From b9dfa9023b22777dc4df8880d51b24d351aaa21f Mon Sep 17 00:00:00 2001
From: jeb228 <jeb228@440791e1-c2bf-4c1e-ad7c-caf3f8b0ebe8>
Date: Thu, 20 May 2010 20:49:42 +0000
Subject: [PATCH] NIHVIVO-160 Start coding the back-end

---
 .../FileAlreadyExistsException.java           |  38 ++++
 .../webapp/utils/filestorage/FileStorage.java | 108 ++++++++++
 .../utils/filestorage/FileStorageHelper.java  |  10 +
 .../utils/filestorage/FileStorageImpl.java    | 192 ++++++++++++++++++
 .../utils/filestorage/package-info.java       | 100 +++++++++
 5 files changed, 448 insertions(+)
 create mode 100644 webapp/test/edu/cornell/mannlib/vitro/webapp/utils/filestorage/FileAlreadyExistsException.java
 create mode 100644 webapp/test/edu/cornell/mannlib/vitro/webapp/utils/filestorage/FileStorage.java
 create mode 100644 webapp/test/edu/cornell/mannlib/vitro/webapp/utils/filestorage/FileStorageHelper.java
 create mode 100644 webapp/test/edu/cornell/mannlib/vitro/webapp/utils/filestorage/FileStorageImpl.java
 create mode 100644 webapp/test/edu/cornell/mannlib/vitro/webapp/utils/filestorage/package-info.java

diff --git a/webapp/test/edu/cornell/mannlib/vitro/webapp/utils/filestorage/FileAlreadyExistsException.java b/webapp/test/edu/cornell/mannlib/vitro/webapp/utils/filestorage/FileAlreadyExistsException.java
new file mode 100644
index 000000000..7bd7a3c75
--- /dev/null
+++ b/webapp/test/edu/cornell/mannlib/vitro/webapp/utils/filestorage/FileAlreadyExistsException.java
@@ -0,0 +1,38 @@
+/* $This file is distributed under the terms of the license in /doc/license.txt$ */
+
+package edu.cornell.mannlib.vitro.webapp.utils.filestorage;
+
+import java.io.IOException;
+
+/**
+ * Indicates that a file already exists with the specified ID, but with a
+ * different filename from the one specified.
+ */
+public class FileAlreadyExistsException extends IOException {
+	private final String id;
+	private final String existingFilename;
+	private final String requestedFilename;
+
+	public FileAlreadyExistsException(String id, String existingFilename,
+			String requestedFilename) {
+		super("File with a different name already exists at this ID: '" + id
+				+ "', requested filename: '" + requestedFilename
+				+ "', existing filename: '" + existingFilename + "'");
+		this.id = id;
+		this.existingFilename = existingFilename;
+		this.requestedFilename = requestedFilename;
+	}
+
+	public String getId() {
+		return id;
+	}
+
+	public String getExistingFilename() {
+		return existingFilename;
+	}
+
+	public String getRequestedFilename() {
+		return requestedFilename;
+	}
+
+}
diff --git a/webapp/test/edu/cornell/mannlib/vitro/webapp/utils/filestorage/FileStorage.java b/webapp/test/edu/cornell/mannlib/vitro/webapp/utils/filestorage/FileStorage.java
new file mode 100644
index 000000000..7abd05cf3
--- /dev/null
+++ b/webapp/test/edu/cornell/mannlib/vitro/webapp/utils/filestorage/FileStorage.java
@@ -0,0 +1,108 @@
+/* $This file is distributed under the terms of the license in /doc/license.txt$ */
+
+package edu.cornell.mannlib.vitro.webapp.utils.filestorage;
+
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.io.InputStream;
+
+import edu.cornell.mannlib.vitro.webapp.ConfigurationProperties;
+
+/**
+ * The "interface" for the File Storage system. All methods are abstract except
+ * for the factory method.
+ */
+public abstract class FileStorage {
+	/**
+	 * If this system property is set, it will be taken as the name of the
+	 * implementing class.
+	 */
+	public static final String PROPERTY_IMPLEMETATION_CLASSNAME = FileStorage.class
+			.getName();
+
+	/**
+	 * The default implementation will use this key to ask
+	 * {@link ConfigurationProperties} for the file storage base directory.
+	 */
+	public static final String PROPERTY_FILE_STORAGE_BASE_DIR = "upload.directory";
+
+	/**
+	 * The default implementation will use this key to ask
+	 * {@link ConfigurationProperties} for the default URI namespace.
+	 */
+	public static final String PROPERTY_DEFAULT_NAMESPACE = "Vitro.defaultNamespace";
+
+	/**
+	 * <p>
+	 * Get an instance of {@link FileStorage}. By default, this will be an
+	 * instance of {@link FileStorageImpl}.
