NIHVIVO-160 Complete the first iteration of coding and testing - especially avoidance of Windows reserved words.

webapp/src/edu/cornell/mannlib/vitro/webapp/utils/filestorage/FileStorage.java

@@ -24,6 +24,16 @@ public interface FileStorage {
 	 */
 	String PROPERTY_DEFAULT_NAMESPACE = "Vitro.defaultNamespace";
 
+	/**
+	 * The name of the root directory, within the base directory.
+	 */
+	public static final String FILE_STORAGE_ROOT = "file_storage_root";
+
+	/**
+	 * The name of the file in the base directory that holds the namespace map.
+	 */
+	public static final String FILE_STORAGE_NAMESPACES_PROPERTIES = "file_storage_namespaces.properties";
+
 	/**
 	 * How often to we insert path separator characters?
 	 */

webapp/src/edu/cornell/mannlib/vitro/webapp/utils/filestorage/FileStorageHelper.java

@@ -42,6 +42,15 @@ public class FileStorageHelper {
 	public static final char[] NAME_SINGLE_CHARACTER_TARGETS = new char[] {
 			'=', '+' };
 
+	/**
+	 * Windows reserves these names (case-insensitive), so they can't be used
+	 * for directories or files.
+	 */
+	public static final String[] WINDOWS_RESERVED_NAMES = new String[] { "CON",
+			"PRN", "AUX", "NUL", "COM1", "COM2", "COM3", "COM4", "COM5",
+			"COM6", "COM7", "COM8", "COM9", "LPT1", "LPT2", "LPT3", "LPT4",
+			"LPT5", "LPT6", "LPT7", "LPT8", "LPT9" };
+
 	/**
 	 * Encode the filename as needed to guard against illegal characters.
 	 * 
@@ -49,8 +58,9 @@ public class FileStorageHelper {
 	 */
 	public static String encodeName(String filename) {
 		String hexed = addHexEncoding(filename);
-		return addSingleCharacterConversions(hexed,
+		String cleaned = addSingleCharacterConversions(hexed,
 				NAME_SINGLE_CHARACTER_SOURCES, NAME_SINGLE_CHARACTER_TARGETS);
+		return excludeWindowsReservedNames(cleaned);
 	}
 
 	/**
@@ -123,17 +133,47 @@ public class FileStorageHelper {
 		return c;
 	}
 
+	/**
+	 * If a requested filename, after cleaning, is one of the Windows reserved
+	 * words, add a tilde in front.
+	 */
+	private static String excludeWindowsReservedNames(String cleanedName) {
+		for (String word : WINDOWS_RESERVED_NAMES) {
+			if (word.equalsIgnoreCase(cleanedName)) {
+				return '~' + cleanedName;
+			}
+		}
+		return cleanedName;
+	}
+
 	/**
 	 * Restore the filename to its original form, removing the encoding.
 	 * 
 	 * @see edu.cornell.mannlib.vitro.webapp.utils.filestorage
 	 */
-	public static String decodeName(String coded) {
-		String hexed = removeSingleCharacterConversions(coded,
+	public static String decodeName(String stored) {
+		String unexcluded = unexcludeWindowsReservedNames(stored);
+		String hexed = removeSingleCharacterConversions(unexcluded,
 				NAME_SINGLE_CHARACTER_SOURCES, NAME_SINGLE_CHARACTER_TARGETS);
 		return removeHexEncoding(hexed);
 	}
 
+	/**
+	 * If the stored filename was a tilde followed by a Windows reserved word,
+	 * strip the tilde.
+	 */
+	private static String unexcludeWindowsReservedNames(String stored) {
+		if (stored.startsWith("~")) {
+			String remainder = stored.substring(1);
+			for (String word : WINDOWS_RESERVED_NAMES) {
+				if (word.equalsIgnoreCase(remainder)) {
+					return remainder;
+				}
+			}
+		}
+		return stored;
+	}
+
 	/**
 	 * Convert common single-character substitutions back to their original
 	 * values.
@@ -186,7 +226,7 @@ public class FileStorageHelper {
 	 * Translate the object ID to a relative directory path. A recognized
 	 * namespace is translated to its prefix, and illegal characters are
 	 * encoded. The resulting string is broken up into 3-character directory
-	 * names (or less).
+	 * names (or less). Windows reserved words are prefixed with tilde.
 	 * 
 	 * @see edu.cornell.mannlib.vitro.webapp.utils.filestorage
 	 */
@@ -206,7 +246,11 @@ public class FileStorageHelper {
 		String cleaned = addSingleCharacterConversions(hexed,
 				PATH_SINGLE_CHARACTER_SOURCES, PATH_SINGLE_CHARACTER_TARGETS);
 		String prefixed = applyPrefixChar(prefix, cleaned);
-		return insertPathDelimiters(prefixed);
+		String brokenUp = insertPathDelimiters(prefixed);
+		String result = excludeWindowsWordsFromPath(brokenUp);
+		LOG.debug("id2Path: id='" + id + "', namespaces='" + namespacesMap
+				+ "', path='" + result + "'");
+		return result;
 	}
 
