SpringBoot学习SpringApplication

曾经终败给现在 2022-01-12 23:09 231阅读 0赞

`SpringApplication`类提供了一种方便的方法来引导从`main（）`方法启动`Spring`应用程序。在许多情况下，您可以委托给静态`SpringApplication.run()`方法，如下例所示:

@SpringBootApplication
    public class Application {
        public static void main(String[] args) {
            SpringApplication.run(Application.class,args);
        }
    }

当你的应用启动成功后， 你会看到类似下面的这些信息：

.   ____          _            __ _ _
     /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
    ( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
     \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
      '  |____| .__|_| |_|_| |_\__, | / / / /
     =========|_|==============|___/=/_/_/_/
     :: Spring Boot ::   v2.1.5.RELEASE
    
    2013-07-31 00:08:16.117  INFO 56603 --- [           main] o.s.b.s.app.SampleApplication            : Starting SampleApplication v0.1.0 on mycomputer with PID 56603 (/apps/myapp.jar started by pwebb)
    2013-07-31 00:08:16.166  INFO 56603 --- [           main] ationConfigServletWebServerApplicationContext : Refreshing org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext@6e5a8246: startup date [Wed Jul 31 00:08:16 PDT 2013]; root of context hierarchy
    2014-03-04 13:09:54.912  INFO 41370 --- [           main] .t.TomcatServletWebServerFactory : Server initialized with port: 8080
    2014-03-04 13:09:56.501  INFO 41370 --- [           main] o.s.b.s.app.SampleApplication            : Started SampleApplication in 2.992 seconds (JVM running for 3.658)

--------------------

启动失败  
如果你的应用启动失败，通过注册`FailureAnalyzers`有机会提供一个专用的错误消息和一个解决问题的具体操作。比如：如果你启动了一个应用，且它占用的端口是8080，但是这个端口已经被占用了，那么你会看到类似如下的信息：

***************************
    APPLICATION FAILED TO START
    ***************************
    
    Description:
    
    Embedded servlet container failed to start. Port 8080 was already in use.
    
    Action:
    
    Identify and stop the process that's listening on port 8080 or configure this application to listen on another port.

从异常信息中，可以看出，内嵌的`servlet`容器启动失败，因为端口8080已经处于使用中。  
解决办法是停止8080端口上的所有进程或者把这个项目配置到别的端口上面。  
`Springboot`提供了很多`FailureAnalyzer`的实现。如果没有任何实现可以处理你的异常，您仍然可以显示完整的条件报告，以便更好地了解出了什么问题。您需要为`org.springframework.boot.autoconfigure.logging.conditionEvaluationReportLoggingListener`启用`DEBUG`属性或启用`DEBUG`日志记录。  
比如：如果你正在用`java -jar`的命令来运行你的项目，你可以使用`debug`属性：

$ java -jar myproject-0.0.1-SNAPSHOT.jar --debug

--------------------

**定制化Banner**  
可以通过将`banner.txt`文件添加到类路径或将`spring.banner.location`属性设置为此类文件的位置来更改在启动时打印的标题。如果文件的编码不是`UTF-8`，则可以设置`spring.banner.charset`。除了文本文件之外，还可以将`banner.gif、banner.jpg`或`banner.png`图像文件添加到类路径，或设置`spring.banner.image.location`属性。图像被转换成一个`ASCII`表示并打印在任何文本`banner`的上方。  
（`banner`可以理解为打印日志，只不过根据配置不同，日志输出的地方也不同）

@FunctionalInterface
    public interface Banner {
    	/**
    	 * Print the banner to the specified print stream.
    	 * @param environment spring的环境
    	 * @param sourceClass 应用的源头类
    	 * @param out the output print stream
    	 */
    	void printBanner(Environment environment, Class<?> sourceClass, PrintStream out);
    	/**
    	 * 一个枚举类型，配置banner的时候可以有下面三种选择.
    	 */
    	enum Mode {
    		/**
    		 * 禁止输出.
    		 */
    		OFF,
    		/**
    		 * 打印到控制台System.out.
    		 */
    		CONSOLE,
    		/**
    		 * 打印到日志文件
    		 */
    		LOG
    	}
    }

