1.創建一個web模塊
(1).創建SpringBoot應用，選中我們需要的模塊；
(2).SpringBoot已經默認將這些場景配置好了，只需要在配置文件中指定少量配置就可以運行起來
(3).自己編寫業務代碼；
自動配置原理
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xxxxAutoConfiguration：幫我們給容器中自動配置組件； xxxxProperties:配置類來封裝配置文件的內容； |
2.SpringBoott對靜態資源的映射規則
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@ConfigurationProperties(prefix = "spring.resources", ignoreUnknownFields = false) public class ResourceProperties implements ResourceLoaderAware { //可以設置和靜態資源有關的參數，緩存時間等 |
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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(); //靜態資源文件夾映射 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()); }
//配置圖標 @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/ 找資源；webjars：以jar包的方式引入靜態資源
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<!--引入jquery-webjar 在訪問的時候只需要寫webjars下面資源的名稱即可 --> <dependency> <groupId>org.webjars</groupId> <artifactId>jquery</artifactId> <version>3.3.1</version> </dependency> |
訪問：localhost:8080/webjars/jquery/3.3.1/jquery.js
(2)."/**" 訪問當前項目的任何資源，到'靜態資源文件夾'找映射
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"classpath:/META-INF/resources/", "classpath:/resources/", "classpath:/static/", "classpath:/public/" "/"：當前項目的根路徑 |
訪問：http://localhost:8080/asserts/js/Chart.min.js
localhost:8080/abc ---> 去靜態資源文件夾裏面找abc
(3).index頁； 靜態資源文件夾下的所有index.html頁面；被"/**"映射；
訪問:localhost:8080/
(4). 圖標**/favicon.ico都在靜態資源文件下找
3.模板引擎
JSP、Velocity、Freemarker、Thymeleaf
SpringBoot推薦使用的Thymeleaf,語法更簡單，功能更強大.
(1).引入thymeleaf
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<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-thymeleaf</artifactId> <!--2.1.6--> </dependency> 切換thymeleaf版本 <properties> <thymeleaf.version>3.0.9.RELEASE</thymeleaf.version> <!-- 佈局功能的支持程序 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頁面放在classpath:/templates/，thymeleaf就能自動渲染;
[1].添加名稱空間
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xmlns:th="http://www.thymeleaf.org" |
[2].使用thymeleaf語法
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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 將div裏面的文本內容設置爲 --> <div th:text="${hello}">這是顯示歡迎信息</div> </body> </html> |
(3).thymeleaf語法
[1].th:text：改變當前元素裏面的文本內容
th:任意html屬性；來替換原生屬性的值
[2].表達式
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Simple expressions:（表達式語法） Variable Expressions: ${...}：獲取變量值；OGNL； 1）、獲取對象的屬性、調用方法 2）、使用內置的基本對象： #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.
${session.foo} 3）、內置的一些工具對象： #execInfo : information about the template being processed. #messages : methods for obtaining externalized messages inside variables expressions, in the same way as they would be obtained using #{…} syntax. #uris : methods for escaping parts of URLs/URIs #conversions : methods for executing the configured conversion service (if any). #dates : methods for java.util.Date objects: formatting, component extraction, etc. #calendars : analogous to #dates , but for java.util.Calendar objects. #numbers : methods for formatting numeric objects. #strings : methods for String objects: contains, startsWith, prepending/appending, etc. #objects : methods for objects in general. #bools : methods for boolean evaluation. #arrays : methods for arrays. #lists : methods for lists. #sets : methods for sets. #maps : methods for maps. #aggregates : methods for creating aggregates on arrays or collections. #ids : methods for dealing with id attributes that might be repeated (for example, as a result of an iteration).
Selection Variable Expressions: *{...}：選擇表達式：和${}在功能上是一樣； 補充：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: #{...}：獲取國際化內容 Link URL Expressions: @{...}：定義URL； @{/order/process(execId=${execId},execType='FAST')} Fragment Expressions: ~{...}：片段引用表達式 <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:（數學運算） Binary operators: + , - , * , / , % Minus sign (unary operator): - Boolean operations:（布爾運算） Binary operators: and , or Boolean negation (unary operator): ! , not Comparisons and equality:（比較運算） Comparators: > , < , >= , <= ( gt , lt , ge , le ) Equality operators: == , != ( eq , ne ) Conditional operators:條件運算（三元運算符） If-then: (if) ? (then) If-then-else: (if) ? (then) : (else) Default: (value) ?: (defaultvalue) Special tokens: No-Operation: _ |
4.SpringMVC自動配置
(1).Spring MVC auto-configuration
Spring Boot 自動配置SpringMVC
SpringBoot對SpringMVC的默認配置(WebMvcAutoConfiguration)
Inclusion of ContentNegotiatingViewResolver and BeanNameViewResolver beans.
