springboot包多大 springboot 1.0 2.0

配置文件与web开发基础

• 5. springboot配置文件

• 1.properties
• 2.ymal

• 2.1、简介
• 2.2、基本语法
• 2.3、数据类型
• 2.4、示例

• 3.在springboot项目中开启配置提示

• 6. web开发

• 1、SpringMVC自动配置概览
• 2、简单功能分析

• 2.1、静态资源访问

• 1、静态资源目录
• 2、静态资源访问前缀
• 3、webjar

• 2.2、欢迎页支持
• 2.3、自定义 `Favicon`
• 2.4、静态资源配置原理

• 1、配置类只有一个有参构造器
• 2、资源处理的默认规则
• 3、欢迎页的处理规则
• 4、favicon

5. springboot配置文件

1.properties

Properties配置文件比较常见，java中也有对应的类，在java基础中也有所设计。

properties以键值对的格式来存储配置信息，如下：

username=root
path=root

2.ymal

2.1、简介

YAML 是 “YAML Ain’t Markup Language”（YAML 不是一种标记语言）的递归缩写。在开发的这种语言时，YAML 的意思其实是：“Yet Another Markup Language”（仍是一种标记语言）。

非常适合用来做以数据为中心的配置文件

2.2、基本语法

• key: value；kv之间有空格（key: value）
• 大小写敏感
• 使用缩进表示层级关系
• 缩进不允许使用tab，只允许空格
• 缩进的空格数不重要，只要相同层级的元素左对齐即可
• '#'表示注释
• 字符串无需加引号，如果要加，’'与""表示字符串内容 会被 转义/不转义

2.3、数据类型

• 字面量：单个的、不可再分的值。date、boolean、string、number、null

k: v

• 对象：键值对的集合。map、hash、set、object

行内写法：  k: {k1:v1,k2:v2,k3:v3}
#或
k: 
    k1: v1
  k2: v2
  k3: v3

• 数组：一组按次序排列的值。array、list、queue

行内写法：  k: [v1,v2,v3]
#或者
k:
 - v1
 - v2
 - v3

2.4、示例

@Data
public class Person {
    
    private String userName;
    private Boolean boss;
    private Date birth;
    private Integer age;
    private Pet pet;
    private String[] interests;
    private List<String> animal;
    private Map<String, Object> score;
    private Set<Double> salarys;
    private Map<String, List<Pet>> allPets;
}

@Data
public class Pet {
    private String name;
    private Double weight;
}

# yaml表示以上对象
person:
  userName: zhangsan
  boss: false
  birth: 2019/12/12 20:12:33
  age: 18
  pet: 
    name: tomcat
    weight: 23.4
  interests: [篮球,游泳]
  animal: 
    - jerry
    - mario
  score:
    english: 
      first: 30
      second: 40
      third: 50
    math: [131,140,148]
    chinese: {first: 128,second: 136}
  salarys: [3999,4999.98,5999.99]
  allPets:
    sick:
      - {name: tom}
      - {name: jerry,weight: 47}
    health: [{name: mario,weight: 47}]

3.在springboot项目中开启配置提示

自定义的类和配置文件绑定一般没有提示。

<!--开启配置提示 -->
<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-configuration-processor</artifactId>
            <optional>true</optional>
  </dependency>


 <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <excludes>
                        <!--在打包时排除配置提示的包 -->
                        <exclude>
                            <groupId>org.springframework.boot</groupId>
                            <artifactId>spring-boot-configuration-processor</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>
        </plugins>
    </build>

6. web开发

1、SpringMVC自动配置概览

Spring Boot provides auto-configuration for Spring MVC that works well with most applications.(大多场景我们都无需自定义配置)

The auto-configuration adds the following features on top of Spring’s defaults:

• Inclusion of ContentNegotiatingViewResolver and BeanNameViewResolver beans.

• 内容协商视图解析器和BeanName视图解析器

• Support for serving static resources, including support for WebJars (covered later in this document)).

• 静态资源（包括webjars）

• Automatic registration of Converter, GenericConverter, and Formatter beans.

• 自动注册 Converter，GenericConverter，Formatter

• Support for HttpMessageConverters (covered later in this document).

• 支持 HttpMessageConverters （后来我们配合内容协商理解原理）

• Automatic registration of MessageCodesResolver (covered later in this document).

• 自动注册 MessageCodesResolver （国际化用）

• Static index.html support.

• 静态index.html 页支持

• Custom Favicon support (covered later in this document).

• 自定义 Favicon

• Automatic use of a ConfigurableWebBindingInitializer bean (covered later in this document).

