无法执行目标org.springframework.boot：spring-boot-maven-plugin：2.1.3.RELEASE：run（default-cli）

Question

我尝试运行Spring Boot应用程序，该应用程序使用maven运行[[spring-boot：run，但仍然有问题，我是java spring boot的新手，我无法解决此问题，如何解决此问题，谢谢，这是问题：

无法执行目标org.springframework.boot：spring-boot-maven-plugin：2.1.3.RELEASE：run（default-cli）在项目应用程序返回时：发生异常运行。 null

pom.xml：

<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>
    <artifactId>app-back</artifactId>
    <name>app-back</name>
    <description>module app backend </description>
    <packaging>war</packaging>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.3.RELEASE</version>
    </parent>

    <properties>
        <start-class>AppApplication</start-class>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
        <hibernate.core.version>5.4.2.Final</hibernate.core.version>
        <maven.war.plugin.version>3.2.0</maven.war.plugin.version>
        <jjwt.version>0.9.1</jjwt.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <exclusions>
                <exclusion>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-starter-tomcat</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-security</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <dependency>
           <groupId>org.springframework.boot</groupId>
           <artifactId>spring-boot-starter-tomcat</artifactId>
           <scope>provided</scope>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>

        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-core</artifactId>
            <version>${hibernate.core.version}</version>
        </dependency>


         <!-- Spring data JPA, default tomcat pool, exclude it -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>

        <!-- https://mvnrepository.com/artifact/io.jsonwebtoken/jjwt -->
        <dependency>
            <groupId>io.jsonwebtoken</groupId>
            <artifactId>jjwt</artifactId>
            <version>${jjwt.version}</version>
        </dependency>

    </dependencies>


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

            <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-war-plugin</artifactId>
                 <version>${maven.war.plugin.version}</version>
                 <configuration>
                    <packagingExcludes>WEB-INF/lib/tomcat-*.jar</packagingExcludes>
                    <warName>app</warName>
                 </configuration>
            </plugin>

            <plugin>
                <artifactId>maven-resources-plugin</artifactId>
                <executions>
                    <execution>
                        <id>copy-resources</id>
                        <phase>validate</phase>
                        <goals><goal>copy-resources</goal></goals>
                        <configuration>
                            <outputDirectory>${basedir}/target/classes/static/</outputDirectory >
                            <resources>
                                <resource>
                                    <directory>../app-front/dist/app-front</directory>
                                </resource>
                            </resources>
                        </configuration>
                    </execution>
                </executions>
            </plugin>

        </plugins>
    </build>

</project>

Answer 1

假设您已经具有嵌入式Tomcat服务器的依赖关系，并且希望以所需的方式运行它，那么您将必须在如下所示的spring boot maven插件中添加主类名称。

<plugin>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-maven-plugin</artifactId>
    <configuration>
        <mainClass>fully qualified Main Class name</mainClass>
    </configuration>
    <executions>
        <execution>
            <goals>
                <goal>repackage</goal>
            </goals>
        </execution>
     </executions>
</plugin>