自動配置了ViewResolver（視圖解析器：根據方法的返回值得到視圖對象（View），視圖對象決定如何渲染（轉發？重定向？））
ContentNegotiatingViewResolver:組合所有的視圖解析器的
如何定製：我們可以自己給容器中添加一個視圖解析器；自動的將其組合進來；
Support for serving static resources, including support for WebJars (see below).
靜態資源文件夾路徑,webjars
Automatic registration of Converter, GenericConverter, Formatter beans.
Converter：轉換器； public String hello(User user)：類型轉換使用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規則 public Formatter<Date> dateFormatter() { return new DateFormatter(this.mvcProperties.getDateFormat());//日期格式化組件 } |
自己添加的格式化器轉換器，我們只需要放在容器中即可
Support for HttpMessageConverters (see below).
HttpMessageConverter：SpringMVC用來轉換Http請求和響應的；User--->Json；
`HttpMessageConverters` 是從容器中確定；獲取所有的HttpMessageConverter；
自己給容器中添加HttpMessageConverter，只需要將自己的組件註冊容器中（@Bean,@Component）
Automatic registration of MessageCodesResolver (see below).
定義錯誤代碼生成規則
Static index.html support.
靜態首頁訪問
Custom Favicon support (see below).
自定義favicon.ico 圖標
Automatic use of a ConfigurableWebBindingInitializer bean (see below).
我們可以配置一個ConfigurableWebBindingInitializer來替換默認的；（添加到容器）
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初始化WebDataBinder； 請求數據=====JavaBean； |
org.springframework.boot.autoconfigure.web：web所有自動場景；
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).擴展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> |
編寫配置類（@Configuration），是WebMvcConfigurerAdapter類型；不能標註@EnableWebMvc;
在保留所有的自動配置情況下，也能用我們擴展的配置
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//使用 WebMvcConfigurer可以來擴展SpringMVC功能 //因爲WebMvcConfigurerAdapter已經過時，所以我們使用接口WebMvcConfigurer替代 @Configuration public class MyMvcConfig implements WebMvcConfigurer { @Override public void addViewControllers(ViewControllerRegistry registry) { //super.addViewControllers(registry) //瀏覽器發送/pluto請求來到success registry.addViewController("/pluto").setViewName("success"); } } |
原理解析：
[1].WebMvcAutoConfiguration是SpringMVC自動配置類
[2].在做其他自動配置時會導入@Import(EnableWebMvcConfiguration.class)
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@Configuration public static class EnableWebMvcConfiguration extends DelegatingWebMvcConfiguration { private final WebMvcConfigurerComposite configurers = new WebMvcConfigurerComposite();
//從容器中獲取所有的WebMvcConfigurer @Autowired(required = false) public void setConfigurers(List<WebMvcConfigurer> configurers) { if (!CollectionUtils.isEmpty(configurers)) { this.configurers.addWebMvcConfigurers(configurers); //一個參考實現；將所有的WebMvcConfigurer相關配置都來一起調用； @Override // public void addViewControllers(ViewControllerRegistry registry) { // for (WebMvcConfigurer delegate : this.delegates) { // delegate.addViewControllers(registry); // } } } } |
[3].容器中所有的WebMvcConfigurer都會一起起作用
[4].手寫的配置類也會被調用
結果：SpringMVC的自動配置和手寫的擴展配置都起作用；
(3).全面接管SpringMVC
SpringBoot對SpringMVC的自動配置不需要；自己配置所有配置；所有的SpringMVC自動配置使其失效。
需要在配置類中添加@EnableWebMvc即可；
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//使用 WebMvcConfigurer可以來擴展SpringMVC功能 //因爲WebMvcConfigurerAdapter已經過時，所以我們使用接口WebMvcConfigurer替代 @EnableWebMvc @Configuration public class MyMvcConfig implements WebMvcConfigurer { @Override public void addViewControllers(ViewControllerRegistry registry) { //super.addViewControllers(registry) //瀏覽器發送/pluto請求來到success registry.addViewController("/pluto").setViewName("success"); } } |
原理解析：@EnableWebMvc自動配置失效
