java - 编译时出现 fatal error : invalid target release: 9

Question

我在 Eclipse 中使用 Spring Dashboard 创建项目。我也尝试过使用 Spring Initializr 创建它并尝试了 java 的版本 8 和 9，但我仍然明白这一点。还尝试更改 Maven 目标。运行配置，maven构建使用的是JavaSE1.8，jre 1.8.0。

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.0.0.RC2</version>
    <relativePath/> <!-- lookup parent from repository -->
</parent>

<properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    <java.version>9</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-thymeleaf</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.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>

命令:

javac version: 9.0.4

Apache Maven 3.5.2
Maven home: C:\Users\arito\Desktop\apache-maven-3.5.2\bin\..
Java version: 1.8.0_152, vendor: Oracle Corporation
Java home: C:\Program Files\Java\jdk1.8.0_152\jre
Default locale: en_US, platform encoding: Cp1252
OS name: "windows 10", version: "10.0", arch: "amd64", family: "windows"

Answer 1

我不得不使用 java 9 而不是 8。

我在 MacOS 中切换了 java 环境:

列出已安装的 java 版本:/usr/libexec/java_home -V

切换到 java 9:export JAVA_HOME=`/usr/libexec/java_home -v 9.0.4`

(我之前安装了java 9)

来源:How to set JAVA_HOME environment variable on Mac OS X 10.9?