**Banner变量**：  
（1）`${application.version}`  
应用程序的版本号，如`manifest.mf`中声明的。例如，实现版本：1.0打印为1.0。  
（2）`${application.formatted-version}`  
应用程序的版本号，如`manifest.mf`中声明的，并格式化为可显示（用括号包围，前缀为`v`）。例如（`v1.0`）。  
（3）`${spring-boot.version}`  
`spring boot`的版本号，比如你使用的是2.1.5  
（4）`${spring-boot.formatted-version}`  
您正在使用的`Springboot`版本，已格式化为显示（用括号括起来，前缀为`v`）。例如（`v2.1.5.`版本）。  
（5）`${Ansi.NAME} (或者 ${AnsiColor.NAME}, ${AnsiBackground.NAME}, ${AnsiStyle.NAME})`  
其中`name`是`ansi`转义码的名称  
（6）`${application.title}`  
在`manifest.mf`中声明的应用程序标题。例如，实现标题：`myapp`打印为`myapp`。  
如果你想以编程的方式生成一个`banner`，你可以使用`SpringApplication`类中的`setBanner(...)`方法，但是你需要实现它的方法`printBanner()`：

new SpringApplication().setBanner(new Banner() {
                @Override
                public void printBanner(Environment environment, Class<?> sourceClass, PrintStream out) {
                    
                }
            });

下面是lambda表达式的写法：

new SpringApplication().setBanner((environment, sourceClass, out) -> {
            });

你也可以通过使用`spring.main.banner-mode`属性来决定`banner`打印到控制台还是日志文件还是不输出。

下面是我做的一个小例子，使用了`Banner.Mode.OFF`，将LOGO关闭了：

@SpringBootApplication
    public class Application {
        public static void main(String[] args) {
            SpringApplication springApplication = new SpringApplication(Application.class);
            //关闭LOGO输出
            springApplication.setBannerMode(Banner.Mode.OFF);
            springApplication.run(args);
        }
    }

