Maven、Spring Initializr 和 Eclipse：如何设置单个主类？

Question

我用 spring initializr 创建了一个 spring maven 项目，它生成了以下 pom：

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.4.8</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.spring-docker-test</groupId>
    <artifactId>spring-boot-docker</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>spring-boot-docker</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>11</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

然后我将生成的zip文件解压，导入到Eclipse中，并将项目的目标设置为spring-boot:run

我还添加了一个项目，如here所述

在src/main/java/hello/Application.java

package hello;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@SpringBootApplication
@RestController
public class Application {

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

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

}

现在，当我尝试“运行方式 > Maven 构建”时，我收到以下错误消息

[ERROR] Failed to execute goal org.springframework.boot:spring-boot-maven-plugin:2.4.8:run (default-cli) on project spring-boot-docker: Execution default-cli of goal org.springframework.boot:spring-boot-maven-plugin:2.4.8:run failed: Unable to find a single main class from the following candidates [hello.Application, com.springdockertest.springbootdocker.SpringBootDockerApplication] -> [Help 1]

如何设置单个主类（在pom.xml 文件中？）

Answer 1

您可以通过在 pom.xml 的 Boot 的 Maven 插件声明中添加 <configuration> 来设置它：

<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>             
            <configuration>    
                <mainClass>hello.Application</mainClass>
            </configuration>
        </plugin>
    </plugins>
</build>