在guns-admin的pom.xml文件的打包方式改为war后，出现异常

clean下然后package，

Failed to execute goal org.apache.maven.plugins:maven-war-plugin:2.2:war (default-war) on project guns-admin: Error assembling WAR: webxml attribute is required (or pre-existing WEB-INF/web.xml if executing in update mode)

target下虽然有打开后发现1kb