1.创建一个web模块
(1).创建SpringBoot应用，选中我们需要的模块；
(2).SpringBoot已经默认将这些场景配置好了，只需要在配置文件中指定少量配置就可以运行起来
(3).自己编写业务代码；
自动配置原理
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xxxxAutoConfiguration：帮我们给容器中自动配置组件； xxxxProperties:配置类来封装配置文件的内容； |
2.SpringBoott对静态资源的映射规则
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@ConfigurationProperties(prefix = "spring.resources",ignoreUnknownFields = false) public class ResourceProperties implements ResourceLoaderAware { //可以设置和静态资源有关的参数，缓存时间等 |
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WebMvcAuotConfiguration： @Override public void addResourceHandlers(ResourceHandlerRegistry registry) { if (!this.resourceProperties.isAddMappings()) { logger.debug("Default resource handling disabled"); return; } Integer cachePeriod = this.resourceProperties.getCachePeriod(); if (!registry.hasMappingForPattern("/webjars/**")) { customizeResourceHandlerRegistration( registry.addResourceHandler("/webjars/**") .addResourceLocations( "classpath:/META-INF/resources/webjars/") .setCachePeriod(cachePeriod)); } String staticPathPattern = this.mvcProperties.getStaticPathPattern(); //静态资源文件夹映射 if (!registry.hasMappingForPattern(staticPathPattern)) { customizeResourceHandlerRegistration( registry.addResourceHandler(staticPathPattern) .addResourceLocations( this.resourceProperties.getStaticLocations()) .setCachePeriod(cachePeriod)); } }
//配置index映射 @Bean public WelcomePageHandlerMapping welcomePageHandlerMapping( ResourceProperties resourceProperties) { return new WelcomePageHandlerMapping(resourceProperties.getWelcomePage(), this.mvcProperties.getStaticPathPattern()); }
//配置图标 @Configuration @ConditionalOnProperty(value = "spring.mvc.favicon.enabled",matchIfMissing = true) public static class FaviconConfiguration {
private final ResourceProperties resourceProperties;
public FaviconConfiguration(ResourceProperties resourceProperties) { this.resourceProperties = resourceProperties; }
@Bean public SimpleUrlHandlerMapping faviconHandlerMapping() { SimpleUrlHandlerMapping mapping = new SimpleUrlHandlerMapping(); mapping.setOrder(Ordered.HIGHEST_PRECEDENCE + 1); //所有 **/favicon.ico mapping.setUrlMap(Collections.singletonMap("**/favicon.ico", faviconRequestHandler())); return mapping; }
@Bean public ResourceHttpRequestHandler faviconRequestHandler() { ResourceHttpRequestHandler requestHandler = new ResourceHttpRequestHandler(); requestHandler .setLocations(this.resourceProperties.getFaviconLocations()); return requestHandler; }
} |
(1). 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
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<!--引入jquery-webjar 在访问的时候只需要写webjars下面资源的名称即可 --> <dependency> <groupId>org.webjars</groupId> <artifactId>jquery</artifactId> <version>3.3.1</version> </dependency> |
访问：localhost:8080/webjars/jquery/3.3.1/jquery.js
(2)."/**" 访问当前项目的任何资源，到'静态资源文件夹'找映射
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"classpath:/META-INF/resources/", "classpath:/resources/", "classpath:/static/", "classpath:/public/" "/"：当前项目的根路径 |
访问：http://localhost:8080/asserts/js/Chart.min.js
localhost:8080/abc ---> 去静态资源文件夹里面找abc
(3).index页； 静态资源文件夹下的所有index.html页面；被"/**"映射；
访问:localhost:8080/
(4). 图标**/favicon.ico都在静态资源文件下找
3.模板引擎
JSP、Velocity、Freemarker、Thymeleaf
SpringBoot推荐使用的Thymeleaf,语法更简单，功能更强大.
(1).引入thymeleaf
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<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-thymeleaf</artifactId> <!--2.1.6--> </dependency> 切换thymeleaf版本 <properties> <thymeleaf.version>3.0.9.RELEASE</thymeleaf.version> <!-- 布局功能的支持程序 thymeleaf3主程序 layout2以上版本 --> <!-- thymeleaf2 layout1--> <thymeleaf-layout-dialect.version>2.2.2</thymeleaf-layout-dialect.version> </properties> |
(2).使用thymeleaf
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@ConfigurationProperties(prefix = "spring.thymeleaf") public class ThymeleafProperties {
private static final Charset DEFAULT_ENCODING = Charset.forName("UTF-8");
private static final MimeType DEFAULT_CONTENT_TYPE = MimeType.valueOf("text/html");
public static final String DEFAULT_PREFIX = "classpath:/templates/";
public static final String DEFAULT_SUFFIX = ".html"; // |
把HTML页面放在classpath:/templates/，thymeleaf就能自动渲染;
[1].添加名称空间
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xmlns:th="http://www.thymeleaf.org" |
[2].使用thymeleaf语法
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<!DOCTYPE html> <html lang="en" xmlns:th="http://www.thymeleaf.org"> <head> <meta charset="UTF-8"> <title>Title</title> </head> <body> <h1>成功！</h1> <!--th:text 将div里面的文本内容设置为 --> <div th:text="${hello}">这是显示欢迎信息</div> </body> </html> |
(3).thymeleaf语法
[1].th:text：改变当前元素里面的文本内容
th:任意html属性；来替换原生属性的值
[2].表达式
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Simple expressions:（表达式语法） Variable Expressions: ${...}：获取变量值；OGNL； 1）、获取对象的属性、调用方法 2）、使用内置的基本对象： #ctx : the context object. #vars: the context variables. #locale : the context locale. #request : (only in Web Contexts) the HttpServletRequest object. #response : (only in Web Contexts) the HttpServletResponse object. #session : (only in Web Contexts) the HttpSession object. #servletContext : (only in Web Contexts) the ServletContext object.
