SpringBoot快速入门。无法启动Tomcat，Process finished with exit code 0问题排查。

一.Spring快速入门

1.创建 Maven 工程

正常创建就可以了

2.添加 SpringBoot的起步依赖

pom.xml

<!--所有的springboot工程都必须继承spring-boot-starter-parent-->
<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.2.4.RELEASE</version>
</parent>

<dependencies>
    <!--web功能的依赖-->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <!--热部署配置-->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-devtools</artifactId>
    </dependency>
    <!--@ConfiguaritionProperties的执行器的配置-->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-configuration-processor</artifactId>
        <optional>true</optional>
    </dependency>
</dependencies>

注意：在使用老版本 SpringBoot 时可能出现了坐标无法导入的情况。
会导致

Process finished with exit code 0

"C:\Program Files\Java\jdk-10.0.2\bin\java.exe" -XX:TieredStopAtLevel=1 -noverify -Dspring.output.ansi.enabled=always -Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.port=9678 -Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.ssl=false -Djava.rmi.server.hostname=localhost -Dspring.liveBeansView.mbeanDomain -Dspring.application.admin.enabled=true "-javaagent:C:\Program Files\JetBrains\IntelliJ IDEA 2018.2.3\lib\idea_rt.jar=9679:C:\Program Files\JetBrains\IntelliJ IDEA 2018.2.3\bin" -Dfile.encoding=UTF-8 -classpath F:\java\SpringBoot_01_01_01\target\classes;C:\Users\lx136\.m2\repository\org\springframework\boot\spring-boot-starter-web\2.0.1.RELEASE\spring-boot-starter-web-2.0.1.RELEASE.jar;C:\Users\lx136\.m2\repository\org\springframework\boot\spring-boot-starter\2.0.1.RELEASE\spring-boot-starter-2.0.1.RELEASE.jar;C:\Users\lx136\.m2\repository\org\springframework\boot\spring-boot-starter-logging\2.0.1.RELEASE\spring-boot-starter-logging-2.0.1.RELEASE.jar;C:\Users\lx136\.m2\repository\ch\qos\logback\logback-classic\1.2.3\logback-classic-1.2.3.jar;C:\Users\lx136\.m2\repository\ch\qos\logback\logback-core\1.2.3\logback-core-1.2.3.jar;C:\Users\lx136\.m2\repository\org\slf4j\slf4j-api\1.7.25\slf4j-api-1.7.25.jar;C:\Users\lx136\.m2\repository\org\apache\logging\log4j\log4j-to-slf4j\2.10.0\log4j-to-slf4j-2.10.0.jar;C:\Users\lx136\.m2\repository\org\apache\logging\log4j\log4j-api\2.10.0\log4j-api-2.10.0.jar;C:\Users\lx136\.m2\repository\org\slf4j\jul-to-slf4j\1.7.25\jul-to-slf4j-1.7.25.jar;C:\Users\lx136\.m2\repository\javax\annotation\javax.annotation-api\1.3.2\javax.annotation-api-1.3.2.jar;C:\Users\lx136\.m2\repository\org\springframework\spring-core\5.0.5.RELEASE\spring-core-5.0.5.RELEASE.jar;C:\Users\lx136\.m2\repository\org\springframework\spring-jcl\5.0.5.RELEASE\spring-jcl-5.0.5.RELEASE.jar;C:\Users\lx136\.m2\repository\org\yaml\snakeyaml\1.19\snakeyaml-1.19.jar;C:\Users\lx136\.m2\repository\org\springframework\boot\spring-boot-starter-json\2.0.1.RELEASE\spring-boot-starter-json-2.0.1.RELEASE.jar;C:\Users\lx136\.m2\repository\com\fasterxml\jackson\core\jackson-databind\2.9.5\jackson-databind-2.9.5.jar;C:\Users\lx136\.m2\repository\com\fasterxml\jackson\core\jackson-annotations\2.9.0\jackson-annotations-2.9.0.jar;C:\Users\lx136\.m2\repository\com\fasterxml\jackson