Question

问题：我正在使用maven并突然遇到一些错误：

For artifact {org.springframework.boot:spring-boot-starter-data-jpa:null:jar}: The version cannot be empty. (org.apache.maven.plugins:maven-resources-plugin:2.6:resources:default-resources:process-resources)

org.apache.maven.artifact.InvalidArtifactRTException: For artifact {org.springframework.boot:spring-boot-starter-data-jpa:null:jar}: The version cannot be empty.
    at org.apache.maven.artifact.DefaultArtifact.validateIdentity(DefaultArtifact.java:148)
    at org.apache.maven.artifact.DefaultArtifact.<init>(DefaultArtifact.java:123)
    at org.apache.maven.artifact.factory.DefaultArtifactFactory.createArtifact(DefaultArtifactFactory.java:157)
    at org.apache.maven.artifact.factory.DefaultArtifactFactory.createDependencyArtifact(DefaultArtifactFactory.java:57)
    at org.apache.maven.project.artifact.MavenMetadataSource.createDependencyArtifact(MavenMetadataSource.java:328)
    at org.apache.maven.project.artifact.MavenMetadataSource.createArtifacts(MavenMetadataSource.java:503)
    at org.apache.maven.lifecycle.internal.DefaultProjectArtifactFactory.createArtifacts(DefaultProjectArtifactFactory.java:50)
    at org.apache.maven.lifecycle.internal.LifecycleDependencyResolver.resolveProjectDependencies(LifecycleDependencyResolver.java:119)
    at org.apache.maven.lifecycle.internal.MojoExecutor.ensureDependenciesAreResolved(MojoExecutor.java:245)
    at org.eclipse.m2e.core.internal.embedder.MavenImpl.execute(MavenImpl.java:330)
    at org.eclipse.m2e.core.internal.embedder.MavenImpl$11.call(MavenImpl.java:1362)
    at org.eclipse.m2e.core.internal.embedder.MavenImpl$11.call(MavenImpl.java:1)
    at org.eclipse.m2e.core.internal.embedder.MavenExecutionContext.executeBare(MavenExecutionContext.java:176)
    at org.eclipse.m2e.core.internal.embedder.MavenExecutionContext.execute(MavenExecutionContext.java:112)
    at org.eclipse.m2e.core.internal.embedder.MavenImpl.execute(MavenImpl.java:1360)
    at org.eclipse.m2e.core.project.configurator.MojoExecutionBuildParticipant.build(MojoExecutionBuildParticipant.java:52)
    at org.eclipse.m2e.core.internal.builder.MavenBuilderImpl.build(MavenBuilderImpl.java:137)
    at org.eclipse.m2e.core.internal.builder.MavenBuilder$1.method(MavenBuilder.java:172)
    at org.eclipse.m2e.core.internal.builder.MavenBuilder$1.method(MavenBuilder.java:1)
    at org.eclipse.m2e.core.internal.builder.MavenBuilder$BuildMethod$1$1.call(MavenBuilder.java:115)
    at org.eclipse.m2e.core.internal.embedder.MavenExecutionContext.executeBare(MavenExecutionContext.java:176)
    at org.eclipse.m2e.core.internal.embedder.MavenExecutionContext.execute(MavenExecutionContext.java:112)
    at org.eclipse.m2e.core.internal.builder.MavenBuilder$BuildMethod$1.call(MavenBuilder.java:105)
    at org.eclipse.m2e.core.internal.embedder.MavenExecutionContext.executeBare(MavenExecutionContext.java:176)
    at org.eclipse.m2e.core.internal.embedder.MavenExecutionContext.execute(MavenExecutionContext.java:151)
    at org.eclipse.m2e.core.internal.embedder.MavenExecutionContext.execute(MavenExecutionContext.java:99)
    at org.eclipse.m2e.core.internal.builder.MavenBuilder$BuildMethod.execute(MavenBuilder.java:86)
    at org.eclipse.m2e.core.internal.builder.MavenBuilder.build(MavenBuilder.java:200)
    at org.eclipse.core.internal.events.BuildManager$2.run(BuildManager.java:735)
    at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
    at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:206)
    at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:246)
    at org.eclipse.core.internal.events.BuildManager$1.run(BuildManager.java:301)
    at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
    at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:304)
    at org.eclipse.core.internal.events.BuildManager.basicBuildLoop(BuildManager.java:360)
    at org.eclipse.core.internal.events.BuildManager.build(BuildManager.java:383)
    at org.eclipse.core.internal.events.AutoBuildJob.doBuild(AutoBuildJob.java:144)
    at org.eclipse.core.internal.events.AutoBuildJob.run(AutoBuildJob.java:235)
    at org.eclipse.core.internal.jobs.Worker.run(Worker.java:55)

