HADOOP-18155. Refactor tests in TestFileUtil (#4063)

(cherry picked from commit d0fa9b5775185bd83e4a767a7dfc13ef89c5154a)

 Conflicts:
	hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/FileUtil.java
	hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/TestFileUtil.java

Co-authored-by: Gautham B A <gautham.bangalore@gmail.com>
(cherry picked from commit 743db6e7b4d2acd893f527c9312e6dbe6eefef4f)

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/FileUtil.java

@@ -40,6 +40,7 @@ import java.nio.charset.StandardCharsets;
 import java.nio.file.AccessDeniedException;
 import java.nio.file.FileSystems;
 import java.nio.file.Files;
+import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.Enumeration;
 import java.util.List;
@@ -971,6 +972,14 @@ public class FileUtil {
           + " would create entry outside of " + outputDir);
     }
 
+    if (entry.isSymbolicLink() || entry.isLink()) {
+      String canonicalTargetPath = getCanonicalPath(entry.getLinkName(), outputDir);
+      if (!canonicalTargetPath.startsWith(targetDirPath)) {
+        throw new IOException(
+            "expanding " + entry.getName() + " would create entry outside of " + outputDir);
+      }
+    }
+
     if (entry.isDirectory()) {
       File subDir = new File(outputDir, entry.getName());
       if (!subDir.mkdirs() && !subDir.isDirectory()) {
@@ -986,10 +995,12 @@ public class FileUtil {
     }
 
     if (entry.isSymbolicLink()) {
-      // Create symbolic link relative to tar parent dir
-      Files.createSymbolicLink(FileSystems.getDefault()
-              .getPath(outputDir.getPath(), entry.getName()),
-          FileSystems.getDefault().getPath(entry.getLinkName()));
+      // Create symlink with canonical target path to ensure that we don't extract
+      // outside targetDirPath
+      String canonicalTargetPath = getCanonicalPath(entry.getLinkName(), outputDir);
+      Files.createSymbolicLink(
+          FileSystems.getDefault().getPath(outputDir.getPath(), entry.getName()),
+          FileSystems.getDefault().getPath(canonicalTargetPath));
       return;
     }
 
@@ -1001,7 +1012,8 @@ public class FileUtil {
     }
 
     if (entry.isLink()) {
-      File src = new File(outputDir, entry.getLinkName());
+      String canonicalTargetPath = getCanonicalPath(entry.getLinkName(), outputDir);
+      File src = new File(canonicalTargetPath);
       HardLink.createHardLink(src, outputFile);
       return;
     }
@@ -1019,6 +1031,20 @@ public class FileUtil {
     }
   }
 
+  /**
+   * Gets the canonical path for the given path.
+   *
+   * @param path      The path for which the canonical path needs to be computed.
+   * @param parentDir The parent directory to use if the path is a relative path.
+   * @return The canonical path of the given path.
+   */
+  private static String getCanonicalPath(String path, File parentDir) throws IOException {
+    java.nio.file.Path targetPath = Paths.get(path);
+    return (targetPath.isAbsolute() ?
+        new File(path) :
+        new File(parentDir, path)).getCanonicalPath();
+  }
+
   /**
    * Class for creating hardlinks.
    * Supports Unix, WindXP.

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/TestFileUtil.java

@@ -42,13 +42,14 @@ import java.net.URISyntaxException;
 import java.net.URL;
 import java.net.UnknownHostException;
 import java.nio.charset.StandardCharsets;
-import java.nio.file.FileSystems;
 import java.nio.file.Files;
+import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
+import java.util.Objects;
 import java.util.jar.Attributes;
 import java.util.jar.JarFile;
 import java.util.jar.Manifest;
@@ -60,9 +61,12 @@ import org.apache.commons.compress.archivers.tar.TarArchiveOutputStream;
 import org.apache.commons.io.FileUtils;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.test.GenericTestUtils;
+import org.apache.hadoop.test.LambdaTestUtils;
 import org.apache.hadoop.util.StringUtils;
 import org.apache.tools.tar.TarEntry;
 import org.apache.tools.tar.TarOutputStream;
+
+import org.assertj.core.api.Assertions;
 import org.junit.After;
 import org.junit.Assert;
 import org.junit.Before;
@@ -158,13 +162,12 @@ public class TestFileUtil {
     FileUtils.forceMkdir(dir1);
     FileUtils.forceMkdir(dir2);
 
