四冠骄、Web開發(fā)
1、簡(jiǎn)介
使用SpringBoot加袋；
1）凛辣、創(chuàng)建SpringBoot應(yīng)用，選中我們需要的模塊锁荔；
2）蟀给、SpringBoot已經(jīng)默認(rèn)將這些場(chǎng)景配置好了蝙砌，只需要在配置文件中指定少量配置就可以運(yùn)行起來(lái)
3）阳堕、自己編寫業(yè)務(wù)代碼跋理；
2、模板引擎
JSP恬总、Velocity前普、Freemarker、Thymeleaf
SpringBoot推薦的Thymeleaf壹堰；
語(yǔ)法更簡(jiǎn)單拭卿，功能更強(qiáng)大；
2.1贱纠、引入thymeleaf峻厚；
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>
切換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>
2.2、Thymeleaf使用
@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";
//
只要我們把HTML頁(yè)面放在classpath:/templates/谆焊，thymeleaf就能自動(dòng)渲染惠桃；
使用：
1、導(dǎo)入thymeleaf的名稱空間
<html lang="en" xmlns:th="http://www.thymeleaf.org">
2辖试、使用thymeleaf語(yǔ)法辜王；
<!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里面的文本內(nèi)容設(shè)置為 -->
<div th:text="${hello}">這是顯示歡迎信息</div>
</body>
</html>
2.3罐孝、語(yǔ)法規(guī)則
1）呐馆、th:text；改變當(dāng)前元素里面的文本內(nèi)容莲兢；
? th：任意html屬性汹来；來(lái)替換原生屬性的值
2）、表達(dá)式改艇？
Simple expressions:（表達(dá)式語(yǔ)法）
a. Variable Expressions: ${...}：獲取變量值俗慈；OGNL；
1）遣耍、獲取對(duì)象的屬性闺阱、調(diào)用方法
2）、使用內(nèi)置的基本對(duì)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.
${session.foo}
3）舵变、內(nèi)置的一些工具對(duì)象：
#execInfo : information about the template being processed.
#messages : methods for obtaining externalized messages inside variables expressions,
# in the same way as they would be obtained using #{…} syntax.
#uris : methods for escaping parts of URLs/URIs
#conversions : methods for executing the configured conversion service (if any).
#dates : methods for java.util.Date objects: formatting, component extraction, etc.
#calendars : analogous to #dates , but for java.util.Calendar objects.
#numbers : methods for formatting numeric objects.
#strings : methods for String objects: contains, startsWith, prepending/appending, etc.
#objects : methods for objects in general.
#bools : methods for boolean evaluation.
#arrays : methods for arrays.
#lists : methods for lists.
#sets : methods for sets.
#maps : methods for maps.
#aggregates : methods for creating aggregates on arrays or collections.
#ids : methods for dealing with id attributes that might be repeated (for example, as a result of an iteration).
b. Selection Variable Expressions: *{...}：選擇表達(dá)式：和${}在功能上是一樣酣溃；
補(bǔ)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>
c. Message Expressions: #{...}：獲取國(guó)際化內(nèi)容
d. Link URL Expressions: @{...}：定義URL；
@{/order/process(execId=${execId},execType='FAST')}
f. Fragment Expressions: ~{...}：片段引用表達(dá)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(shù)學(xué)運(yùn)算）
Binary operators: + , - , * , / , %
Minus sign (unary operator): -
Boolean operations:（布爾運(yùn)算）
Binary operators: and , or
Boolean negation (unary operator): ! , not
Comparisons and equality:（比較運(yùn)算）
Comparators: > , < , >= , <= ( gt , lt , ge , le )
Equality operators: == , != ( eq , ne )
Conditional operators:條件運(yùn)算（三元運(yùn)算符）
If-then: (if) ? (then)
If-then-else: (if) ? (then) : (else)
Default: (value) ?: (defaultvalue)
Special tokens:
No-Operation: _
3纪隙、SpringMVC自動(dòng)配置
1. Spring MVC auto-configuration
Spring Boot 自動(dòng)配置好了SpringMVC
以下是SpringBoot對(duì)SpringMVC的默認(rèn)配置:（WebMvcAutoConfiguration）
-
Inclusion of
ContentNegotiatingViewResolverandBeanNameViewResolverbeans.- 自動(dòng)配置了ViewResolver（視圖解析器：根據(jù)方法的返回值得到視圖對(duì)象（View）赊豌，視圖對(duì)象決定如何渲染（轉(zhuǎn)發(fā)？重定向绵咱？））
- ContentNegotiatingViewResolver：組合所有的視圖解析器的碘饼；
- 如何定制：我們可以自己給容器中添加一個(gè)視圖解析器；自動(dòng)的將其組合進(jìn)來(lái)；
Support for serving static resources, including support for WebJars (see below).靜態(tài)資源文件夾路徑,webjars
Static
index.htmlsupport. 靜態(tài)首頁(yè)訪問(wèn)-
Custom
Faviconsupport (see below). favicon.ico?
-
自動(dòng)注冊(cè)了 of
Converter,GenericConverter,Formatterbeans.-
Converter：轉(zhuǎn)換器艾恼； public String hello(User user)：類型轉(zhuǎn)換使用Converter -
Formatter格式化器住涉； 2017.12.17===Date；
-
@Bean
@ConditionalOnProperty(prefix = "spring.mvc", name = "date-format")//在文件中配置日期格式化的規(guī)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(zhuǎn)換器钠绍，我們只需要放在容器中即可
-
Support for
HttpMessageConverters(see below).HttpMessageConverter：SpringMVC用來(lái)轉(zhuǎn)換Http請(qǐng)求和響應(yīng)的舆声；User---Json；-
HttpMessageConverters是從容器中確定柳爽；獲取所有的HttpMessageConverter媳握；自己給容器中添加HttpMessageConverter，只需要將自己的組件注冊(cè)容器中（@Bean,@Component）
?
