use maven image instead of downloading

jackson/CVE-2017-7525/Dockerfile

@@ -1,16 +1,20 @@
+FROM maven:3-jdk-7 AS builder
+
+MAINTAINER phithon <[email protected]>
+
+COPY ./ /usr/src/
+
+WORKDIR /usr/src
+
+RUN cd /usr/src; \
+    mvn -U clean package -Dmaven.test.skip=true
+
 FROM vulhub/java:7u21-jdk
 
 LABEL MAINTAINER="b1ngz <[email protected]>"
 
-COPY . /usr/src
-
-RUN set -ex \
-    && mkdir -p /opt/maven \
-    && wget -qO- http://www-us.apache.org/dist/maven/maven-3/3.5.4/binaries/apache-maven-3.5.4-bin.tar.gz | tar zx -C /opt/maven --strip-components=1 \
-    && update-alternatives --install /usr/bin/mvn mvn /opt/maven/bin/mvn 100 \
-    && cd /usr/src \
-    && mvn -U clean package -Dmaven.test.skip=true
+COPY --from=builder /usr/src/target/jackson.jar /jackson.jar
 
 EXPOSE 8080
 
-CMD ["java", "-jar", "/usr/src/target/jackson.jar"]
+CMD ["java", "-jar", "/jackson.jar"]