[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}) //容器中沒有這個組件的時候，這個自動配置類才生效 @ConditionalOnMissingBean({WebMvcConfigurationSupport.class}) @AutoConfigureOrder(-2147483638) @AutoConfigureAfter({DispatcherServletAutoConfiguration.class, TaskExecutionAutoConfiguration.class, ValidationAutoConfiguration.class}) public class WebMvcAutoConfiguration { |
[4].@EnableWebMvc將WebMvcConfigurationSupport組件導入進來
[5].導入的WebMvcConfigurationSupport只是SpringMVC最基本的功能
5.修改SpringBoot的默認配置
模式：
(1).SpringBoot在自動配置很多組件的時候，先看容器中有沒有用戶自己配置的（@Bean、@Component）如果有就用用戶配置的，如果沒有，才自動配置；如果有些組件可以有多個（ViewResolver）將用戶配置的和自己默認的組合起來；
(2).在SpringBoot中有非常多的xxxConfigurer幫助我們進行擴展配置
(3).在SpringBoot中v 有很多的xxxCustomizer幫助我們進行定製配置
6.RestfulCRUD
(1).訪問首頁(默認)
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//使用 WebMvcConfigurer可以來擴展SpringMVC功能 //因爲WebMvcConfigurerAdapter已經過時，所以我們使用接口WebMvcConfigurer替代 //@EnableWebMvc @Configuration public class MyMvcConfig implements WebMvcConfigurer { @Override public void addViewControllers(ViewControllerRegistry registry) { //super.addViewControllers(registry) //瀏覽器發送/pluto請求來到success registry.addViewController("/pluto").setViewName("success"); }
//所有的WebMvcConfigurer組件會一起起作用 //@Bean將組件註冊在容器中 @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).國際化
[1].編寫國際化配置文件
[2].使用ResourceBundleMessageSource管理國際化資源文件
[3].在頁面使用fmt:message取出國際化內容
實現步驟：
[1].編寫國際化配置文件
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#login_zh_CN.properties login.btn=登錄 login.password=密碼 login.remember=記住我 login.tip=請登錄 login.username=用戶名
#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=登錄~ login.password=密碼~ login.remember=記住我~ login.tip=請登錄~ login.username=用戶名~ |
[2].SpringBoot自動配置好了管理國際化資源文件的組件
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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"; //我們的配置文件可以直接放在類路徑下叫messages.properties；
@Bean public MessageSource messageSource() { ResourceBundleMessageSource messageSource = new ResourceBundleMessageSource(); if (StringUtils.hasText(this.basename)) { //設置國際化資源文件的基礎名（去掉語言國家代碼的） 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].取出國際化內容
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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> |
如果出現亂碼的現象，那麼只需要重新改下編碼就行。可以設置全局配置，也可以設置項目配置。以下是全局配置
效果：根據瀏覽器語言設置的信息切換了國際化
原理解析：國際化Locale(區域信息對象)；LocaleResolver(獲取區域信息對象)
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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; } 默認的就是根據請求頭帶來的區域信息獲取Locale進行國際化 |
[4].點擊鏈接切換國際化
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/** * 可以在連接上攜帶區域信息 */ 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).登錄
開發期間模板引擎頁面修改以後，如果想實時生效,需要執行以下兩個步驟
[1].禁用模板引擎的緩存
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# 禁用緩存 spring.thymeleaf.cache=false |
[2].重新編譯
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頁面修改完成以後ctrl+f9 |
登陸錯誤消息的顯示
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<p style="color: red" th:text="${msg}" th:if="${not #strings.isEmpty(msg)}"></p> |
防止表單重複提交的辦法：重定向
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#LoginController.java if(!StringUtils.isEmpty(username)&& "123456".equals(password)){ //登錄成功 防止表單重複提交，可以重定向到主頁 return "redirect:/main.html"; |
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#MyMvcConfig.java //所有的WebMvcConfigurer組件會一起起作用 //@Bean將組件註冊在容器中 @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).攔截器進行登陸檢查
[1].攔截器
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/** * 登錄檢查 */ 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){ //未登錄 返回登錄頁面 request.setAttribute("msg","沒有權限請先登錄"); request.getRequestDispatcher("/index.html").forward(request,response); return false; }else { //已登錄 放行請求 return true; } } } |