输出如下：

D:\Java8\jdk1.8.0_211\bin\java.exe -XX:TieredStopAtLevel=1 -noverify -Dspring.output.ansi.enabled=always -Dcom.sun.management.jmxremote -Dspring.jmx.enabled=true -Dspring.liveBeansView.mbeanDomain -Dspring.application.admin.enabled=true "-javaagent:C:\Program Files\JetBrains\IntelliJ IDEA 2019.1.1\lib\idea_rt.jar=58174:C:\Program Files\JetBrains\IntelliJ IDEA 2019.1.1\bin" -Dfile.encoding=UTF-8 -classpath D:\Java8\jdk1.8.0_211\jre\lib\charsets.jar;D:\Java8\jdk1.8.0_211\jre\lib\deploy.jar;D:\Java8\jdk1.8.0_211\jre\lib\ext\access-bridge-64.jar;D:\Java8\jdk1.8.0_211\jre\lib\ext\cldrdata.jar;D:\Java8\jdk1.8.0_211\jre\lib\ext\dnsns.jar;D:\Java8\jdk1.8.0_211\jre\lib\ext\jaccess.jar;D:\Java8\jdk1.8.0_211\jre\lib\ext\jfxrt.jar;D:\Java8\jdk1.8.0_211\jre\lib\ext\localedata.jar;D:\Java8\jdk1.8.0_211\jre\lib\ext\nashorn.jar;D:\Java8\jdk1.8.0_211\jre\lib\ext\sunec.jar;D:\Java8\jdk1.8.0_211\jre\lib\ext\sunjce_provider.jar;D:\Java8\jdk1.8.0_211\jre\lib\ext\sunmscapi.jar;D:\Java8\jdk1.8.0_211\jre\lib\ext\sunpkcs11.jar;D:\Java8\jdk1.8.0_211\jre\lib\ext\zipfs.jar;D:\Java8\jdk1.8.0_211\jre\lib\javaws.jar;D:\Java8\jdk1.8.0_211\jre\lib\jce.jar;D:\Java8\jdk1.8.0_211\jre\lib\jfr.jar;D:\Java8\jdk1.8.0_211\jre\lib\jfxswt.jar;D:\Java8\jdk1.8.0_211\jre\lib\jsse.jar;D:\Java8\jdk1.8.0_211\jre\lib\management-agent.jar;D:\Java8\jdk1.8.0_211\jre\lib\plugin.jar;D:\Java8\jdk1.8.0_211\jre\lib\resources.jar;D:\Java8\jdk1.8.0_211\jre\lib\rt.jar;D:\demo\target\classes;C:\maven\mvn_repo3.0\org\springframework\boot\spring-boot-starter-web\2.1.5.RELEASE\spring-boot-starter-web-2.1.5.RELEASE.jar;C:\maven\mvn_repo3.0\org\springframework\boot\spring-boot-starter\2.1.5.RELEASE\spring-boot-starter-2.1.5.RELEASE.jar;C:\maven\mvn_repo3.0\org\springframework\boot\spring-boot-starter-logging\2.1.5.RELEASE\spring-boot-starter-logging-2.1.5.RELEASE.jar;C:\maven\mvn_repo3.0\ch\qos\logback\logback-classic\1.2.3\logback-classic-1.2.3.jar;C:\maven\mvn_repo3.0\ch\qos\logback\logback-core\1.2.3\logback-core-1.2.3.jar;C:\maven\mvn_repo3.0\org\apache\logging\log4j\log4j-to-slf4j\2.11.2\log4j-to-slf4j-2.11.2.jar;C:\maven\mvn_repo3.0\org\apache\logging\log4j\log4j-api\2.11.2\log4j-api-2.11.2.jar;C:\maven\mvn_repo3.0\org\slf4j\jul-to-slf4j\1.7.26\jul-to-slf4j-1.7.26.jar;C:\maven\mvn_repo3.0\javax\annotation\javax.annotation-api\1.3.2\javax.annotation-api-1.3.2.jar;C:\maven\mvn_repo3.0\org\yaml\snakeyaml\1.23\snakeyaml-1.23.jar;C:\maven\mvn_repo3.0\org\springframework\boot\spring-boot-starter-json\2.1.5.RELEASE\spring-boot-starter-json-2.1.5.RELEASE.jar;C:\maven\mvn_repo3.0\com\fasterxml\jackson\core\jackson-databind\2.9.8\jackson-databind-2.9.8.jar;C:\maven\mvn_repo3.0\com\fasterxml\jackson\core\jackson-annotations\2.9.0\jackson-annotations-2.9.0.jar;C:\maven\mvn_repo3.0\com\fasterxml\jackson\core\jackson-core\2.9.8\jackson-core-2.9.8.jar;C:\maven\mvn_repo3.0\com\fasterxml\jackson\datatype\jackson-datatype-jdk8\2.9.8\jackson-datatype-jdk8-2.9.8.jar;C:\maven\mvn_repo3.0\com\fasterxml\jackson\datatype\jackson-datatype-jsr310\2.9.8\jackson-datatype-jsr310-2.9.8.jar;C:\maven\mvn_repo3.0\com\fasterxml\jackson\module\jackson-module-parameter-names\2.9.8\jackson-module-parameter-names-2.9.8.jar;C:\maven\mvn_repo3.0\org\springframework\boot\spring-boot-starter-tomcat\2.1.5.RELEASE\spring-boot-starter-tomcat-2.1.5.RELEASE.jar;C:\maven\mvn_repo3.0\org\apache\tomcat\embed\tomcat-embed-core\9.0.19\tomcat-embed-core-9.0.19.jar;C:\maven\mvn_repo3.0\org\apache\tomcat\embed\tomcat-embed-el\9.0.19\tomcat-embed-el-9.0.19.jar;C:\maven\mvn_repo3.0\org\apache\tomcat\embed\tomcat-embed-websocket\9.0.19\tomcat-embed-websocket-9.0.19.jar;C:\maven\mvn_repo3.0\org\hibernate\validator\hibernate-validator\6.0.16.Final\hibernate-validator-6.0.16.Final.jar;C:\maven\mvn_repo3.0\javax\validation\validation-api\2.0.1.Final\validation-api-2.0.1.Final.jar;C:\maven\mvn_repo3.0\org\jboss\logging\jboss-logging\3.3.2.Final\jboss-logging-3.3.2.Final.jar;C:\maven\mvn_repo3.0\com\fasterxml\classmate\1.4.0\classmate-1.4.0.jar;C:\maven\mvn_repo3.0\org\springframework\spring-web\5.1.7.RELEASE\spring-web-5.1.7.RELEASE.jar;C:\maven\mvn_repo3.0\org\springframework\spring-beans\5.1.7.RELEASE\spring-beans-5.1.7.RELEASE.jar;C:\maven\mvn_repo3.0\org\springframework\spring-webmvc\5.1.7.RELEASE\spring-webmvc-5.1.7.RELEASE.jar;C:\maven\mvn_repo3.0\org\springframework\spring-aop\5.1.7.RELEASE\spring-aop-5.1.7.RELEASE.jar;C:\maven\mvn_repo3.0\org\springframework\spring-context\5.1.7.RELEASE\spring-context-5.1.7.RELEASE.jar;C:\maven\mvn_repo3.0\org\springframework\spring-expression\5.1.7.RELEASE\spring-expression-5.1.7.RELEASE.jar;C:\maven\mvn_repo3.0\org\slf4j\slf4j-api\1.7.26\slf4j-api-1.7.26.jar;C:\maven\mvn_repo3.0\org\springframework\spring-core\5.1.7.RELEASE\spring-core-5.1.7.RELEASE.jar;C:\maven\mvn_repo3.0\org\springframework\spring-jcl\5.1.7.RELEASE\spring-jcl-5.1.7.RELEASE.jar;C:\maven\mvn_repo3.0\org\springframework\boot\spring-boot-devtools\2.1.5.RELEASE\spring-boot-devtools-2.1.5.RELEASE.jar;C:\maven\mvn_repo3.0\org\springframework\boot\spring-boot\2.1.5.RELEASE\spring-boot-2.1.5.RELEASE.jar;C:\maven\mvn_repo3.0\org\springframework\boot\spring-boot-autoconfigure\2.1.5.RELEASE\spring-boot-autoconfigure-2.1.5.RELEASE.jar com.example.demo.Application
    2019-06-17 21:52:49.078  INFO 6200 --- [  restartedMain] com.example.demo.Application             : Starting Application on DESKTOP-J2GV336 with PID 6200 (D:\demo\target\classes started by danis in D:\demo)
    2019-06-17 21:52:49.083  INFO 6200 --- [  restartedMain] com.example.demo.Application             : No active profile set, falling back to default profiles: default
    2019-06-17 21:52:49.184  INFO 6200 --- [  restartedMain] .e.DevToolsPropertyDefaultsPostProcessor : Devtools property defaults active! Set 'spring.devtools.add-properties' to 'false' to disable
    2019-06-17 21:52:49.184  INFO 6200 --- [  restartedMain] .e.DevToolsPropertyDefaultsPostProcessor : For additional web related logging consider setting the 'logging.level.web' property to 'DEBUG'
    2019-06-17 21:52:51.143  INFO 6200 --- [  restartedMain] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 8080 (http)
    2019-06-17 21:52:51.171  INFO 6200 --- [  restartedMain] o.apache.catalina.core.StandardService   : Starting service [Tomcat]
    2019-06-17 21:52:51.171  INFO 6200 --- [  restartedMain] org.apache.catalina.core.StandardEngine  : Starting Servlet engine: [Apache Tomcat/9.0.19]
    2019-06-17 21:52:51.272  INFO 6200 --- [  restartedMain] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
    2019-06-17 21:52:51.272  INFO 6200 --- [  restartedMain] o.s.web.context.ContextLoader            : Root WebApplicationContext: initialization completed in 2088 ms
    2019-06-17 21:52:51.519  INFO 6200 --- [  restartedMain] o.s.s.concurrent.ThreadPoolTaskExecutor  : Initializing ExecutorService 'applicationTaskExecutor'
    2019-06-17 21:52:51.735  INFO 6200 --- [  restartedMain] o.s.b.d.a.OptionalLiveReloadServer       : LiveReload server is running on port 35729
    2019-06-17 21:52:51.822  INFO 6200 --- [  restartedMain] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8080 (http) with context path ''
    2019-06-17 21:52:51.827  INFO 6200 --- [  restartedMain] com.example.demo.Application             : Started Application in 3.327 seconds (JVM running for 5.033)