 	/**
@@ -232,9 +276,31 @@ public class FileStorageHelper {
 			}
 			path.append(prefixed.charAt(i));
 		}
+		LOG.debug("Insert path delimiters to '" + prefixed + "' giving '"
+				+ path + "'");
 		return path.toString();
 	}
 
+	/**
+	 * Check each part in the path, and if it is a Windows reserved word, add a
+	 * tilde. This only applies to the relative path.
+	 */
+	private static String excludeWindowsWordsFromPath(String rawPath) {
+		String path = rawPath.replace(File.separatorChar, '/');
+		String[] parts = path.split("/");
+		
+		StringBuilder newPath = new StringBuilder();
+		
+		for (int i = 0; i < parts.length; i++) {
+			String part = excludeWindowsReservedNames(parts[i]);
+			if (i > 0) {
+				newPath.append(File.separatorChar);
+			}
+			newPath.append(part);
+		}
+		return newPath.toString();
+	}
+
 	/**
 	 * Translate the object ID and the file storage root directory into a full
 	 * path to the directory that would represent that ID.

webapp/src/edu/cornell/mannlib/vitro/webapp/utils/filestorage/FileStorageImpl.java

@@ -14,6 +14,7 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.io.PrintWriter;
+import java.io.Reader;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
@@ -69,10 +70,10 @@ public class FileStorageImpl implements FileStorage {
 		checkNamespacesValid(namespaces);
 
 		this.baseDir = baseDir;
-		this.rootDir = new File(this.baseDir, "file_storage_root");
+		this.rootDir = new File(this.baseDir, FILE_STORAGE_ROOT);
 
 		this.namespaceFile = new File(baseDir,
-				"file_storage_namespaces.properties");
+				FILE_STORAGE_NAMESPACES_PROPERTIES);
 
 		if (rootDir.exists() && namespaceFile.exists()) {
 			this.namespacesMap = confirmNamespaces(namespaces);
@@ -80,15 +81,15 @@ public class FileStorageImpl implements FileStorage {
 			this.namespacesMap = mapNamespaces(namespaces);
 			initializeStorage();
 		} else if (rootDir.exists()) {
-			throw new IllegalStateException(
-					"Storage directory '' has been partially initialized. '"
-							+ rootDir.getPath() + "' exists, but '"
-							+ namespaceFile.getPath() + "' does not.");
+			throw new IllegalStateException("Storage directory '"
+					+ baseDir.getPath() + "' has been partially initialized. '"
+					+ FILE_STORAGE_ROOT + "' exists, but '"
+					+ FILE_STORAGE_NAMESPACES_PROPERTIES + "' does not.");
 		} else {
-			throw new IllegalStateException(
-					"Storage directory '' has been partially initialized. '"
-							+ namespaceFile.getPath() + "' exists, but '"
-							+ rootDir.getPath() + "' does not.");
+			throw new IllegalStateException("Storage directory '"
+					+ baseDir.getPath() + "' has been partially initialized. '"
+					+ FILE_STORAGE_NAMESPACES_PROPERTIES + "' exists, but '"
+					+ FILE_STORAGE_ROOT + "' does not.");
 		}
 	}
 