Automatic registration of
MessageCodesResolver(see below).定義錯(cuò)誤代碼生成規(guī)則-
Automatic use of a
ConfigurableWebBindingInitializerbean (see below).我們可以配置一個(gè)ConfigurableWebBindingInitializer來(lái)替換默認(rèn)的磷脯；（添加到容器）
初始化WebDataBinder蛾找； 請(qǐng)求數(shù)據(jù)=====JavaBean；
org.springframework.boot.autoconfigure.web：web的所有自動(dòng)場(chǎng)景赵誓；
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.
If you want to take complete control of Spring MVC, you can add your own @Configuration annotated with @EnableWebMvc.
2打毛、擴(kuò)展SpringMVC
<mvc:view-controller path="/hello" view-name="success"/>
<mvc:interceptors>
<mvc:interceptor>
<mvc:mapping path="/hello"/>
<bean></bean>
</mvc:interceptor>
</mvc:interceptors>
編寫一個(gè)配置類（@Configuration），是WebMvcConfigurerAdapter類型架曹；不能標(biāo)注@EnableWebMvc;
既保留了所有的自動(dòng)配置隘冲，也能用我們擴(kuò)展的配置；
/**
* @Author: cuzz
* @Date: 2018/9/21 14:29
* @Description:
*/
@Configuration
// WebMvcConfigurerAdapter過(guò)時(shí),使用WebMvcConfigurer接口
public class MyMvcConfig implements WebMvcConfigurer {
@Override
public void addViewControllers(ViewControllerRegistry registry) {
// 瀏覽器發(fā)送 /cuzz 請(qǐng)求來(lái)到 success
registry.addViewController("/cuzz").setViewName("success");
}
}
原理：
? 1）绑雄、WebMvcAutoConfiguration是SpringMVC的自動(dòng)配置類
? 2）展辞、在做其他自動(dòng)配置時(shí)會(huì)導(dǎo)入；@Import(EnableWebMvcConfiguration.class)
@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(gè)參考實(shí)現(xiàn)万牺；將所有的WebMvcConfigurer相關(guān)配置都來(lái)一起調(diào)用罗珍；
@Override
// public void addViewControllers(ViewControllerRegistry registry) {
// for (WebMvcConfigurer delegate : this.delegates) {
// delegate.addViewControllers(registry);
// }
}
}
}
? 3）、容器中所有的WebMvcConfigurer都會(huì)一起起作用脚粟；
? 4）覆旱、我們的配置類也會(huì)被調(diào)用；
? 效果：SpringMVC的自動(dòng)配置和我們的擴(kuò)展配置都會(huì)起作用核无；
3扣唱、全面接管SpringMVC；
SpringBoot對(duì)SpringMVC的自動(dòng)配置不需要了团南，所有都是我們自己配置；所有的SpringMVC的自動(dòng)配置都失效了
我們需要在配置類中添加@EnableWebMvc即可吐根；
//使用WebMvcConfigurerAdapter可以來(lái)擴(kuò)展SpringMVC的功能
@EnableWebMvc
@Configuration
public class MyMvcConfig extends WebMvcConfigurerAdapter {
@Override
public void addViewControllers(ViewControllerRegistry registry) {
// super.addViewControllers(registry);
//瀏覽器發(fā)送 /atguigu 請(qǐng)求來(lái)到 success
registry.addViewController("/atguigu").setViewName("success");
}
}
原理：
為什么@EnableWebMvc自動(dòng)配置就失效了拷橘；
1）@EnableWebMvc的核心
@Import(DelegatingWebMvcConfiguration.class)
public @interface EnableWebMvc {
2）、
@Configuration
public class DelegatingWebMvcConfiguration extends WebMvcConfigurationSupport {
3）檩帐、
@Configuration
@ConditionalOnWebApplication
@ConditionalOnClass({ Servlet.class, DispatcherServlet.class,
WebMvcConfigurerAdapter.class })
// 容器中沒(méi)有這個(gè)組件的時(shí)候，這個(gè)自動(dòng)配置類才生效
@ConditionalOnMissingBean(WebMvcConfigurationSupport.class)
@AutoConfigureOrder(Ordered.HIGHEST_PRECEDENCE + 10)
@AutoConfigureAfter({ DispatcherServletAutoConfiguration.class,
ValidationAutoConfiguration.class })
public class WebMvcAutoConfiguration {
4）穷绵、@EnableWebMvc將WebMvcConfigurationSupport組件導(dǎo)入進(jìn)來(lái)轿塔；
5）特愿、導(dǎo)入的WebMvcConfigurationSupport只是SpringMVC最基本的功能仲墨；
5、如何修改SpringBoot的默認(rèn)配置
模式：
? 1）揍障、SpringBoot在自動(dòng)配置很多組件的時(shí)候目养，先看容器中有沒(méi)有用戶自己配置的（@Bean、@Component）如果有就用用戶配置的毒嫡，如果沒(méi)有癌蚁，才自動(dòng)配置；如果有些組件可以有多個(gè)（ViewResolver）將用戶配置的和自己默認(rèn)的組合起來(lái)兜畸；
? 2）努释、在SpringBoot中會(huì)有非常多的xxxConfigurer幫助我們進(jìn)行擴(kuò)展配置
? 3）、在SpringBoot中會(huì)有很多的xxxCustomizer幫助我們進(jìn)行定制配置
6咬摇、RestfulCRUD
1）逸邦、默認(rèn)訪問(wèn)首頁(yè)
/**
* @Author: cuzz
* @Date: 2018/9/21 14:29
* @Description:
*/
@Configuration
// WebMvcConfigurerAdapter過(guò)時(shí),使用WebMvcConfigurer接口
public class MyMvcConfig implements WebMvcConfigurer {
@Override
public void addViewControllers(ViewControllerRegistry registry) {
registry.addViewController("/cuzz").setViewName("success");
}
// 所有的WebMvcConfigurerAdapter組件都會(huì)一起起作用
@Bean
public WebMvcConfigurer webMvcConfigurer() {
WebMvcConfigurer webMvcConfigurer = new WebMvcConfigurer() {
@Override
public void addViewControllers(ViewControllerRegistry registry) {
registry.addViewController("/").setViewName("login");
registry.addViewController("/index.html").setViewName("login");
}
};
return webMvcConfigurer;
}
}
2）芒珠、國(guó)際化
1）裹芝、編寫國(guó)際化配置文件；
2）蜈漓、使用ResourceBundleMessageSource管理國(guó)際化資源文件
3）、在頁(yè)面使用fmt:message取出國(guó)際化內(nèi)容
i18n = internationalization（國(guó)際化）的縮寫有额，首位的i和末尾的n之間有18個(gè)字母，所以就簡(jiǎn)寫為i18n了
步驟：
new -> add properties file to resource bundle 要先新建一個(gè)properties文件，xxx_en_US.properties語(yǔ)言和國(guó)家
1）洒擦、編寫國(guó)際化配置文件秦踪，抽取頁(yè)面需要顯示的國(guó)際化消息
2）聊疲、SpringBoot自動(dòng)配置好了管理國(guó)際化資源文件的組件贡珊；
@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爱致；
@Bean
public MessageSource messageSource() {
ResourceBundleMessageSource messageSource = new ResourceBundleMessageSource();
if (StringUtils.hasText(this.basename)) {
//設(shè)置國(guó)際化資源文件的基礎(chǔ)名（去掉語(yǔ)言國(guó)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）妻往、去頁(yè)面獲取國(guó)際化的值忘朝；
<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<meta name="description" content="">
<meta name="author" content="">
<title>Signin Template for Bootstrap</title>
<!-- Bootstrap core CSS -->
<link href="asserts/css/bootstrap.min.css" th:href="@{/webjars/bootstrap/4.0.0/css/bootstrap.css}" rel="stylesheet">
<!-- Custom styles for this template -->
<link href="asserts/css/signin.css" th:href="@{/asserts/css/signin.css}" rel="stylesheet">
</head>
<body class="text-center">
<form class="form-signin" action="dashboard.html">
<img class="mb-4" th:src="@{/asserts/img/bootstrap-solid.svg}" src="asserts/img/bootstrap-solid.svg" alt="" width="72" height="72">
<h1 class="h3 mb-3 font-weight-normal" th:text="#{login.tip}">Please sign in</h1>
<label class="sr-only" th:text="#{login.username}">Username</label>
<input type="text" class="form-control" placeholder="Username" th:placeholder="#{login.username}" required="" autofocus="">
<label class="sr-only" th:text="#{login.password}">Password</label>
<input type="password" class="form-control" placeholder="Password" th:placeholder="#{login.password}" required="">
<div class="checkbox mb-3">
<label>
<input type="checkbox" value="remember-me"/> [[#{login.remember}]]
</label>
</div>
<button class="btn btn-lg btn-primary btn-block" type="submit" th:text="#{login.btn}">Sign in</button>
<p class="mt-5 mb-3 text-muted">? 2017-2018</p>
<a class="btn btn-sm">中文</a>
<a class="btn btn-sm">English</a>
</form>
</body>
</html>
效果：根據(jù)瀏覽器語(yǔ)言設(shè)置的信息切換了國(guó)際化；
原理：
? 國(guó)際化Locale（區(qū)域信息對(duì)象）晌畅；LocaleResolver（獲取區(qū)域信息對(duì)象）；
@Bean
@ConditionalOnMissingBean
@ConditionalOnProperty(prefix = "spring.mvc", name = "locale")
public LocaleResolver localeResolver() {
if (this.mvcProperties
.getLocaleResolver() == WebMvcProperties.LocaleResolver.FIXED) {
return new FixedLocaleResolver(this.mvcProperties.getLocale());
}
AcceptHeaderLocaleResolver localeResolver = new AcceptHeaderLocaleResolver();
localeResolver.setDefaultLocale(this.mvcProperties.getLocale());
return localeResolver;
}
默認(rèn)的就是根據(jù)請(qǐng)求頭帶來(lái)的區(qū)域信息獲取Locale進(jìn)行國(guó)際化
4）、點(diǎn)擊鏈接切換國(guó)際化
/**
* 可以在連接上攜帶區(qū)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) {
}
// 國(guó)際化注入
@Bean
public LocaleResolver localeResolver(){
return new MyLocaleResolver();
}
}
3）、登陸
開發(fā)期間模板引擎頁(yè)面修改以后勺良，要實(shí)時(shí)生效
1）、禁用模板引擎的緩存
# 禁用緩存
spring.thymeleaf.cache=false
2）忙芒、頁(yè)面修改完成以后ctrl+f9：重新編譯；
登陸錯(cuò)誤消息的顯示
<p style="color: red" th:text="${msg}" th:if="${not #strings.isEmpty(msg)}"></p>
4）潮峦、攔截器進(jìn)行登陸檢查
攔截器
/**
* 登陸檢查耕渴，
*/
public class LoginHandlerInterceptor implements HandlerInterceptor {
