<build>
?? ??? ?<plugins>
?? ??? ??? ?<!-- 設置JDK 9版本 -->
?? ??? ??? ? <plugin>
?? ??? ??? ??? ?<groupId>org.apache.maven.plugins</groupId>
?? ??? ??? ??? ?<artifactId>maven-compiler-plugin</artifactId>
?? ??? ??? ??? ?<configuration>
?? ??? ??? ??? ??? ?<source>9</source>
?? ??? ??? ??? ??? ?<target>9</target>
?? ??? ??? ??? ??? ?<encoding>UTF-8</encoding>
?? ??? ??? ??? ??? ?<showWarnings>true</showWarnings>
?? ??? ??? ??? ?</configuration>
?? ??? ??? ?</plugin>
?? ??? ?</plugins>
?? ?</build>