@@ -222,9 +223,11 @@ public class FileStorageImpl implements FileStorage {
 	private Map<Character, String> confirmNamespaces(
 			Collection<String> namespaces) throws IOException {
 		Map<Character, String> map;
+		Reader reader = null;
 		try {
+			reader = new FileReader(this.namespaceFile);
 			Properties props = new Properties();
-			props.load(new FileReader(this.namespaceFile));
+			props.load(reader);
 			map = new HashMap<Character, String>();
 			for (Object key : props.keySet()) {
 				char keyChar = key.toString().charAt(0);
@@ -232,6 +235,14 @@ public class FileStorageImpl implements FileStorage {
 			}
 		} catch (Exception e) {
 			throw new IOException("Problem loading the namespace file.");
+		} finally {
+			if (reader != null) {
+				try {
+					reader.close();
+				} catch (IOException e) {
+					e.printStackTrace();
+				}
+			}
 		}
 
 		Set<String> requestedNamespaces = new HashSet<String>(namespaces);
@@ -248,12 +259,29 @@ public class FileStorageImpl implements FileStorage {
 		return map;
 	}
 
+	// ----------------------------------------------------------------------
+	// package access methods -- used in unit tests.
+	// ----------------------------------------------------------------------
+
+	File getBaseDir() {
+		return this.baseDir;
+	}
+
+	Map<Character, String> getNamespaces() {
+		return this.namespacesMap;
+	}
+
 	// ----------------------------------------------------------------------
 	// Public methods
 	// ----------------------------------------------------------------------
 
 	/**
 	 * {@inheritDoc}
+	 * 
+	 * <p>
+	 * Before creating the file, we may need to create one or more parent
+	 * directories to put it in.
+	 * </p>
 	 */
 	@Override
 	public void createFile(String id, String filename, InputStream bytes)
@@ -266,6 +294,16 @@ public class FileStorageImpl implements FileStorage {
 
 		File file = FileStorageHelper.getFullPath(this.rootDir, id, filename,
 				this.namespacesMap);
+		File parent = file.getParentFile();
+
+		if (!parent.exists()) {
+			parent.mkdirs();
+			if (!parent.exists()) {
+				throw new IOException(
+						"Failed to create parent directories for file with ID '"
+								+ id + "', file location '" + file + "'");
+			}
+		}
 
 		OutputStream out = null;
 		try {

webapp/src/edu/cornell/mannlib/vitro/webapp/utils/filestorage/package-info.java

@@ -134,8 +134,17 @@
  *     </li> 
  *     <li>
  *       <strong>Path breakdown</strong> -
- *       Finally, path separator characters are inserted after every third 
- *       character in the processed ID string.
+ *       Path separator characters are inserted after every third character 
+ *       in the processed ID string.
+ *     </li> 
+ *     <li>
+ *       <strong>Exclusion of reserved Windows filenames</strong> -
+ *       Windows will not permit certain specific filename or directory names,
+ *       so if any part of the path would be equal to one of those reserved
+ *       names, it is prefixed with a tilde. The reserved names are:
+ *       CON, PRN, AUX, NUL, COM1, COM2, COM3, COM4, COM5, COM6, COM7, COM8, 
+ *       COM9, LPT1, LPT2, LPT3, LPT4, LPT5, LPT6, LPT7, LPT8, and LPT9.
+ *       And remember, Windows is case-insensitive. 
  *     </li> 
  *   </ul>
  *   Examples:
@@ -161,7 +170,8 @@
  * 
  * <p>
  *   The encoding process is the same as the "rare character encoding" and 
- *   "common character encoding" steps used for ID encoding.
+ *   "common character encoding" steps used for ID encoding, except that 
+ *   periods are not encoded.
  * </p>
  */
 

webapp/test/edu/cornell/mannlib/vitro/webapp/utils/filestorage/FileStorageHelperTest.java

@@ -48,6 +48,16 @@ public class FileStorageHelperTest {
 	private static File FULL_RESULT_PATH = new File(
 			"/usr/local/vivo/uploads/file_storage_root/b~n/323/4,X/XX/myPhoto.jpg");
 
