Initial revision

From-SVN: r102074

libjava/classpath/gnu/java/net/protocol/file/Connection.java

@@ -0,0 +1,319 @@
+/* FileURLConnection.java -- URLConnection class for "file" protocol
+   Copyright (C) 1998, 1999, 2003 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+ 
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+package gnu.java.net.protocol.file;
+
+import gnu.classpath.SystemProperties;
+
+import java.io.BufferedInputStream;
+import java.io.BufferedOutputStream;
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.FilePermission;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.io.OutputStreamWriter;
+import java.io.Writer;
+import java.net.ProtocolException;
+import java.net.URL;
+import java.net.URLConnection;
+import java.security.Permission;
+import java.text.SimpleDateFormat;
+import java.util.Date;
+import java.util.Locale;
+
+/**
+ * This subclass of java.net.URLConnection models a URLConnection via
+ * the "file" protocol.
+ *
+ * @author Aaron M. Renn (arenn@urbanophile.com)
+ * @author Nic Ferrier (nferrier@tapsellferrier.co.uk)
+ * @author Warren Levy (warrenl@cygnus.com)
+ */
+public class Connection extends URLConnection
+{
+  /**
+   * Default permission for a file
+   */
+  private static final String DEFAULT_PERMISSION = "read";
+
+  private static class StaticData
+  {
+    /**
+     * HTTP-style DateFormat, used to format the last-modified header.
+     */
+    static SimpleDateFormat dateFormat
+      = new SimpleDateFormat("EEE, dd MMM yyyy hh:mm:ss 'GMT'",
+                             new Locale ("En", "Us", "Unix"));
+
+    static String lineSeparator =
+      SystemProperties.getProperty("line.separator");
+  }
+
+  
+  /**
+   * This is a File object for this connection
+   */
+  private File file;
+
+  /**
+   * If a directory, contains a list of files in the directory.
+   */
+  private byte[] directoryListing;
+
+  /**
+   * InputStream if we are reading from the file
+   */
+  private InputStream inputStream;
+
+  /**
+   * OutputStream if we are writing to the file
+   */
+  private OutputStream outputStream;
+  
+  /**
+   * FilePermission to read the file
+   */
+  private FilePermission permission;
+
+  /**
+   * Calls superclass constructor to initialize.
+   */
+  public Connection(URL url)
+  {
+    super (url);
+
+    permission = new FilePermission(getURL().getFile(), DEFAULT_PERMISSION);
+  }
+  
+  /**
+   * "Connects" to the file by opening it.
+   */
+  public void connect() throws IOException
+  {
+    // Call is ignored if already connected.
+    if (connected)
+      return;
+    
+    // If not connected, then file needs to be openned.
+    file = new File (getURL().getFile());
+
+    if (! file.isDirectory())
+      {
+	if (doInput)
+	  inputStream = new BufferedInputStream(new FileInputStream(file));
+    
+	if (doOutput)
+	  outputStream = new BufferedOutputStream(new FileOutputStream(file));
+      }
+    else
+      {
+	if (doInput)
+	  {
+            inputStream = new ByteArrayInputStream(getDirectoryListing());
+	  }
+
+	if (doOutput)
+	  throw new ProtocolException
+	    ("file: protocol does not support output on directories");
+      }
+    
+    connected = true;
+  }
+
+  /**
+   * Populates the <code>directoryListing</code> field with a byte array
+   * containing a representation of the directory listing.
+   */
+  byte[] getDirectoryListing()
+    throws IOException
+  {
+    if (directoryListing == null)
+      {
+        ByteArrayOutputStream sink = new ByteArrayOutputStream();
+        // NB uses default character encoding for this system
+        Writer writer = new OutputStreamWriter(sink);
+    
+        String[] files = file.list();
+    
+        for (int i = 0; i < files.length; i++)
+          {
+            writer.write(files[i]);
+            writer.write(StaticData.lineSeparator);
+          }
+
+        directoryListing = sink.toByteArray();
+      }
+    return directoryListing;  
+  }
+  
+  /**
+   * Opens the file for reading and returns a stream for it.
+   *
+   * @return An InputStream for this connection.
+   *
+   * @exception IOException If an error occurs
+   */
+  public InputStream getInputStream()
+    throws IOException
+  {
+    if (!doInput)
+      throw new ProtocolException("Can't open InputStream if doInput is false");
+    
+    if (!connected)
+      connect();
+    
+    return inputStream;
+  }
+
+  /**
+   * Opens the file for writing and returns a stream for it.
+   *
+   * @return An OutputStream for this connection.
+   *
+   * @exception IOException If an error occurs.
+   */
+  public OutputStream getOutputStream()
+    throws IOException
+  {
+    if (!doOutput)
+      throw new
+	ProtocolException("Can't open OutputStream if doOutput is false");
+
+    if (!connected)
+      connect();
+    
+    return outputStream;
+  }
+
+  /**
+   * Get the last modified time of the resource.
+   *
+   * @return the time since epoch that the resource was modified.
+   */
+  public long getLastModified()
+  {
+    try
+      {
+	if (!connected)
+	  connect();
+
+	return file.lastModified();
+      }
+    catch (IOException e)
+      {
+	return -1;
+      }
+  }
+  
+  /**
+   *  Get an http-style header field. Just handle a few common ones. 
+   */
+  public String getHeaderField(String field)
+  {
+    try
+      {
+	if (!connected)
+	  connect();
+
+	if (field.equals("content-type"))
+          return guessContentTypeFromName(file.getName());
+	else if (field.equals("content-length"))
+          {
+            if (file.isDirectory())
+              {
+                return Integer.toString(getContentLength());
+              }
+            return Long.toString(file.length());
+          }
+	else if (field.equals("last-modified"))
+	  {
+	    synchronized (StaticData.dateFormat)
+	      {
+        	return StaticData.dateFormat.format(
+                        new Date(file.lastModified()));
+	      }
+	  }
+      }
+    catch (IOException e)
+      {
+        // Fall through.
+      }
+    return null;
+  }
+
+  /**
+   * Get the length of content.
+   *
+   * @return the length of the content.
+   */
+  public int getContentLength()
+  {
+    try
+      {
+	if (!connected)
+	  connect();
+        
+        if (file.isDirectory())
+          {
+            return getDirectoryListing().length;
+          }
+	return (int) file.length();
+      }
+    catch (IOException e)
+      {
+	return -1;
+      }
+  }
+  
+  /**
+   * This method returns a <code>Permission</code> object representing the
+   * permissions required to access this URL.  This method returns a
+   * <code>java.io.FilePermission</code> for the file's path with a read
+   * permission.
+   *
+   * @return A Permission object
+   */
+  public Permission getPermission() throws IOException
+  {
+    return permission;
+  }
+}