//目標(biāo)方法執(zhí)行之前
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
Object user = request.getSession().getAttribute("loginUser");
if(user == null){
//未登陸础米，返回登陸頁(yè)面
request.setAttribute("msg","沒(méi)有權(quán)限請(qǐng)先登陸");
request.getRequestDispatcher("/index.html").forward(request,response);
return false;
}else{
//已登陸栏赴，放行請(qǐng)求
return true;
}
}
@Override
public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
}
@Override
public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
}
}
注冊(cè)攔截器
/**
* @Author: cuzz
* @Date: 2018/9/21 14:29
* @Description:
*/
@Configuration
// WebMvcConfigurerAdapter過(guò)時(shí),使用WebMvcConfigurer接口
public class MyMvcConfig implements WebMvcConfigurer {
@Override
public void addViewControllers(ViewControllerRegistry registry) {
registry.addViewController("/cuzz").setViewName("success");
}
//注冊(cè)攔截器
@Override
public void addInterceptors(InterceptorRegistry registry) {
//super.addInterceptors(registry);
//靜態(tài)資源； *.css , *.js
//SpringBoot已經(jīng)做好了靜態(tài)資源映射
registry.addInterceptor(new LoginHandlerInterceptor()).addPathPatterns("/**")
.excludePathPatterns("/index.html","/","/user/login");
}
// 所有的WebMvcConfigurerAdapter組件都會(huì)一起起作用
@Bean
public WebMvcConfigurer webMvcConfigurer() {
WebMvcConfigurer webMvcConfigurer = 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 webMvcConfigurer;
}
@Bean
public LocaleResolver localeResolver() {
return new MyLocaleResolver();
}
}
5）译打、CRUD-員工列表
實(shí)驗(yàn)要求：
1）赋续、RestfulCRUD：CRUD滿足Rest風(fēng)格条霜；
URI： /資源名稱/資源標(biāo)識(shí) HTTP請(qǐng)求方式區(qū)分對(duì)資源CRUD操作
| 普通CRUD（uri來(lái)區(qū)分操作） | RestfulCRUD | |
|---|---|---|
| 查詢 | getEmp | emp---GET |
| 添加 | addEmp?xxx | emp---POST |
| 修改 | updateEmp?id=xxx&xxx=xx | emp/{id}---PUT |
| 刪除 | deleteEmp?id=1 | emp/{id}---DELETE |
2）气筋、實(shí)驗(yàn)的請(qǐng)求架構(gòu);
| 實(shí)驗(yàn)功能 | 請(qǐng)求URI | 請(qǐng)求方式 |
|---|---|---|
| 查詢所有員工 | emps | GET |
| 查詢某個(gè)員工(來(lái)到修改頁(yè)面) | emp/1 | GET |
| 來(lái)到添加頁(yè)面 | emp | GET |
| 添加員工 | emp | POST |
| 來(lái)到修改頁(yè)面（查出員工進(jìn)行信息回顯） | emp/1 | GET |
| 修改員工 | emp | PUT |
| 刪除員工 | emp/1 | DELETE |
3）、員工列表：
thymeleaf公共頁(yè)面元素抽取
1、抽取公共片段
<div th:fragment="copy">
© 2011 The Good Thymes Virtual Grocery
</div>
2瓤球、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(rèn)效果：
insert的公共片段在div標(biāo)簽中
如果使用th:insert等屬性進(jìn)行引入，可以不用寫~{}：
行內(nèi)寫法可以加上：[[~{}]];[(~{})]蝴罪；
三種引入公共片段的th屬性：
th:insert：將公共片段整個(gè)插入到聲明引入的元素中
th:replace：將聲明引入的元素替換為公共片段
th:include：將被引入的片段的內(nèi)容包含進(jìn)這個(gè)標(biāo)簽中
<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(shí)候傳入?yún)?shù)：
<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(cè)邊欄;傳入?yún)?shù)-->
<div th:replace="commons/bar::#sidebar(activeUri='emps')"></div>
6）、CRUD-員工添加
添加頁(yè)面
<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>
提交的數(shù)據(jù)格式不對(duì)：生日：日期；
2017-12-12第步；2017/12/12；2017.12.12翩隧；
日期的格式化；SpringMVC將頁(yè)面提交的值需要轉(zhuǎn)換為指定的類型;
2017-12-12---Date涝婉； 類型轉(zhuǎn)換，格式化;
默認(rèn)日期是按照/的方式最住；
7）、CRUD-員工修改
修改添加二合一表單
<!--需要區(qū)分是員工修改還是添加；-->
<form th:action="@{/emp}" method="post">
<!--發(fā)送put請(qǐng)求修改員工數(shù)據(jù)-->
<!--
1茂翔、SpringMVC中配置HiddenHttpMethodFilter;（SpringBoot自動(dòng)配置好的）
2、頁(yè)面創(chuàng)建一個(gè)post表單
3悔政、創(chuàng)建一個(gè)input項(xiàng)，name="_method";值就是我們指定的請(qǐng)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="${emp!=null}?'修改':'添加'">添加</button>
</form>
8）集畅、CRUD-員工刪除
<tr th:each="emp:${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(dāng)前員工的
$("#deleteEmpForm").attr("action",$(this).attr("del_uri")).submit();
return false;
});
</script>
7、錯(cuò)誤處理機(jī)制
1）迫摔、SpringBoot默認(rèn)的錯(cuò)誤處理機(jī)制
默認(rèn)效果：
? 1）、瀏覽器纱烘，返回一個(gè)默認(rèn)的錯(cuò)誤頁(yè)面
瀏覽器發(fā)送請(qǐng)求的請(qǐng)求頭：
? 2）帆阳、如果是其他客戶端山宾，默認(rèn)響應(yīng)一個(gè)json數(shù)據(jù)
?
