SpringBoot---web开发
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1、简介
使用SpringBoot;
1)、创建SpringBoot应用,选中我们需要的模块;
2)、SpringBoot已经默认将这些场景配置好了,只需要在配置文件中指定少量配置就可以运行起来
3)、自己编写业务代码;
自动配置原理?
这个场景SpringBoot帮我们配置了什么?能不能修改?能修改哪些配置?能不能扩展?xxx
xxxxAutoConfiguration:帮我们给容器中自动配置组件;
xxxxProperties:配置类来封装配置文件的内容;
2、SpringBoot对静态资源的映射规则
@ConfigurationProperties(prefix = "spring.resources", ignoreUnknownFields = false) public class ResourceProperties implements ResourceLoaderAware { //可以设置和静态资源有关的参数,缓存时间等
WebMvcAuotConfiguration: @Override public void addResourceHandlers(ResourceHandlerRegistry registry) { if (!this.resourceProperties.isAddMappings()) { logger.debug("Default resource handling disabled"); return; } Integer cachePeriod = this.resourceProperties.getCachePeriod(); if (!registry.hasMappingForPattern("/webjars/**")) { customizeResourceHandlerRegistration( registry.addResourceHandler("/webjars/**") .addResourceLocations( "classpath:/META‐INF/resources/webjars/") .setCachePeriod(cachePeriod)); } String staticPathPattern = this.mvcProperties.getStaticPathPattern(); //静态资源文件夹映射 if (!registry.hasMappingForPattern(staticPathPattern)) { customizeResourceHandlerRegistration( registry.addResourceHandler(staticPathPattern) .addResourceLocations( this.resourceProperties.getStaticLocations()) .setCachePeriod(cachePeriod)); } } //配置欢迎页映射 @Bean public WelcomePageHandlerMapping welcomePageHandlerMapping( ResourceProperties resourceProperties) { return new WelcomePageHandlerMapping(resourceProperties.getWelcomePage(), this.mvcProperties.getStaticPathPattern()); } //配置喜欢的图标 @Configuration @ConditionalOnProperty(value = "spring.mvc.favicon.enabled", matchIfMissing = true)
public static class FaviconConfiguration {
private final ResourceProperties resourceProperties;
public FaviconConfiguration(ResourceProperties resourceProperties) {
this.resourceProperties = resourceProperties;
}
@Bean
public SimpleUrlHandlerMapping faviconHandlerMapping() {
SimpleUrlHandlerMapping mapping = new SimpleUrlHandlerMapping();
mapping.setOrder(Ordered.HIGHEST_PRECEDENCE + 1);
//所有 **/favicon.ico
mapping.setUrlMap(Collections.singletonMap("**/favicon.ico",
faviconRequestHandler()));
return mapping;
}
@Bean
public ResourceHttpRequestHandler faviconRequestHandler() {
ResourceHttpRequestHandler requestHandler = new
ResourceHttpRequestHandler();
requestHandler
.setLocations(this.resourceProperties.getFaviconLocations());
return requestHandler;
}
}
1)、所有 /webjars/** ,都去 classpath:/META-INF/resources/webjars/ 找资源;
webjars:以jar包的方式引入静态资源;
http://www.webjars.org/
localhost:8080/webjars/jquery/3.3.1/jquery.js
<!‐‐引入jquery‐webjar‐‐>在访问的时候只需要写webjars下面资源的名称即可
<dependency>
<groupId>org.webjars</groupId>
<artifactId>jquery</artifactId>
<version>3.3.1</version>
</dependency>
2)、"/**" 访问当前项目的任何资源,都去(静态资源的文件夹)找映射
"classpath:/META‐INF/resources/", "classpath:/resources/", "classpath:/static/", "classpath:/public/" "/":当前项目的根路径
localhost:8080/abc === 去静态资源文件夹里面找abc
3)、欢迎页; 静态资源文件夹下的所有index.html页面;被"/**"映射;
localhost:8080/ 找index页面
4)、所有的 **/favicon.ico 都是在静态资源文件下找;
3、模板引擎
JSP、Velocity、Freemarker、Thymeleaf
SpringBoot推荐的Thymeleaf;
语法更简单,功能更强大;
1、引入thymeleaf;
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring‐boot‐starter‐thymeleaf</artifactId>
2.1.6
</dependency>
切换thymeleaf版本
<properties>
<thymeleaf.version>3.0.9.RELEASE</thymeleaf.version>
<!‐‐ 布局功能的支持程序 thymeleaf3主程序 layout2以上版本 ‐‐>
<!‐‐ thymeleaf2 layout1‐‐>
<thymeleaf‐layout‐dialect.version>2.2.2</thymeleaf‐layout‐dialect.version>
</properties>
2、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";
只要我们把HTML页面放在classpath:/templates/,thymeleaf就能自动渲染;
使用:
1、导入thymeleaf的名称空间
<html lang="en" xmlns:th="http://www.thymeleaf.org">
2、使用thymeleaf语法;
<!DOCTYPE html> <html lang="en" xmlns:th="http://www.thymeleaf.org"> <head> <meta charset="UTF‐8"> <title>Title</title> </head> <body> <h1>成功!</h1> <!‐‐th:text 将div里面的文本内容设置为 ‐‐> <div th:text="${hello}">这是显示欢迎信息</div> </body> </html>
3、语法规则
1)、th:text;改变当前元素里面的文本内容;
th:任意html属性;来替换原生属性的值
2)、表达式?