-    new File(del, FILE).createNewFile();
-    File tmpFile = new File(tmp, FILE);
-    tmpFile.createNewFile();
+    Verify.createNewFile(new File(del, FILE));
+    File tmpFile = Verify.createNewFile(new File(tmp, FILE));
 
     // create files
-    new File(dir1, FILE).createNewFile();
-    new File(dir2, FILE).createNewFile();
+    Verify.createNewFile(new File(dir1, FILE));
+    Verify.createNewFile(new File(dir2, FILE));
 
     // create a symlink to file
     File link = new File(del, LINK);
@@ -173,7 +176,7 @@ public class TestFileUtil {
     // create a symlink to dir
     File linkDir = new File(del, "tmpDir");
     FileUtil.symLink(tmp.toString(), linkDir.toString());
-    Assert.assertEquals(5, del.listFiles().length);
+    Assert.assertEquals(5, Objects.requireNonNull(del.listFiles()).length);
 
     // create files in partitioned directories
     createFile(partitioned, "part-r-00000", "foo");
@@ -200,13 +203,9 @@ public class TestFileUtil {
   private File createFile(File directory, String name, String contents)
       throws IOException {
     File newFile = new File(directory, name);
-    PrintWriter pw = new PrintWriter(newFile);
-    try {
+    try (PrintWriter pw = new PrintWriter(newFile)) {
       pw.println(contents);
     }
-    finally {
-      pw.close();
-    }
     return newFile;
   }
 
@@ -218,11 +217,11 @@ public class TestFileUtil {
 
     //Test existing directory with no files case 
     File newDir = new File(tmp.getPath(),"test");
-    newDir.mkdir();
+    Verify.mkdir(newDir);
     Assert.assertTrue("Failed to create test dir", newDir.exists());
     files = FileUtil.listFiles(newDir);
     Assert.assertEquals(0, files.length);
-    newDir.delete();
+    assertTrue(newDir.delete());
     Assert.assertFalse("Failed to delete test dir", newDir.exists());
     
     //Test non-existing directory case, this throws 
@@ -244,11 +243,11 @@ public class TestFileUtil {
 
     //Test existing directory with no files case 
     File newDir = new File(tmp.getPath(),"test");
-    newDir.mkdir();
+    Verify.mkdir(newDir);
     Assert.assertTrue("Failed to create test dir", newDir.exists());
     files = FileUtil.list(newDir);
     Assert.assertEquals("New directory unexpectedly contains files", 0, files.length);
-    newDir.delete();
+    assertTrue(newDir.delete());
     Assert.assertFalse("Failed to delete test dir", newDir.exists());
     
     //Test non-existing directory case, this throws 
@@ -266,7 +265,7 @@ public class TestFileUtil {
   public void testFullyDelete() throws IOException {
     boolean ret = FileUtil.fullyDelete(del);
     Assert.assertTrue(ret);
-    Assert.assertFalse(del.exists());
+    Verify.notExists(del);
     validateTmpDir();
   }
 
@@ -279,13 +278,13 @@ public class TestFileUtil {
   @Test (timeout = 30000)
   public void testFullyDeleteSymlinks() throws IOException {
     File link = new File(del, LINK);
-    Assert.assertEquals(5, del.list().length);
+    assertDelListLength(5);
     // Since tmpDir is symlink to tmp, fullyDelete(tmpDir) should not
     // delete contents of tmp. See setupDirs for details.
     boolean ret = FileUtil.fullyDelete(link);
     Assert.assertTrue(ret);
-    Assert.assertFalse(link.exists());
-    Assert.assertEquals(4, del.list().length);
+    Verify.notExists(link);
+    assertDelListLength(4);
     validateTmpDir();
 
     File linkDir = new File(del, "tmpDir");
@@ -293,8 +292,8 @@ public class TestFileUtil {
     // delete contents of tmp. See setupDirs for details.
     ret = FileUtil.fullyDelete(linkDir);
     Assert.assertTrue(ret);
-    Assert.assertFalse(linkDir.exists());
-    Assert.assertEquals(3, del.list().length);
+    Verify.notExists(linkDir);
+    assertDelListLength(3);
     validateTmpDir();
   }
 
