不清楚这种用法业界用得多不对，感觉蛮好玩的 

完整文件
FROM maven:3-ibm-semeru-21-jammy as mvn_build
WORKDIR app
COPY . .
# RUN mvn dependency:go-offline
RUN mvn clean package \
    -U -DskipTests \
    -Dmaven.repo.local=/root/.m2/repository \
    -Dorg.slf4j.simpleLogger.log.org.apache.maven.cli.transfer.Slf4jMavenTransferListener=warn \
    -T$(grep -c ^processor /proc/cpuinfo)

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FROM e...