${session.foo} 3）、内置的一些工具对象： #execInfo : information about the template being processed. #messages : methods for obtaining externalized messages inside variables expressions,in the same way as they would be obtained using #{…} syntax. #uris : methods for escaping parts of URLs/URIs #conversions : methods for executing the configured conversion service (if any). #dates : methods for java.util.Date objects: formatting,component extraction,etc. #calendars : analogous to #dates,but for java.util.Calendar objects. #numbers : methods for formatting numeric objects. #strings : methods for String objects: contains,startsWith,prepending/appending,etc. #objects : methods for objects in general. #bools : methods for boolean evaluation. #arrays : methods for arrays. #lists : methods for lists. #sets : methods for sets. #maps : methods for maps. #aggregates : methods for creating aggregates on arrays or collections. #ids : methods for dealing with id attributes that might be repeated (for example,as a result of an iteration).
Selection Variable Expressions: *{...}：选择表达式：和${}在功能上是一样； 补充：配合 th:object="${session.user}： <div th:object="${session.user}"> <p>Name: <span th:text="*{firstName}">Sebastian</span>.</p> <p>Surname: <span th:text="*{lastName}">Pepper</span>.</p> <p>Nationality: <span th:text="*{nationality}">Saturn</span>.</p> </div>
Message Expressions: #{...}：获取国际化内容 Link URL Expressions: @{...}：定义URL； @{/order/process(execId=${execId},execType='FAST')} Fragment Expressions: ~{...}：片段引用表达式 <div th:insert="~{commons :: main}">...</div>
Literals（字面量） Text literals: 'one text','Another one!',… Number literals: 0,34,3.0,12.3,… Boolean literals: true,false Null literal: null Literal tokens: one,sometext,main,… Text operations:（文本操作） String concatenation: + Literal substitutions: |The name is ${name}| Arithmetic operations:（数学运算） Binary operators: +,-,*,/,% Minus sign (unary operator): - Boolean operations:（布尔运算） Binary operators: and,or Boolean negation (unary operator): !,not Comparisons and equality:（比较运算） Comparators: >,<,>=,<= ( gt,lt,ge,le ) Equality operators: ==,!= ( eq,ne ) Conditional operators:条件运算（三元运算符） If-then: (if) ? (then) If-then-else: (if) ? (then) : (else) Default: (value) ?: (defaultvalue) Special tokens: No-Operation: _ |
4.SpringMVC自动配置
(1).Spring MVC auto-configuration
Spring Boot 自动配置SpringMVC
SpringBoot对SpringMVC的默认配置(WebMvcAutoConfiguration)
Inclusion of ContentNegotiatingViewResolver and BeanNameViewResolver beans.
自动配置了ViewResolver（视图解析器：根据方法的返回值得到视图对象（View），视图对象决定如何渲染（转发？重定向？））
ContentNegotiatingViewResolver:组合所有的视图解析器的
如何定制：我们可以自己给容器中添加一个视图解析器；自动的将其组合进来；
Support for serving static resources,including support for WebJars (see below).
静态资源文件夹路径,webjars
Automatic registration of Converter, GenericConverter, Formatter beans.
Converter：转换器； public String hello(User user)：类型转换使用Converter
Formatter格式化器； 2017.12.17===Date；
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@Bean @ConditionalOnProperty(prefix = "spring.mvc",name = "date-format")//在文件中配置日期格式化的规则 public Formatter<Date> dateFormatter() { return new DateFormatter(this.mvcProperties.getDateFormat());//日期格式化组件 } |
自己添加的格式化器转换器，我们只需要放在容器中即可
Support for HttpMessageConverters (see below).
HttpMessageConverter：SpringMVC用来转换Http请求和响应的；User--->Json；
`HttpMessageConverters` 是从容器中确定；获取所有的HttpMessageConverter；
自己给容器中添加HttpMessageConverter，只需要将自己的组件注册容器中（@Bean,@Component）
Automatic registration of MessageCodesResolver (see below).
定义错误代码生成规则
Static index.html support.
静态首页访问
Custom Favicon support (see below).
自定义favicon.ico 图标
Automatic use of a ConfigurableWebBindingInitializer bean (see below).
我们可以配置一个ConfigurableWebBindingInitializer来替换默认的；（添加到容器）
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初始化WebDataBinder； 请求数据=====JavaBean； |
org.springframework.boot.autoconfigure.web：web所有自动场景；
If you want to keep Spring Boot MVC features,and you just want to add additional MVC configuration (interceptors,formatters,view controllers etc.) you can add your own @Configuration class of type WebMvcConfigurerAdapter,but without @EnableWebMvc. If you wish to provide custom instances of RequestMappingHandlerMapping, RequestMappingHandlerAdapter or ExceptionHandlerExceptionResolver you can declare a WebMvcRegistrationsAdapter instance providing such components.