@@ -310,16 +309,16 @@ public class TestFileUtil {
     // to make y as a dangling link to file tmp/x
     boolean ret = FileUtil.fullyDelete(tmp);
     Assert.assertTrue(ret);
-    Assert.assertFalse(tmp.exists());
+    Verify.notExists(tmp);
 
     // dangling symlink to file
     File link = new File(del, LINK);
-    Assert.assertEquals(5, del.list().length);
+    assertDelListLength(5);
     // Even though 'y' is dangling symlink to file tmp/x, fullyDelete(y)
     // should delete 'y' properly.
     ret = FileUtil.fullyDelete(link);
     Assert.assertTrue(ret);
-    Assert.assertEquals(4, del.list().length);
+    assertDelListLength(4);
 
     // dangling symlink to directory
     File linkDir = new File(del, "tmpDir");
@@ -327,22 +326,22 @@ public class TestFileUtil {
     // delete tmpDir properly.
     ret = FileUtil.fullyDelete(linkDir);
     Assert.assertTrue(ret);
-    Assert.assertEquals(3, del.list().length);
+    assertDelListLength(3);
   }
 
   @Test (timeout = 30000)
   public void testFullyDeleteContents() throws IOException {
     boolean ret = FileUtil.fullyDeleteContents(del);
     Assert.assertTrue(ret);
-    Assert.assertTrue(del.exists());
-    Assert.assertEquals(0, del.listFiles().length);
+    Verify.exists(del);
+    Assert.assertEquals(0, Objects.requireNonNull(del.listFiles()).length);
     validateTmpDir();
   }
 
   private void validateTmpDir() {
-    Assert.assertTrue(tmp.exists());
-    Assert.assertEquals(1, tmp.listFiles().length);
-    Assert.assertTrue(new File(tmp, FILE).exists());
+    Verify.exists(tmp);
+    Assert.assertEquals(1, Objects.requireNonNull(tmp.listFiles()).length);
+    Verify.exists(new File(tmp, FILE));
   }
 
   /**
@@ -366,15 +365,15 @@ public class TestFileUtil {
    * @throws IOException
    */
   private void setupDirsAndNonWritablePermissions() throws IOException {
-    new MyFile(del, FILE_1_NAME).createNewFile();
+    Verify.createNewFile(new MyFile(del, FILE_1_NAME));
 
     // "file1" is non-deletable by default, see MyFile.delete().
 
-    xSubDir.mkdirs();
-    file2.createNewFile();
+    Verify.mkdirs(xSubDir);
+    Verify.createNewFile(file2);
 
-    xSubSubDir.mkdirs();
-    file22.createNewFile();
+    Verify.mkdirs(xSubSubDir);
+    Verify.createNewFile(file22);
 
     revokePermissions(file22);
     revokePermissions(xSubSubDir);
@@ -382,8 +381,8 @@ public class TestFileUtil {
     revokePermissions(file2);
     revokePermissions(xSubDir);
 
-    ySubDir.mkdirs();
-    file3.createNewFile();
+    Verify.mkdirs(ySubDir);
+    Verify.createNewFile(file3);
 
     File tmpFile = new File(tmp, FILE);
     tmpFile.createNewFile();
@@ -448,6 +447,88 @@ public class TestFileUtil {
     validateAndSetWritablePermissions(false, ret);
   }
 