所以我已将工件版本<version>1.3.5.RELEASE</version>添加到spring-boot-starter-data-jpa。不幸的是，我仍然遇到同样的问题。我甚至清理了maven的缓存。 maven -> update项目没有帮助并project -> clean没有帮助

问题：我还能做错什么？

的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>
    <groupId>SpringDataDemo</groupId>
    <artifactId>SpringDataDemo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>war</packaging>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
            <plugin>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.5.1</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                </configuration>
            </plugin>
            <plugin>
                <artifactId>maven-war-plugin</artifactId>
                <version>2.6</version>
                <configuration>
                    <warSourceDirectory>WebContent</warSourceDirectory>
                    <failOnMissingWebXml>false</failOnMissingWebXml>
                </configuration>
            </plugin>
        </plugins>
    </build>

    <repositories>
        <repository>
            <id>spring-releases</id>
            <name>Spring Releases</name>
            <url>https://repo.spring.io/libs-release</url>
        </repository>
        <repository>
            <id>org.jboss.repository.releases</id>
            <name>JBoss Maven Release Repository</name>
            <url>https://repository.jboss.org/nexus/content/repositories/releases</url>
        </repository>
    </repositories>

    <pluginRepositories>
        <pluginRepository>
            <id>spring-releases</id>
            <name>Spring Releases</name>
            <url>https://repo.spring.io/libs-release</url>
        </pluginRepository>
    </pluginRepositories>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
            <version>1.3.5.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>com.h2database</groupId>
            <artifactId>h2</artifactId>
            <version>1.4.192</version>
        </dependency>

    </dependencies>


</project>

如果真的是版本号的问题，Eclipse会将奇怪的行标记为红色：

Answer 1

您需要继承Spring Boot的父POM：

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>1.3.5.RELEASE</version>
</parent>

此父POM为您可能在项目中使用的工件声明了许多依赖项版本，这样您就不需要自己指定它。

来自docs：

每个版本的Spring Boot都提供了一个依赖的策划列表支持。实际上，您不需要为任何版本提供版本构建配置中的这些依赖项与Spring Boot一样为你管理。当你升级Spring Boot本身时，这些依赖关系也将以一致的方式升级。

另见：

Getting Started - Building an Application with Spring Boot

Answer 2

以下插件声明中缺少该版本：

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

只需添加版本：

        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
            <version>1.3.5.RELEASE</version>
        </plugin>

Answer 3

如果不在子pom.xml中，则需要在父pom.xml中添加版本

    import java.io.IOException;
    import java.io.FileWriter;
    import java.io.BufferedReader;
    import java.io.FileReader;
    import java.util.ArrayList;
    import java.util.Scanner;

    class Main {

    // menu method
     static void menu() {
       System.out.println("------------------------------------------------------");
       System.out.println("| Enter 1 to input airport details                   |");
       System.out.println("| Enter 2 to input flight details                    |");
       System.out.println("| Enter 3 to enter price plan and calculate profit   |");
       System.out.println("| Enter 4 to clear data                              |");
       System.out.println("| Enter 5 to quit                                    |");
       System.out.println("------------------------------------------------------");
  
    }

      // text file
      public static void main(String[] argv) throws Exception {
        BufferedReader myFile = new BufferedReader(new FileReader("Airports.txt"));
        ArrayList<String> listOfLines = new ArrayList<>();

        String line = myFile.readLine();
        while (line != null) {
           listOfLines.add(line);
           line = myFile.readLine();

        }
        myFile.close();


       // main code
       Scanner scanner = new Scanner(System.in);

       System.out.println("\n" + "Welcome");
       menu();

       int menuChoice = scanner.nextInt();

       if (menuChoice == 5) {
       System.out.println("\n" + "You have selected quit");
       System.out.println("Program ending.");
      
       } else if (menuChoice == 1) {
        System.out.println("\n" + "You have selected input airport details");
        System.out.println("\n" + "Enter 3 letter airport code for UK airport");
        String ukCode = scanner.next();

        if (ukCode == "LPL" || ukCode == "BOH") {
        
         //where I want to read csv text file and compare user input
       }
     }
   }
 }

父pom.xml

- Parent Module
|-pom.xml
|-Child
    |-pom.xml

子pom.xml

<dependency>
    <groupId>jakarta.xml.bind</groupId>
    <artifactId>jakarta.xml.bind-api</artifactId>
    <version>2.3.2</version>
</dependency>

Maven - 对于工件，版本不能为空

3 个答案: