基於openjdk部署鏡像，POI報空指針異常的坑

原始使用鏡像：openjdk8-alpine

FROM alpine:3.10

RUN echo 'https://mirrors.aliyun.com/alpine/v3.10/main' > /etc/apk/repositories \
    && echo 'https://mirrors.aliyun.com/alpine/v3.10/community' >> /etc/apk/repositories \
    && apk update && apk add --no-cache tzdata openjdk8 \
    && ln -sf /usr/share/zoneinfo/Asia/Shanghai /etc/localtime \
    && echo "Asia/Shanghai" > /etc/timezone \
    && echo "export JAVA_HOME=/usr/lib/jvm/default-jvm" >> /etc/profile \
    && echo "export PATH=$JAVA_HOME/bin:$PATH" >> /etc/profile 

ENV JAVA_HOME=/usr/lib/jvm/default-jvm LANG=zh_CN.UTF8
ENV PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:$JAVA_HOME/jre/bin:$JAVA_HOME/bin

COPY startup.sh /startup.sh

CMD ["/bin/sh"]

安裝fontconfig後仍不起作用

FROM alpine:3.10

RUN echo 'https://mirrors.aliyun.com/alpine/v3.10/main' > /etc/apk/repositories \
    && echo 'https://mirrors.aliyun.com/alpine/v3.10/community' >> /etc/apk/repositories \
    && apk update && apk add --no-cache tzdata openjdk8 fontconfig \
    && fc-cache --force \
    && ln -sf /usr/share/zoneinfo/Asia/Shanghai /etc/localtime \
    && echo "Asia/Shanghai" > /etc/timezone \
    && echo "export JAVA_HOME=/usr/lib/jvm/default-jvm" >> /etc/profile \
    && echo "export PATH=$JAVA_HOME/bin:$PATH" >> /etc/profile 

ENV JAVA_HOME=/usr/lib/jvm/default-jvm LANG=zh_CN.UTF8
ENV PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:$JAVA_HOME/jre/bin:$JAVA_HOME/bin

COPY startup.sh /startup.sh

CMD ["/bin/sh"]

更換oraclejdk

1. 登錄docker hub
2. 搜素Oracle Java 8 SE，找到官方鏡像
6. 執行docker pull store/oracle/serverjre:8
7. 修改應用的Dockerfile FROM store/oracle/serverjre:8