原理：
? 可以參照ErrorMvcAutoConfiguration绷杜；錯(cuò)誤處理的自動(dòng)配置；
給容器中添加了以下組件
? 1、DefaultErrorAttributes：
幫我們?cè)陧?yè)面共享信息培他；
@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途蒋、BasicErrorController：處理默認(rèn)/error請(qǐng)求
@Controller
@RequestMapping("${server.error.path:${error.path:/error}}")
public class BasicErrorController extends AbstractErrorController {
@RequestMapping(produces = "text/html")//產(chǎn)生html類型的數(shù)據(jù)梯醒；瀏覽器發(fā)送的請(qǐng)求來(lái)到這個(gè)方法處理
public ModelAndView errorHtml(HttpServletRequest request,
HttpServletResponse response) {
HttpStatus status = getStatus(request);
Map<String, Object> model = Collections.unmodifiableMap(getErrorAttributes(
request, isIncludeStackTrace(request, MediaType.TEXT_HTML)));
response.setStatus(status.value());
//去哪個(gè)頁(yè)面作為錯(cuò)誤頁(yè)面；包含頁(yè)面地址和頁(yè)面內(nèi)容
ModelAndView modelAndView = resolveErrorView(request, response, status, model);
return (modelAndView == null ? new ModelAndView("error", model) : modelAndView);
}
@RequestMapping
@ResponseBody //產(chǎn)生json數(shù)據(jù)号胚，其他客戶端來(lái)到這個(gè)方法處理；
public ResponseEntity<Map<String, Object>> error(HttpServletRequest request) {
Map<String, Object> body = getErrorAttributes(request,
isIncludeStackTrace(request, MediaType.ALL));
HttpStatus status = getStatus(request);
return new ResponseEntity<Map<String, Object>>(body, status);
}
? 3、ErrorPageCustomizer：
@Value("${error.path:/error}")
private String path = "/error"; 系統(tǒng)出現(xiàn)錯(cuò)誤以后來(lái)到error請(qǐng)求進(jìn)行處理驾茴；（web.xml注冊(cè)的錯(cuò)誤頁(yè)面規(guī)則）
? 4、DefaultErrorViewResolver：
@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(rèn)SpringBoot可以去找到一個(gè)頁(yè)面？ error/404
String errorViewName = "error/" + viewName;
//模板引擎可以解析這個(gè)頁(yè)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);
}
//模板引擎不可用们拙，就在靜態(tài)資源文件夾下找errorViewName對(duì)應(yīng)的頁(yè)面 error/404.html
return resolveResource(errorViewName, model);
}
? 步驟：
? 一但系統(tǒng)出現(xiàn)4xx或者5xx之類的錯(cuò)誤突勇；ErrorPageCustomizer就會(huì)生效（定制錯(cuò)誤的響應(yīng)規(guī)則）埂奈；就會(huì)來(lái)到/error請(qǐng)求芹敌；就會(huì)被BasicErrorController處理；
? 1）響應(yīng)頁(yè)面幌衣；去哪個(gè)頁(yè)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）、如果定制錯(cuò)誤響應(yīng)：
1）班缎、如何定制錯(cuò)誤的頁(yè)面；
? 1）、有模板引擎的情況下满葛；error/狀態(tài)碼; 【將錯(cuò)誤頁(yè)面命名為 錯(cuò)誤狀態(tài)碼.html 放在模板引擎文件夾里面的 error文件夾下】，發(fā)生此狀態(tài)碼的錯(cuò)誤就會(huì)來(lái)到 對(duì)應(yīng)的頁(yè)面锄贷；
? 我們可以使用4xx和5xx作為錯(cuò)誤頁(yè)面的文件名來(lái)匹配這種類型的所有錯(cuò)誤，精確優(yōu)先（優(yōu)先尋找精確的狀態(tài)碼.html）；
? 頁(yè)面能獲取的信息；
? timestamp：時(shí)間戳
? status：狀態(tài)碼
? error：錯(cuò)誤提示
? exception：異常對(duì)象
? message：異常消息
? errors：JSR303數(shù)據(jù)校驗(yàn)的錯(cuò)誤都在這里
? 2）勿决、沒(méi)有模板引擎（模板引擎找不到這個(gè)錯(cuò)誤頁(yè)面），靜態(tài)資源文件夾下找咆繁；
? 3）、以上都沒(méi)有錯(cuò)誤頁(yè)面坏为，就是默認(rèn)來(lái)到SpringBoot默認(rèn)的錯(cuò)誤提示頁(yè)面；
2）够颠、如何定制錯(cuò)誤的json數(shù)據(jù)牢硅；
? 1）综苔、自定義異常處理&返回定制json數(shù)據(jù)；
@ControllerAdvice
public class MyExceptionHandler {
@ResponseBody
@ExceptionHandler(UserNotExistException.class)
public Map<String,Object> handleException(Exception e){
Map<String,Object> map = new HashMap<>();
map.put("code","user.notexist");
map.put("message",e.getMessage());
return map;
}
}
//沒(méi)有自適應(yīng)效果...