(2).扩展SpringMVC
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<mvc:view-controller path="/hello" view-name="success"/> <mvc:interceptors> <mvc:interceptor> <mvc:mapping path="/hello"/> <bean></bean> </mvc:interceptor> </mvc:interceptors> |
编写配置类（@Configuration），是WebMvcConfigurerAdapter类型；不能标注@EnableWebMvc;
在保留所有的自动配置情况下，也能用我们扩展的配置
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//使用 WebMvcConfigurer可以来扩展SpringMVC功能 //因为WebMvcConfigurerAdapter已经过时，所以我们使用接口WebMvcConfigurer替代 @Configuration public class MyMvcConfig implements WebMvcConfigurer { @Override public void addViewControllers(ViewControllerRegistry registry) { //super.addViewControllers(registry) //浏览器发送/pluto请求来到success registry.addViewController("/pluto").setViewName("success"); } } |
原理解析：
[1].WebMvcAutoConfiguration是SpringMVC自动配置类
[2].在做其他自动配置时会导入@Import(EnableWebMvcConfiguration.class)
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@Configuration public static class EnableWebMvcConfiguration extends DelegatingWebMvcConfiguration { private final WebMvcConfigurerComposite configurers = new WebMvcConfigurerComposite();
//从容器中获取所有的WebMvcConfigurer @Autowired(required = false) public void setConfigurers(List<WebMvcConfigurer> configurers) { if (!CollectionUtils.isEmpty(configurers)) { this.configurers.addWebMvcConfigurers(configurers); //一个参考实现；将所有的WebMvcConfigurer相关配置都来一起调用； @Override // public void addViewControllers(ViewControllerRegistry registry) { // for (WebMvcConfigurer delegate : this.delegates) { // delegate.addViewControllers(registry); // } } } } |
[3].容器中所有的WebMvcConfigurer都会一起起作用
[4].手写的配置类也会被调用
结果：SpringMVC的自动配置和手写的扩展配置都起作用；
(3).全面接管SpringMVC
SpringBoot对SpringMVC的自动配置不需要；自己配置所有配置；所有的SpringMVC自动配置使其失效。
需要在配置类中添加@EnableWebMvc即可；
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//使用 WebMvcConfigurer可以来扩展SpringMVC功能 //因为WebMvcConfigurerAdapter已经过时，所以我们使用接口WebMvcConfigurer替代 @EnableWebMvc @Configuration public class MyMvcConfig implements WebMvcConfigurer { @Override public void addViewControllers(ViewControllerRegistry registry) { //super.addViewControllers(registry) //浏览器发送/pluto请求来到success registry.addViewController("/pluto").setViewName("success"); } } |
原理解析：@EnableWebMvc自动配置失效
[1].@EnableWebMvc的核心
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@Retention(RetentionPolicy.RUNTIME) @Target({ElementType.TYPE}) @Documented @Import({DelegatingWebMvcConfiguration.class}) public @interface EnableWebMvc { } |
[2].DelegatingWebMvcConfiguration
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@Configuration( proxyBeanMethods = false ) public class DelegatingWebMvcConfiguration extends WebMvcConfigurationSupport { |
[3].WebMvcAutoConfiguration
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@Configuration( proxyBeanMethods = false ) @ConditionalOnWebApplication( type = Type.SERVLET ) @ConditionalOnClass({Servlet.class,DispatcherServlet.class,WebMvcConfigurer.class}) //容器中没有这个组件的时候，这个自动配置类才生效 @ConditionalOnMissingBean({WebMvcConfigurationSupport.class}) @AutoConfigureOrder(-2147483638) @AutoConfigureAfter({DispatcherServletAutoConfiguration.class,TaskExecutionAutoConfiguration.class,ValidationAutoConfiguration.class}) public class WebMvcAutoConfiguration { |
[4].@EnableWebMvc将WebMvcConfigurationSupport组件导入进来
[5].导入的WebMvcConfigurationSupport只是SpringMVC最基本的功能
5.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中有非常多的xxxConfigurer帮助我们进行扩展配置
(3).在SpringBoot中v 有很多的xxxCustomizer帮助我们进行定制配置
6.RestfulCRUD
(1).访问首页(默认)
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//使用 WebMvcConfigurer可以来扩展SpringMVC功能 //因为WebMvcConfigurerAdapter已经过时，所以我们使用接口WebMvcConfigurer替代 //@EnableWebMvc @Configuration public class MyMvcConfig implements WebMvcConfigurer { @Override public void addViewControllers(ViewControllerRegistry registry) { //super.addViewControllers(registry) //浏览器发送/pluto请求来到success registry.addViewController("/pluto").setViewName("success"); }
//所有的WebMvcConfigurer组件会一起起作用 //@Bean将组件注册在容器中 @Bean
public WebMvcConfigurer webMvcConfigurer(){ WebMvcConfigurer dapter = new WebMvcConfigurer() { @Override public void addViewControllers(ViewControllerRegistry registry) { registry.addViewController("/").setViewName("login"); registry.addViewController("/index.html").setViewName("login"); } }; return dapter; } } |
(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
实现步骤：
[1].编写国际化配置文件
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#login_zh_CN.properties login.btn=登录 login.password=密码 login.remember=记住我 login.tip=请登录 login.username=用户名
#login_en_US.properties login.btn=Sing In login.password=Password login.remember=remember me login.tip=Please sign in login.username=UserName
#login.properties login.btn=登录~ login.password=密码~ login.remember=记住我~ login.tip=请登录~ login.username=用户名~ |
[2].SpringBoot自动配置好了管理国际化资源文件的组件
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@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].取出国际化内容
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<!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> |
如果出现乱码的现象，那么只需要重新改下编码就行。可以设置全局配置，也可以设置项目配置。以下是全局配置
效果：根据浏览器语言设置的信息切换了国际化
原理解析：国际化Locale(区域信息对象)；LocaleResolver(获取区域信息对象)
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@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
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/** * 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).登录
开发期间模板引擎页面修改以后，如果想实时生效,需要执行以下两个步骤
[1].禁用模板引擎的缓存
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# 禁用缓存 spring.thymeleaf.cache=false |
[2].重新编译
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页面修改完成以后ctrl+f9 |
登陆错误消息的显示
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<p style="color: red" th:text="${msg}" th:if="${not #strings.isEmpty(msg)}"></p> |
防止表单重复提交的办法：重定向
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#LoginController.java if(!StringUtils.isEmpty(username)&& "123456".equals(password)){ //登录成功 防止表单重复提交，可以重定向到主页 return "redirect:/main.html"; |
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#MyMvcConfig.java //所有的WebMvcConfigurer组件会一起起作用 //@Bean将组件注册在容器中 @Bean public WebMvcConfigurer webMvcConfigurer(){ WebMvcConfigurer dapter = new WebMvcConfigurer() { @Override public void addViewControllers(ViewControllerRegistry registry) { registry.addViewController("/").setViewName("login"); registry.addViewController("/index.html").setViewName("login"); registry.addViewController("/main.html").setViewName("dashboard"); } }; return dapter; } |
(4).拦截器进行登陆检查
[1].拦截器
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/** * 登录检查 */ public class LoginHandlerInterceptor implements HandlerInterceptor{ //目标方法执行之前 @Override public boolean preHandle(HttpServletRequest request,Object handler) throws Exception { Object user = request.getSession().getAttribute("loginUser"); if(user==null){ //未登录 返回登录页面 request.setAttribute("msg","没有权限请先登录"); request.getRequestDispatcher("/index.html").forward(request,response); return false; }else { //已登录 放行请求 return true; } } } |
[2].注册拦截器
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//所有的WebMvcConfigurer组件会一起起作用 //@Bean将组件注册在容器中 @Bean public WebMvcConfigurer webMvcConfigurer(){ WebMvcConfigurer dapter = 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 @Override public void addInterceptors(InterceptorRegistry registry) { //super.addInterceptors(registry); //静态资源 *.css *.js //springboot已经做了静态资源映射 registry.addInterceptor(new LoginHandlerInterceptor()).addPathPatterns("/**") .excludePathPatterns("/index.html","/","/user/login"); }
};
return dapter; } |
(5).CRUD-员工列表
[1].需求分析
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
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普通CRUD（uri来区分操作） |
RestfulCRUD |
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查询 |
getEmp |
emp---GET |
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添加 |
addEmp?xxx |
emp---POST |
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修改 |
updateEmp?id=xxx&xxx=xx |
emp/{id}---PUT |
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删除 |
deleteEmp?id=1 |
emp/{id}---DELETE |
[2].实验的请求架构
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实验功能 |
请求URI |
请求方式 |
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查询所有员工 |
emps |
GET |
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查询某个员工(来到修改页面) |
emp/1 |
GET |
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来到添加页面 |
emp |
GET |
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添加员工 |
emp |
POST |
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来到修改页面（查出员工进行信息回显） |
emp/1 |
GET |
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修改员工 |
emp |
PUT |
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删除员工 |
emp/1 |
DELETE |
[3].员工列表
thymeleaf公共页面元素抽取
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1、抽取公共片段 <div th:fragment="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
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<footer th:fragment="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> © 2011 The Good Thymes Virtual Grocery </footer> </div>
<footer> © 2011 The Good Thymes Virtual Grocery </footer>
<div> © 2011 The Good Thymes Virtual Grocery </div> |
引入片段的时候传入参数
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<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> |
(6).CRUD-员工添加
templates/emp/add.html
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<form> <div class="form-group"> <label>LastName</label> <input type="text" class="form-control" placeholder="zhangsan"> </div> <div class="form-group"> <label>Email</label> <input type="email" class="form-control" placeholder="zhangsan@atguigu.com"> </div> <div class="form-group"> <label>Gender</label><br/> <div class="form-check form-check-inline"> <input class="form-check-input" type="radio" name="gender" value="1"> <label class="form-check-label">男</label> </div> <div class="form-check form-check-inline"> <input class="form-check-input" type="radio" name="gender" value="0"> <label class="form-check-label">女</label> </div> </div> <div class="form-group"> <label>department</label> <select class="form-control"> <option>1</option> <option>2</option> <option>3</option> <option>4</option> <option>5</option> </select> </div> <div class="form-group"> <label>Birth</label> <input type="text" class="form-control" placeholder="zhangsan"> </div> <button type="submit" class="btn btn-primary">添加</button> </form> |
[1].格式问题
若提交的日期格式不对，则会出现404
SpringMVC将页面提交的值需要转换为指定的类型
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spring: mvc: format: date: yyyy-MM-dd |
(7).CRUD-员工修改
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<!--需要区分是员工修改还是添加；--> <form th:action="@{/emp}" method="post"> <!--发送put请求修改员工数据--> <!-- 1、SpringMVC中配置HiddenHttpMethodFilter;（SpringBoot自动配置好的） 2、页面创建一个post表单 3、创建一个input项，name="_method";值就是我们指定的请求方式 --> <input type="hidden" name="_method" value="put" th:if="${emp!=null}"/> <input type="hidden" name="id" th:if="${emp!=null}" th:value="${emp.id}"> <div class="form-group"> <label>LastName</label> <input name="lastName" type="text" class="form-control" placeholder="zhangsan" th:value="${emp!=null}?${emp.lastName}"> </div> <div class="form-group"> <label>Email</label> <input name="email" type="email" class="form-control" placeholder="zhangsan@atguigu.com" th:value="${emp!=null}?${emp.email}"> </div> <div class="form-group"> <label>Gender</label><br/> <div class="form-check form-check-inline"> <input class="form-check-input" type="radio" name="gender" value="1" th:checked="${emp!