+  /**
+   * Asserts if the {@link TestFileUtil#del} meets the given expected length.
+   *
+   * @param expectedLength The expected length of the {@link TestFileUtil#del}.
+   */
+  private void assertDelListLength(int expectedLength) {
+    Assertions.assertThat(del.list()).describedAs("del list").isNotNull().hasSize(expectedLength);
+  }
+
+  /**
+   * Helper class to perform {@link File} operation and also verify them.
+   */
+  public static class Verify {
+    /**
+     * Invokes {@link File#createNewFile()} on the given {@link File} instance.
+     *
+     * @param file The file to call {@link File#createNewFile()} on.
+     * @return The result of {@link File#createNewFile()}.
+     * @throws IOException As per {@link File#createNewFile()}.
+     */
+    public static File createNewFile(File file) throws IOException {
+      assertTrue("Unable to create new file " + file, file.createNewFile());
+      return file;
+    }
+
+    /**
+     * Invokes {@link File#mkdir()} on the given {@link File} instance.
+     *
+     * @param file The file to call {@link File#mkdir()} on.
+     * @return The result of {@link File#mkdir()}.
+     */
+    public static File mkdir(File file) {
+      assertTrue("Unable to mkdir for " + file, file.mkdir());
+      return file;
+    }
+
+    /**
+     * Invokes {@link File#mkdirs()} on the given {@link File} instance.
+     *
+     * @param file The file to call {@link File#mkdirs()} on.
+     * @return The result of {@link File#mkdirs()}.
+     */
+    public static File mkdirs(File file) {
+      assertTrue("Unable to mkdirs for " + file, file.mkdirs());
+      return file;
+    }
+
+    /**
+     * Invokes {@link File#delete()} on the given {@link File} instance.
+     *
+     * @param file The file to call {@link File#delete()} on.
+     * @return The result of {@link File#delete()}.
+     */
+    public static File delete(File file) {
+      assertTrue("Unable to delete " + file, file.delete());
+      return file;
+    }
+
+    /**
+     * Invokes {@link File#exists()} on the given {@link File} instance.
+     *
+     * @param file The file to call {@link File#exists()} on.
+     * @return The result of {@link File#exists()}.
+     */
+    public static File exists(File file) {
+      assertTrue("Expected file " + file + " doesn't exist", file.exists());
+      return file;
+    }
+
+    /**
+     * Invokes {@link File#exists()} on the given {@link File} instance to check if the
+     * {@link File} doesn't exists.
+     *
+     * @param file The file to call {@link File#exists()} on.
+     * @return The negation of the result of {@link File#exists()}.
+     */
+    public static File notExists(File file) {
+      assertFalse("Expected file " + file + " must not exist", file.exists());
+      return file;
+    }
+  }
+
   /**
    * Extend {@link File}. Same as {@link File} except for two things: (1) This
    * treats file1Name as a very special file which is not delete-able
@@ -580,14 +661,13 @@ public class TestFileUtil {
       FileUtil.chmod(partitioned.getAbsolutePath(), "0777", true/*recursive*/);
     }
   }
-  
+
   @Test (timeout = 30000)
-  public void testUnTar() throws IOException {
+  public void testUnTar() throws Exception {
     // make a simple tar:
     final File simpleTar = new File(del, FILE);
-    OutputStream os = new FileOutputStream(simpleTar); 
-    TarOutputStream tos = new TarOutputStream(os);
-    try {
+    OutputStream os = new FileOutputStream(simpleTar);
+    try (TarOutputStream tos = new TarOutputStream(os)) {
       TarEntry te = new TarEntry("/bar/foo");
       byte[] data = "some-content".getBytes("UTF-8");
       te.setSize(data.length);
@@ -596,55 +676,42 @@ public class TestFileUtil {
       tos.closeEntry();
       tos.flush();
       tos.finish();
-    } finally {
-      tos.close();
     }
 
     // successfully untar it into an existing dir:
     FileUtil.unTar(simpleTar, tmp);
     // check result:
-    assertTrue(new File(tmp, "/bar/foo").exists());
+    Verify.exists(new File(tmp, "/bar/foo"));
     assertEquals(12, new File(tmp, "/bar/foo").length());
-    
-    final File regularFile = new File(tmp, "QuickBrownFoxJumpsOverTheLazyDog");
-    regularFile.createNewFile();
-    assertTrue(regularFile.exists());
-    try {
-      FileUtil.unTar(simpleTar, regularFile);
-      assertTrue("An IOException expected.", false);
-    } catch (IOException ioe) {
-      // okay
-    }
+
+    final File regularFile =
+        Verify.createNewFile(new File(tmp, "QuickBrownFoxJumpsOverTheLazyDog"));
+    LambdaTestUtils.intercept(IOException.class, () -> FileUtil.unTar(simpleTar, regularFile));
   }
   
