java - Maven:MojoExecutionException。请添加 'mainClass' 属性

Question

我正在学习 Spring 教程，但一直停留在 creating RestController App 11.4 它只是没有运行。

[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 1.544 s
[INFO] Finished at: 2016-04-07T14:55:36+03:00
[INFO] Final Memory: 19M/304M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.springframework.boot:spring-boot-maven-plugin:1.3.3.RELEASE:run (default-cli) on project myproject: Unable to find a suitable main class, please add a 'mainClass' property -> [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

$JAVA_HOME 和 $PATH 已就位

$ mvn -v
Apache Maven 3.3.9 (bb52d8502b132ec0a5a3f4c09453c07478323dc5; 2015-11-10T19:41:47+03:00)
Maven home: C:\Users\User\Desktop\apache-maven-3.3.9
Java version: 1.8.0_77, vendor: Oracle Corporation
Java home: C:\Program Files\Java\jdk1.8.0_77\jre
Default locale: ru_RU, platform encoding: Cp1251
OS name: "windows 8.1", version: "6.3", arch: "amd64", family: "dos"

这是一个教程，应该很简单，对吧？已经花两个小时了。谁能解释一下吗？)

更新1:pom.xml

<?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.example</groupId>
<artifactId>myproject</artifactId>
<version>0.0.1-SNAPSHOT</version>

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>1.3.3.RELEASE</version>
</parent>

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
</dependencies>
</project>

示例.java

import org.springframework.boot.*;
import org.springframework.boot.autoconfigure.*;
import org.springframework.stereotype.*;
import org.springframework.web.bind.annotation.*;

@RestController
@EnableAutoConfiguration
public class Example {

    @RequestMapping("/")
    String home() {
       return "Hello World!";
    }

    public static void main(String[] args) throws Exception {
        SpringApplication.run(Example.class, args);
    }
}

Answer 1

整个问题是我将所有内容都放在同一个文件夹中。但拥有 src/main/java 文件夹很重要。谁会知道呢! >_<

example
└── pom.xml
    src
    └── main
        └── java
            └── Example.java

现在一切正常。

感谢大家，特别是 Tunaki 的提示。