https://docs.spring.io/spring-boot/docs/2.0.3.RELEASE/reference/htmlsingle/#getting-started
根据上面的文章，开始搭建spring服务。
package bikePlane.solicitor;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.Bean;
import java.util.Arrays;
@SpringBootApplication
public class Application {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
@Bean
public CommandLineRunner commandLineRunner(ApplicationContext ctx) {
return args -> {
System.out.println("Let's inspect the beans provided by Spring Boot:");
String[] beanNames = ctx.getBeanDefinitionNames();
Arrays.sort(beanNames);
for (String beanName : beanNames) {
System.out.println(beanName);
}
};
}
}
/**
* Alipay.com Inc.
* Copyright (c) 2004-2018 All Rights Reserved.
*/
package bikePlane.solicitor;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
/**
* 作为数据的主要入口,通过该入口将参数传入.
* @author qz.zzm
* @version $Id: MainEntry.java, v 0.1 2018年07月29日 下午1:08 qz.zzm Exp $
*/
@RestController
@EnableAutoConfiguration
public class MainEntry {
@RequestMapping("/")
String home() {
return "Hello World!";
}
public static void main(String[] args) throws Exception {
SpringApplication.run(MainEntry.class, args);
}
}
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.bikePlane</groupId>
<artifactId>lawyer</artifactId>
<version>1.0-SNAPSHOT</version>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.3.RELEASE</version>
</parent>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
</dependencies>
<properties>
<java.version>1.8</java.version>
</properties>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
<!--<repositories>-->
<!--<repository>-->
<!--<id>spring-releases</id>-->
<!--<url>https://repo.spring.io/libs-release</url>-->
<!--</repository>-->
<!--</repositories>-->
<!--<pluginRepositories>-->
<!--<pluginRepository>-->
<!--<id>spring-releases</id>-->
<!--<url>https://repo.spring.io/libs-release</url>-->
<!--</pluginRepository>-->
<!--</pluginRepositories>-->
</project>
其中关于注释的部分：
执行 mvn spring-boot:run
可以正常执行。
但是如果
Application上面的 @SpringBootApplication 注释去掉。那么就会报错：
[ERROR] Failed to execute goal org.springframework.boot:spring-boot-maven-plugin:2.0.2.RELEASE:run (default-cli) on project gs-spring-boot: Execution default-cli of goal org.springframework.boot:spring-boot-maven-plugin:2.0.2.RELEASE:run failed: Unable to find a single main class from the following candidates [hello.HelloController, hello.Application] -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/PluginExecutionException
这个时候，添加了，后面注释掉的maven就能正确执行。
说明这两个使用了不同的包，而我本地没有这俄国包。从远端拉。
https://blog.csdn.net/mr_ooo/article/details/54341184
在这个网站中找到的解决方法。
其实就是强制指定了pluginRepositories的maven库，说明本地里面的包缺失了部分内容。
但是，其实原因是因为两个都有main函数，实验了下，
删除@SpringBootApplication 的情况：
-情况1:注释掉 Application 类中的 main : 执行正确
-情况2:注视掉 MainEntry类中的main:
报错：
[ERROR] Failed to execute goal org.springframework.boot:spring-boot-maven-plugin:2.0.3.RELEASE:run (default-cli) on project lawyer: An exception occurred while running. null: InvocationTargetException: Unable to start web server; nested exception is org.springframework.context.ApplicationContextException: Unable to start ServletWebServerApplicationContext due to missing ServletWebServerFactory bean. -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException
问题说明，情况1的时候，执行了main函数，然后，执行
SpringApplication.run(Application.class, args); 之后，在spring启动环节中尝试找：
String[] beanNames = this.getBeanFactory().getBeanNamesForType(ServletWebServerFactory.class);
但是没有找到注释 @SpringBootApplication 或是其他的相关的注解的类，所以找到有效的类，然后失败了，而第二个方式使用了@EnableAutoConfiguration ，走了默认配置，所以执行成功了。
@EnableAutoConfiguration
一旦使用该项目，则使用spring自动构造默认配置，然后使用默认配置。
$ jar tvf target/lawyer-1.0-SNAPSHOT.jar
$ java -jar target/lawyer-1.0-SNAPSHOT.jar
