<plugin>

                <groupId>org.apache.maven.plugins</groupId>

                <artifactId>maven-compiler-plugin</artifactId>

                <version>3.8.0</version>

                <configuration>

                    <source>11</source>

                    <target>11</target>

                </configuration>

            </plugin>

D:\workspace\java\signal-server>mvn -v

Apache Maven 3.6.2 (40f52333136460af0dc0d7232c0dc0bcf0d9e117; 2019-08-27T23:06:16+08:00)

Maven home: E:\develop\apache-maven\bin\..

Java version: 1.8.0_201, vendor: Oracle Corporation, runtime: C:\Program Files\Java\jdk1.8.0_201\jre

Default locale: zh_CN, platform encoding: GBK

OS name: "windows 10", version: "10.0", arch: "amd64", family: "windows"

根据参考文字，将 plugin中的source改为当前 jdk的版本

<plugin>

                <groupId>org.apache.maven.plugins</groupId>

                <artifactId>maven-compiler-plugin</artifactId>

                <version>3.8.0</version>

                <configuration>

                    <source>1.8</source>

                    <target>11</target>

                </configuration>

            </plugin>

References

1. [Fatal error compiling: 无效的目标发行版: 1.8 -> Help 1] (zhuan)