Initial revision

From-SVN: r102075

libjava/classpath/vm/reference/java/io/VMFile.java

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+/* VMFile.java -- Class for methods natively accessing files
+   Copyright (C) 2004  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 java.io;
+
+import gnu.classpath.Configuration;
+import gnu.java.io.PlatformHelper;
+
+
+/**
+ * @author Michael Koch (konqueror@gmx.de)
+ */
+final class VMFile
+{
+  // FIXME: We support only case sensitive filesystems currently.
+  static final boolean IS_CASE_SENSITIVE = true;
+  static final boolean IS_DOS_8_3 = false;
+
+  static
+  {
+    if (Configuration.INIT_LOAD_LIBRARY)
+      {
+	System.loadLibrary("javaio");
+      }
+  }
+
+  /*
+   * This native method does the actual work of getting the last file
+   * modification time.  It also does the existence check to avoid the
+   * overhead of a call to exists()
+   */
+  static native long lastModified(String path);
+
+  /*
+   * This native method sets the permissions to make the file read only.
+   */
+  static native boolean setReadOnly(String path);
+
+  /**
+   * This method is used to create a temporary file
+   */
+  static native boolean create(String path) throws IOException;
+
+  /*
+   * This native function actually produces the list of file in this
+   * directory
+   */
+  static native String[] list(String dirpath);
+
+  /*
+   * This native method actually performs the rename.
+   */
+  static native boolean renameTo(String targetpath, String destpath);
+
+  /*
+   * This native method actually determines the length of the file and
+   * handles the existence check
+   */
+  static native long length(String path);
+
+  /*
+   * This native method does the actual checking of file existence.
+   */
+  static native boolean exists(String path);
+
+  /*
+   * This native method handles the actual deleting of the file
+   */
+  static native boolean delete(String path);
+
+  /*
+   * This method does the actual setting of the modification time.
+   */
+  static native boolean setLastModified(String path, long time);
+
+  /*
+   * This native method actually creates the directory
+   */
+  static native boolean mkdir(String dirpath);
+
+  /*
+   * This native method does the actual check of whether or not a file
+   * is a plain file or not.  It also handles the existence check to
+   * eliminate the overhead of a call to exists()
+   */
+  static native boolean isFile(String path);
+
+  /**
+   * This native method checks file permissions for writing
+   */
+  static synchronized native boolean canWrite(String path);
+
+  /**
+   * This methods checks if a directory can be written to.
+   */
+  static boolean canWriteDirectory(File dir)
+  {
+    try
+      {
+        String filename = IS_DOS_8_3 ? "tst" : "test-dir-write";
+        File test = File.createTempFile(filename, null, dir);
+        return (test != null && test.delete());
+      }
+    catch (IOException ioe)
+      {
+        return false;
+      }
+  }
+
+  /**
+   * This native method checks file permissions for reading
+   */
+  static synchronized native boolean canRead(String path);
+
+  /*
+   * This method does the actual check of whether or not a file is a
+   * directory or not.  It also handle the existence check to eliminate
+   * the overhead of a call to exists()
+   */
+  static native boolean isDirectory(String dirpath);
+
+  /**
+   * This method returns an array of filesystem roots.  Some operating systems
+   * have volume oriented filesystem.  This method provides a mechanism for
+   * determining which volumes exist.  GNU systems use a single hierarchical
+   * filesystem, so will have only one "/" filesystem root.
+   *
+   * @return An array of <code>File</code> objects for each filesystem root
+   * available.
+   *
+   * @since 1.2
+   */
+  static File[] listRoots()
+  {
+	File[] roots = new File[1];
+	roots[0] = new File("/");
+	return roots;
+  }
+
+  /**
+   * This method tests whether or not this file represents a "hidden" file.
+   * On GNU systems, a file is hidden if its name begins with a "."
+   * character.  Files with these names are traditionally not shown with
+   * directory listing tools.
+   *
+   * @return <code>true</code> if the file is hidden, <code>false</code>
+   * otherwise.
+   *
+   * @since 1.2
+   */
+  static boolean isHidden(String path)
+  {
+	// FIXME: this only works on UNIX
+	return getName(path).startsWith(".");
+  }
+
+  /**
+   * This method returns the name of the file.  This is everything in the
+   * complete path of the file after the last instance of the separator
+   * string.
+   *
+   * @return The file name
+   */
+  static String getName(String path)
+  {
+	int pos = PlatformHelper.lastIndexOfSeparator(path);
+	if (pos == -1)
+	  return path;
+	
+	if (PlatformHelper.endWithSeparator(path))
+	  return "";
+	
+	return path.substring(pos + File.separator.length());
+  }
+
+  /**
+   * This method returns a canonical representation of the pathname of
+   * the given path.  The actual form of the canonical representation is
+   * different.  On the GNU system, the canonical form differs from the
+   * absolute form in that all relative file references to "." and ".."
+   * are resolved and removed.
+   * <p>
+   * Note that this method, unlike the other methods which return path
+   * names, can throw an IOException.  This is because native method 
+   * might be required in order to resolve the canonical path
+   *
+   * @exception IOException If an error occurs
+   */
+  public static String toCanonicalForm(String path) throws IOException
+  {
+	// FIXME: this only works on UNIX
+	return PlatformHelper.toCanonicalForm(path);
+  }
+}