? 2）、轉(zhuǎn)發(fā)到/error進(jìn)行自適應(yīng)響應(yīng)效果處理
@ExceptionHandler(UserNotExistException.class)
public String handleException(Exception e, HttpServletRequest request){
Map<String,Object> map = new HashMap<>();
//傳入我們自己的錯(cuò)誤狀態(tài)碼 4xx 5xx妖胀，否則就不會(huì)進(jìn)入定制錯(cuò)誤頁(yè)面的解析流程
/**
* Integer statusCode = (Integer) request
.getAttribute("javax.servlet.error.status_code");
*/
request.setAttribute("javax.servlet.error.status_code",500);
map.put("code","user.notexist");
map.put("message",e.getMessage());
//轉(zhuǎn)發(fā)到/error
return "forward:/error";
}
3）爬坑、將我們的定制數(shù)據(jù)攜帶出去赁遗；
出現(xiàn)錯(cuò)誤以后涨薪，會(huì)來(lái)到/error請(qǐng)求，會(huì)被BasicErrorController處理侠姑，響應(yīng)出去可以獲取的數(shù)據(jù)是由getErrorAttributes得到的（是AbstractErrorController（ErrorController）規(guī)定的方法）；
? 1、完全來(lái)編寫一個(gè)ErrorController的實(shí)現(xiàn)類【或者是編寫AbstractErrorController的子類】鬼店，放在容器中；
? 2巍棱、頁(yè)面上能用的數(shù)據(jù)，或者是json返回能用的數(shù)據(jù)都是通過(guò)errorAttributes.getErrorAttributes得到倒得；
? 容器中DefaultErrorAttributes.getErrorAttributes()谊路；默認(rèn)進(jìn)行數(shù)據(jù)處理的潮梯；
自定義ErrorAttributes
//給容器中加入我們自己定義的ErrorAttributes
@Component
public class MyErrorAttributes extends DefaultErrorAttributes {
@Override
public Map<String, Object> getErrorAttributes(RequestAttributes requestAttributes, boolean includeStackTrace) {
Map<String, Object> map = super.getErrorAttributes(requestAttributes, includeStackTrace);
map.put("company","atguigu");
return map;
}
}
最終的效果：響應(yīng)是自適應(yīng)的脱羡，可以通過(guò)定制ErrorAttributes改變需要返回的內(nèi)容帆竹，
8、配置嵌入式Servlet容器
SpringBoot默認(rèn)使用Tomcat作為嵌入式的Servlet容器；
問(wèn)題熔恢？
1）、如何定制和修改Servlet容器的相關(guān)配置；
1衅谷、修改和server有關(guān)的配置（ServerProperties【也是EmbeddedServletContainerCustomizer】）蚀苛；
server.port=8081
server.context-path=/crud
server.tomcat.uri-encoding=UTF-8
//通用的Servlet容器設(shè)置
server.xxx
//Tomcat的設(shè)置
server.tomcat.xxx
2、編寫一個(gè)EmbeddedServletContainerCustomizer：嵌入式的Servlet容器的定制器渗蟹；來(lái)修改Servlet容器的配置
@Bean //一定要將這個(gè)定制器加入到容器中
public EmbeddedServletContainerCustomizer embeddedServletContainerCustomizer(){
return new EmbeddedServletContainerCustomizer() {
//定制嵌入式的Servlet容器相關(guān)的規(guī)則
@Override
public void customize(ConfigurableEmbeddedServletContainer container) {
container.setPort(8083);
}
};
}
2）辨嗽、注冊(cè)Servlet三大組件【Servlet屉佳、Filter、Listener】
由于SpringBoot默認(rèn)是以jar包的方式啟動(dòng)嵌入式的Servlet容器來(lái)啟動(dòng)SpringBoot的web應(yīng)用髓堪，沒(méi)有web.xml文件。
注冊(cè)三大組件用以下方式
ServletRegistrationBean
//注冊(cè)三大組件
@Bean
public ServletRegistrationBean myServlet(){
ServletRegistrationBean registrationBean = new ServletRegistrationBean(new MyServlet(),"/myServlet");
return registrationBean;
}
FilterRegistrationBean
@Bean
public FilterRegistrationBean myFilter(){
FilterRegistrationBean registrationBean = new FilterRegistrationBean();
registrationBean.setFilter(new MyFilter());
registrationBean.setUrlPatterns(Arrays.asList("/hello","/myServlet"));
return registrationBean;
}
ServletListenerRegistrationBean
@Bean
public ServletListenerRegistrationBean myListener(){
ServletListenerRegistrationBean<MyListener> registrationBean = new ServletListenerRegistrationBean<>(new MyListener());
return registrationBean;
}
SpringBoot幫我們自動(dòng)SpringMVC的時(shí)候争群，自動(dòng)的注冊(cè)SpringMVC的前端控制器翔试；DIspatcherServlet冲泥；
DispatcherServletAutoConfiguration中：
@Bean(name = DEFAULT_DISPATCHER_SERVLET_REGISTRATION_BEAN_NAME)
@ConditionalOnBean(value = DispatcherServlet.class, name = DEFAULT_DISPATCHER_SERVLET_BEAN_NAME)
public ServletRegistrationBean dispatcherServletRegistration(
DispatcherServlet dispatcherServlet) {
ServletRegistrationBean registration = new ServletRegistrationBean(