+	private static Map<Character, String> WINDOWS_PREFIX_MAP = initWindowsPrefixMap();
+	/** This reserved word will be modified. */
+	private static String WINDOWS_NAME = "lpT8";
+	/** This ID would translate to a path with a reserved word. */
+	private static String WINDOWS_ID = "prefix:createdConflict";
+	/** Not allowed to change the root, even if it contains reserved words. */
+	private static File WINDOWS_ROOT = new File("/usr/aux/root/");
+	private static File WINDOWS_FULL_PATH = new File(
+			"/usr/aux/root/a~c/rea/ted/~Con/fli/ct/~lpT8");
+
 	private static Map<Character, String> EMPTY_NAMESPACES = Collections
 			.emptyMap();
 	private static Map<Character, String> NAMESPACES = initPrefixMap();
@@ -59,6 +69,12 @@ public class FileStorageHelperTest {
 		return map;
 	}
 
+	private static Map<Character, String> initWindowsPrefixMap() {
+		Map<Character, String> map = new HashMap<Character, String>();
+		map.put('a', "prefix:");
+		return map;
+	}
+
 	// ----------------------------------------------------------------------
 	// encodeName
 	// ----------------------------------------------------------------------
@@ -199,4 +215,11 @@ public class FileStorageHelperTest {
 		assertEquals("fullPath", FULL_RESULT_PATH, actual);
 	}
 
+	@Test
+	public void checkWindowsExclusions() {
+		File actual = FileStorageHelper.getFullPath(WINDOWS_ROOT, WINDOWS_ID,
+				WINDOWS_NAME, WINDOWS_PREFIX_MAP);
+		assertEquals("windows exclusion", WINDOWS_FULL_PATH, actual);
+	}
+
 }

webapp/test/edu/cornell/mannlib/vitro/webapp/utils/filestorage/FileStorageImplTest.java

@@ -2,9 +2,26 @@
 
 package edu.cornell.mannlib.vitro.webapp.utils.filestorage;
 
+import static org.junit.Assert.*;
+import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
-import org.junit.Ignore;
+import java.io.ByteArrayInputStream;
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+import org.apache.log4j.Level;
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
 import org.junit.Test;
 
 import edu.cornell.mannlib.vitro.testing.AbstractTestClass;
@@ -14,105 +31,243 @@ import edu.cornell.mannlib.vitro.testing.AbstractTestClass;
  * {@link FileStorageFactoryTest}.
  */
 public class FileStorageImplTest extends AbstractTestClass {
-	@Ignore
-	@Test
-	public void baseDirDoesntExist() {
-		fail("baseDirDoesntExist not implemented");
+	private static final List<String> EMPTY_NAMESPACES = Collections
+			.emptyList();
+
+	private static File tempDir;
+	private static FileStorageImpl generalFs;
+
+	@BeforeClass
+	public static void createSomeDirectories() throws IOException {
+		tempDir = createTempDirectory(FileStorageImplTest.class.getSimpleName());
+		generalFs = createFileStorage("general");
 	}
 
-	@Ignore
-	@Test
-	public void partialInitializationRoot() {
-		fail("partialInitializationRoot not implemented");
+	@AfterClass
+	public static void cleanUp() {
+		if (tempDir != null) {
+			purgeDirectoryRecursively(tempDir);
+		}
 	}
 
-	@Ignore
-	@Test
-	public void partialInitializationNamespaces() {
-		fail("partialInitializationNamespaces not implemented");
+	@Test(expected = IllegalArgumentException.class)
+	public void baseDirDoesntExist() throws IOException {
+		File baseDir = new File(tempDir, "doesntExist");
+		new FileStorageImpl(baseDir, EMPTY_NAMESPACES);
 	}
 
-	@Ignore
-	@Test
-	public void notInitialized() {
-		fail("notInitialized not implemented");
+	@Test(expected = IllegalStateException.class)
+	public void partialInitializationRoot() throws IOException {
+		File baseDir = new File(tempDir, "partialWithRoot");
+		baseDir.mkdir();
+		new File(baseDir, FileStorage.FILE_STORAGE_ROOT).mkdir();
+
+		new FileStorageImpl(baseDir, EMPTY_NAMESPACES);
 	}
 
-	@Ignore
-	@Test
-	public void initializedOK() {
-		fail("initializedOK not implemented");
+	@Test(expected = IllegalStateException.class)
+	public void partialInitializationNamespaces() throws IOException {
+		File baseDir = new File(tempDir, "partialWithNamespaces");
+		baseDir.mkdir();
+		new File(baseDir, FileStorage.FILE_STORAGE_NAMESPACES_PROPERTIES)
+				.createNewFile();
+
+		new FileStorageImpl(baseDir, EMPTY_NAMESPACES);
 	}
 