=null}?${emp.gender==1}"> <label class="form-check-label">男</label> </div> <div class="form-check form-check-inline"> <input class="form-check-input" type="radio" name="gender" value="0" th:checked="${emp!=null}?${emp.gender==0}"> <label class="form-check-label">女</label> </div> </div> <div class="form-group"> <label>department</label> <!--提交的是部门的id--> <select class="form-control" name="department.id"> <option th:selected="${emp!=null}?${dept.id == emp.department.id}" th:value="${dept.id}" th:each="dept:${depts}" th:text="${dept.departmentName}">1</option> </select> </div> <div class="form-group"> <label>Birth</label> <input name="birth" type="text" class="form-control" placeholder="zhangsan" th:value="${emp!=null}?${#dates.format(emp.birth,'yyyy-MM-dd HH:mm')}"> </div> <button type="submit" class="btn btn-primary" th:text="${emp!=null}?'修改':'添加'">添加</button> </form> |
(8).CRUD-员工删除
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<tr th:each="emp:${emps}"> <td th:text="${emp.id}"></td> <td>[[${emp.lastName}]]</td> <td th:text="${emp.email}"></td> <td th:text="${emp.gender}==0?'女':'男'"></td> <td th:text="${emp.department.departmentName}"></td> <td th:text="${#dates.format(emp.birth,'yyyy-MM-dd HH:mm')}"></td> <td> <a class="btn btn-sm btn-primary" th:href="@{/emp/}+${emp.id}">编辑</a> <button th:attr="del_uri=@{/emp/}+${emp.id}" class="btn btn-sm btn-danger deleteBtn">删除</button> </td> </tr>
<script> $(".deleteBtn").click(function(){ //删除当前员工的 $("#deleteEmpForm").attr("action",$(this).attr("del_uri")).submit(); return false; }); </script> |
7.错误处理机制
(1).SpringBoot默认的错误处理机制
[1].默认效果
浏览器:返回一个默认的错误页面
浏览器发送请求的请求头
其它客户端:默认响应一个json数据
[2].原理
ErrorMvcAutoConfiguration:错误处理自动配置
1].DefaultErrorAttributes
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帮我们在页面共享信息； @Override public Map<String,Object> getErrorAttributes(RequestAttributes requestAttributes, boolean includeStackTrace) { Map<String,Object> errorAttributes = new LinkedHashMap<String,Object>(); errorAttributes.put("timestamp",new Date()); addStatus(errorAttributes,requestAttributes); addErrorDetails(errorAttributes,requestAttributes,includeStackTrace); addPath(errorAttributes,requestAttributes); return errorAttributes; } |
2].BasicErrorController
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@Controller @RequestMapping({"${server.error.path:${error.path:/error}}"}) public class BasicErrorController extends AbstractErrorController { private final ErrorProperties errorProperties; |
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#产生html类型的数据,浏览器发送的请求来到这个方法处理 @RequestMapping( produces = {"text/html"} ) public ModelAndView errorHtml(HttpServletRequest request,HttpServletResponse response) { HttpStatus status = this.getStatus(request); Map<String,Object> model = Collections.unmodifiableMap(this.getErrorAttributes(request,this.getErrorAttributeOptions(request,MediaType.TEXT_HTML))); response.setStatus(status.value()); //到那个页面作为错误页面；包含页面地址和页面内容 ModelAndView modelAndView = this.resolveErrorView(request,response,status,model); return modelAndView != null ? modelAndView : new ModelAndView("error",model); }
#产生json数据，其他客户端来到这个方法处理 @RequestMapping public ResponseEntity<Map<String,Object>> error(HttpServletRequest request) { HttpStatus status = this.getStatus(request); if (status == HttpStatus.NO_CONTENT) { return new ResponseEntity(status); } else { Map<String,Object> body = this.getErrorAttributes(request,MediaType.ALL)); return new ResponseEntity(body,status); } } |
3].ErrorMvcAutoConfiguration.ErrorPageCustomizer
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#系统出现错误后到error请求进行处理 #web.xml注册的错误页面规则 public class ErrorProperties { @Value("${error.path:/error}") private String path = "/error"; |
4].DefaultErrorViewResolverConfiguration
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@Override public ModelAndView resolveErrorView(HttpServletRequest request,HttpStatus status, Map<String,Object> model) { ModelAndView modelAndView = resolve(String.valueOf(status),model); if (modelAndView == null && SERIES_VIEWS.containsKey(status.series())) { modelAndView = resolve(SERIES_VIEWS.get(status.series()),model); } return modelAndView; }
private ModelAndView resolve(String viewName,Map<String,Object> model) { //默认SpringBoot可以去找到一个页面？ error/404 String errorViewName = "error/" + viewName;
//模板引擎可以解析这个页面地址就用模板引擎解析 TemplateAvailabilityProvider provider = this.templateAvailabilityProviders .getProvider(errorViewName,this.applicationContext); if (provider != null) { //模板引擎可用的情况下返回到errorViewName指定的视图地址 return new ModelAndView(errorViewName,model); } //模板引擎不可用，就在静态资源文件夹下找errorViewName对应的页面 error/404.html return resolveResource(errorViewName,model); } |
[3].步骤
系统出现4xx或者5xx的错误；ErrorPageCustomizer就会生效（定制错误的响应规则）；来到/error请求；被BasicErrorController处理；
1].响应页面
页面是由DefaultErrorViewResolver解析得到的
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protected ModelAndView resolveErrorView(HttpServletRequest request, HttpServletResponse response,Object> model) { //所有的ErrorViewResolver得到ModelAndView for (ErrorViewResolver resolver : this.errorViewResolvers) { ModelAndView modelAndView = resolver.resolveErrorView(request,model); if (modelAndView != null) { return modelAndView; } } return null; } |
(2).定制错误响应
[1].如何定制错误页面
1].模板引擎存在
有模板引擎的情况下；error/状态码；将错误页面命名为 错误状态码.html 放在模板引擎文件夹里面的 error文件夹下
我们可以使用4xx和5xx作为错误页面的文件名来匹配这种类型的所有错误，精确优先（优先寻找精确的状态码.html）；
页面能获取的信息
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timestamp |
时间戳 |
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status |
状态码 |
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error |
错误提示 |
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exception |
异常对象 |
