fixes #VFS-834: Updated to avoid prematurely closing file objects.

commons-vfs2/src/main/java/org/apache/commons/vfs2/impl/VFSClassLoader.java

@@ -239,10 +239,11 @@ protected Enumeration<URL> findResources(final String name) throws IOException {
         final List<URL> result = new ArrayList<>(2);
 
         for (final FileObject baseFile : resources) {
-            try (FileObject file = baseFile.resolveFile(name, NameScope.DESCENDENT_OR_SELF)) {
-                if (FileObjectUtils.exists(file)) {
-                    result.add(new Resource(name, baseFile, file).getURL());
-                }
+            final FileObject file = baseFile.resolveFile(name, NameScope.DESCENDENT_OR_SELF);
+            if (FileObjectUtils.exists(file)) {
+                result.add(new Resource(name, baseFile, file).getURL());
+            } else {
+                file.close();
             }
         }
 
@@ -312,10 +313,11 @@ private boolean isSealed(final Resource res) throws FileSystemException {
      */
     private Resource loadResource(final String name) throws FileSystemException {
         for (final FileObject baseFile : resources) {
-            try (FileObject file = baseFile.resolveFile(name, NameScope.DESCENDENT_OR_SELF)) {
-                if (FileObjectUtils.exists(file)) {
-                    return new Resource(name, baseFile, file);
-                }
+            final FileObject file = baseFile.resolveFile(name, NameScope.DESCENDENT_OR_SELF);
+            if (FileObjectUtils.exists(file)) {
+                return new Resource(name, baseFile, file);
+            } else {
+                file.close();
             }
         }
         return null;

commons-vfs2/src/test/java/org/apache/commons/vfs2/AbstractProviderTestCase.java

@@ -114,14 +114,24 @@ protected void assertSameContent(final String expected, final FileObject file) t
      * are encoded using UTF-8.
      */
     protected void assertSameURLContent(final String expected, final URLConnection connection) throws Exception {
+        try (InputStream in = connection.getInputStream()) {
+            assertSameURLContent(expected, in, connection);
+        }
+    }
+
+    /**
+     * Asserts that the content of a file is the same as expected. Checks the length reported by getContentLength() is
+     * correct, then reads the content as a byte stream and compares the result with the expected content. Assumes files
+     * are encoded using UTF-8.
+     */
+    protected void assertSameURLContent(final String expected, final InputStream instr, final URLConnection connection) throws Exception {
         // Get file content as a binary stream
         final byte[] expectedBin = expected.getBytes(StandardCharsets.UTF_8);
 
         // Check lengths
         assertEquals("same content length", expectedBin.length, connection.getContentLength());
 
         // Read content into byte array
-        final InputStream instr = connection.getInputStream();
         final ByteArrayOutputStream outstr;
         try {
             outstr = new ByteArrayOutputStream();

commons-vfs2/src/test/java/org/apache/commons/vfs2/impl/VfsClassLoaderTests.java

@@ -19,6 +19,7 @@
 import static org.apache.commons.vfs2.VfsTestUtils.getTestDirectoryFile;
 
 import java.io.File;
+import java.io.InputStream;
 import java.io.PrintWriter;
 import java.net.URL;
 import java.net.URLConnection;
@@ -196,11 +197,23 @@ public void testLoadClass() throws Exception {
     public void testLoadResource() throws Exception {
         final VFSClassLoader loader = createClassLoader();
 
-        final URL resource = loader.getResource("read-tests/file1.txt");
+        final URL resource1 = loader.getResource("read-tests/file1.txt");
+        assertNotNull(resource1);
+        final URLConnection urlCon1 = resource1.openConnection();
+        final InputStream instr1 = urlCon1.getInputStream();
 
-        assertNotNull(resource);
-        final URLConnection urlCon = resource.openConnection();
-        assertSameURLContent(FILE1_CONTENT, urlCon);
+        // VFS-834: testing that getting the resource again does not close out the previous input stream.
+        final URL resource2 = loader.getResource("read-tests/file1.txt");
+        assertNotNull(resource2);
+        final URLConnection urlCon2 = resource2.openConnection();
+
+        assertSameURLContent(FILE1_CONTENT, instr1, urlCon1);
+
+        // For tar files, getting the second input stream will reset the input (see TarFileSystem.resetTarFile())
+        // hence we need to actually get the input stream after asserting the contents of the first one.
+        final InputStream instr2 = urlCon2.getInputStream();
+
+        assertSameURLContent(FILE1_CONTENT, instr2, urlCon2);
     }
 
     /**