[2].註冊攔截器
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//所有的WebMvcConfigurer組件會一起起作用 //@Bean將組件註冊在容器中 @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"); }
//註冊攔截器 @Override public void addInterceptors(InterceptorRegistry registry) { //super.addInterceptors(registry); //靜態資源 *.css *.js //springboot已經做了靜態資源映射 registry.addInterceptor(new LoginHandlerInterceptor()).addPathPatterns("/**") .excludePathPatterns("/index.html","/","/user/login"); }
};
return dapter; } |
(5).CRUD-員工列表
[1].需求分析
RestfulCRUD：CRUD滿足Rest風格；
URI:/資源名稱/資源標識 HTTP請求方式區分對資源CRUD操作
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普通CRUD（uri來區分操作） |
RestfulCRUD |
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查詢 |
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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刪除 |
deleteEmp?id=1 |
emp/{id}---DELETE |
[2].實驗的請求架構
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實驗功能 |
請求URI |
請求方式 |
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查詢所有員工 |
emps |
GET |
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查詢某個員工(來到修改頁面) |
emp/1 |
GET |
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來到添加頁面 |
emp |
GET |
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添加員工 |
emp |
POST |
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來到修改頁面（查出員工進行信息回顯） |
emp/1 |
GET |
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修改員工 |
emp |
PUT |
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刪除員工 |
emp/1 |
DELETE |
[3].員工列表
thymeleaf公共頁面元素抽取
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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::選擇器 ~{templatename::fragmentname}:模板名::片段名
3、默認效果： insert的公共片段在div標籤中 如果使用th:insert等屬性進行引入，可以不用寫~{}： 行內寫法可以加上：[[~{}]];[(~{})]； |
三種引入公共片段的th屬性:
th:insert：將公共片段整個插入到聲明引入的元素中
th:replace：將聲明引入的元素替換爲公共片段
th:include：將被引入的片段的內容包含進這個標籤中
|
<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> |
引入片段的時候傳入參數
|
<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>
<!--引入側邊欄;傳入參數--> <div th:replace="commons/bar::#sidebar(activeUri='emps')"></div> |
(6).CRUD-員工添加
templates/emp/add.html
|
<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="[email protected]"> </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].格式問題
若提交的日期格式不對，則會出現404
SpringMVC將頁面提交的值需要轉換爲指定的類型
|
spring: mvc: format: date: yyyy-MM-dd |
(7).CRUD-員工修改
|
<!--需要區分是員工修改還是添加；--> <form th:action="@{/emp}" method="post"> <!--發送put請求修改員工數據--> <!-- 1、SpringMVC中配置HiddenHttpMethodFilter;（SpringBoot自動配置好的） 2、頁面創建一個post表單 3、創建一個input項，name="_method";值就是我們指定的請求方式 --> <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}?${emp.lastName}"> </div> <div class="form-group"> <label>Email</label> <input name="email" type="email" class="form-control" placeholder="[email protected]" th:value="${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}?${emp.gender==0}"> <label class="form-check-label">女</label> </div> </div> <div class="form-group"> <label>department</label> <!--提交的是部門的id--> <select class="form-control" name="department.id"> <option th:selected="${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="${emp!=null}?'修改':'添加'">添加</button> </form> |
(8).CRUD-員工刪除
|
<tr th:each="emp:${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/}+${emp.id}">編輯</a> <button th:attr="del_uri=@{/emp/}+${emp.id}" class="btn btn-sm btn-danger deleteBtn">刪除</button> </td> </tr>