默认是会输出LOGO的：

输出信息如下：

D:\Java8\jdk1.8.0_211\bin\java.exe -XX:TieredStopAtLevel=1 -noverify -Dspring.output.ansi.enabled=always -Dcom.sun.management.jmxremote -Dspring.jmx.enabled=true -Dspring.liveBeansView.mbeanDomain -Dspring.application.admin.enabled=true "-javaagent:C:\Program Files\JetBrains\IntelliJ IDEA 2019.1.1\lib\idea_rt.jar=58312:C:\Program Files\JetBrains\IntelliJ IDEA 2019.1.1\bin" -Dfile.encoding=UTF-8 -classpath D:\Java8\jdk1.8.0_211\jre\lib\charsets.jar;D:\Java8\jdk1.8.0_211\jre\lib\deploy.jar;D:\Java8\jdk1.8.0_211\jre\lib\ext\access-bridge-64.jar;D:\Java8\jdk1.8.0_211\jre\lib\ext\cldrdata.jar;D:\Java8\jdk1.8.0_211\jre\lib\ext\dnsns.jar;D:\Java8\jdk1.8.0_211\jre\lib\ext\jaccess.jar;D:\Java8\jdk1.8.0_211\jre\lib\ext\jfxrt.jar;D:\Java8\jdk1.8.0_211\jre\lib\ext\localedata.jar;D:\Java8\jdk1.8.0_211\jre\lib\ext\nashorn.jar;D:\Java8\jdk1.8.0_211\jre\lib\ext\sunec.jar;D:\Java8\jdk1.8.0_211\jre\lib\ext\sunjce_provider.jar;D:\Java8\jdk1.8.0_211\jre\lib\ext\sunmscapi.jar;D:\Java8\jdk1.8.0_211\jre\lib\ext\sunpkcs11.jar;D:\Java8\jdk1.8.0_211\jre\lib\ext\zipfs.jar;D:\Java8\jdk1.8.0_211\jre\lib\javaws.jar;D:\Java8\jdk1.8.0_211\jre\lib\jce.jar;D:\Java8\jdk1.8.0_211\jre\lib\jfr.jar;D:\Java8\jdk1.8.0_211\jre\lib\jfxswt.jar;D:\Java8\jdk1.8.0_211\jre\lib\jsse.jar;D:\Java8\jdk1.8.0_211\jre\lib\management-agent.jar;D:\Java8\jdk1.8.0_211\jre\lib\plugin.jar;D:\Java8\jdk1.8.0_211\jre\lib\resources.jar;D:\Java8\jdk1.8.0_211\jre\lib\rt.jar;D:\demo\target\classes;C:\maven\mvn_repo3.0\org\springframework\boot\spring-boot-starter-web\2.1.5.RELEASE\spring-boot-starter-web-2.1.5.RELEASE.jar;C:\maven\mvn_repo3.0\org\springframework\boot\spring-boot-starter\2.1.5.RELEASE\spring-boot-starter-2.1.5.RELEASE.jar;C:\maven\mvn_repo3.0\org\springframework\boot\spring-boot-starter-logging\2.1.5.RELEASE\spring-boot-starter-logging-2.1.5.RELEASE.jar;C:\maven\mvn_repo3.0\ch\qos\logback\logback-classic\1.2.3\logback-classic-1.2.3.jar;C:\maven\mvn_repo3.0\ch\qos\logback\logback-core\1.2.3\logback-core-1.2.3.jar;C:\maven\mvn_repo3.0\org\apache\logging\log4j\log4j-to-slf4j\2.11.2\log4j-to-slf4j-2.11.2.jar;C:\maven\mvn_repo3.0\org\apache\logging\log4j\log4j-api\2.11.2\log4j-api-2.11.2.jar;C:\maven\mvn_repo3.0\org\slf4j\jul-to-slf4j\1.7.26\jul-to-slf4j-1.7.26.jar;C:\maven\mvn_repo3.0\javax\annotation\javax.annotation-api\1.3.2\javax.annotation-api-1.3.2.jar;C:\maven\mvn_repo3.0\org\yaml\snakeyaml\1.23\snakeyaml-1.23.jar;C:\maven\mvn_repo3.0\org\springframework\boot\spring-boot-starter-json\2.1.5.RELEASE\spring-boot-starter-json-2.1.5.RELEASE.jar;C:\maven\mvn_repo3.0\com\fasterxml\jackson\core\jackson-databind\2.9.8\jackson-databind-2.9.8.jar;C:\maven\mvn_repo3.0\com\fasterxml\jackson\core\jackson-annotations\2.9.0\jackson-annotations-2.9.0.jar;C:\maven\mvn_repo3.0\com\fasterxml\jackson\core\jackson-core\2.9.8\jackson-core-2.9.8.jar;C:\maven\mvn_repo3.0\com\fasterxml\jackson\datatype\jackson-datatype-jdk8\2.9.8\jackson-datatype-jdk8-2.9.8.jar;C:\maven\mvn_repo3.0\com\fasterxml\jackson\datatype\jackson-datatype-jsr310\2.9.8\jackson-datatype-jsr310-2.9.8.jar;C:\maven\mvn_repo3.0\com\fasterxml\jackson\module\jackson-module-parameter-names\2.9.8\jackson-module-parameter-names-2.9.8.jar;C:\maven\mvn_repo3.0\org\springframework\boot\spring-boot-starter-tomcat\2.1.5.RELEASE\spring-boot-starter-tomcat-2.1.5.RELEASE.jar;C:\maven\mvn_repo3.0\org\apache\tomcat\embed\tomcat-embed-core\9.0.19\tomcat-embed-core-9.0.19.jar;C:\maven\mvn_repo3.0\org\apache\tomcat\embed\tomcat-embed-el\9.0.19\tomcat-embed-el-9.0.19.jar;C:\maven\mvn_repo3.0\org\apache\tomcat\embed\tomcat-embed-websocket\9.0.19\tomcat-embed-websocket-9.0.19.jar;C:\maven\mvn_repo3.0\org\hibernate\validator\hibernate-validator\6.0.16.Final\hibernate-validator-6.0.16.Final.jar;C:\maven\mvn_repo3.0\javax\validation\validation-api\2.0.1.Final\validation-api-2.0.1.Final.jar;C:\maven\mvn_repo3.0\org\jboss\logging\jboss-logging\3.3.2.Final\jboss-logging-3.3.2.Final.jar;C:\maven\mvn_repo3.0\com\fasterxml\classmate\1.4.0\classmate-1.4.0.jar;C:\maven\mvn_repo3.0\org\springframework\spring-web\5.1.7.RELEASE\spring-web-5.1.7.RELEASE.jar;C:\maven\mvn_repo3.0\org\springframework\spring-beans\5.1.7.RELEASE\spring-beans-5.1.7.RELEASE.jar;C:\maven\mvn_repo3.0\org\springframework\spring-webmvc\5.1.7.RELEASE\spring-webmvc-5.1.7.RELEASE.jar;C:\maven\mvn_repo3.0\org\springframework\spring-aop\5.1.7.RELEASE\spring-aop-5.1.7.RELEASE.jar;C:\maven\mvn_repo3.0\org\springframework\spring-context\5.1.7.RELEASE\spring-context-5.1.7.RELEASE.jar;C:\maven\mvn_repo3.0\org\springframework\spring-expression\5.1.7.RELEASE\spring-expression-5.1.7.RELEASE.jar;C:\maven\mvn_repo3.0\org\slf4j\slf4j-api\1.7.26\slf4j-api-1.7.26.jar;C:\maven\mvn_repo3.0\org\springframework\spring-core\5.1.7.RELEASE\spring-core-5.1.7.RELEASE.jar;C:\maven\mvn_repo3.0\org\springframework\spring-jcl\5.1.7.RELEASE\spring-jcl-5.1.7.RELEASE.jar;C:\maven\mvn_repo3.0\org\springframework\boot\spring-boot-devtools\2.1.5.RELEASE\spring-boot-devtools-2.1.5.RELEASE.jar;C:\maven\mvn_repo3.0\org\springframework\boot\spring-boot\2.1.5.RELEASE\spring-boot-2.1.5.RELEASE.jar;C:\maven\mvn_repo3.0\org\springframework\boot\spring-boot-autoconfigure\2.1.5.RELEASE\spring-boot-autoconfigure-2.1.5.RELEASE.jar com.example.demo.Application
    