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message |
异常消息 |
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errors |
JSR303数据校验的错误 |
2].模板引擎不存在
模板引擎找不到这个错误页面,静态资源文件夹下找；
3].其它
以上都没有错误页面，就是默认来到SpringBoot默认的错误提示页面；
[2].如何定制错误json数据
1].自定义异常处理&返回定制json数据
8.配置嵌入式Servlet容器
SpringBoot默认使用Tomcat作为嵌入式的Servlet容器
(1).定制|修改Servlet容器配置
[1].修改server相关配置(ServerProperties)
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server.port=8081 server.context-path=/crud server.tomcat.uri-encoding=UTF-8
//通用的Servlet容器设置 server.xxx //Tomcat的设置 server.tomcat.xxx |
[2].WebServerFactoryCustomizer
编写WebServerFactoryCustomizer：嵌入式Servlet容器定制器；修改Servlet容器的配置
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//spring1.0支持 EmbeddedServletContainerCustomizer //spring2.0支持 webServerFactoryCustomizer //参考文档：https://blog.csdn.net/Stitch__/article/details/88751497 @Bean public WebServerFactoryCustomizer webServerFactoryCustomizer(){
return new WebServerFactoryCustomizer <ConfigurableWebServerFactory>() {
//定制嵌入式的servlet容器相关规则 @Override public void customize(ConfigurableWebServerFactory factory) { factory.setPort(8088); } }; } |
(2).注册Servlet三大组件(Servlet、Filter、Listener)
注册三大组件用以下方式：ServletRegistrationBean、FilterRegistrationBean、ServletListenerRegistrationBean
[1].ServletRegistrationBean
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@Bean public FilterRegistrationBean myFilter(){ FilterRegistrationBean registrationBean = new FilterRegistrationBean(); registrationBean.setFilter(new MyFilter()); registrationBean.setUrlPatterns(Arrays.asList("/hello","/myServlet")); return registrationBean; } |
[2].FilterRegistrationBean
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@Bean public FilterRegistrationBean myFilter(){ FilterRegistrationBean registrationBean = new FilterRegistrationBean(); registrationBean.setFilter(new MyFilter()); registrationBean.setUrlPatterns(Arrays.asList("/hello","/myServlet")); return registrationBean; } |
[3].ServletListenerRegistrationBean
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@Bean public ServletListenerRegistrationBean myListener(){ ServletListenerRegistrationBean<MyListener> registrationBean = new ServletListenerRegistrationBean(new MyListener()); return registrationBean; } |
SpringBoot帮我们自动SpringMVC的时候，自动的注册SpringMVC的前端控制器；DIspatcherServlet；
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@Bean( name = {"dispatcherServletRegistration"} ) @ConditionalOnBean( value = {DispatcherServlet.class}, name = {"dispatcherServlet"} ) public DispatcherServletRegistrationBean dispatcherServletRegistration(DispatcherServlet dispatcherServlet,WebMvcProperties webMvcProperties,ObjectProvider<MultipartConfigElement> multipartConfig) { DispatcherServletRegistrationBean registration = new DispatcherServletRegistrationBean(dispatcherServlet,webMvcProperties.getServlet().getPath()); //默认拦截：/ 所有请求 包括静态资源 但是不拦截jsp /*会拦截jsp //可以通过server.serverletPath修改SrpingMVC前段控制器默认拦截的请求 registration.setName("dispatcherServlet"); registration.setLoadOnStartup(webMvcProperties.getServlet().getLoadOnStartup()); multipartConfig.ifAvailable(registration::setMultipartConfig); return registration; } } |
(3).springboot使用其它servlet容器
[1].tomcat
Tomcat(默认使用)
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<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> 引入web模块默认就是使用嵌入式的Tomcat作为Servlet容器； </dependency> |
[2].Jetty
目前只在springboot1.5.10版本上可以成功，spring2.0版本的都有错误
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<!-- 引入web模块 --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> <exclusions> <exclusion> <artifactId>spring-boot-starter-tomcat</artifactId> <groupId>org.springframework.boot</groupId> </exclusion> </exclusions> </dependency>
<!--引入其他的Servlet容器--> <dependency> <artifactId>spring-boot-starter-jetty</artifactId> <groupId>org.springframework.boot</groupId> </dependency> |
[3].Undertow
Undertow在springBoot1.5.10和SpringBoot2.0都成功运行
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<!-- 引入web模块 --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> <exclusions> <exclusion> <artifactId>spring-boot-starter-tomcat</artifactId> <groupId>org.springframework.boot</groupId> </exclusion> </exclusions> </dependency>
<!--引入其他的Servlet容器--> <dependency> <artifactId>spring-boot-starter-undertow</artifactId> <groupId>org.springframework.boot</groupId> </dependency> |
(4).嵌入式Servlet容器自动配置原理
[1].SpringBoot1.5.10版本
EmbeddedServletContainerAutoConfiguration:嵌入式的Servlet容器自动配置
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@AutoConfigureOrder(Ordered.HIGHEST_PRECEDENCE) @Configuration @ConditionalOnWebApplication @Import(BeanPostProcessorsRegistrar.class) //导入BeanPostProcessorsRegistrar：Spring注解版；给容器中导入一些组件 //导入了EmbeddedServletContainerCustomizerBeanPostProcessor： //后置处理器：bean初始化前后（创建完对象，还没赋值赋值）执行初始化工作 public class EmbeddedServletContainerAutoConfiguration {
@Configuration @ConditionalOnClass({ Servlet.class,Tomcat.class })//判断当前是否引入了Tomcat依赖； @ConditionalOnMissingBean(value = EmbeddedServletContainerFactory.class,search = SearchStrategy.CURRENT)//判断当前容器没有用户自己定义EmbeddedServletContainerFactory：嵌入式的Servlet容器工厂；作用：创建嵌入式的Servlet容器 public static class EmbeddedTomcat {
@Bean public TomcatEmbeddedServletContainerFactory tomcatEmbeddedServletContainerFactory() { return new TomcatEmbeddedServletContainerFactory(); }
}
/** * Nested configuration if Jetty is being used. */ @Configuration @ConditionalOnClass({ Servlet.class,Server.class,Loader.class, WebAppContext.class }) @ConditionalOnMissingBean(value = EmbeddedServletContainerFactory.class,search = SearchStrategy.CURRENT) public static class EmbeddedJetty {
@Bean public JettyEmbeddedServletContainerFactory jettyEmbeddedServletContainerFactory() { return new JettyEmbeddedServletContainerFactory(); }