+	 * </p>
+	 * <p>
+	 * If the System Property named by
+	 * {#SYSTEM_PROPERTY_IMPLEMETATION_CLASSNAME} is set, it must contain the
+	 * name of the implementation class, which must be a sub-class of
+	 * {@link FileStorage}, and must have a public, no-argument constructor.
+	 * </p>
+	 */
+	public static FileStorage getInstance() {
+		String className = System.getProperty(PROPERTY_IMPLEMETATION_CLASSNAME);
+		if (className == null) {
+			return new FileStorageImpl();
+		}
+
+		try {
+			Class<?> clazz = Class.forName(className);
+			Object instance = clazz.newInstance();
+			return FileStorage.class.cast(instance);
+		} catch (ClassNotFoundException e) {
+			throw new IllegalArgumentException(
+					"Can't create a FileStorage instance", e);
+		} catch (ClassCastException e) {
+			throw new IllegalArgumentException(
+					"Can't create a FileStorage instance", e);
+		} catch (InstantiationException e) {
+			throw new IllegalArgumentException(
+					"Can't create a FileStorage instance", e);
+		} catch (IllegalAccessException e) {
+			throw new IllegalArgumentException(
+					"Can't create a FileStorage instance", e);
+		}
+	}
+
+	/**
+	 * Store the bytes from this stream as a file with the specified ID and
+	 * filename. If the file already exists, it is over-written.
+	 * 
+	 * @throws FileAlreadyExistsException
+	 *             if a file already exists with this ID but with a different
+	 *             filename.
+	 * 
+	 */
+	public abstract void createFile(String id, String filename,
+			InputStream bytes) throws FileAlreadyExistsException, IOException;
+
+	/**
+	 * If a file exists with this ID, get its name.
+	 * 
+	 * @return The name of the file (un-encoded) if it exists, or
+	 *         <code>null</code> if it does not.
+	 */
+	public abstract String getFilename(String id) throws IOException;
+
+	/**
+	 * Get the contents of the file with this ID and this filename.
+	 * 
+	 * @throws FileNotFoundException
+	 *             if there is no file that matches this ID and filename.
+	 */
+	public abstract byte[] getfile(String id, String filename)
+			throws FileNotFoundException, IOException;
+
+	/**
+	 * If a file exists with this ID, it will be deleted, regardless of the file
+	 * name. If no such file exists, no action is taken, no exception is thrown.
+	 * 
+	 * @return <code>true<code> if a file existed, <code>false</code> otherwise.
+	 */
+	public abstract boolean deleteFile(String id) throws IOException;
+}
diff --git a/webapp/test/edu/cornell/mannlib/vitro/webapp/utils/filestorage/FileStorageHelper.java b/webapp/test/edu/cornell/mannlib/vitro/webapp/utils/filestorage/FileStorageHelper.java
new file mode 100644
index 000000000..6060496c6
--- /dev/null
+++ b/webapp/test/edu/cornell/mannlib/vitro/webapp/utils/filestorage/FileStorageHelper.java
@@ -0,0 +1,10 @@
+/* $This file is distributed under the terms of the license in /doc/license.txt$ */
+
+package edu.cornell.mannlib.vitro.webapp.utils.filestorage;
+
+/**
+ * TODO
+ */
+public class FileStorageHelper {
+
+}
diff --git a/webapp/test/edu/cornell/mannlib/vitro/webapp/utils/filestorage/FileStorageImpl.java b/webapp/test/edu/cornell/mannlib/vitro/webapp/utils/filestorage/FileStorageImpl.java
new file mode 100644
index 000000000..5ec7d243d
--- /dev/null
+++ b/webapp/test/edu/cornell/mannlib/vitro/webapp/utils/filestorage/FileStorageImpl.java
@@ -0,0 +1,192 @@
+/* $This file is distributed under the terms of the license in /doc/license.txt$ */
+
+package edu.cornell.mannlib.vitro.webapp.utils.filestorage;
+
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.Collection;
+import java.util.Collections;
+
+import edu.cornell.mannlib.vitro.webapp.ConfigurationProperties;
+
+/**
+ * The default implementation of {@link FileStorage}.
+ */
+public class FileStorageImpl extends FileStorage {
+
+	// static FileStorage getInstance()
+	// gets baseDir and namespaces from ConfigurationProperties
+	// gets instance class from system properties
+	// throws IllegalStateException if requires properties are missing
+	// throws IOException
+	//	
+	// void createFile(String id, String filename, InputStream bytes)
+	// stores the bytes as a file with this name under this id
+	// if the file already exists, over-writes it
+	// throws FileAlreadyExistsException if a file already exists under this id
+	// with a different name
+	// throws IOException
+	//
+	// String getfilename(String id)
+	// returns the name of the file at this ID, or null if there is none.