\core\jackson-core\2.9.5\jackson-core-2.9.5.jar;C:\Users\lx136\.m2\repository\com\fasterxml\jackson\datatype\jackson-datatype-jdk8\2.9.5\jackson-datatype-jdk8-2.9.5.jar;C:\Users\lx136\.m2\repository\com\fasterxml\jackson\datatype\jackson-datatype-jsr310\2.9.5\jackson-datatype-jsr310-2.9.5.jar;C:\Users\lx136\.m2\repository\com\fasterxml\jackson\module\jackson-module-parameter-names\2.9.5\jackson-module-parameter-names-2.9.5.jar;C:\Users\lx136\.m2\repository\org\springframework\boot\spring-boot-starter-tomcat\2.0.1.RELEASE\spring-boot-starter-tomcat-2.0.1.RELEASE.jar;C:\Users\lx136\.m2\repository\org\apache\tomcat\embed\tomcat-embed-el\8.5.29\tomcat-embed-el-8.5.29.jar;C:\Users\lx136\.m2\repository\org\apache\tomcat\embed\tomcat-embed-websocket\8.5.29\tomcat-embed-websocket-8.5.29.jar;C:\Users\lx136\.m2\repository\org\hibernate\validator\hibernate-validator\6.0.9.Final\hibernate-validator-6.0.9.Final.jar;C:\Users\lx136\.m2\repository\javax\validation\validation-api\2.0.1.Final\validation-api-2.0.1.Final.jar;C:\Users\lx136\.m2\repository\org\jboss\logging\jboss-logging\3.3.2.Final\jboss-logging-3.3.2.Final.jar;C:\Users\lx136\.m2\repository\com\fasterxml\classmate\1.3.4\classmate-1.3.4.jar;C:\Users\lx136\.m2\repository\org\springframework\spring-web\5.0.5.RELEASE\spring-web-5.0.5.RELEASE.jar;C:\Users\lx136\.m2\repository\org\springframework\spring-beans\5.0.5.RELEASE\spring-beans-5.0.5.RELEASE.jar;C:\Users\lx136\.m2\repository\org\springframework\spring-webmvc\5.0.5.RELEASE\spring-webmvc-5.0.5.RELEASE.jar;C:\Users\lx136\.m2\repository\org\springframework\spring-aop\5.0.5.RELEASE\spring-aop-5.0.5.RELEASE.jar;C:\Users\lx136\.m2\repository\org\springframework\spring-context\5.0.5.RELEASE\spring-context-5.0.5.RELEASE.jar;C:\Users\lx136\.m2\repository\org\springframework\spring-expression\5.0.5.RELEASE\spring-expression-5.0.5.RELEASE.jar;C:\Users\lx136\.m2\repository\org\springframework\boot\spring-boot-devtools\2.0.1.RELEASE\spring-boot-devtools-2.0.1.RELEASE.jar;C:\Users\lx136\.m2\repository\org\springframework\boot\spring-boot\2.0.1.RELEASE\spring-boot-2.0.1.RELEASE.jar;C:\Users\lx136\.m2\repository\org\springframework\boot\spring-boot-autoconfigure\2.0.1.RELEASE\spring-boot-autoconfigure-2.0.1.RELEASE.jar;C:\Users\lx136\.m2\repository\org\springframework\boot\spring-boot-configuration-processor\2.0.1.RELEASE\spring-boot-configuration-processor-2.0.1.RELEASE.jar com.lx.MySpringBootApplication
14:44:58.960 [main] DEBUG org.springframework.boot.devtools.settings.DevToolsSettings - Included patterns for restart : []
14:44:58.961 [main] DEBUG org.springframework.boot.devtools.settings.DevToolsSettings - Excluded patterns for restart : [/spring-boot-starter-[\w-]+/, /spring-boot/target/classes/, /spring-boot-starter/target/classes/, /spring-boot-devtools/target/classes/, /spring-boot-actuator/target/classes/, /spring-boot-autoconfigure/target/classes/]
14:44:58.962 [main] DEBUG org.springframework.boot.devtools.restart.ChangeableUrls - Matching URLs for reloading : [file:/F:/java/SpringBoot_01_01_01/target/classes/]