}
/** * Nested configuration if Undertow is being used. */ @Configuration @ConditionalOnClass({ Servlet.class,Undertow.class,SslClientAuthMode.class }) @ConditionalOnMissingBean(value = EmbeddedServletContainerFactory.class,search = SearchStrategy.CURRENT) public static class EmbeddedUndertow {
@Bean public UndertowEmbeddedServletContainerFactory undertowEmbeddedServletContainerFactory() { return new UndertowEmbeddedServletContainerFactory(); }
} |
1].EmbeddedServletContainerFactory
EmbeddedServletContainerFactory:嵌入式Servlet容器工厂
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public interface EmbeddedServletContainerFactory {
//获取嵌入式的Servlet容器 EmbeddedServletContainer getEmbeddedServletContainer( ServletContextInitializer... initializers);
} |
2].EmbeddedServletContainer
EmbeddedServletContainer:嵌入式的Servlet容器
3].TomcatEmbeddedServletContainerFactory
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@Override public EmbeddedServletContainer getEmbeddedServletContainer( ServletContextInitializer... initializers) { //创建一个Tomcat Tomcat tomcat = new Tomcat();
//配置Tomcat的基本环节 File baseDir = (this.baseDirectory != null ? this.baseDirectory : createTempDir("tomcat")); tomcat.setBaseDir(baseDir.getAbsolutePath()); Connector connector = new Connector(this.protocol); tomcat.getService().addConnector(connector); customizeConnector(connector); tomcat.setConnector(connector); tomcat.getHost().setAutoDeploy(false); configureEngine(tomcat.getEngine()); for (Connector additionalConnector : this.additionalTomcatConnectors) { tomcat.getService().addConnector(additionalConnector); } prepareContext(tomcat.getHost(),initializers);
//将配置好的Tomcat传入进去，返回一个EmbeddedServletContainer；并且启动Tomcat服务器 return getTomcatEmbeddedServletContainer(tomcat); } |
4].嵌入式容器配置修改
对嵌入式容器的配置修改是需要一下支持生效
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ServerProperties、EmbeddedServletContainerCustomizer |
5]修改原理
EmbeddedServletContainerCustomizerBeanPostProcessor
容器中导入了EmbeddedServletContainerCustomizerBeanPostProcessor
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//初始化之前 @Override public Object postProcessBeforeInitialization(Object bean,String beanName) throws BeansException { //如果当前初始化的是一个ConfigurableEmbeddedServletContainer类型的组件 if (bean instanceof ConfigurableEmbeddedServletContainer) { // postProcessBeforeInitialization((ConfigurableEmbeddedServletContainer) bean); } return bean; }
private void postProcessBeforeInitialization( ConfigurableEmbeddedServletContainer bean) { //获取所有的定制器，调用每一个定制器的customize方法来给Servlet容器进行属性赋值； for (EmbeddedServletContainerCustomizer customizer : getCustomizers()) { customizer.customize(bean); } }
private Collection<EmbeddedServletContainerCustomizer> getCustomizers() { if (this.customizers == null) { // Look up does not include the parent context this.customizers = new ArrayList<EmbeddedServletContainerCustomizer>( this.beanFactory //从容器中获取所有这葛类型的组件：EmbeddedServletContainerCustomizer //定制Servlet容器，给容器中可以添加一个EmbeddedServletContainerCustomizer类型的组件 .getBeansOfType(EmbeddedServletContainerCustomizer.class, false,false) .values()); Collections.sort(this.customizers,AnnotationAwareOrderComparator.INSTANCE); this.customizers = Collections.unmodifiableList(this.customizers); } return this.customizers; }
ServerProperties也是定制器 |
6].步骤
1).SpringBoot根据导入的依赖情况，给容器中添加相应的
EmbeddedServletContainerFactory【TomcatEmbeddedServletContainerFactory】
2).容器中某个组件要创建对象就会惊动后置处理器
EmbeddedServletContainerCustomizerBeanPostProcessor；只要是嵌入式的Servlet容器工厂，后置处理器就工作；
3).后置处理器，从容器中获取所有的EmbeddedServletContainerCustomizer，调用定制器的定制方法
[2].SpringBoot2.0版本
(5).嵌入式Servlet容器启动原理
问题：
①.何时创建嵌入式的Servlet容器工厂
②.何时获取嵌入式的Servlet容器并启动Tomcat
[1].获取嵌入式的Servlet容器工厂
1].SpringBoot应用启动运行run方法
2].refreshContext
refreshContext(context);
SpringBoot刷新IOC容器【创建IOC容器对象，并初始化容器，创建容器中的每一个组件】；
如果是web应用创建AnnotationConfigEmbeddedWebApplicationContext，否则：AnnotationConfigApplicationContext
3].refresh
refresh(context);
refresh刷新刚才创建好的ioc容器；
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public void refresh() throws BeansException,IllegalStateException { synchronized (this.startupShutdownMonitor) { // Prepare this context for refreshing. prepareRefresh();
// Tell the subclass to refresh the internal bean factory. ConfigurableListableBeanFactory beanFactory = obtainFreshBeanFactory();
// Prepare the bean factory for use in this context. prepareBeanFactory(beanFactory);
try { // Allows post-processing of the bean factory in context subclasses. postProcessBeanFactory(beanFactory);
// Invoke factory processors registered as beans in the context. invokeBeanFactoryPostProcessors(beanFactory);
// Register bean processors that intercept bean creation. registerBeanPostProcessors(beanFactory);
// Initialize message source for this context. initMessageSource();
// Initialize event multicaster for this context. initApplicationEventMulticaster();
// Initialize other special beans in specific context subclasses. onRefresh();
// Check for listener beans and register them. registerListeners();
// Instantiate all remaining (non-lazy-init) singletons. finishBeanFactoryInitialization(beanFactory);
// Last step: publish corresponding event. finishRefresh(); }
catch (BeansException ex) { if (logger.isWarnEnabled()) { logger.warn("Exception encountered during context initialization - " + "cancelling refresh attempt: " + ex); }
// Destroy already created singletons to avoid dangling resources. destroyBeans();
// Reset 'active' flag. cancelRefresh(ex);
// Propagate exception to caller. throw ex; }
finally { // Reset common introspection caches in Spring's core,since we // might not ever need metadata for singleton beans anymore... resetCommonCaches(); } } } |
4].onRefresh
onRefresh()web的ioc容器重写了onRefresh方法