   @Test (timeout = 30000)
   public void testReplaceFile() throws IOException {
-    final File srcFile = new File(tmp, "src");
-    
     // src exists, and target does not exist:
-    srcFile.createNewFile();
-    assertTrue(srcFile.exists());
+    final File srcFile = Verify.createNewFile(new File(tmp, "src"));
     final File targetFile = new File(tmp, "target");
-    assertTrue(!targetFile.exists());
+    Verify.notExists(targetFile);
     FileUtil.replaceFile(srcFile, targetFile);
-    assertTrue(!srcFile.exists());
-    assertTrue(targetFile.exists());
+    Verify.notExists(srcFile);
+    Verify.exists(targetFile);
 
     // src exists and target is a regular file: 
-    srcFile.createNewFile();
-    assertTrue(srcFile.exists());
+    Verify.createNewFile(srcFile);
+    Verify.exists(srcFile);
     FileUtil.replaceFile(srcFile, targetFile);
-    assertTrue(!srcFile.exists());
-    assertTrue(targetFile.exists());
+    Verify.notExists(srcFile);
+    Verify.exists(targetFile);
     
     // src exists, and target is a non-empty directory: 
-    srcFile.createNewFile();
-    assertTrue(srcFile.exists());
-    targetFile.delete();
-    targetFile.mkdirs();
-    File obstacle = new File(targetFile, "obstacle");
-    obstacle.createNewFile();
-    assertTrue(obstacle.exists());
+    Verify.createNewFile(srcFile);
+    Verify.exists(srcFile);
+    Verify.delete(targetFile);
+    Verify.mkdirs(targetFile);
+    File obstacle = Verify.createNewFile(new File(targetFile, "obstacle"));
     assertTrue(targetFile.exists() && targetFile.isDirectory());
     try {
       FileUtil.replaceFile(srcFile, targetFile);
@@ -653,9 +720,9 @@ public class TestFileUtil {
       // okay
     }
     // check up the post-condition: nothing is deleted:
-    assertTrue(srcFile.exists());
+    Verify.exists(srcFile);
     assertTrue(targetFile.exists() && targetFile.isDirectory());
-    assertTrue(obstacle.exists());
+    Verify.exists(obstacle);
   }
   
   @Test (timeout = 30000)
@@ -668,13 +735,13 @@ public class TestFileUtil {
     assertTrue(tmp1.exists() && tmp2.exists());
     assertTrue(tmp1.canWrite() && tmp2.canWrite());
     assertTrue(tmp1.canRead() && tmp2.canRead());
-    tmp1.delete();
-    tmp2.delete();
+    Verify.delete(tmp1);
+    Verify.delete(tmp2);
     assertTrue(!tmp1.exists() && !tmp2.exists());
   }
   
   @Test (timeout = 30000)
-  public void testUnZip() throws IOException {
+  public void testUnZip() throws Exception {
     // make sa simple zip
     final File simpleZip = new File(del, FILE);
     OutputStream os = new FileOutputStream(simpleZip); 
@@ -695,18 +762,12 @@ public class TestFileUtil {
     // successfully unzip it into an existing dir:
     FileUtil.unZip(simpleZip, tmp);
     // check result:
-    assertTrue(new File(tmp, "foo").exists());
+    Verify.exists(new File(tmp, "foo"));
     assertEquals(12, new File(tmp, "foo").length());
-    
-    final File regularFile = new File(tmp, "QuickBrownFoxJumpsOverTheLazyDog");
-    regularFile.createNewFile();
-    assertTrue(regularFile.exists());
-    try {
-      FileUtil.unZip(simpleZip, regularFile);
-      assertTrue("An IOException expected.", false);
-    } catch (IOException ioe) {
-      // okay
-    }
+
+    final File regularFile =
+        Verify.createNewFile(new File(tmp, "QuickBrownFoxJumpsOverTheLazyDog"));
+    LambdaTestUtils.intercept(IOException.class, () -> FileUtil.unZip(simpleZip, regularFile));
   }
 
   @Test (timeout = 30000)
@@ -752,24 +813,24 @@ public class TestFileUtil {
     final File dest = new File(del, "dest");
     boolean result = FileUtil.copy(fs, srcPath, dest, false, conf);
     assertTrue(result);
-    assertTrue(dest.exists());
+    Verify.exists(dest);
     assertEquals(content.getBytes().length 
         + System.getProperty("line.separator").getBytes().length, dest.length());
-    assertTrue(srcFile.exists()); // should not be deleted
+    Verify.exists(srcFile); // should not be deleted
     