      .   ____          _            __ _ _
     /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
    ( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
     \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
      '  |____| .__|_| |_|_| |_\__, | / / / /
     =========|_|==============|___/=/_/_/_/
     :: Spring Boot ::        (v2.1.5.RELEASE)
    
    2019-06-17 21:54:44.709  INFO 10540 --- [  restartedMain] com.example.demo.Application             : Starting Application on DESKTOP-J2GV336 with PID 10540 (D:\demo\target\classes started by danis in D:\demo)
    2019-06-17 21:54:44.713  INFO 10540 --- [  restartedMain] com.example.demo.Application             : No active profile set, falling back to default profiles: default
    2019-06-17 21:54:44.774  INFO 10540 --- [  restartedMain] .e.DevToolsPropertyDefaultsPostProcessor : Devtools property defaults active! Set 'spring.devtools.add-properties' to 'false' to disable
    2019-06-17 21:54:44.774  INFO 10540 --- [  restartedMain] .e.DevToolsPropertyDefaultsPostProcessor : For additional web related logging consider setting the 'logging.level.web' property to 'DEBUG'
    2019-06-17 21:54:46.549  INFO 10540 --- [  restartedMain] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 8080 (http)
    2019-06-17 21:54:46.572  INFO 10540 --- [  restartedMain] o.apache.catalina.core.StandardService   : Starting service [Tomcat]
    2019-06-17 21:54:46.572  INFO 10540 --- [  restartedMain] org.apache.catalina.core.StandardEngine  : Starting Servlet engine: [Apache Tomcat/9.0.19]
    2019-06-17 21:54:46.650  INFO 10540 --- [  restartedMain] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
    2019-06-17 21:54:46.650  INFO 10540 --- [  restartedMain] o.s.web.context.ContextLoader            : Root WebApplicationContext: initialization completed in 1876 ms
    2019-06-17 21:54:46.868  INFO 10540 --- [  restartedMain] o.s.s.concurrent.ThreadPoolTaskExecutor  : Initializing ExecutorService 'applicationTaskExecutor'
    2019-06-17 21:54:47.004  INFO 10540 --- [  restartedMain] o.s.b.d.a.OptionalLiveReloadServer       : LiveReload server is running on port 35729
    2019-06-17 21:54:47.050  INFO 10540 --- [  restartedMain] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8080 (http) with context path ''
    2019-06-17 21:54:47.055  INFO 10540 --- [  restartedMain] com.example.demo.Application             : Started Application in 2.842 seconds (JVM running for 4.068)

当然也可以在`YAML`文件中这样写：

spring:
    	main:
    		banner-mode: "off"

传递给`SpringApplication`的构造函数参数是`SpringBean`的配置源。在大多数情况下，这些是对`@Configuration`类的引用，但它们也可以是对`XML`配置或应该扫描的包的引用。  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTI5MzQzMjU_size_16_color_FFFFFF_t_70]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTI5MzQzMjU_size_16_color_FFFFFF_t_70]: /images/20220112/0dcdf9c06b2c49f38ecf6e8ac5666bb1.png