+	// throws IOException
+	//	
+	// byte[] getFile(String id, String filename)
+	// gets the bytes from the file
+	// throws FileNotFoundException if the file does not exist
+	// throws IOException
+	//
+	// boolean deleteFile(String id)
+	// removes the file at this id, returns true
+	// if no such file, takes no action, returns false
+	// throws IOException
+	//		
+	// FileStorageImpl
+	//
+
+	/**
+	 * Use the configuration properties to create an instance.
+	 * 
+	 * @throws IllegalArgumentException
+	 *             if the configuration property for the base directory is
+	 *             missing, or if it doesn't point to an existing, writeable
+	 *             directory.
+	 * @throws IllegalArgumentException
+	 *             if the configuration property for the default namespace is
+	 *             missing, or if it isn't in the expected form.
+	 */
+	FileStorageImpl() {
+		this(figureBaseDir(), figureFileNamespace());
+	}
+
+	// package-level constructor(File baseDir, Collection<String> namespaces),
+	// gets properties from arguments
+	// if baseDir is not initialized with file_storage_root and
+	// file_storage_prefixMap, do it.
+	// otherwise check for correctness and consistency
+	// throws IllegalStateException if partially initialized
+	// throws IllegalStateException if already initialized and namespaces don't
+	// match
+
+	/**
+	 * Use the arguments to create an instance. If the base directory is empty,
+	 * initialize it. Otherwise, check that it was initialized to the same
+	 * namespaces.
+	 * 
+	 * @throws IllegalArgumentException
+	 *             if the configuration property doesn't point to an existing,
+	 *             writeable directory.
+	 */
+	FileStorageImpl(File baseDir, Collection<String> namespaces) {
+		if (baseDir == null) {
+			throw new NullPointerException("baseDir may not be null.");
+		}
+		if (namespaces == null) {
+			throw new NullPointerException("namespaces may not be null.");
+		}
+		if (!baseDir.exists()) {
+			throw new IllegalArgumentException(
+					"File upload directory does not exist: '"
+							+ baseDir.getPath() + "'");
+		}
+		if (!baseDir.isDirectory()) {
+			throw new IllegalArgumentException(
+					"File upload directory is not a directory: '"
+							+ baseDir.getPath() + "'");
+		}
+		if (!baseDir.canWrite()) {
+			throw new IllegalArgumentException(
+					"File upload directory is not writeable: '"
+							+ baseDir.getPath() + "'");
+		}
+
+	}
+
+	/**
+	 * Get the configuration property for the file storage base directory, and
+	 * check that it points to an existing, writeable directory.
+	 */
+	private static File figureBaseDir() {
+		String baseDirPath = ConfigurationProperties
+				.getProperty(PROPERTY_FILE_STORAGE_BASE_DIR);
+		if (baseDirPath == null) {
+			throw new IllegalArgumentException(
+					"Configuration properties must contain a value for '"
+							+ PROPERTY_FILE_STORAGE_BASE_DIR + "'");
+		}
+		return new File(baseDirPath);
+	}
+
+	/**
+	 * Get the configuration property for the default namespace, and derive the
+	 * file namespace from it. The default namespace is assumed to be in this
+	 * form: <code>http://vivo.mydomain.edu/individual/</code>
+	 * 
+	 * @returns the file namespace is assumed to be in this form:
+	 *          <code>http://vivo.mydomain.edu/file/</code>
+	 */
+	private static Collection<String> figureFileNamespace() {
+		String defaultNamespace = ConfigurationProperties
+				.getProperty(PROPERTY_DEFAULT_NAMESPACE);
+		if (defaultNamespace == null) {
+			throw new IllegalArgumentException(
+					"Configuration properties must contain a value for '"
+							+ PROPERTY_DEFAULT_NAMESPACE + "'");
+		}
+
+		String defaultSuffix = "/individual/";
+		String fileSuffix = "/file/";
+
+		if (!defaultNamespace.endsWith(defaultSuffix)) {
+			throw new IllegalArgumentException(
+					"Default namespace does not match the expected form: '"
+							+ defaultNamespace + "'");
+		}
+
+		int hostLength = defaultNamespace.length() - defaultSuffix.length();
+		String fileNamespace = defaultNamespace.substring(0, hostLength)
+				+ fileSuffix;
+		return Collections.singleton(fileNamespace);
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public void createFile(String id, String filename, InputStream bytes)
+			throws FileAlreadyExistsException, IOException {
+		// TODO Auto-generated method stub
+		throw new RuntimeException("FileStorage.createFile() not implemented.");
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public boolean deleteFile(String id) throws IOException {
+		// TODO Auto-generated method stub
+		throw new RuntimeException("FileStorage.deleteFile() not implemented.");
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public String getFilename(String id) throws IOException {
+		// TODO Auto-generated method stub
+		throw new RuntimeException("FileStorage.getFilename() not implemented.");
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public byte[] getfile(String id, String filename)
+			throws FileNotFoundException, IOException {
+		// TODO Auto-generated method stub
+		throw new RuntimeException("FileStorage.getfile() not implemented.");
+	}
+
+}
diff --git a/webapp/test/edu/cornell/mannlib/vitro/webapp/utils/filestorage/package-info.java b/webapp/test/edu/cornell/mannlib/vitro/webapp/utils/filestorage/package-info.java
new file mode 100644
index 000000000..157d6a660
--- /dev/null
+++ b/webapp/test/edu/cornell/mannlib/vitro/webapp/utils/filestorage/package-info.java
@@ -0,0 +1,100 @@
+/**
+ * <p>
+ * The code in this package implements the Vitro file-storage system.