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::        (v2.0.1.RELEASE)

2020-02-18 14:44:59.143  INFO 33400 --- [  restartedMain] com.lx.MySpringBootApplication           : Starting MySpringBootApplication on DESKTOP-FN4QH6S with PID 33400 (F:\java\SpringBoot_01_01_01\target\classes started by lx136 in F:\java\SpringBoot_01_01_01)
2020-02-18 14:44:59.144  INFO 33400 --- [  restartedMain] com.lx.MySpringBootApplication           : No active profile set, falling back to default profiles: default
2020-02-18 14:44:59.197  INFO 33400 --- [  restartedMain] s.c.a.AnnotationConfigApplicationContext : Refreshing org.springframework.context.annotation.AnnotationConfigApplicationContext@a0c9d6c: startup date [Tue Feb 18 14:44:59 CST 2020]; root of context hierarchy
WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by org.springframework.cglib.core.ReflectUtils$1 (file:/C:/Users/lx136/.m2/repository/org/springframework/spring-core/5.0.5.RELEASE/spring-core-5.0.5.RELEASE.jar) to method java.lang.ClassLoader.defineClass(java.lang.String,byte[],int,int,java.security.ProtectionDomain)
WARNING: Please consider reporting this to the maintainers of org.springframework.cglib.core.ReflectUtils$1
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release
2020-02-18 14:44:59.784  INFO 33400 --- [  restartedMain] o.s.b.d.a.OptionalLiveReloadServer       : LiveReload server is running on port 35729
2020-02-18 14:44:59.796  INFO 33400 --- [  restartedMain] o.s.j.e.a.AnnotationMBeanExporter        : Registering beans for JMX exposure on startup
2020-02-18 14:44:59.806  INFO 33400 --- [  restartedMain] com.lx.MySpringBootApplication           : Started MySpringBootApplication in 0.828 seconds (JVM running for 2.097)
2020-02-18 14:44:59.808  INFO 33400 --- [       Thread-7] s.c.a.AnnotationConfigApplicationContext : Closing org.springframework.context.annotation.AnnotationConfigApplicationContext@a0c9d6c: startup date [Tue Feb 18 14:44:59 CST 2020]; root of context hierarchy
2020-02-18 14:44:59.810  INFO 33400 --- [       Thread-7] o.s.j.e.a.AnnotationMBeanExporter        : Unregistering JMX-exposed beans on shutdown

Process finished with exit code 0

出先这种情况后跑是跑的起来的，但这不是正常运行。
要么重新下载，要么本地引入jar包，要么换版本。

重新引入2.2.4后正常

如果选择jar包的方式，别找我，我也没有

3.编写 SpringBoot 的引导类

需要通过 SpringBoot 提供的引导类起步 SpringBoot 才可以进行访问。
通过注解的方式

package com.lx;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication//进行注解，确定为引导类
public class MySpringBootApplication {
    public static void main(String[] args) {
        SpringApplication.run(MySpringBootApplication.class,args);
    }
}

4.编写 SpringBoot 的引导类

需在 SpringBoot 引导类同级包中，或者子包中创建 Controller
通过注解的方式来配置

package com.lx.controller;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
@Controller
public class QuickDemo1 {
    @RequestMapping("/start")
    @ResponseBody
    public String quick(){
        return "Spring Boot Start";
    }
}

4.测试

直接运行，访问 http://localhost:8080/start
8080端口号是Tomcat的默认端口号。也可以通过 本机IP:8080/start 来进行访问。