5].createEmbeddedServletContainer
webioc容器会创建嵌入式的Servlet容器；
createEmbeddedServletContainer();
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|
6].获取嵌入式的Servlet容器工厂
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EmbeddedServletContainerFactory containerFactory = getEmbeddedServletContainerFactory(); |
从ioc容器中获取EmbeddedServletContainerFactory 组件；TomcatEmbeddedServletContainerFactory创建对象，后置处理器一看是这个对象，就获取所有的定制器来先定制Servlet容器的相关配置；
7].使用容器工厂获取嵌入式的Servlet容器
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this.embeddedServletContainer = containerFactory.getEmbeddedServletContainer(getSelfInitializer()); |
8].嵌入式的Servlet容器创建对象并启动Servlet容器
先启动嵌入式的Servlet容器，再将ioc容器中剩下没有创建出的对象获取出来
IOC容器启动创建嵌入式的Servlet容器
9.外置Servlet容器
嵌入式Servlet容器：应用打成可执行的jar
嵌入式Servlet容器优点：简单、便携
嵌入式Servlet容器缺点：默认不支持JSP、优化定制比较复杂(使用定制器[ServerProperties、自定义EmbeddedServletContainerCustomizer[，自己编写嵌入式Servlet容器的创建工厂[EmbeddedServletContainerFactory[);
外置式Servlet容器：外面安装Tomcat---应用war包的方式打包；
(1).步骤
[1].创建war项目
利用idea创建好目录结构
[2].修改pom文件
将嵌入式的Tomcat指定为provided
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<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-tomcat</artifactId> <scope>provided</scope> </dependency> |
[3].SpringBootServletInitializer
编写一个SpringBootServletInitializer的子类，并调用configure方法
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public class ServletInitializer extends SpringBootServletInitializer {
@Override protected SpringApplicationBuilder configure(SpringApplicationBuilder application) { //传入SpringBoot应用的主程序 return application.sources(SpringBoot04WebJspApplication.class); }
} |
[4].启动服务器
(2).原理
jar包:执行SpringBoot主类main方法,启动ioc容器,创建嵌入式Servlet容器；
war包:启动服务器,服务器启动SpringBoot应用[SpringBootServletInitializer],启动ioc容器;
[1].规则
1].服务器启动（web应用启动）会创建当前web应用里面每一个jar包里面ServletContainerInitializer实例
2].ServletContainerInitializer的实现放在jar包的META-INF/services文件夹下，有一个名为javax.servlet.ServletContainerInitializer的文件，内容就是ServletContainerInitializer的实现类的全类名
3].使用@HandlesTypes，在应用启动的时候加载需要的类；
[2].流程
1].启动Tomcat
2].org\springframework\spring-web\4.3.14.RELEASE\spring-web-4.3.14.RELEASE.jar!\META-INF\services\javax.servlet.ServletContainerInitializer：
Spring的web模块里面有这个文件：
org.springframework.web.SpringServletContainerInitializer
3].SpringServletContainerInitializer
将@HandlesTypes(WebApplicationInitializer.class)标注的所有这个类型的类都传入到onStartup方法的Set<Class<?>>；为这些WebApplicationInitializer类型的类创建实例；
4].每一个WebApplicationInitializer都调用自己的onStartup；
5].相当于我们的SpringBootServletInitializer的类会被创建对象，并执行onStartup方法
6].SpringBootServletInitializer实例执行onStartup的时候会createRootApplicationContext；创建容器
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protected WebApplicationContext createRootApplicationContext( ServletContext servletContext) { //1、创建SpringApplicationBuilder SpringApplicationBuilder builder = createSpringApplicationBuilder(); StandardServletEnvironment environment = new StandardServletEnvironment(); environment.initPropertySources(servletContext,null); builder.environment(environment); builder.main(getClass()); ApplicationContext parent = getExistingRootWebApplicationContext(servletContext); if (parent != null) { this.logger.info("Root context already created (using as parent)."); servletContext.setAttribute( WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE,null); builder.initializers(new ParentContextApplicationContextInitializer(parent)); } builder.initializers( new ServletContextApplicationContextInitializer(servletContext)); builder.contextClass(AnnotationConfigEmbeddedWebApplicationContext.class);
//调用configure方法，子类重写了这个方法，将SpringBoot的主程序类传入了进来 builder = configure(builder);
//使用builder创建一个Spring应用 SpringApplication application = builder.build(); if (application.getSources().isEmpty() && AnnotationUtils .findAnnotation(getClass(),Configuration.class) != null) { application.getSources().add(getClass()); } Assert.state(!application.getSources().isEmpty(), "No SpringApplication sources have been defined. Either override the " + "configure method or add an @Configuration annotation"); // Ensure error pages are registered if (this.registerErrorPageFilter) { application.getSources().add(ErrorPageFilterConfiguration.class); } //启动Spring应用 return run(application); } |
7].Spring的应用就启动并且创建IOC容器
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public ConfigurableApplicationContext run(String... args) { StopWatch stopWatch = new StopWatch(); stopWatch.start(); ConfigurableApplicationContext context = null; FailureAnalyzers analyzers = null; configureHeadlessProperty(); SpringApplicationRunListeners listeners = getRunListeners(args); listeners.starting(); try { ApplicationArguments applicationArguments = new DefaultApplicationArguments( args); ConfigurableEnvironment environment = prepareEnvironment(listeners, applicationArguments); Banner printedBanner = printBanner(environment); context = createApplicationContext(); analyzers = new FailureAnalyzers(context); prepareContext(context,environment,listeners,applicationArguments, printedBanner);
//刷新IOC容器 refreshContext(context); afterRefresh(context,applicationArguments); listeners.finished(context,null); stopWatch.stop(); if (this.logStartupInfo) { new StartupInfoLogger(this.mainApplicationClass) .logStarted(getApplicationLog(),stopWatch); } return context; } catch (Throwable ex) { handleRunFailure(context,analyzers,ex); throw new IllegalStateException(ex); } } |
重要：启动Servlet容器，再启动SpringBoot应用
参考文档
https://docs.spring.io/spring-boot/docs/1.5.9.RELEASE/reference/htmlsingle/#howto-use-thymeleaf-3
https://github.com/thymeleaf/thymeleaf/releases
https://github.com/ultraq/thymeleaf-layout-dialect/releases
https://www.thymeleaf.org/documentation.html
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