+ * </p>
+ * 
+ * <h1>Relationship to PairTree</h1>
+ * 
+ * <p>
+ * The system incorporates a number of ideas from the PairTree specification, 
+ *   <ul>
+ *     <li>
+ *       The basic pairtree algorithm – 
+ *       mapping an encoded identifier string into a filesystem directory path.
+ *     </li>
+ *     <li>
+ *       Identifier string cleaning – 
+ *       encoding identifiers in a two-step process so that all illegal 
+ *       characters are eliminated, but some commonly-used 
+ *       illegal characters are handled by simple substitution.
+ *       Actually, it becomes a three-step process because namespaces are 
+ *       invoved.
+ *     </li>
+ *   </ul> 
+ * but is different in several respects:
+ *   <ul>
+ *     <li>
+ *       Each “object” will consist only of a single file, 
+ *       causing the entire issue of object encapsulation to be moot.
+ *     </li>
+ *     <li>
+ *       Filenames will be cleaned in the same manner as identifiers, 
+ *       guarding against illegal characters in filenames.
+ *     </li>
+ *     <li>
+ *       Character encoding will include backslashes, 
+ *       for compatibility with Windows.
+ *     </li>
+ *     <li>
+ *       Character encoding will include tildes, to allow for "namespaces". 
+ *     </li>
+ *     <li>
+ *       A namespace/prefix capability will be used to shorten file paths, 
+ *       but with more flexibility than the prefix algorithm given in the specification.
+ *     </li>
+ *   </ul> 
+ * </p>
+ *
+ * <h1>Directory structure</h1>
+ * 
+ * <p>
+ *   A typical structure would look like this:
+ *   <pre>
+ *   + basedir
+ *   |
+ *   +--+ file_storage_namespaces.properties
+ *   |
+ *   +--+ file_storage_root
+ *   </pre>
+ *   The <code>file_storage_root</code> directory contains the subdirectories 
+ *   that implement the encoded IDs, and the final directory for each ID will 
+ *   contain a single file that corresponds to that ID. 
+ * </p>
+ * 
+ * <h1>Namespaces</h1>
+ * 
+ * <p>
+ *   To reduce the length of the file paths, the system will can be initialized
+ *   to recognize certain sets of characters (loosely termed "namespaces") and
+ *   to replace them with a given prefix and separator character during ID 
+ *   encoding. 
+ * </p>
+ * <p>
+ *   For example, the sytem might be initialized with a "namespace" of 
+ *   "http://vivo.mydomain.edu/file/". If that is the only namespace, it will
+ *   be internally assigned a prefix of "a", so a URI like this:
+ *   <pre>http://vivo.mydomain.edu/file/n3424/myPhoto.jpg</pre>
+ *   would be converted to this:
+ *   <pre>a~n3424/myPhoto.jpg</pre>
+ * </p>
+ * 
+ * <h1>ID encoding</h1>
+ * 
+ * <p>
+ * </p>
+ * 
+ * <h1>Filename encoding</h1>
+ * 
+ * <p>
+ *   The name of the file is encoded as needed to guard against illegal 
+ *   characters for the filesystem, but in practice we expect little encoding
+ *   to be required, since few files are named with the special characters.
+ * </p>
+ * 
+ * <p></p>
+ * <p></p>
+ * <p></p>
+ * <p></p>
+ */
+
+package edu.cornell.mannlib.vitro.webapp.utils.filestorage;