     // copy regular file, delete src:
-    dest.delete();
-    assertTrue(!dest.exists());
+    Verify.delete(dest);
+    Verify.notExists(dest);
     result = FileUtil.copy(fs, srcPath, dest, true, conf);
     assertTrue(result);
-    assertTrue(dest.exists());
+    Verify.exists(dest);
     assertEquals(content.getBytes().length 
         + System.getProperty("line.separator").getBytes().length, dest.length());
-    assertTrue(!srcFile.exists()); // should be deleted
+    Verify.notExists(srcFile); // should be deleted
     
     // copy a dir:
-    dest.delete();
-    assertTrue(!dest.exists());
+    Verify.delete(dest);
+    Verify.notExists(dest);
     srcPath = new Path(partitioned.toURI());
     result = FileUtil.copy(fs, srcPath, dest, true, conf);
     assertTrue(result);
@@ -781,7 +842,7 @@ public class TestFileUtil {
       assertEquals(3 
           + System.getProperty("line.separator").getBytes().length, f.length());
     }
-    assertTrue(!partitioned.exists()); // should be deleted
+    Verify.notExists(partitioned); // should be deleted
   }  
 
   @Test (timeout = 30000)
@@ -869,8 +930,8 @@ public class TestFileUtil {
     // create the symlink
     FileUtil.symLink(file.getAbsolutePath(), link.getAbsolutePath());
 
-    Assert.assertTrue(file.exists());
-    Assert.assertTrue(link.exists());
+    Verify.exists(file);
+    Verify.exists(link);
 
     File link2 = new File(del, "_link2");
 
@@ -880,10 +941,10 @@ public class TestFileUtil {
     // Make sure the file still exists
     // (NOTE: this would fail on Java6 on Windows if we didn't
     // copy the file in FileUtil#symlink)
-    Assert.assertTrue(file.exists());
+    Verify.exists(file);
 
-    Assert.assertTrue(link2.exists());
-    Assert.assertFalse(link.exists());
+    Verify.exists(link2);
+    Verify.notExists(link);
   }
 
   /**
@@ -898,13 +959,13 @@ public class TestFileUtil {
     // create the symlink
     FileUtil.symLink(file.getAbsolutePath(), link.getAbsolutePath());
 
-    Assert.assertTrue(file.exists());
-    Assert.assertTrue(link.exists());
+    Verify.exists(file);
+    Verify.exists(link);
 
     // make sure that deleting a symlink works properly
-    Assert.assertTrue(link.delete());
-    Assert.assertFalse(link.exists());
-    Assert.assertTrue(file.exists());
+    Verify.delete(link);
+    Verify.notExists(link);
+    Verify.exists(file);
   }
 
   /**
@@ -931,13 +992,13 @@ public class TestFileUtil {
     Assert.assertEquals(data.length, file.length());
     Assert.assertEquals(data.length, link.length());
 
-    file.delete();
-    Assert.assertFalse(file.exists());
+    Verify.delete(file);
+    Verify.notExists(file);
 
     Assert.assertEquals(0, link.length());
 
-    link.delete();
-    Assert.assertFalse(link.exists());
+    Verify.delete(link);
+    Verify.notExists(link);
   }
 
   /**
@@ -1003,7 +1064,7 @@ public class TestFileUtil {
   public void testSymlinkSameFile() throws IOException {
     File file = new File(del, FILE);
 
-    file.delete();
+    Verify.delete(file);
 
     // Create a symbolic link
     // The operation should succeed
@@ -1076,21 +1137,21 @@ public class TestFileUtil {
 