• 自动使用 ConfigurableWebBindingInitializer ，（DataBinder负责将请求数据绑定到JavaBean上）

If you want to keep those Spring Boot MVC customizations and make more MVC customizations (interceptors, formatters, view controllers, and other features), you can add your own @Configuration class of type WebMvcConfigurer but without @EnableWebMvc.

不用@EnableWebMvc注解。使用 @Configuration + WebMvcConfigurer 自定义规则

If you want to provide custom instances of RequestMappingHandlerMapping, RequestMappingHandlerAdapter, or ExceptionHandlerExceptionResolver, and still keep the Spring Boot MVC customizations, you can declare a bean of type WebMvcRegistrations and use it to provide custom instances of those components.

声明 WebMvcRegistrations 改变默认底层组件

If you want to take complete control of Spring MVC, you can add your own @Configuration annotated with @EnableWebMvc, or alternatively add your own @Configuration-annotated DelegatingWebMvcConfiguration as described in the Javadoc of @EnableWebMvc.

使用 @EnableWebMvc+@Configuration+DelegatingWebMvcConfiguration 全面接管SpringMVC

2、简单功能分析

2.1、静态资源访问

1、静态资源目录

只要静态资源放在类路径下： /static、/public 、/resources/、META-INF/resources

访问 ： 当前项目根路径/ + 静态资源名

原理： 静态映射/**。

请求进来，先去找Controller看能不能处理。不能处理的所有请求又都交给静态资源处理器。静态资源也找不到则响应404页面

改变默认的静态资源路径

spring:
  mvc:
    static-path-pattern: /res/**

  resources:
    static-locations: [classpath:/haha/]

2、静态资源访问前缀

默认无前缀

spring:
  mvc:
    static-path-pattern: /res/**

当前项目 + static-path-pattern + 静态资源名 = 静态资源文件夹下找

3、webjar

自动映射 /webjars/**

https://www.webjars.org/

<dependency>
            <groupId>org.webjars</groupId>
            <artifactId>jquery</artifactId>
            <version>3.5.1</version>
        </dependency>

访问地址：http://localhost:8080/webjars/jquery/3.5.1/jquery.js 后面地址要按照依赖里面的包路径

2.2、欢迎页支持

• 静态资源路径下 index.html

• 可以配置静态资源路径
• 但是不可以配置静态资源的访问前缀。否则导致 index.html不能被默认访问

spring:
#  mvc:
#    static-path-pattern: /res/**   这个会导致welcome page功能失效

  resources:
    static-locations: [classpath:/haha/]

• controller能处理/index
• 
  

2.3、自定义 Favicon

favicon.ico 放在静态资源目录下即可。

spring:
#  mvc:
#    static-path-pattern: /res/**   这个会导致 Favicon 功能失效

2.4、静态资源配置原理

• SpringBoot启动默认加载 xxxAutoConfiguration 类（自动配置类）
• SpringMVC功能的自动配置类 WebMvcAutoConfiguration，生效

@Configuration(proxyBeanMethods = false)
@ConditionalOnWebApplication(type = Type.SERVLET)
@ConditionalOnClass({ Servlet.class, DispatcherServlet.class, WebMvcConfigurer.class })
@ConditionalOnMissingBean(WebMvcConfigurationSupport.class)
@AutoConfigureOrder(Ordered.HIGHEST_PRECEDENCE + 10)
@AutoConfigureAfter({ DispatcherServletAutoConfiguration.class, TaskExecutionAutoConfiguration.class,
        ValidationAutoConfiguration.class })
public class WebMvcAutoConfiguration {}

• 给容器中配了什么。

@Configuration(proxyBeanMethods = false)
    @Import(EnableWebMvcConfiguration.class)
    @EnableConfigurationProperties({ WebMvcProperties.class, ResourceProperties.class })
    @Order(0)
    public static class WebMvcAutoConfigurationAdapter implements WebMvcConfigurer {}

• 配置文件的相关属性和xxx进行了绑定。WebMvcProperties==spring.mvc、ResourceProperties==spring.resources