-	@Ignore
 	@Test
-	public void initializedNamespacesDontMatch() {
-		fail("initializedNamespacesDontMatch not implemented");
+	public void notInitializedNoNamespaces() throws IOException {
+		File baseDir = new File(tempDir, "emptyNoNamespaces");
+		baseDir.mkdir();
+
+		FileStorageImpl fs = new FileStorageImpl(baseDir,
+				new ArrayList<String>());
+		assertEquals("baseDir", baseDir, fs.getBaseDir());
+		assertEqualSets("namespaces", new String[0], fs.getNamespaces()
+				.values());
 	}
 
-	@Ignore
 	@Test
-	public void createFileOriginal() {
-		fail("createFileOriginal not implemented");
+	public void notInitializedNamespaces() throws IOException {
+		String[] namespaces = new String[] { "ns1", "ns2" };
+		String dirName = "emptyWithNamespaces";
+
+		FileStorageImpl fs = createFileStorage(dirName, namespaces);
+
+		assertEquals("baseDir", new File(tempDir, dirName), fs.getBaseDir());
+		assertEqualSets("namespaces", namespaces, fs.getNamespaces().values());
 	}
 
-	@Ignore
 	@Test
-	public void createFileOverwrite() {
-		fail("createFileOverwrite not implemented");
+	public void initializedOK() throws IOException {
+		createFileStorage("initializeTwiceTheSame", "ns1", "ns2");
+		createFileStorage("initializeTwiceTheSame", "ns2", "ns1");
 	}
 
-	@Ignore
-	@Test
-	public void createFileConflictingName() {
-		fail("createFileConflictingName not implemented");
+	@Test(expected = IllegalStateException.class)
+	public void initializedNamespacesDontMatch() throws IOException {
+		createFileStorage("initializeTwiceDifferent", "ns1", "ns2");
+		createFileStorage("initializeTwiceDifferent", "ns2");
 	}
 
-	@Ignore
 	@Test
-	public void getFilenameExists() {
-		fail("getFilenameExists not implemented");
+	public void createFileOriginal() throws IOException {
+		String id = "createOriginal";
+		String filename = "someName.txt";
+		String contents = "these contents";
+		InputStream bytes = new ByteArrayInputStream(contents.getBytes());
+
+		generalFs.createFile(id, filename, bytes);
+
+		assertFileContents(generalFs, id, filename, contents);
 	}
 
-	@Ignore
 	@Test
-	public void getFilenameDoesntExist() {
-		fail("getFilenameDoesntExist not implemented");
+	public void createFileOverwrite() throws IOException {
+		String id = "createOverwrite";
+		String filename = "someName.txt";
+
+		String contents1 = "these contents";
+		InputStream bytes1 = new ByteArrayInputStream(contents1.getBytes());
+
+		String contents2 = "a different string";
+		InputStream bytes2 = new ByteArrayInputStream(contents2.getBytes());
+
+		generalFs.createFile(id, filename, bytes1);
+		generalFs.createFile(id, filename, bytes2);
+
+		assertFileContents(generalFs, id, filename, contents2);
 	}
 
-	@Ignore
 	@Test
-	public void getFilenameMultipleFiles() {
-		fail("getFilenameMultipleFiles not implemented");
+	public void createFileConflictingName() throws IOException {
+		String id = "createConflict";
+		String filename1 = "someName.txt";
+		String filename2 = "secondFileName.txt";
+		String contents = "these contents";
+		InputStream bytes = new ByteArrayInputStream(contents.getBytes());
+
+		generalFs.createFile(id, filename1, bytes);
+		try {
+			generalFs.createFile(id, filename2, bytes);
+			fail("Expected FileAlreadyExistsException.");
+		} catch (FileAlreadyExistsException e) {
+			// expected it.
+		}
 	}
 
-	@Ignore
 	@Test
-	public void getFileFound() {
-		fail("getFilenameFound not implemented");
+	public void getFilenameExists() throws IOException {
+		String id = "filenameExists";
+		String filename = "theName.txt";
+		String contents = "the contents";
+		InputStream bytes = new ByteArrayInputStream(contents.getBytes());
+
+		generalFs.createFile(id, filename, bytes);
+
+		assertEquals("filename", filename, generalFs.getFilename(id));
 	}
 