<script> $(".deleteBtn").click(function(){ //刪除當前員工的 $("#deleteEmpForm").attr("action",$(this).attr("del_uri")).submit(); return false; }); </script> |
7.錯誤處理機制
(1).SpringBoot默認的錯誤處理機制
[1].默認效果
瀏覽器:返回一個默認的錯誤頁面
瀏覽器發送請求的請求頭
其它客戶端:默認響應一個json數據
[2].原理
ErrorMvcAutoConfiguration:錯誤處理自動配置
1].DefaultErrorAttributes
|
幫我們在頁面共享信息； @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; |
|
#產生html類型的數據,瀏覽器發送的請求來到這個方法處理 @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()); //到那個頁面作爲錯誤頁面；包含頁面地址和頁面內容 ModelAndView modelAndView = this.resolveErrorView(request, response, status, model); return modelAndView != null ? modelAndView : new ModelAndView("error", model); }
#產生json數據，其他客戶端來到這個方法處理 @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, this.getErrorAttributeOptions(request, MediaType.ALL)); return new ResponseEntity(body, status); } } |
3].ErrorMvcAutoConfiguration.ErrorPageCustomizer
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#系統出現錯誤後到error請求進行處理 #web.xml註冊的錯誤頁面規則 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) { //默認SpringBoot可以去找到一個頁面？ error/404 String errorViewName = "error/" + viewName;
//模板引擎可以解析這個頁面地址就用模板引擎解析 TemplateAvailabilityProvider provider = this.templateAvailabilityProviders .getProvider(errorViewName, this.applicationContext); if (provider != null) { //模板引擎可用的情況下返回到errorViewName指定的視圖地址 return new ModelAndView(errorViewName, model); } //模板引擎不可用，就在靜態資源文件夾下找errorViewName對應的頁面 error/404.html return resolveResource(errorViewName, model); } |
[3].步驟
系統出現4xx或者5xx的錯誤；ErrorPageCustomizer就會生效（定製錯誤的響應規則）；來到/error請求；被BasicErrorController處理；
1].響應頁面
頁面是由DefaultErrorViewResolver解析得到的
|
protected ModelAndView resolveErrorView(HttpServletRequest request, HttpServletResponse response, HttpStatus status, Map<String, Object> model) { //所有的ErrorViewResolver得到ModelAndView for (ErrorViewResolver resolver : this.errorViewResolvers) { ModelAndView modelAndView = resolver.resolveErrorView(request, status, model); if (modelAndView != null) { return modelAndView; } } return null; } |
(2).定製錯誤響應
[1].如何定製錯誤頁面
1].模板引擎存在
有模板引擎的情況下；error/狀態碼；將錯誤頁面命名爲 錯誤狀態碼.html 放在模板引擎文件夾裏面的 error文件夾下
我們可以使用4xx和5xx作爲錯誤頁面的文件名來匹配這種類型的所有錯誤，精確優先（優先尋找精確的狀態碼.html）；
頁面能獲取的信息
|
|
|
|
timestamp |
時間戳 |
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status |
狀態碼 |
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error |
錯誤提示 |
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exception |
異常對象 |
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message |
異常消息 |
|
errors |
JSR303數據校驗的錯誤 |
2].模板引擎不存在
模板引擎找不到這個錯誤頁面,靜態資源文件夾下找；
3].其它
以上都沒有錯誤頁面，就是默認來到SpringBoot默認的錯誤提示頁面；
[2].如何定製錯誤json數據
1].自定義異常處理&返回定製json數據
8.配置嵌入式Servlet容器
SpringBoot默認使用Tomcat作爲嵌入式的Servlet容器
(1).定製|修改Servlet容器配置
[1].修改server相關配置(ServerProperties)
|
server.port=8081 server.context-path=/crud server.tomcat.uri-encoding=UTF-8
//通用的Servlet容器設置 server.xxx //Tomcat的設置 server.tomcat.xxx |
[2].WebServerFactoryCustomizer
編寫WebServerFactoryCustomizer：嵌入式Servlet容器定製器；修改Servlet容器的配置
|
//spring1.0支持 EmbeddedServletContainerCustomizer //spring2.0支持 webServerFactoryCustomizer //參考文檔：https://blog.csdn.net/Stitch__/article/details/88751497 @Bean public WebServerFactoryCustomizer webServerFactoryCustomizer(){
return new WebServerFactoryCustomizer <ConfigurableWebServerFactory>() {
//定製嵌入式的servlet容器相關規則 @Override public void customize(ConfigurableWebServerFactory factory) { factory.setPort(8088); } }; } |
