以 springboot  hello 应用为例 

REPOSITORY   TAG       IMAGE ID       CREATED         SIZE
dyyx/hello   v3        0d2106a8a3d2   7 minutes ago   100MB
dyyx/hello   v2        a0bc850ca9e1   15 hours ago    309MB
dyyx/hello   v1        c478a67bbc60   3 minutes ago   660MB

# FROM java:8
# openjdk:8-jre-alpine
# openjdk:8u312-slim
FROM openjdk:8-jre-alpine

java:8                v1   660MB
openjdk:8u312-slim    v2   309MB
openjdk:8-jre-alpine  v3   100MB



 springboot应用打docker镜像