dispatcherServlet, this.serverProperties.getServletMapping());
//默認(rèn)攔截： / 所有請(qǐng)求志秃；包靜態(tài)資源，但是不攔截jsp請(qǐng)求碑定； /*會(huì)攔截jsp
//可以通過(guò)server.servletPath來(lái)修改SpringMVC前端控制器默認(rèn)攔截的請(qǐng)求路徑
registration.setName(DEFAULT_DISPATCHER_SERVLET_BEAN_NAME);
registration.setLoadOnStartup(
this.webMvcProperties.getServlet().getLoadOnStartup());
if (this.multipartConfig != null) {
registration.setMultipartConfig(this.multipartConfig);
}
return registration;
}
2）六敬、SpringBoot能不能支持其他的Servlet容器；
3）审编、替換為其他嵌入式Servlet容器
默認(rèn)支持：
Tomcat（默認(rèn)使用）
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
引入web模塊默認(rèn)就是使用嵌入式的Tomcat作為Servlet容器；
</dependency>
Jetty
<!-- 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>
Undertow
<!-- 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(dòng)配置原理；
EmbeddedServletContainerAutoConfiguration：嵌入式的Servlet容器自動(dòng)配置景描？
@AutoConfigureOrder(Ordered.HIGHEST_PRECEDENCE)
@Configuration
@ConditionalOnWebApplication
@Import(BeanPostProcessorsRegistrar.class)
//導(dǎo)入BeanPostProcessorsRegistrar：Spring注解版；給容器中導(dǎo)入一些組件
//導(dǎo)入了EmbeddedServletContainerCustomizerBeanPostProcessor：
//后置處理器：bean初始化前后（創(chuàng)建完對(duì)象，還沒(méi)賦值賦值）執(zhí)行初始化工作
public class EmbeddedServletContainerAutoConfiguration {
@Configuration
@ConditionalOnClass({ Servlet.class, Tomcat.class })//判斷當(dāng)前是否引入了Tomcat依賴弄唧；
@ConditionalOnMissingBean(value = EmbeddedServletContainerFactory.class, search = SearchStrategy.CURRENT)//判斷當(dāng)前容器沒(méi)有用戶自己定義EmbeddedServletContainerFactory：嵌入式的Servlet容器工廠侯养；作用：創(chuàng)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）麸俘、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）逞泄、EmbeddedServletContainer：（嵌入式的Servlet容器）
3）、以TomcatEmbeddedServletContainerFactory為例
@Override
public EmbeddedServletContainer getEmbeddedServletContainer(
ServletContextInitializer... initializers) {
//創(chuàng)建一個(gè)Tomcat
Tomcat tomcat = new Tomcat();
//配置Tomcat的基本環(huán)節(jié)
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(jìn)去，返回一個(gè)EmbeddedServletContainer；并且啟動(dòng)Tomcat服務(wù)器
return getTomcatEmbeddedServletContainer(tomcat);
}
4）加矛、我們對(duì)嵌入式容器的配置修改是怎么生效？
ServerProperties苛茂、EmbeddedServletContainerCustomizer
EmbeddedServletContainerCustomizer：定制器幫我們修改了Servlet容器的配置？
怎么修改的原理？
5）净刮、容器中導(dǎo)入了EmbeddedServletContainerCustomizerBeanPostProcessor
//初始化之前
@Override
public Object postProcessBeforeInitialization(Object bean, String beanName)
throws BeansException {
//如果當(dāng)前初始化的是一個(gè)ConfigurableEmbeddedServletContainer類型的組件
if (bean instanceof ConfigurableEmbeddedServletContainer) {
//
postProcessBeforeInitialization((ConfigurableEmbeddedServletContainer) bean);
}
return bean;
}
private void postProcessBeforeInitialization(
ConfigurableEmbeddedServletContainer bean) {
//獲取所有的定制器，調(diào)用每一個(gè)定制器的customize方法來(lái)給Servlet容器進(jìn)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
//定制Servlet容器座哩，給容器中可以添加一個(gè)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也是定制器
步驟：
1）、SpringBoot根據(jù)導(dǎo)入的依賴情況溶浴，給容器中添加相應(yīng)的EmbeddedServletContainerFactory【TomcatEmbeddedServletContainerFactory】
2）闯两、容器中某個(gè)組件要?jiǎng)?chuàng)建對(duì)象就會(huì)驚動(dòng)后置處理器；EmbeddedServletContainerCustomizerBeanPostProcessor；
只要是嵌入式的Servlet容器工廠稽煤，后置處理器就工作驰坊；
3）皮璧、后置處理器，從容器中獲取所有的EmbeddedServletContainerCustomizer转培，調(diào)用定制器的定制方法
5）恶导、嵌入式Servlet容器啟動(dòng)原理；
什么時(shí)候創(chuàng)建嵌入式的Servlet容器工廠浸须？什么時(shí)候獲取嵌入式的Servlet容器并啟動(dòng)Tomcat惨寿；
獲取嵌入式的Servlet容器工廠：
1）、SpringBoot應(yīng)用啟動(dòng)運(yùn)行run方法