(2).註冊Servlet三大組件(Servlet、Filter、Listener)
註冊三大組件用以下方式：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
|
@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幫我們自動SpringMVC的時候，自動的註冊SpringMVC的前端控制器；DIspatcherServlet；
|
@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()); //默認攔截：/ 所有請求 包括靜態資源 但是不攔截jsp /*會攔截jsp //可以通過server.serverletPath修改SrpingMVC前段控制器默認攔截的請求 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(默認使用)
|
<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> 引入web模塊默認就是使用嵌入式的Tomcat作爲Servlet容器； </dependency> |
[2].Jetty
目前只在springboot1.5.10版本上可以成功，spring2.0版本的都有錯誤
|
<!-- 引入web模塊 --> <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都成功運行
|
<!-- 引入web模塊 --> <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容器自動配置原理
[1].SpringBoot1.5.10版本
EmbeddedServletContainerAutoConfiguration:嵌入式的Servlet容器自動配置
|
@AutoConfigureOrder(Ordered.HIGHEST_PRECEDENCE) @Configuration @ConditionalOnWebApplication @Import(BeanPostProcessorsRegistrar.class) //導入BeanPostProcessorsRegistrar：Spring註解版；給容器中導入一些組件 //導入了EmbeddedServletContainerCustomizerBeanPostProcessor： //後置處理器：bean初始化前後（創建完對象，還沒賦值賦值）執行初始化工作 public class EmbeddedServletContainerAutoConfiguration {
@Configuration @ConditionalOnClass({ Servlet.class, Tomcat.class })//判斷當前是否引入了Tomcat依賴； @ConditionalOnMissingBean(value = EmbeddedServletContainerFactory.class, search = SearchStrategy.CURRENT)//判斷當前容器沒有用戶自己定義EmbeddedServletContainerFactory：嵌入式的Servlet容器工廠；作用：創建嵌入式的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容器工廠
|
public interface EmbeddedServletContainerFactory {
//獲取嵌入式的Servlet容器 EmbeddedServletContainer getEmbeddedServletContainer( ServletContextInitializer... initializers);
} |
2].EmbeddedServletContainer
EmbeddedServletContainer:嵌入式的Servlet容器
3].TomcatEmbeddedServletContainerFactory
|
@Override public EmbeddedServletContainer getEmbeddedServletContainer( ServletContextInitializer... initializers) { //創建一個Tomcat Tomcat tomcat = new Tomcat();
//配置Tomcat的基本環節 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);
//將配置好的Tomcat傳入進去，返回一個EmbeddedServletContainer；並且啓動Tomcat服務器 return getTomcatEmbeddedServletContainer(tomcat); } |
4].嵌入式容器配置修改
對嵌入式容器的配置修改是需要一下支持生效
|
ServerProperties、EmbeddedServletContainerCustomizer |
5]修改原理
EmbeddedServletContainerCustomizerBeanPostProcessor
容器中導入了EmbeddedServletContainerCustomizerBeanPostProcessor
|
//初始化之前 @Override public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException { //如果當前初始化的是一個ConfigurableEmbeddedServletContainer類型的組件 if (bean instanceof ConfigurableEmbeddedServletContainer) { // postProcessBeforeInitialization((ConfigurableEmbeddedServletContainer) bean); } return bean; }
private void postProcessBeforeInitialization( ConfigurableEmbeddedServletContainer bean) { //獲取所有的定製器，調用每一個定製器的customize方法來給Servlet容器進行屬性賦值； 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 //從容器中獲取所有這葛類型的組件：EmbeddedServletContainerCustomizer //定製Servlet容器，給容器中可以添加一個EmbeddedServletContainerCustomizer類型的組件 .getBeansOfType(EmbeddedServletContainerCustomizer.class, false, false) .values()); Collections.sort(this.customizers, AnnotationAwareOrderComparator.INSTANCE); this.customizers = Collections.unmodifiableList(this.customizers); } return this.customizers; }
ServerProperties也是定製器 |
6].步驟
1).SpringBoot根據導入的依賴情況，給容器中添加相應的
EmbeddedServletContainerFactory【TomcatEmbeddedServletContainerFactory】
2).容器中某個組件要創建對象就會驚動後置處理器
