If the system property java.nio.file.spi.DefaultFileSystemProvider is set to the name of a class in a JAR file on the class path then it leads to an NPE in the ZipFile code. This is a bootstrapping/initialization issue (and a regression since JDK 9) due to the ZipFile code needing to use the default file system provider. We may have to change ZipFile to use the built-in file system provider, at least for the class path case.


$ java -cp classes:provider.jar -Djava.nio.file.spi.DefaultFileSystemProvider=TestProvider org.test.Test

Exception in thread "main" java.lang.Error: java.lang.NullPointerException: Cannot invoke "java.nio.file.FileSystem.getPath(String, String[])" because the return value of "java.nio.file.FileSystems.getDefault()" is null
at java.base/java.nio.file.FileSystems$DefaultFileSystemHolder.getDefaultProvider(FileSystems.java:133)
at java.base/java.nio.file.FileSystems$DefaultFileSystemHolder$1.run(FileSystems.java:102)
at java.base/java.nio.file.FileSystems$DefaultFileSystemHolder$1.run(FileSystems.java:100)
at java.base/java.security.AccessController.doPrivileged(AccessController.java:312)
at java.base/java.nio.file.FileSystems$DefaultFileSystemHolder.defaultFileSystem(FileSystems.java:100)
at java.base/java.nio.file.FileSystems$DefaultFileSystemHolder.<clinit>(FileSystems.java:94)
at java.base/java.nio.file.FileSystems.getDefault(FileSystems.java:182)
at org.test.Test.main(Test.java:7)
Caused by: java.lang.NullPointerException: Cannot invoke "java.nio.file.FileSystem.getPath(String, String[])" because the return value of "java.nio.file.FileSystems.getDefault()" is null
at java.base/java.io.File.toPath(File.java:2318)
at java.base/java.util.zip.ZipFile$Source.get(ZipFile.java:1246)
at java.base/java.util.zip.ZipFile$CleanableResource.<init>(ZipFile.java:707)
at java.base/java.util.zip.ZipFile.<init>(ZipFile.java:241)
at java.base/java.util.zip.ZipFile.<init>(ZipFile.java:172)
at java.base/java.util.jar.JarFile.<init>(JarFile.java:349)
at java.base/jdk.internal.loader.URLClassPath$JarLoader.getJarFile(URLClassPath.java:816)
at java.base/jdk.internal.loader.URLClassPath$JarLoader$1.run(URLClassPath.java:761)
at java.base/jdk.internal.loader.URLClassPath$JarLoader$1.run(URLClassPath.java:754)
at java.base/java.security.AccessController.doPrivileged(AccessController.java:691)
at java.base/jdk.internal.loader.URLClassPath$JarLoader.ensureOpen(URLClassPath.java:753)
at java.base/jdk.internal.loader.URLClassPath$JarLoader.<init>(URLClassPath.java:728)
at java.base/jdk.internal.loader.URLClassPath$3.run(URLClassPath.java:496)
at java.base/jdk.internal.loader.URLClassPath$3.run(URLClassPath.java:479)
at java.base/java.security.AccessController.doPrivileged(AccessController.java:691)
at java.base/jdk.internal.loader.URLClassPath.getLoader(URLClassPath.java:478)
at java.base/jdk.internal.loader.URLClassPath.getLoader(URLClassPath.java:447)
at java.base/jdk.internal.loader.URLClassPath.getResource(URLClassPath.java:316)
at java.base/jdk.internal.loader.BuiltinClassLoader.findClassOnClassPathOrNull(BuiltinClassLoader.java:750)
at java.base/jdk.internal.loader.BuiltinClassLoader.loadClassOrNull(BuiltinClassLoader.java:676)
at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:634)
at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:182)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:519)
at java.base/java.lang.Class.forName0(Native Method)
at java.base/java.lang.Class.forName(Class.java:466)
at java.base/java.nio.file.FileSystems$DefaultFileSystemHolder.getDefaultProvider(FileSystems.java:123)
... 7 more