2）删窒、refreshContext(context);SpringBoot刷新IOC容器【創(chuàng)建IOC容器對(duì)象裂垦，并初始化容器诚亚，創(chuàng)建容器中的每一個(gè)組件】夷家；如果是web應(yīng)用創(chuàng)建AnnotationConfigEmbeddedWebApplicationContext，否則：AnnotationConfigApplicationContext
3）县爬、refresh(context);刷新剛才創(chuàng)建好的ioc容器斩狱；
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）秕岛、 onRefresh(); web的ioc容器重寫了onRefresh方法
5）遏考、webioc容器會(huì)創(chuàng)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 組件截歉；TomcatEmbeddedServletContainerFactory創(chuàng)建對(duì)象墅诡，后置處理器一看是這個(gè)對(duì)象，就獲取所有的定制器來(lái)先定制Servlet容器的相關(guān)配置；
7）变抽、使用容器工廠獲取嵌入式的Servlet容器：this.embeddedServletContainer = containerFactory .getEmbeddedServletContainer(getSelfInitializer());
8）锰提、嵌入式的Servlet容器創(chuàng)建對(duì)象并啟動(dòng)Servlet容器；
先啟動(dòng)嵌入式的Servlet容器区拳，再將ioc容器中剩下沒(méi)有創(chuàng)建出的對(duì)象獲取出來(lái)乞而；
IOC容器啟動(dòng)創(chuàng)建嵌入式的Servlet容器
9、使用外置的Servlet容器
嵌入式Servlet容器：應(yīng)用打成可執(zhí)行的jar
? 優(yōu)點(diǎn)：簡(jiǎn)單、便攜污朽；
? 缺點(diǎn)：默認(rèn)不支持JSP淤齐、優(yōu)化定制比較復(fù)雜（使用定制器【ServerProperties喇勋、自定義EmbeddedServletContainerCustomizer】，自己編寫嵌入式Servlet容器的創(chuàng)建工廠【EmbeddedServletContainerFactory】）；
外置的Servlet容器：外面安裝Tomcat---應(yīng)用war包的方式打包；
步驟
1）甫男、必須創(chuàng)建一個(gè)war項(xiàng)目婆跑；（利用idea創(chuàng)建好目錄結(jié)構(gòu)）
- new project or new module
- create
- web.xml
- 添加外部tomcat啟動(dòng)
2）、將嵌入式的Tomcat指定為provided芽突；
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-tomcat</artifactId>
<scope>provided</scope>
</dependency>
3）、必須編寫一個(gè)SpringBootServletInitializer的子類诞丽，并調(diào)用configure方法
public class ServletInitializer extends SpringBootServletInitializer {
@Override
protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
//傳入SpringBoot應(yīng)用的主程序
return application.sources(SpringBoot04WebJspApplication.class);
}
}
4）枷餐、啟動(dòng)服務(wù)器就可以使用卫病；
原理
jar包：執(zhí)行SpringBoot主類的main方法，啟動(dòng)ioc容器擂错，創(chuàng)建嵌入式的Servlet容器；
war包：?jiǎn)?dòng)服務(wù)器，服務(wù)器啟動(dòng)SpringBoot應(yīng)用【SpringBootServletInitializer】绒瘦，啟動(dòng)ioc容器骄蝇；
servlet3.0（Spring注解版）：
8.2.4 Shared libraries / runtimes pluggability：
規(guī)則：
? 1）絮短、服務(wù)器啟動(dòng)（web應(yīng)用啟動(dòng)）會(huì)創(chuàng)建當(dāng)前web應(yīng)用里面每一個(gè)jar包里面ServletContainerInitializer實(shí)例：
? 2）、ServletContainerInitializer的實(shí)現(xiàn)放在jar包的META-INF/services文件夾下，有一個(gè)名為javax.servlet.ServletContainerInitializer的文件拌喉，內(nèi)容就是ServletContainerInitializer的實(shí)現(xiàn)類的全類名
? 3）、還可以使用@HandlesTypes舷丹，在應(yīng)用啟動(dòng)的時(shí)候加載我們感興趣的類语盈；
流程：
1）垫毙、啟動(dòng)Tomcat
2）傲醉、org\springframework\spring-web\4.3.14.RELEASE\spring-web-4.3.14.RELEASE.jar!\META-INF\services\javax.servlet.ServletContainerInitializer：
Spring的web模塊里面有這個(gè)文件：org.springframework.web.SpringServletContainerInitializer
3）撵渡、SpringServletContainerInitializer將@HandlesTypes(WebApplicationInitializer.class)標(biāo)注的所有這個(gè)類型的類都傳入到onStartup方法的Set<Class<?>>；為這些WebApplicationInitializer類型的類創(chuàng)建實(shí)例；
4）宴凉、每一個(gè)WebApplicationInitializer都調(diào)用自己的onStartup；
5）、相當(dāng)于我們的SpringBootServletInitializer的類會(huì)被創(chuàng)建對(duì)象，并執(zhí)行onStartup方法
6）、SpringBootServletInitializer實(shí)例執(zhí)行onStartup的時(shí)候會(huì)createRootApplicationContext；創(chuàng)建容器
protected WebApplicationContext createRootApplicationContext(
ServletContext servletContext) {
//1、創(chuàng)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(diào)用configure方法捎谨，子類重寫了這個(gè)方法憔维，將SpringBoot的主程序類傳入了進(jìn)來(lái)
builder = configure(builder);
//使用builder創(chuàng)建一個(gè)Spring應(yīng)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);
}
//啟動(dòng)Spring應(yīng)用
return run(application);
}
7）涛救、Spring的應(yīng)用就啟動(dòng)并且創(chuàng)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);
}
}
啟動(dòng)Servlet容器，再啟動(dòng)SpringBoot應(yīng)用
