Re: [cp-patches] Re: FYI: java/io/FileInputStream.java& java/io/FileOutputStream.java

[Dalibor Topic]

Dalibor Topic wrote:
> Jeroen Frijters wrote:
>
> > > Another strategy to implement this in the FileChannelImpl constructor 
> > > would be to call open() first, and then to check whether what we have 
> > > opened is a directory, and if it is one to call close() + throw 
> > > FileNotFoundException in that case. Does that sound OK?
> >
> >
> >
> > That sounds like a good approach to me. I would think it would be pretty
> > efficient too.
>
>
> OK, I'll post a patch that does that, without the close() part, after 
> some more testing and writing a muave test case. Thanks for your help!

Attached. ChangeLog:

2005-03-10  Dalibor Topic  <address@hidden>

        * libraries/javalib/gnu/java/nio/channels/FileChannelImpl.java
        (FileChannelImpl(Sting, int)): Removed.
        (FileChannelImpl(File, int)) Added. Check if opened file is a 
directory.

        * libraries/javalib/java/io/FileInputStream.java (FileInputStream):
        Fixed javadocs. Call FileChannelImpl(File, int).

        * libraries/javalib/java/io/FileOutputStream.java 
(FileInputStream):
        Call FileChannelImpl(File, int).

        * libraries/javalib/java/io/RandomAccessFile.java 
(RandomAccessFile):
        Call FileChannelImpl(File, int). Switched constructors around.

cheers,
dalibor topic

Index: gnu/java/nio/channels/FileChannelImpl.java
===================================================================
RCS file: 
/cvsroot/classpath/classpath/gnu/java/nio/channels/FileChannelImpl.java,v
retrieving revision 1.8
diff -u -r1.8 FileChannelImpl.java
--- gnu/java/nio/channels/FileChannelImpl.java  17 Feb 2005 12:57:27 -0000      
1.8
+++ gnu/java/nio/channels/FileChannelImpl.java  10 Mar 2005 01:09:29 -0000
@@ -41,6 +41,7 @@
 import gnu.classpath.Configuration;
 import gnu.java.nio.FileLockImpl;
 
+import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.nio.ByteBuffer;
@@ -101,10 +102,16 @@
   }
 
   /* Open a file.  MODE is a combination of the above mode flags. */
-  public FileChannelImpl (String path, int mode) throws FileNotFoundException
+  public FileChannelImpl (File file, int mode) throws FileNotFoundException
   {
+    final String path = file.getPath();
     fd = open (path, mode);
     this.mode = mode;
+
+    // First open the file and then check if it is a a directory
+    // to avoid race condition.
+    if (file.isDirectory())
+      throw new FileNotFoundException(file.getPath() + " is a directory");
   }
 
   /* Used by init() (native code) */
Index: java/io/FileInputStream.java
===================================================================
RCS file: /cvsroot/classpath/classpath/java/io/FileInputStream.java,v
retrieving revision 1.31
diff -u -r1.31 FileInputStream.java
--- java/io/FileInputStream.java        3 Mar 2005 08:56:02 -0000       1.31
+++ java/io/FileInputStream.java        10 Mar 2005 01:09:33 -0000
@@ -76,7 +76,8 @@
    * @param name The name of the file this stream should read from
    *
    * @exception SecurityException If read access to the file is not allowed
-   * @exception FileNotFoundException If the file does not exist.
+   * @exception FileNotFoundException If the file does not exist 
+   * or if it is a directory
    */
   public FileInputStream(String name) throws FileNotFoundException
   {
@@ -97,7 +98,8 @@
    * @param file The <code>File</code> object this stream should read from
    *
    * @exception SecurityException If read access to the file is not allowed
-   * @exception FileNotFoundException If the file does not exist.
+   * @exception FileNotFoundException If the file does not exist
+   * or if it is a directory.
    */
   public FileInputStream(File file) throws FileNotFoundException
   {
@@ -105,7 +107,7 @@
     if (s != null)
       s.checkRead(file.getPath());
 
-    ch = new FileChannelImpl (file.getPath(), FileChannelImpl.READ);
+    ch = new FileChannelImpl (file, FileChannelImpl.READ);
   }
 
   /**
Index: java/io/FileOutputStream.java
===================================================================
RCS file: /cvsroot/classpath/classpath/java/io/FileOutputStream.java,v
retrieving revision 1.34
diff -u -r1.34 FileOutputStream.java
--- java/io/FileOutputStream.java       3 Mar 2005 08:56:02 -0000       1.34
+++ java/io/FileOutputStream.java       10 Mar 2005 01:09:33 -0000
@@ -155,10 +155,10 @@
     if (s != null)
       s.checkWrite(file.getPath());
 
