**spring-boot-maven-plugin:2.3.4.RELEASE** ```java package test; import org.springframework.boot.autoconfigure.SpringBootApplication; import java.io.IOException; import java.net.JarURLConnection; import java.net.URLConnection; @SpringBootApplication public class App { public static void main(String[] args) throws IOException { URLConnection urlConnection = App.class.getResource("/test/App.class").openConnection(); if (urlConnection instanceof JarURLConnection) { JarURLConnection jarURLConnection = (JarURLConnection) urlConnection; // will case java.lang.IllegalStateException: zip file closed jarURLConnection.getJarFile().stream(); } } } ``` The reason causing this problem is _org.springframework.boot.loader.jar.JarFileWrapper_ not override method _stream()_