Spring Boot 创建新项目时 pom.xml 出错

Question

我有 java 8 并将其升级到 java 11，但是当我为新的 Spring boot 项目设置时，我在 pom.xml 中收到以下错误：

第一次创建项目时的 pom.xml 是：

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

然后因为我用的是java 11，所以我改成了：

<properties>
   <java.version>1.11</java.version>
 </properties>

当我再次 maven 安装项目时，几乎许多红色标记消失了，但它仍然向我显示：(当我将鼠标指针靠近那个红色标记时，它没有向我显示任何错误消息提示)

我的 pom.xml 看起来像这样：

<?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>2.2.0.M4</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.ashwin.rws</groupId>
    <artifactId>restful-web-services</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>restful-web-services</name>
    <description>Restful web services</description>

    <properties>
         <java.version>1.11</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>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>com.h2database</groupId>
            <artifactId>h2</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>junit</groupId>
                    <artifactId>junit</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>

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

    <repositories>
        <repository>
            <id>spring-snapshots</id>
            <name>Spring Snapshots</name>
            <url>https://repo.spring.io/snapshot</url>
            <snapshots>
                <enabled>true</enabled>
            </snapshots>
        </repository>
        <repository>
            <id>spring-milestones</id>
            <name>Spring Milestones</name>
            <url>https://repo.spring.io/milestone</url>
        </repository>
    </repositories>
    <pluginRepositories>
        <pluginRepository>
            <id>spring-snapshots</id>
            <name>Spring Snapshots</name>
            <url>https://repo.spring.io/snapshot</url>
            <snapshots>
                <enabled>true</enabled>
            </snapshots>
        </pluginRepository>
        <pluginRepository>
            <id>spring-milestones</id>
            <name>Spring Milestones</name>
            <url>https://repo.spring.io/milestone</url>
        </pluginRepository>
    </pluginRepositories>

</project>

当我构建我的项目时，它向我展示了：

Answer 1

java 11 的正确方法是

<properties>
   <java.version>11</java.version>
</properties>

how-to-specify-java-11-version-in-spring-spring-boot-pom-xml