1、配置类只有一个有参构造器

//有参构造器所有参数的值都会从容器中确定
//ResourceProperties resourceProperties；获取和spring.resources绑定的所有的值的对象
//WebMvcProperties mvcProperties 获取和spring.mvc绑定的所有的值的对象
//ListableBeanFactory beanFactory Spring的beanFactory
//HttpMessageConverters 找到所有的HttpMessageConverters
//ResourceHandlerRegistrationCustomizer 找到 资源处理器的自定义器。=========
//DispatcherServletPath  
//ServletRegistrationBean   给应用注册Servlet、Filter....
    public WebMvcAutoConfigurationAdapter(ResourceProperties resourceProperties, WebMvcProperties mvcProperties,
                ListableBeanFactory beanFactory, ObjectProvider<HttpMessageConverters> messageConvertersProvider,
                ObjectProvider<ResourceHandlerRegistrationCustomizer> resourceHandlerRegistrationCustomizerProvider,
                ObjectProvider<DispatcherServletPath> dispatcherServletPath,
                ObjectProvider<ServletRegistrationBean<?>> servletRegistrations) {
            this.resourceProperties = resourceProperties;
            this.mvcProperties = mvcProperties;
            this.beanFactory = beanFactory;
            this.messageConvertersProvider = messageConvertersProvider;
            this.resourceHandlerRegistrationCustomizer = resourceHandlerRegistrationCustomizerProvider.getIfAvailable();
            this.dispatcherServletPath = dispatcherServletPath;
            this.servletRegistrations = servletRegistrations;
        }

2、资源处理的默认规则

@Override
        public void addResourceHandlers(ResourceHandlerRegistry registry) {
            if (!this.resourceProperties.isAddMappings()) {
                logger.debug("Default resource handling disabled");
                return;
            }
            Duration cachePeriod = this.resourceProperties.getCache().getPeriod();
            CacheControl cacheControl = this.resourceProperties.getCache().getCachecontrol().toHttpCacheControl();
            //webjars的规则
            if (!registry.hasMappingForPattern("/webjars/**")) {
                customizeResourceHandlerRegistration(registry.addResourceHandler("/webjars/**")
                        .addResourceLocations("classpath:/META-INF/resources/webjars/")
                        .setCachePeriod(getSeconds(cachePeriod)).setCacheControl(cacheControl));
            }
            
            //
            String staticPathPattern = this.mvcProperties.getStaticPathPattern();
            if (!registry.hasMappingForPattern(staticPathPattern)) {
                customizeResourceHandlerRegistration(registry.addResourceHandler(staticPathPattern)
                        .addResourceLocations(getResourceLocations(this.resourceProperties.getStaticLocations()))
                        .setCachePeriod(getSeconds(cachePeriod)).setCacheControl(cacheControl));
            }
        }
==============application.yaml==================
//spring:
//#  mvc:
//#    static-path-pattern: /res/**
      resources:
    	add-mappings: false   禁用所有静态资源规则
================================
@ConfigurationProperties(prefix = "spring.resources", ignoreUnknownFields = false)
public class ResourceProperties {

    private static final String[] CLASSPATH_RESOURCE_LOCATIONS = { "classpath:/META-INF/resources/",
            "classpath:/resources/", "classpath:/static/", "classpath:/public/" };

    /**
     * Locations of static resources. Defaults to classpath:[/META-INF/resources/,
     * /resources/, /static/, /public/].
     */
    private String[] staticLocations = CLASSPATH_RESOURCE_LOCATIONS;

3、欢迎页的处理规则

HandlerMapping：处理器映射。保存了每一个Handler能处理哪些请求。  

    @Bean
        public WelcomePageHandlerMapping welcomePageHandlerMapping(ApplicationContext applicationContext,
                FormattingConversionService mvcConversionService, ResourceUrlProvider mvcResourceUrlProvider) {
            WelcomePageHandlerMapping welcomePageHandlerMapping = new WelcomePageHandlerMapping(
                    new TemplateAvailabilityProviders(applicationContext), applicationContext, getWelcomePage(),
                    this.mvcProperties.getStaticPathPattern());
            welcomePageHandlerMapping.setInterceptors(getInterceptors(mvcConversionService, mvcResourceUrlProvider));
            welcomePageHandlerMapping.setCorsConfigurations(getCorsConfigurations());
            return welcomePageHandlerMapping;
        }

    WelcomePageHandlerMapping(TemplateAvailabilityProviders templateAvailabilityProviders,
            ApplicationContext applicationContext, Optional<Resource> welcomePage, String staticPathPattern) {
        if (welcomePage.isPresent() && "/**".equals(staticPathPattern)) {
            //要用欢迎页功能，必须是/**
            logger.info("Adding welcome page: " + welcomePage.get());
            setRootViewName("forward:index.html");
        }
        else if (welcomeTemplateExists(templateAvailabilityProviders, applicationContext)) {
            // 调用Controller  /index
            logger.info("Adding welcome page template: index");
            setRootViewName("index");
        }
    }

4、favicon

在static文件夹下放如文件：favicon.ico，springboot会自动加载到网页的标题上。