Simple expressions:(表达式语法) Variable Expressions: ${...}:获取变量值;OGNL; 1)、获取对象的属性、调用方法 2)、使用内置的基本对象: #ctx : the context object. #vars: the context variables. #locale : the context locale. #request : (only in Web Contexts) the HttpServletRequest object. #response : (only in Web Contexts) the HttpServletResponse object. #session : (only in Web Contexts) the HttpSession object. #servletContext : (only in Web Contexts) the ServletContext object. ${session.foo} 3)、内置的一些工具对象: #execInfo : information about the template being processed. #messages : methods for obtaining externalized messages inside variables expressions, in the same way as they would be obtained using #{…} syntax. #uris : methods for escaping parts of URLs/URIs #conversions : methods for executing the configured conversion service (if any). #dates : methods for java.util.Date objects: formatting, component extraction, etc. #calendars : analogous to #dates , but for java.util.Calendar objects. #numbers : methods for formatting numeric objects. #strings : methods for String objects: contains, startsWith, prepending/appending, etc. #objects : methods for objects in general. #bools : methods for boolean evaluation. #arrays : methods for arrays. #lists : methods for lists. #sets : methods for sets. #maps : methods for maps. #aggregates : methods for creating aggregates on arrays or collections. #ids : methods for dealing with id attributes that might be repeated (for example, as a result of an iteration). Selection Variable Expressions: *{...}:选择表达式:和${}在功能上是一样; 补充:配合 th:object="${session.user}: <div th:object="${session.user}"> <p>Name: <span th:text="*{firstName}">Sebastian</span>.</p> <p>Surname: <span th:text="*{lastName}">Pepper</span>.</p> <p>Nationality: <span th:text="*{nationality}">Saturn</span>.</p> </div> Message Expressions: #{...}:获取国际化内容 Link URL Expressions: @{...}:定义URL; @{/order/process(execId=${execId},execType=\'FAST\')} Fragment Expressions: ~{...}:片段引用表达式 <div th:insert="~{commons :: main}">...</div> Literals(字面量) Text literals: \'one text\' , \'Another one!\' ,… Number literals: 0 , 34 , 3.0 , 12.3 ,… Boolean literals: true , false Null literal: null Literal tokens: one , sometext , main ,… Text operations:(文本操作) String concatenation: + Literal substitutions: |The name is ${name}| Arithmetic operations:(数学运算) Binary operators: + , ‐ , * , / , % Minus sign (unary operator): ‐ Boolean operations:(布尔运算) Binary operators: and , or Boolean negation (unary operator): ! , not Comparisons and equality:(比较运算) Comparators: > , < , >= , <= ( gt , lt , ge , le ) Equality operators: == , != ( eq , ne ) Conditional operators:条件运算(三元运算符) If‐then: (if) ? (then) If‐then‐else: (if) ? (then) : (else) Default: (value) ?: (defaultvalue) Special tokens: No‐Operation: _
4、SpringMVC自动配置
https://docs.spring.io/spring-boot/docs/1.5.10.RELEASE/reference/htmlsingle/#boot-features-developingweb-applications
1. Spring MVC auto-configuration
Spring Boot 自动配置好了SpringMVC
以下是SpringBoot对SpringMVC的默认配置:(WebMvcAutoConfiguration)
Inclusion of ContentNegotiatingViewResolver and BeanNameViewResolver beans.