     String parentDir = untarDir.getCanonicalPath() + Path.SEPARATOR + "name";
     File testFile = new File(parentDir + Path.SEPARATOR + "version");
-    Assert.assertTrue(testFile.exists());
+    Verify.exists(testFile);
     Assert.assertTrue(testFile.length() == 0);
     String imageDir = parentDir + Path.SEPARATOR + "image";
     testFile = new File(imageDir + Path.SEPARATOR + "fsimage");
-    Assert.assertTrue(testFile.exists());
+    Verify.exists(testFile);
     Assert.assertTrue(testFile.length() == 157);
     String currentDir = parentDir + Path.SEPARATOR + "current";
     testFile = new File(currentDir + Path.SEPARATOR + "fsimage");
-    Assert.assertTrue(testFile.exists());
+    Verify.exists(testFile);
     Assert.assertTrue(testFile.length() == 4331);
     testFile = new File(currentDir + Path.SEPARATOR + "edits");
-    Assert.assertTrue(testFile.exists());
+    Verify.exists(testFile);
     Assert.assertTrue(testFile.length() == 1033);
     testFile = new File(currentDir + Path.SEPARATOR + "fstime");
-    Assert.assertTrue(testFile.exists());
+    Verify.exists(testFile);
     Assert.assertTrue(testFile.length() == 8);
   }
 
@@ -1151,9 +1212,9 @@ public class TestFileUtil {
     }
 
     // create non-jar files, which we expect to not be included in the classpath
-    Assert.assertTrue(new File(tmp, "text.txt").createNewFile());
-    Assert.assertTrue(new File(tmp, "executable.exe").createNewFile());
-    Assert.assertTrue(new File(tmp, "README").createNewFile());
+    Verify.createNewFile(new File(tmp, "text.txt"));
+    Verify.createNewFile(new File(tmp, "executable.exe"));
+    Verify.createNewFile(new File(tmp, "README"));
 
     // create classpath jar
     String wildcardPath = tmp.getCanonicalPath() + File.separator + "*";
@@ -1239,9 +1300,9 @@ public class TestFileUtil {
     }
 
     // create non-jar files, which we expect to not be included in the result
-    assertTrue(new File(tmp, "text.txt").createNewFile());
-    assertTrue(new File(tmp, "executable.exe").createNewFile());
-    assertTrue(new File(tmp, "README").createNewFile());
+    Verify.createNewFile(new File(tmp, "text.txt"));
+    Verify.createNewFile(new File(tmp, "executable.exe"));
+    Verify.createNewFile(new File(tmp, "README"));
 
     // pass in the directory
     String directory = tmp.getCanonicalPath();
@@ -1275,7 +1336,7 @@ public class TestFileUtil {
       uri4 = new URI(uris4);
       uri5 = new URI(uris5);
       uri6 = new URI(uris6);
-    } catch (URISyntaxException use) {
+    } catch (URISyntaxException ignored) {
     }
     // Set up InetAddress
     inet1 = mock(InetAddress.class);
@@ -1298,7 +1359,7 @@ public class TestFileUtil {
       when(InetAddress.getByName(uris3)).thenReturn(inet3);
       when(InetAddress.getByName(uris4)).thenReturn(inet4);
       when(InetAddress.getByName(uris5)).thenReturn(inet5);
-    } catch (UnknownHostException ue) {
+    } catch (UnknownHostException ignored) {
     }
 
     fs1 = mock(FileSystem.class);
@@ -1318,62 +1379,87 @@ public class TestFileUtil {
   @Test
   public void testCompareFsNull() throws Exception {
     setupCompareFs();
-    assertEquals(FileUtil.compareFs(null,fs1),false);
-    assertEquals(FileUtil.compareFs(fs1,null),false);
+    assertFalse(FileUtil.compareFs(null, fs1));
+    assertFalse(FileUtil.compareFs(fs1, null));
   }
 
   @Test
   public void testCompareFsDirectories() throws Exception {
     setupCompareFs();
-    assertEquals(FileUtil.compareFs(fs1,fs1),true);
-    assertEquals(FileUtil.compareFs(fs1,fs2),false);
-    assertEquals(FileUtil.compareFs(fs1,fs5),false);
-    assertEquals(FileUtil.compareFs(fs3,fs4),true);
-    assertEquals(FileUtil.compareFs(fs1,fs6),false);
+    assertTrue(FileUtil.compareFs(fs1, fs1));
+    assertFalse(FileUtil.compareFs(fs1, fs2));
+    assertFalse(FileUtil.compareFs(fs1, fs5));
+    assertTrue(FileUtil.compareFs(fs3, fs4));
+    assertFalse(FileUtil.compareFs(fs1, fs6));
   }
 