-    ch = new FileChannelImpl (file.getPath(), (append
-                                    ? FileChannelImpl.WRITE
-                                    | FileChannelImpl.APPEND
-                                    : FileChannelImpl.WRITE));
+   ch = new FileChannelImpl (file, (append
+                                   ? FileChannelImpl.WRITE
+                                   | FileChannelImpl.APPEND
+                                   : FileChannelImpl.WRITE));
   }
 
   /**
Index: java/io/RandomAccessFile.java
===================================================================
RCS file: /cvsroot/classpath/classpath/java/io/RandomAccessFile.java,v
retrieving revision 1.44
diff -u -r1.44 RandomAccessFile.java
--- java/io/RandomAccessFile.java       16 Feb 2005 11:18:37 -0000      1.44
+++ java/io/RandomAccessFile.java       10 Mar 2005 01:09:33 -0000
@@ -86,38 +86,12 @@
    * illegal value
    * @exception SecurityException If the requested access to the file 
    * is not allowed
-   * @exception IOException If any other error occurs
+   * @exception FileNotFoundException If the file is a directory, or 
+   * any other error occurs
    */
   public RandomAccessFile (File file, String mode)
     throws FileNotFoundException
   {
-    this (file.getPath(), mode);
-  }
-
-  /**
-   * This method initializes a new instance of <code>RandomAccessFile</code>
-   * to read from the specified file name with the specified access mode.
-   * The access mode is either "r" for read only access, "rw" for read
-   * write access, "rws" for synchronized read/write access of both
-   * content and metadata, or "rwd" for read/write access
-   * where only content is required to be synchronous.
-   * <p>
-   * Note that a <code>SecurityManager</code> check is made prior to
-   * opening the file to determine whether or not this file is allowed to
-   * be read or written.
-   *
-   * @param fileName The name of the file to read and/or write
-   * @param mode "r", "rw", "rws", or "rwd"
-   *
-   * @exception IllegalArgumentException If <code>mode</code> has an 
-   * illegal value
-   * @exception SecurityException If the requested access to the file 
-   * is not allowed
-   * @exception FileNotFoundException If any other error occurs
-   */
-  public RandomAccessFile (String fileName, String mode)
-    throws FileNotFoundException
-  {
     int fdmode;
     if (mode.equals("r"))
       fdmode = FileChannelImpl.READ;
@@ -136,6 +110,8 @@
     else
       throw new IllegalArgumentException ("invalid mode: " + mode);
 
+    final String fileName = file.getPath();
+
     // The obligatory SecurityManager stuff
     SecurityManager s = System.getSecurityManager();
     if (s != null)
@@ -146,13 +122,41 @@
           s.checkWrite(fileName);
       }
 
-    ch = new FileChannelImpl (fileName, fdmode);
+    ch = new FileChannelImpl (file, fdmode);
     fd = new FileDescriptor(ch);
     out = new DataOutputStream (new FileOutputStream (fd));
     in = new DataInputStream (new FileInputStream (fd));
   }
 
   /**
+   * This method initializes a new instance of <code>RandomAccessFile</code>
+   * to read from the specified file name with the specified access mode.
+   * The access mode is either "r" for read only access, "rw" for read
+   * write access, "rws" for synchronized read/write access of both
+   * content and metadata, or "rwd" for read/write access
+   * where only content is required to be synchronous.
+   * <p>
+   * Note that a <code>SecurityManager</code> check is made prior to
+   * opening the file to determine whether or not this file is allowed to
+   * be read or written.
+   *
+   * @param fileName The name of the file to read and/or write
+   * @param mode "r", "rw", "rws", or "rwd"
+   *
+   * @exception IllegalArgumentException If <code>mode</code> has an 
+   * illegal value
+   * @exception SecurityException If the requested access to the file 
+   * is not allowed
+   * @exception FileNotFoundException If the file is a directory or 
+   * any other error occurs
+   */
+  public RandomAccessFile (String fileName, String mode)
+    throws FileNotFoundException
+  {
+    this (new File(fileName), mode);
+  }
+
+  /**
    * This method closes the file and frees up all file related system
    * resources.  Since most operating systems put a limit on how many files
    * may be opened at any given time, it is a good idea to close all files