapter {

@Override
public void addViewControllers(ViewControllerRegistry registry) {
// super.addViewControllers(registry);
//浏览器发送 /atguigu 请求来到 success
registry.addViewController("/atguigu").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;
}
}

2)、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

步骤:

1)、编写国际化配置文件,抽取页面需要显示的国际化消息

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;
}

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 Bootstrap</title>
<!-- Bootstrap core CSS -->
<link href="asserts/css/bootstrap.min.css" th:href="@{/webjars/bootstrap/4.0.0/css/bootstrap.css}" rel="stylesheet">
<!-- Custom styles for this template -->
<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 in</h1>
<label class="sr-only" th:text="#{login.username}">Username</label>
<input type="text" class="form-control" placeholder="Username" th:placeholder="#{login.username}" required="" autofocus="">
<label class="sr-only" th:text="#{login.password}">Password</label>
<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 in</button>
<p class="mt-5 mb-3 text-muted">© 2017-2018</p>
<a class="btn btn-sm">中文</a>
<a class="btn btn-sm">English</a>
</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());
}
AcceptHeaderLocaleResolver localeResolver = new AcceptHeaderLocaleResolver();
localeResolver.setDefaultLocale(this.mvcProperties.getLocale());
return localeResolver;
}
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

4)、点击链接切换国际化

/**
* 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) {

}
}

@Bean
public LocaleResolver localeResolver(){
return new MyLocaleResolver();
}
}
### 3)、登陆

开发期间模板引擎页面修改以后,要实时生效

1)、禁用模板引擎的缓存

禁用缓存

spring.thymeleaf.cache=false

2)、页面修改完成以后ctrl+f9:重新编译;

登陆错误消息的显示

```html
<p style="color: red" th:text="${msg}" th:if="${not #strings.isEmpty(msg)}"></p>

4)、拦截器进行登陆检查

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 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 {

}
}

注册拦截器

//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;
}

5)、CRUD-员工列表

实验要求:

1)、RestfulCRUD:CRUD满足Rest风格;

URI: /资源名称/资源标识 HTTP请求方式区分对资源CRUD操作

普通CRUD(uri来区分操作) RestfulCRUD
查询 getEmp emp—GET
添加 addEmp?xxx emp—POST
修改 updateEmp?id=xxx&xxx=xx emp/{id}—PUT
删除 deleteEmp?id=1 emp/{id}—DELETE

2)、实验的请求架构;

实验功能 请求URI 请求方式
查询所有员工 emps GET
查询某个员工(来到修改页面) emp/1 GET
来到添加页面 emp GET
添加员工 emp POST
来到修改页面(查出员工进行信息回显) emp/1 GET
修改员工 emp PUT
删除员工 emp/1 DELETE

3)、员工列表:

thymeleaf公共页面元素抽取

1、抽取公共片段
<div th:fragment="copy">
&copy; 2011 The Good Thymes Virtual Grocery
</div>

2、引入公共片段
<div th:insert="~{footer :: copy}"></div>
~{templatename::selector}:模板名::选择器
~{templatename::fragmentname}:模板名::片段名

3、默认效果:
insert的公共片段在div标签中
如果使用th:insert等属性进行引入,可以不用写~{}:
行内写法可以加上:[[~{}]];[(~{})];

三种引入公共片段的th属性:

th:insert:将公共片段整个插入到声明引入的元素中

th:replace:将声明引入的元素替换为公共片段

th:include:将被引入的片段的内容包含进这个标签中

<footer th:fragment="copy">
&copy; 2011 The Good Thymes Virtual Grocery
</footer>

引入方式
<div th:insert="footer :: copy"></div>
<div th:replace="footer :: copy"></div>
<div th:include="footer :: copy"></div>

效果
<div>
<footer>
&copy; 2011 The Good Thymes Virtual Grocery
</footer>
</div>

<footer>
&copy; 2011 The Good Thymes Virtual Grocery
</footer>

<div>
&copy; 2011 The Good Thymes Virtual Grocery
</div>

引入片段的时候传入参数:

<nav class="col-md-2 d-none d-md-block bg-light sidebar" id="sidebar">
<div class="sidebar-sticky">
<ul class="nav flex-column">
<li class="nav-item">
<a class="nav-link active"
th:class="${activeUri=='main.html'?'nav-link active':'nav-link'}"
href="#" th:href="@{/main.html}">
<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="feather feather-home">
<path d="M3 9l9-7 9 7v11a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2z"></path>
<polyline points="9 22 9 12 15 12 15 22"></polyline>
</svg>
Dashboard <span class="sr-only">(current)</span>
</a>
</li>

<!--引入侧边栏;传入参数-->
<div th:replace="commons/bar::#sidebar(activeUri='emps')"></div>
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