EmbeddedServletContainerCustomizerBeanPostProcessor；只要是嵌入式的Servlet容器工廠，後置處理器就工作；
3).後置處理器，從容器中獲取所有的EmbeddedServletContainerCustomizer，調用定製器的定製方法
[2].SpringBoot2.0版本
(5).嵌入式Servlet容器啓動原理
問題：
①.何時創建嵌入式的Servlet容器工廠
②.何時獲取嵌入式的Servlet容器並啓動Tomcat
[1].獲取嵌入式的Servlet容器工廠
1].SpringBoot應用啓動運行run方法
2].refreshContext
refreshContext(context);
SpringBoot刷新IOC容器【創建IOC容器對象，並初始化容器，創建容器中的每一個組件】；
如果是web應用創建AnnotationConfigEmbeddedWebApplicationContext，否則：AnnotationConfigApplicationContext
3].refresh
refresh(context);
refresh刷新剛纔創建好的ioc容器；
|
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容器重寫了onRefresh方法
5].createEmbeddedServletContainer
webioc容器會創建嵌入式的Servlet容器；
createEmbeddedServletContainer();
|
|
6].獲取嵌入式的Servlet容器工廠
|
EmbeddedServletContainerFactory containerFactory = getEmbeddedServletContainerFactory(); |
從ioc容器中獲取EmbeddedServletContainerFactory 組件；TomcatEmbeddedServletContainerFactory創建對象，後置處理器一看是這個對象，就獲取所有的定製器來先定製Servlet容器的相關配置；
7].使用容器工廠獲取嵌入式的Servlet容器
|
this.embeddedServletContainer = containerFactory.getEmbeddedServletContainer(getSelfInitializer()); |
8].嵌入式的Servlet容器創建對象並啓動Servlet容器
先啓動嵌入式的Servlet容器，再將ioc容器中剩下沒有創建出的對象獲取出來
IOC容器啓動創建嵌入式的Servlet容器
9.外置Servlet容器
嵌入式Servlet容器：應用打成可執行的jar
嵌入式Servlet容器優點：簡單、便攜
嵌入式Servlet容器缺點：默認不支持JSP、優化定製比較複雜(使用定製器[ServerProperties、自定義EmbeddedServletContainerCustomizer[，自己編寫嵌入式Servlet容器的創建工廠[EmbeddedServletContainerFactory[);
外置式Servlet容器：外面安裝Tomcat---應用war包的方式打包；
(1).步驟
[1].創建war項目
利用idea創建好目錄結構
[2].修改pom文件
將嵌入式的Tomcat指定爲provided
|
<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-tomcat</artifactId> <scope>provided</scope> </dependency> |
[3].SpringBootServletInitializer
編寫一個SpringBootServletInitializer的子類，並調用configure方法
|
public class ServletInitializer extends SpringBootServletInitializer {
@Override protected SpringApplicationBuilder configure(SpringApplicationBuilder application) { //傳入SpringBoot應用的主程序 return application.sources(SpringBoot04WebJspApplication.class); }
} |
[4].啓動服務器
(2).原理
jar包:執行SpringBoot主類main方法,啓動ioc容器,創建嵌入式Servlet容器；
war包:啓動服務器,服務器啓動SpringBoot應用[SpringBootServletInitializer],啓動ioc容器;
[1].規則
1].服務器啓動（web應用啓動）會創建當前web應用裏面每一個jar包裏面ServletContainerInitializer實例
2].ServletContainerInitializer的實現放在jar包的META-INF/services文件夾下，有一個名爲javax.servlet.ServletContainerInitializer的文件，內容就是ServletContainerInitializer的實現類的全類名
3].使用@HandlesTypes，在應用啓動的時候加載需要的類；
[2].流程
1].啓動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模塊裏面有這個文件：
org.springframework.web.SpringServletContainerInitializer
3].SpringServletContainerInitializer
將@HandlesTypes(WebApplicationInitializer.class)標註的所有這個類型的類都傳入到onStartup方法的Set<Class<?>>；爲這些WebApplicationInitializer類型的類創建實例；
4].每一個WebApplicationInitializer都調用自己的onStartup；
5].相當於我們的SpringBootServletInitializer的類會被創建對象，並執行onStartup方法
6].SpringBootServletInitializer實例執行onStartup的時候會createRootApplicationContext；創建容器
|
protected WebApplicationContext createRootApplicationContext( ServletContext servletContext) { //1、創建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);
//調用configure方法，子類重寫了這個方法，將SpringBoot的主程序類傳入了進來 builder = configure(builder);
//使用builder創建一個Spring應用 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); } //啓動Spring應用 return run(application); } |
7].Spring的應用就啓動並且創建IOC容器
|
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, listeners, analyzers, ex); throw new IllegalStateException(ex); } } |
重要：啓動Servlet容器，再啓動SpringBoot應用
參考文檔
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