-	@Ignore
 	@Test
-	public void getFileNotFound() {
-		fail("getFileNotFound not implemented");
+	public void getFilenameDoesntExist() throws IOException {
+		assertNull("null filename", generalFs.getFilename("neverHeardOfIt"));
 	}
 
-	@Ignore
 	@Test
-	public void getFileTooLarge() {
-		fail("getFileTooLarge not implemented");
+	public void getInputStreamFound() throws IOException {
+		String id = "inputStreamExists";
+		String filename = "myFile";
+		String contents = "Some stuff to put into my file.";
+		InputStream bytes = new ByteArrayInputStream(contents.getBytes());
+
+		generalFs.createFile(id, filename, bytes);
+
+		assertFileContents(generalFs, id, filename, contents);
+		assertEquals("getInputStream", contents, readAll(generalFs
+				.getInputStream(id, filename)));
 	}
 
-	@Ignore
-	@Test
-	public void deleteFileExists() {
-		fail("deleteFileExists not implemented");
+	@Test(expected = FileNotFoundException.class)
+	public void getInputStreamNotFound() throws IOException {
+		generalFs.getInputStream("notFound", "nothing");
 	}
 
-	@Ignore
 	@Test
-	public void deleteFileDoesntExist() {
-		fail("deleteFileDoesntExist not implemented");
+	public void deleteFileExists() throws IOException {
+		String id = "deleteMe";
+		String filename = "deadFile";
+		String contents = "Some stuff to put into my file.";
+		InputStream bytes = new ByteArrayInputStream(contents.getBytes());
+
+		generalFs.createFile(id, filename, bytes);
+		generalFs.deleteFile(id);
+		assertNull("deleted filename", generalFs.getFilename(id));
+	}
+
+	@Test
+	public void deleteFileDoesntExist() throws IOException {
+		generalFs.deleteFile("totallyBogus");
+	}
+
+	@Test
+	public void exerciseWindowsExclusions() throws FileAlreadyExistsException,
+			IOException {
+		// setLoggerLevel(FileStorageHelper.class, Level.DEBUG);
+		String id = "nul";
+		String filename = "COM1";
+		String contents = "Windows doesn't like certain names.";
+		InputStream bytes = new ByteArrayInputStream(contents.getBytes());
+
+		generalFs.createFile(id, filename, bytes);
+
+		assertFileContents(generalFs, id, filename, contents);
+		assertEquals("filename", filename, generalFs.getFilename(id));
+		assertEquals("getInputStream", contents, readAll(generalFs
+				.getInputStream(id, filename)));
+	}
+
+	// ----------------------------------------------------------------------
+	// helper methods
+	// ----------------------------------------------------------------------
+
+	private static FileStorageImpl createFileStorage(String dirName,
+			String... namespaces) throws IOException {
+		File baseDir = new File(tempDir, dirName);
+		baseDir.mkdir();
+		return new FileStorageImpl(baseDir, Arrays.asList(namespaces));
+	}
+
+	private <T> void assertEqualSets(String message, T[] expected,
+			Collection<T> actual) {
+		Set<T> expectedSet = new HashSet<T>(Arrays.asList(expected));
+		if (expectedSet.size() != expected.length) {
+			fail("message: expected array contains duplicate elements: "
+					+ Arrays.deepToString(expected));
+		}
+
+		Set<T> actualSet = new HashSet<T>(actual);
+		if (actualSet.size() != actual.size()) {
+			fail("message: actual collection contains duplicate elements: "
+					+ actual);
+		}
+
+		assertEquals(message, expectedSet, actualSet);
+	}
+
+	/**
+	 * This file storage should contain a file with this ID and this name, and
+	 * it should have these contents.
+	 */
+	private void assertFileContents(FileStorageImpl fs, String id,
+			String filename, String expectedContents) throws IOException {
+		File rootDir = new File(fs.getBaseDir(), FileStorage.FILE_STORAGE_ROOT);
+		File path = FileStorageHelper.getFullPath(rootDir, id, filename, fs
+				.getNamespaces());
+
+		assertTrue("file exists: " + path, path.exists());
+
+		String actualContents = readFile(path);
+
+		assertEquals("file contents", expectedContents, actualContents);
 	}
 }