   @Test(timeout = 8000)
   public void testCreateSymbolicLinkUsingJava() throws IOException {
     final File simpleTar = new File(del, FILE);
     OutputStream os = new FileOutputStream(simpleTar);
-    TarArchiveOutputStream tos = new TarArchiveOutputStream(os);
-    File untarFile = null;
-    try {
+    try (TarArchiveOutputStream tos = new TarArchiveOutputStream(os)) {
       // Files to tar
       final String tmpDir = "tmp/test";
       File tmpDir1 = new File(tmpDir, "dir1/");
       File tmpDir2 = new File(tmpDir, "dir2/");
-      // Delete the directories if they already exist
-      tmpDir1.mkdirs();
-      tmpDir2.mkdirs();
+      Verify.mkdirs(tmpDir1);
+      Verify.mkdirs(tmpDir2);
 
-      java.nio.file.Path symLink = FileSystems
-          .getDefault().getPath(tmpDir1.getPath() + "/sl");
+      java.nio.file.Path symLink = Paths.get(tmpDir1.getPath(), "sl");
 
       // Create Symbolic Link
-      Files.createSymbolicLink(symLink,
-          FileSystems.getDefault().getPath(tmpDir2.getPath())).toString();
+      Files.createSymbolicLink(symLink, Paths.get(tmpDir2.getPath()));
       assertTrue(Files.isSymbolicLink(symLink.toAbsolutePath()));
-      // put entries in tar file
+      // Put entries in tar file
       putEntriesInTar(tos, tmpDir1.getParentFile());
       tos.close();
 
-      untarFile = new File(tmpDir, "2");
-      // Untar using java
+      File untarFile = new File(tmpDir, "2");
+      // Untar using Java
       FileUtil.unTarUsingJava(simpleTar, untarFile, false);
 
       // Check symbolic link and other directories are there in untar file
       assertTrue(Files.exists(untarFile.toPath()));
-      assertTrue(Files.exists(FileSystems.getDefault().getPath(untarFile
-          .getPath(), tmpDir)));
-      assertTrue(Files.isSymbolicLink(FileSystems.getDefault().getPath(untarFile
-          .getPath().toString(), symLink.toString())));
-
+      assertTrue(Files.exists(Paths.get(untarFile.getPath(), tmpDir)));
+      assertTrue(Files.isSymbolicLink(Paths.get(untarFile.getPath(), symLink.toString())));
     } finally {
       FileUtils.deleteDirectory(new File("tmp"));
-      tos.close();
     }
+  }
+
+  @Test(expected = IOException.class)
+  public void testCreateArbitrarySymlinkUsingJava() throws IOException {
+    final File simpleTar = new File(del, FILE);
+    OutputStream os = new FileOutputStream(simpleTar);
 
+    File rootDir = new File("tmp");
+    try (TarArchiveOutputStream tos = new TarArchiveOutputStream(os)) {
+      tos.setLongFileMode(TarArchiveOutputStream.LONGFILE_GNU);
+
+      // Create arbitrary dir
+      File arbitraryDir = new File(rootDir, "arbitrary-dir/");
+      Verify.mkdirs(arbitraryDir);
+
+      // We will tar from the tar-root lineage
+      File tarRoot = new File(rootDir, "tar-root/");
+      File symlinkRoot = new File(tarRoot, "dir1/");
+      Verify.mkdirs(symlinkRoot);
+
+      // Create Symbolic Link to an arbitrary dir
+      java.nio.file.Path symLink = Paths.get(symlinkRoot.getPath(), "sl");
+      Files.createSymbolicLink(symLink, arbitraryDir.toPath().toAbsolutePath());
+
+      // Put entries in tar file
+      putEntriesInTar(tos, tarRoot);
+      putEntriesInTar(tos, new File(symLink.toFile(), "dir-outside-tar-root/"));
+      tos.close();
+
+      // Untar using Java
+      File untarFile = new File(rootDir, "extracted");
+      FileUtil.unTarUsingJava(simpleTar, untarFile, false);
+    } finally {
+      FileUtils.deleteDirectory(rootDir);
+    }
   }
 
   private void putEntriesInTar(TarArchiveOutputStream tos, File f)
@@ -1450,7 +1536,7 @@ public class TestFileUtil {
     String result = FileUtil.readLink(file);
     Assert.assertEquals("", result);
 
-    file.delete();
+    Verify.delete(file);
   }
 
   /**