Eclipse显示“ Maven配置问题：未知”

Question

我刚刚导入了在eclipse中在https://start.spring.io/中创建的spingboot项目。我尝试导入两次，但是问题仍然存在。已经尝试执行mvn更新，mvn全新安装，试图清除项目，但是这些都没有用。这是pom xml文件的第一行中的问题。我不知道如何解决这个问题。我正在使用Java 11

这是完整的POM文件：

<?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>
<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.1.5.RELEASE</version>
    <relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.in28minutes.springboot.rest.example</groupId>
<artifactId>spring-boot-2-jpa-with-hibernate-and-h2</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>spring-boot-2-jpa-with-hibernate-and-h2</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-data-jpa</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-devtools</artifactId>
        <scope>runtime</scope>
    </dependency>
    <dependency>
        <groupId>com.h2database</groupId>
        <artifactId>h2</artifactId>
        <scope>runtime</scope>
    </dependency>
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <optional>true</optional>
    </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>

Answer 1

这似乎是Eclipse中的错误：https： //bugs.eclipse.org/bugs/show_bug.cgi？id = 547340

您可以通过将Maven jar插件版本从3.1.2暂时降级到3.1.1来解决此问题。将此添加到属性部分：

<maven-jar-plugin.version>3.1.1</maven-jar-plugin.version>

因此，您的pom将如下所示：

<?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>
<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.1.5.RELEASE</version>
    <relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.in28minutes.springboot.rest.example</groupId>
<artifactId>spring-boot-2-jpa-with-hibernate-and-h2</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>spring-boot-2-jpa-with-hibernate-and-h2</name>
<description>Demo project for Spring Boot</description>

<properties>
    <java.version>11</java.version>
    <maven-jar-plugin.version>3.1.1</maven-jar-plugin.version>
</properties>

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

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-devtools</artifactId>
        <scope>runtime</scope>
    </dependency>
    <dependency>
        <groupId>com.h2database</groupId>
        <artifactId>h2</artifactId>
        <scope>runtime</scope>
    </dependency>
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <optional>true</optional>
    </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>

更新： 已发布修复程序。单击帮助>在Eclipse / STS中检查更新，然后安装最新的m2e连接器。

Answer 2

第1步：

降级到 <maven-jar-plugin.version>3.1.1</maven-jar-plugin.version>

<properties>
    <java.version>X</java.version>
    <maven-jar-plugin.version>3.1.1</maven-jar-plugin.version>
</properties>

步骤 2 更新项目

• 右键单击您的项目
• 前往 Maven
• 点击更新项目
• 清理并重新运行您的应用程序

Answer 3

<maven-jar-plugin.version>3.1.1</maven-jar-plugin.version>

在属性标签下的 pom.xml 中添加此依赖项