自动配置了ViewResolver(视图解析器:根据方法的返回值得到视图对象(View),视图对象决定如何
渲染(转发?重定向?))
ContentNegotiatingViewResolver:组合所有的视图解析器的;
如何定制:我们可以自己给容器中添加一个视图解析器;自动的将其组合进来;
Support for serving static resources, including support for WebJars (see below).静态资源文件夹路
径,webjars
Static index.html support. 静态首页访问
Custom Favicon support (see below). favicon.ico
自动注册了 of Converter , GenericConverter , Formatter beans.
Converter:转换器; public String hello(User user):类型转换使用Converter
Formatter 格式化器; 2017.12.17===Date;
@Bean @ConditionalOnProperty(prefix = "spring.mvc", name = "date‐format")//在文件中配置日期格 式化的规则 public Formatter<Date> dateFormatter() { return new DateFormatter(this.mvcProperties.getDateFormat());//日期格式化组件 }
自己添加的格式化器转换器,我们只需要放在容器中即可
Support for HttpMessageConverters (see below).
HttpMessageConverter:SpringMVC用来转换Http请求和响应的;User---Json;
HttpMessageConverters 是从容器中确定;获取所有的HttpMessageConverter;
自己给容器中添加HttpMessageConverter,只需要将自己的组件注册容器中
(@Bean,@Component)
Automatic registration of MessageCodesResolver (see below).定义错误代码生成规则
Automatic use of a ConfigurableWebBindingInitializer bean (see below).
我们可以配置一个ConfigurableWebBindingInitializer来替换默认的;(添加到容器)
初始化WebDataBinder;
请求数据=====JavaBean;
org.springframework.boot.autoconfigure.web:web的所有自动场景;
If you want to keep Spring Boot MVC features, and you just want to add additional MVC configuration
(interceptors, formatters, view controllers etc.) you can add your own @Configuration class of type
WebMvcConfigurerAdapter , but without @EnableWebMvc . If you wish to provide custom instances of
RequestMappingHandlerMapping , RequestMappingHandlerAdapter or ExceptionHandlerExceptionResolver
you can declare a WebMvcRegistrationsAdapter instance providing such components.
If you want to take complete control of Spring MVC, you can add your own @Configuration annotated with
@EnableWebMvc
2、扩展SpringMVC
<mvc:view‐controller path="/hello" view‐name="success"/> <mvc:interceptors> <mvc:interceptor> <mvc:mapping path="/hello"/> <bean></bean> </mvc:interceptor> </mvc:interceptors>
编写一个配置类(@Configuration),是WebMvcConfigurerAdapter类型;不能标注@EnableWebMvc;
既保留了所有的自动配置,也能用我们扩展的配置;
//使用WebMvcConfigurerAdapter可以来扩展SpringMVC的功能 @Configuration public class MyMvcConfig extends WebMvcConfigurerAdapter { @Override public void addViewControllers(ViewControllerRegistry registry) { // super.addViewControllers(registry); //浏览器发送 /atguigu 请求来到 success registry.addViewController("/atguigu").setViewName("success"); } }
原理:
1)、WebMvcAutoConfiguration是SpringMVC的自动配置类
2)、在做其他自动配置时会导入;@Import(EnableWebMvcConfiguration.class)
@Configuration public static class EnableWebMvcConfiguration extends DelegatingWebMvcConfiguration { private final WebMvcConfigurerComposite configurers = new WebMvcConfigurerComposite(); //从容器中获取所有的WebMvcConfigurer @Autowired(required = false) public void setConfigurers(List<WebMvcConfigurer> configurers) { if (!CollectionUtils.isEmpty(configurers)) { this.configurers.addWebMvcConfigurers(configurers); //一个参考实现;将所有的WebMvcConfigurer相关配置都来一起调用; @Override // public void addViewControllers(ViewControllerRegistry registry) { // for (WebMvcConfigurer delegate : this.delegates) { // delegate.addViewControllers(registry); // } } } }
3)、容器中所有的WebMvcConfigurer都会一起起作用;
4)、我们的配置类也会被调用;
效果:SpringMVC的自动配置和我们的扩展配置都会起作用;
3、全面接管SpringMVC;
SpringBoot对SpringMVC的自动配置不需要了,所有都是我们自己配置;所有的SpringMVC的自动配置都失效了
我们需要在配置类中添加@EnableWebMvc即可;
//使用WebMvcConfigurerAdapter可以来扩展SpringMVC的功能 @EnableWebMvc @Configuration public class MyMvcConfig extends WebMvcConfigurerAdapter { @Override public void addViewControllers(ViewControllerRegistry registry) { // super.addViewControllers(registry); //浏览器发送 /atguigu 请求来到 success registry.addViewController("/atguigu").setViewName("success"); } }
原理:
为什么@EnableWebMvc自动配置就失效了;
1)@EnableWebMvc的核心
@Import(DelegatingWebMvcConfiguration.class) public @interface EnableWebMvc {
2)、
@Configuration public class DelegatingWebMvcConfiguration extends WebMvcConfigurationSupport {
3)、
@Configuration @ConditionalOnWebApplication @ConditionalOnClass({ Servlet.class, DispatcherServlet.class, WebMvcConfigurerAdapter.class }) //容器中没有这个组件的时候,这个自动配置类才生效 @ConditionalOnMissingBean(WebMvcConfigurationSupport.class) @AutoConfigureOrder(Ordered.HIGHEST_PRECEDENCE + 10) @AutoConfigureAfter({ DispatcherServletAutoConfiguration.class, ValidationAutoConfiguration.class }) public class WebMvcAutoConfiguration {
4)、@EnableWebMvc将WebMvcConfigurationSupport组件导入进来;
5)、导入的WebMvcConfigurationSupport只是SpringMVC最基本的功能;
5、如何修改SpringBoot的默认配置
模式:
1)、SpringBoot在自动配置很多组件的时候,先看容器中有没有用户自己配置的(@Bean、@Component)如
果有就用用户配置的,如果没有,才自动配置;如果有些组件可以有多个(ViewResolver)将用户配置的和自己默
认的组合起来;
2)、在SpringBoot中会有非常多的xxxConfigurer帮助我们进行扩展配置
3)、在SpringBoot中会有很多的xxxCustomizer帮助我们进行定制配置
6、RestfulCRUD
1)、默认访问首页
//使用WebMvcConfigurerAdapter可以来扩展SpringMVC的功能 //@EnableWebMvc 不要接管SpringMVC @Configuration public class MyMvcConfig extends WebMvcConfigurerAdapter { @Override public void addViewControllers(ViewControllerRegistry registry) { // super.addViewControllers(registry); //浏览器发送 /atguigu 请求来到 success registry.addViewController("/atguigu").setViewName("success"); } //所有的WebMvcConfigurerAdapter组件都会一起起作用 @Bean //将组件注册在容器 public WebMvcConfigurerAdapter webMvcConfigurerAdapter(){ WebMvcConfigurerAdapter adapter = new WebMvcConfigurerAdapter() { @Override public void addViewControllers(ViewControllerRegistry registry) { registry.addViewController("/").setViewName("login"); registry.addViewController("/index.html").setViewName("login"); } }; return adapter; } }
2)、国际化
1)、编写国际化配置文件;
2)、使用ResourceBundleMessageSource管理国际化资源文件
3)、在页面使用fmt:message取出国际化内容
步骤:
1)、编写国际化配置文件,抽取页面需要显示的国际化消息
2)、SpringBoot自动配置好了管理国际化资源文件的组件;
@ConfigurationProperties(prefix = "spring.messages") public class MessageSourceAutoConfiguration { /** * Comma‐separated list of basenames (essentially a fully‐qualified classpath * location), each following the ResourceBundle convention with relaxed support for * slash based locations. If it doesn\'t contain a package qualifier (such as * "org.mypackage"), it will be resolved from the classpath root. */ private String basename = "messages"; //我们的配置文件可以直接放在类路径下叫messages.properties; @Bean public MessageSource messageSource() { ResourceBundleMessageSource messageSource = new ResourceBundleMessageSource(); if (StringUtils.hasText(this.basename)) { //设置国际化资源文件的基础名(去掉语言国家代码的) messageSource.setBasenames(StringUtils.commaDelimitedListToStringArray( StringUtils.trimAllWhitespace(this.basename))); } if (this.encoding != null) { messageSource.setDefaultEncoding(this.encoding.name()); } messageSource.setFallbackToSystemLocale(this.fallbackToSystemLocale); messageSource.setCacheSeconds(this.cacheSeconds); messageSource.setAlwaysUseMessageFormat(this.alwaysUseMessageFormat); return messageSource; }
3)、去页面获取国际化的值;
<!DOCTYPE html> <html lang="en" xmlns:th="http://www.thymeleaf.org"> <head> <meta http‐equiv="Content‐Type" content="text/html; charset=UTF‐8"> <meta name="viewport" content="width=device‐width, initial‐scale=1, shrink‐to‐ fit=no"> <meta name="description" content=""> <meta name="author" content=""> <title>Signin Template for Bootstrap</title> <!‐‐ Bootstrap core CSS ‐‐> <link href="asserts/css/bootstrap.min.css" th:href="@{/webjars/bootstrap/4.0.0/css/bootstrap.css}" rel="stylesheet"> <!‐‐ Custom styles for this template ‐‐> <link href="asserts/css/signin.css" th:href="@{/asserts/css/signin.css}" rel="stylesheet"> </head> <body class="text‐center"> <form class="form‐signin" action="dashboard.html"> <img class="mb‐4" th:src="@{/asserts/img/bootstrap‐solid.svg}" src="asserts/img/bootstrap‐solid.svg" alt="" width="72" height="72"> <h1 class="h3 mb‐3 font‐weight‐normal" th:text="#{login.tip}">Please sign in</h1> <label class="sr‐only" th:text="#{login.username}">Username</label> <input type="text" class="form‐control" placeholder="Username" th:placeholder="# {login.username}" required="" autofocus=""> <label class="sr‐only" th:text="#{login.password}">Password</label> <input type="password" class="form‐control" placeholder="Password" th:placeholder="#{login.password}" required=""> <div class="checkbox mb‐3"> <label> <input type="checkbox" value="remember‐me"/> [[#{login.remember}]] </label> </div> <button class="btn btn‐lg btn‐primary btn‐block" type="submit" th:text="# {login.btn}">Sign in</button> <p class="mt‐5 mb‐3 text‐muted">© 2017‐2018</p> <a class="btn btn‐sm">中文</a> <a class="btn btn‐sm">English</a> </form> </body> </html>
效果:根据浏览器语言设置的信息切换了国际化;
原理:
国际化Locale(区域信息对象);LocaleResolver(获取区域信息对象);
@Bean @ConditionalOnMissingBean @ConditionalOnProperty(prefix = "spring.mvc", name = "locale") public LocaleResolver localeResolver() { if (this.mvcProperties .getLocaleResolver() == WebMvcProperties.LocaleResolver.FIXED) { return new FixedLocaleResolver(this.mvcProperties.getLocale()); } AcceptHeaderLocaleResolver localeResolver = new AcceptHeaderLocaleResolver(); localeResolver.setDefaultLocale(this.mvcProperties.getLocale()); return localeResolver; } 默认的就是根据请求头带来的区域信息获取Locale进行国际化
4)、点击链接切换国际化
/** * 可以在连接上携带区域信息 */ public class MyLocaleResolver implements LocaleResolver { @Override public Locale resolveLocale(HttpServletRequest request) { String l = request.getParameter("l"); Locale locale = Locale.getDefault(); if(!StringUtils.isEmpty(l)){ String[] split = l.split("_"); locale = new Locale(split[0],split[1]); } return locale; } @Override public void setLocale(HttpServletRequest request, HttpServletResponse response, Locale locale) { } } @Bean public LocaleResolver localeResolver(){ return new MyLocaleResolver(); } }
3)、登陆
开发期间模板引擎页面修改以后,要实时生效
1)、禁用模板引擎的缓存
# 禁用缓存 spring.thymeleaf.cache=false
2)、页面修改完成以后ctrl+f9:重新编译;
登陆错误消息的显示
<p style="color: red" th:text="${msg}" th:if="${not #strings.isEmpty(msg)}"></p>
4)、拦截器进行登陆检查
拦截器
/** * 登陆检查, */ public class LoginHandlerInterceptor implements HandlerInterceptor { //目标方法执行之前 @Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception { Object user = request.getSession().getAttribute("loginUser"); if(user == null){ //未登陆,返回登陆页面 request.setAttribute("msg","没有权限请先登陆"); request.getRequestDispatcher("/index.html").forward(request,response); return false; }else{ //已登陆,放行请求 return true; } } @Override public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception { } @Override public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception { }
}
注册拦截器
//所有的WebMvcConfigurerAdapter组件都会一起起作用 @Bean //将组件注册在容器 public WebMvcConfigurerAdapter webMvcConfigurerAdapter(){ WebMvcConfigurerAdapter adapter = new WebMvcConfigurerAdapter() { @Override public void addViewControllers(ViewControllerRegistry registry) { registry.addViewController("/").setViewName("login"); registry.addViewController("/index.html").setViewName("login"); registry.addViewController("/main.html").setViewName("dashboard"); } //注册拦截器 @Override public void addInterceptors(InterceptorRegistry registry) { //super.addInterceptors(registry); //静态资源; *.css , *.js //SpringBoot已经做好了静态资源映射 registry.addInterceptor(new LoginHandlerInterceptor()).addPathPatterns("/**") .excludePathPatterns("/index.html","/","/user/login"); } }; return adapter; }
5)、CRUD-员工列表
实验要求:
1)、RestfulCRUD:CRUD满足Rest风格;
URI: /资源名称/资源标识 HTTP请求方式区分对资源CRUD操作
2)、实验的请求架构;
3)、员工列表:
thymeleaf公共页面元素抽取
1、抽取公共片段 <div th:fragment="copy"> © 2011 The Good Thymes Virtual Grocery </div> 2、引入公共片段 <div th:insert="~{footer :: copy}"></div> ~{templatename::selector}:模板名::选择器 ~{templatename::fragmentname}:模板名::片段名 3、默认效果: insert的公共片段在div标签中 如果使用th:insert等属性进行引入,可以不用写~{}: 行内写法可以加上:[[~{}]];[(~{})];
三种引入公共片段的th属性:
th:insert:将公共片段整个插入到声明引入的元素中
th:replace:将声明引入的元素替换为公共片段
th:include:将被引入的片段的内容包含进这个标签中
<footer th:fragment="copy"> © 2011 The Good Thymes Virtual Grocery </footer> 引入方式 <div th:insert="footer :: copy"></div> <div th:replace="footer :: copy"></div> <div th:include="footer :: copy"></div> 效果 <div> <footer> © 2011 The Good Thymes Virtual Grocery </footer> </div> <footer> © 2011 The Good Thymes Virtual Grocery </footer> <div> © 2011 The Good Thymes Virtual Grocery </div>
引入片段的时候传入参数:
<nav class="col‐md‐2 d‐none d‐md‐block bg‐light sidebar" id="sidebar"> <div class="sidebar‐sticky"> <ul class="nav flex‐column"> <li class="nav‐item"> <a class="nav‐link active" th:class="${activeUri==\'main.html\'?\'nav‐link active\':\'nav‐link\'}" href="#" th:href="@{/main.html}"> <svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke‐width="2" stroke‐ linecap="round" stroke‐linejoin="round" class="feather feather‐home"> <path d="M3 9l9‐7 9 7v11a2 2 0 0 1‐2 2H5a2 2 0 0 1‐2‐2z"></path> <polyline points="9 22 9 12 15 12 15 22"></polyline> </svg> Dashboard <span class="sr‐only">(current)</span> </a> </li> <!‐‐引入侧边栏;传入参数‐‐> <div th:replace="commons/bar::#sidebar(activeUri=\'emps\')"></div>
6)、CRUD-员工添加
添加页面
<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>
提交的数据格式不对:生日:日期;
2017-12-12;2017/12/12;2017.12.12;
日期的格式化;SpringMVC将页面提交的值需要转换为指定的类型;
2017-12-12---Date; 类型转换,格式化;
默认日期是按照/的方式;
7)、CRUD-员工修改
修改添加二合一表单
<!‐‐需要区分是员工修改还是添加;‐‐> <form th:action="@{/emp}" method="post"> <!‐‐发送put请求修改员工数据‐‐> <!‐‐ 1、SpringMVC中配置HiddenHttpMethodFilter;(SpringBoot自动配置好的) 2、页面创建一个post表单 3、创建一个input项,name="_method";值就是我们指定的请求方式 ‐‐> <input type="hidden" name="_method" value="put" th:if="${emp!=null}"/> <input type="hidden" name="id" th:if="${emp!=null}" th:value="${emp.id}"> <div class="form‐group"> <label>LastName</label> <input name="lastName" type="text" class="form‐control" placeholder="zhangsan" th:value="${emp!=null}?${emp.lastName}"> </div> <div class="form‐group"> <label>Email</label> <input name="email" type="email" class="form‐control" placeholder="zhangsan@atguigu.com" th:value="${emp!=null}?${emp.email}"> </div> <div class="form‐group"> <label>Gender</label><br/> <div class="form‐check form‐check‐inline"> <input class="form‐check‐input" type="radio" name="gender" value="1" th:checked="${emp!=null}?${emp.gender==1}"> <label class="form‐check‐label">男</label> </div> <div class="form‐check form‐check‐inline"> <input class="form‐check‐input" type="radio" name="gender" value="0" th:checked="${emp!=null}?${emp.gender==0}"> <label class="form‐check‐label">女</label> </div> </div> <div class="form‐group"> <label>department</label> <!‐‐提交的是部门的id‐‐> <select class="form‐control" name="department.id"> <option th:selected="${emp!=null}?${dept.id == emp.department.id}" th:value="${dept.id}" th:each="dept:${depts}" th:text="${dept.departmentName}">1</option> </select> </div> <div class="form‐group"> <label>Birth</label> <input name="birth" type="text" class="form‐control" placeholder="zhangsan" th:value="${emp!=null}?${#dates.format(emp.birth, \'yyyy‐MM‐dd HH:mm\')}"> </div> <button type="submit" class="btn btn‐primary" th:text="${emp!=null}?\'修改\':\'添加\'">添加 </button> </form>
8)、CRUD-员工删除
<tr th:each="emp:${emps}"> <td th:text="${emp.id}"></td> <td>[[${emp.lastName}]]</td> <td th:text="${emp.email}"></td> <td th:text="${emp.gender}==0?\'女\':\'男\'"></td> <td th:text="${emp.department.departmentName}"></td> <td th:text="${#dates.format(emp.birth, \'yyyy‐MM‐dd HH:mm\')}"></td> <td> <a class="btn btn‐sm btn‐primary" th:href="@{/emp/}+${emp.id}">编辑</a> <button th:attr="del_uri=@{/emp/}+${emp.id}" class="btn btn‐sm btn‐danger deleteBtn">删除</button> </td> </tr> <script> $(".deleteBtn").click(function(){ //删除当前员工的 $("#deleteEmpForm").attr("action",$(this).attr("del_uri")).submit(); return false; }); </script>
7、错误处理机制
1)、SpringBoot默认的错误处理机制
默认效果:
1)、浏览器,返回一个默认的错误页面
浏览器发送请求的请求头:
原理:
可以参照ErrorMvcAutoConfiguration;错误处理的自动配置;
给容器中添加了以下组件
1、DefaultErrorAttributes:
帮我们在页面共享信息; @Override public Map<String, Object> getErrorAttributes(RequestAttributes requestAttributes, boolean includeStackTrace) { Map<String, Object> errorAttributes = new LinkedHashMap<String, Object>(); errorAttributes.put("timestamp", new Date()); addStatus(errorAttributes, requestAttributes); addErrorDetails(errorAttributes, requestAttributes, includeStackTrace); addPath(errorAttributes, requestAttributes); return errorAttributes; }
2、BasicErrorController:处理默认/error请求
@Controller @RequestMapping("${server.error.path:${error.path:/error}}") public class BasicErrorController extends AbstractErrorController { @RequestMapping(produces = "text/html")//产生html类型的数据;浏览器发送的请求来到这个方法处理 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()); //去哪个页面作为错误页面;包含页面地址和页面内容 ModelAndView modelAndView = resolveErrorView(request, response, status, model); return (modelAndView == null ? new ModelAndView("error", model) : modelAndView); } @RequestMapping @ResponseBody //产生json数据,其他客户端来到这个方法处理; 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"; 系统出现错误以后来到error请求进行处理;(web.xml注册的错误页 面规则)
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) { //默认SpringBoot可以去找到一个页面? error/404 String errorViewName = "error/" + viewName; //模板引擎可以解析这个页面地址就用模板引擎解析 TemplateAvailabilityProvider provider = this.templateAvailabilityProviders .getProvider(errorViewName, this.applicationContext); if (provider != null) { //模板引擎可用的情况下返回到errorViewName指定的视图地址 return new ModelAndView(errorViewName, model); } //模板引擎不可用,就在静态资源文件夹下找errorViewName对应的页面 error/404.html以上是关于SpringBoot---web开发的主要内容,如果未能解决你的问题,请参考以下文章