readme.md

Spring-mvc

servlet

servlet-scope

• PageContext

  • 生命周期
    • 发送JSP页面请求时创建
    • JSP页面响应结束销毁
  • 作用域
    • 单一JSP页面

• Request

  • 生命周期
    • 在发送请求时Request存在，当请求结束Request销毁
  • 作用
    • 负责在请求过程中数据交互
  • 作用域
    • 一个请求
  • Spring中对应
    • org.springframework.web.context.WebApplicationContext#SCOPE_REQUEST

• Session

  • 生命周期
    • request.getSession() 调用时，校验是否存在session ， 如果不存在则创建
    • 销毁
      • 不正当销毁：强制关闭服务器
      • session一定量的时间内没有使用，自动进行销毁
      • session.invalidate()手动销毁
  • 作用域
    • 一个会话
  • Spring中对应
    • org.springframework.web.context.WebApplicationContext#SCOPE_SESSION

• ServletContext

  • 生命周期

    • web应用加载到容器，此时ServletContext 就是整个web应用
    • 当服务器关闭、web应用从容器中移除，ServletContext被销毁

  • 作用域

    • 整个web应用

  • Spring中对应

    • org.springframework.web.context.WebApplicationContext#SCOPE_APPLICATION

thymeleaf

配置

• Properties配置内容

# THYMELEAF (ThymeleafAutoConfiguration)
spring.thymeleaf.cache=true # Whether to enable template caching.
spring.thymeleaf.check-template=true # Whether to check that the template exists before rendering it.
spring.thymeleaf.check-template-location=true # Whether to check that the templates location exists.
spring.thymeleaf.enabled=true # Whether to enable Thymeleaf view resolution for Web frameworks.
spring.thymeleaf.enable-spring-el-compiler=false # Enable the SpringEL compiler in SpringEL expressions.
spring.thymeleaf.encoding=UTF-8 # Template files encoding.
spring.thymeleaf.excluded-view-names= # Comma-separated list of view names (patterns allowed) that should be excluded from resolution.
spring.thymeleaf.mode=HTML # Template mode to be applied to templates. See also Thymeleaf's TemplateMode enum.
spring.thymeleaf.prefix=classpath:/templates/ # Prefix that gets prepended to view names when building a URL.
spring.thymeleaf.reactive.chunked-mode-view-names= # Comma-separated list of view names (patterns allowed) that should be the only ones executed in CHUNKED mode when a max chunk size is set.
spring.thymeleaf.reactive.full-mode-view-names= # Comma-separated list of view names (patterns allowed) that should be executed in FULL mode even if a max chunk size is set.
spring.thymeleaf.reactive.max-chunk-size=0B # Maximum size of data buffers used for writing to the response.
spring.thymeleaf.reactive.media-types= # Media types supported by the view technology.
spring.thymeleaf.render-hidden-markers-before-checkboxes=false # Whether hidden form inputs acting as markers for checkboxes should be rendered before the checkbox element itself.
spring.thymeleaf.servlet.content-type=text/html # Content-Type value written to HTTP responses.
spring.thymeleaf.servlet.produce-partial-output-while-processing=true # Whether Thymeleaf should start writing partial output as soon as possible or buffer until template processing is finished.
spring.thymeleaf.suffix=.html # Suffix that gets appended to view names when building a URL.
spring.thymeleaf.template-resolver-order= # Order of the template resolver in the chain.
spring.thymeleaf.view-names= # Comma-separated list of view names (patterns allowed) that can be resolved.

• org.springframework.boot.autoconfigure.thymeleaf.ThymeleafProperties 配置内容的对应类

  @ConfigurationProperties(prefix = "spring.thymeleaf")
  public class ThymeleafProperties {
  
     private static final Charset DEFAULT_ENCODING = StandardCharsets.UTF_8;
  
     public static final String DEFAULT_PREFIX = "classpath:/templates/";
  
     public static final String DEFAULT_SUFFIX = ".html";
      ...
  }

• 通过 @ConfigurationProperties(prefix = "spring.thymeleaf") 前缀找到对应的 配置属性

• 模板寻址

  • prefix-view-name+suffix

    	public static final String DEFAULT_PREFIX = "classpath:/templates/";
    	public static final String DEFAULT_SUFFIX = ".html";

    @Controller
    public class Tcontroller {
    
        @GetMapping("/")
        public String hello(Model model) {
            model.addAttribute("message", "hello");
            return "h1";
        }
    
    }

    默认情况下 地址为 classpath:/templates/ + hello方法的返回值 + ".html"

    • /target/classes/templates/h1.html

内置变量

• execInfo
  • 对应JAVA 类 org.thymeleaf.expression.ExecutionInfo
• messages
  • 对应JAVA 类 org.thymeleaf.expression.Messages
• uris
  • 对应JAVA 类 org.thymeleaf.expression.Uris
• conversions
  • 对应JAVA 类 org.thymeleaf.expression.Conversions
• dates
  • 对应JAVA 类 org.thymeleaf.expression.Dates
• calendars
  • 对应JAVA 类 org.thymeleaf.expression.Calendars
• numbers
  • 对应JAVA 类 org.thymeleaf.expression.Numbers
• strings
  • 对应JAVA 类 org.thymeleaf.expression.Strings
• objects
  • 对应JAVA 类 org.thymeleaf.expression.Objects
• bools
  • 对应JAVA 类 org.thymeleaf.expression.Bools
• arrays
  • 对应JAVA 类 org.thymeleaf.expression.Arrays
• lists
  • 对应JAVA 类 org.thymeleaf.expression.Lists
• sets
  • 对应JAVA 类 org.thymeleaf.expression.Sets
• maps
  • 对应JAVA 类 org.thymeleaf.expression.Maps
• aggregates
  • 对应JAVA 类 org.thymeleaf.expression.Aggregates
• ids
  • 对应JAVA 类 org.thymeleaf.expression.Ids

使用方法

一般用${#内置变量名称.方法函数 }

<p th:text="${#strings.toUpperCase(upp)}">Hello</p>

@ModelAttribute(name = "upp")
public String upp(){
    return "jkll";
}

渲染 ThymeleafView

• Spring-mvc 渲染view 逻辑基本相同 详细查看这篇文章

• org.thymeleaf.spring5.view.ThymeleafView#renderFragment

              viewTemplateEngine.process(templateName, processMarkupSelectors, context, (Writer)templateWriter);
  

  

  • 数据有了，模板名称有了 ，接下来进行路径组合

    • org.thymeleaf.TemplateEngine#process(org.thymeleaf.TemplateSpec, org.thymeleaf.context.IContext, java.io.Writer) 中的具体解析

      templateManager.parseAndProcess(templateSpec, context, writer);

      public void parseAndProcess(TemplateSpec templateSpec, IContext context, Writer writer) {
        ....
            // 第一次访问时 通过resolveTemplate 进行模板初始化
                    TemplateResolution templateResolution = resolveTemplate(this.configuration, (String)null, template, templateResolutionAttributes, true);
      
          ...
      }

      • org.thymeleaf.engine.TemplateManager#resolveTemplate

        处理完成后

        

        • 内容部分org.thymeleaf.TemplateEngine#process(org.thymeleaf.TemplateSpec, org.thymeleaf.context.IContext, java.io.Writer)

          public final void process(TemplateSpec templateSpec, IContext context, Writer writer) {
              ...
                  try {
                          writer.flush();
                      } catch (IOException var11) {
                          throw new TemplateOutputException("An error happened while flushing output writer", templateSpec.getTemplate(), -1, -1, var11);
                      } 
                  
          }

          • org.apache.catalina.connector.CoyoteWriter#flush

                public void flush() {
                    if (!this.error) {
                        try {
                            this.ob.flush();
                        } catch (IOException var2) {
                            this.error = true;
                        }
            
                    }
                }

            

            

            • 到此路径 + 模板替换具体数据都完成 可以在网页中正常看到内容