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Win32FileSystem.javaAPI DocJava SE 6 API19582Tue Jun 10 00:32:44 BST 2008java.io

Win32FileSystem

public class Win32FileSystem extends FileSystem

Fields Summary
private final char
slash
private final char
altSlash
private final char
semicolon
private static String[]
driveDirCache
private ExpiringCache
cache
private ExpiringCache
prefixCache
Constructors Summary
public Win32FileSystem()

	slash = ((String) AccessController.doPrivileged(
              new GetPropertyAction("file.separator"))).charAt(0);
	semicolon = ((String) AccessController.doPrivileged(
              new GetPropertyAction("path.separator"))).charAt(0);
	altSlash = (this.slash == '\\") ? '/" : '\\";
    
Methods Summary
private booleanaccess(java.lang.String path)

	try {
	    SecurityManager security = System.getSecurityManager();
	    if (security != null) security.checkRead(path);
	    return true;
	} catch (SecurityException x) {
	    return false;
	}
    
public java.lang.Stringcanonicalize(java.lang.String path)


          
        // If path is a drive letter only then skip canonicalization
        int len = path.length();
        if ((len == 2) && 
            (isLetter(path.charAt(0))) &&
            (path.charAt(1) == ':")) {
            char c = path.charAt(0);
            if ((c >= 'A") && (c <= 'Z"))
                return path;
            return "" + ((char) (c-32)) + ':";
        } else if ((len == 3) && 
                   (isLetter(path.charAt(0))) &&
                   (path.charAt(1) == ':") &&
                   (path.charAt(2) == '\\")) {
            char c = path.charAt(0);
            if ((c >= 'A") && (c <= 'Z"))
                return path;
            return "" + ((char) (c-32)) + ':" + '\\";
        }
        if (!useCanonCaches) {
            return canonicalize0(path);
        } else {
            String res = cache.get(path);
            if (res == null) {
		String dir = null;
		String resDir = null;
                if (useCanonPrefixCache) {
                    dir = parentOrNull(path);
                    if (dir != null) {
                        resDir = prefixCache.get(dir);
                        if (resDir != null) {
                            // Hit only in prefix cache; full path is canonical,
                            // but we need to get the canonical name of the file
                            // in this directory to get the appropriate capitalization
                            String filename = path.substring(1 + dir.length());
                            res = canonicalizeWithPrefix(resDir, filename);
                            cache.put(dir + File.separatorChar + filename, res);
                        }
                    }
                }
                if (res == null) {
                    res = canonicalize0(path);
                    cache.put(path, res);
                    if (useCanonPrefixCache && dir != null) {
                        resDir = parentOrNull(res);
                        if (resDir != null) {
                            File f = new File(res);
                            if (f.exists() && !f.isDirectory()) {
                                prefixCache.put(dir, resDir);
                            }
                        }
                    }
                }
            }
            assert canonicalize0(path).equalsIgnoreCase(res);
            return res;
        }
    
protected native java.lang.Stringcanonicalize0(java.lang.String path)

protected java.lang.StringcanonicalizeWithPrefix(java.lang.String canonicalPrefix, java.lang.String filename)

        return canonicalizeWithPrefix0(canonicalPrefix,
                                       canonicalPrefix + File.separatorChar + filename);
    
protected native java.lang.StringcanonicalizeWithPrefix0(java.lang.String canonicalPrefix, java.lang.String pathWithCanonicalPrefix)

public native booleancheckAccess(java.io.File f, int access)

public intcompare(java.io.File f1, java.io.File f2)

	return f1.getPath().compareToIgnoreCase(f2.getPath());
    
public native booleancreateDirectory(java.io.File f)

public native booleancreateFileExclusively(java.lang.String path)

public booleandelete(java.io.File f)

        // Keep canonicalization caches in sync after file deletion
        // and renaming operations. Could be more clever than this
        // (i.e., only remove/update affected entries) but probably
        // not worth it since these entries expire after 30 seconds
        // anyway.
        cache.clear();
        prefixCache.clear();
        return delete0(f);
    
protected native booleandelete0(java.io.File f)

private static intdriveIndex(char d)


         
	if ((d >= 'a") && (d <= 'z")) return d - 'a";
	if ((d >= 'A") && (d <= 'Z")) return d - 'A";
	return -1;
    
public java.lang.StringfromURIPath(java.lang.String path)

	String p = path;
	if ((p.length() > 2) && (p.charAt(2) == ':")) {
	    // "/c:/foo" --> "c:/foo"
	    p = p.substring(1);
	    // "c:/foo/" --> "c:/foo", but "c:/" --> "c:/"
	    if ((p.length() > 3) && p.endsWith("/"))
		p = p.substring(0, p.length() - 1);
	} else if ((p.length() > 1) && p.endsWith("/")) {
	    // "/foo/" --> "/foo"
	    p = p.substring(0, p.length() - 1);
	}
	return p;
    
public native intgetBooleanAttributes(java.io.File f)

public java.lang.StringgetDefaultParent()

	return ("" + slash);
    
private java.lang.StringgetDrive(java.lang.String path)

	int pl = prefixLength(path);
	return (pl == 3) ? path.substring(0, 2) : null;
    
protected native java.lang.StringgetDriveDirectory(int drive)

private java.lang.StringgetDriveDirectory(char drive)

	int i = driveIndex(drive);
	if (i < 0) return null;
	String s = driveDirCache[i];
	if (s != null) return s;
	s = getDriveDirectory(i + 1);
	driveDirCache[i] = s;
	return s;
    
public native longgetLastModifiedTime(java.io.File f)

public native longgetLength(java.io.File f)

public chargetPathSeparator()

	return semicolon;
    
public chargetSeparator()

	return slash;
    
public longgetSpace(java.io.File f, int t)

 	if (f.exists()) {
 	    File file = (f.isDirectory() ? f : f.getParentFile());
 	    return getSpace0(file, t);
 	}
 	return 0;
    
private native longgetSpace0(java.io.File f, int t)

private java.lang.StringgetUserPath()

	/* For both compatibility and security,
	   we must look this up every time */
	return normalize(System.getProperty("user.dir"));
    
public inthashCode(java.io.File f)

	/* Could make this more efficient: String.hashCodeIgnoreCase */
	return f.getPath().toLowerCase(Locale.ENGLISH).hashCode() ^ 1234321;
    
private static native voidinitIDs()

public booleanisAbsolute(java.io.File f)

	int pl = f.getPrefixLength();
	return (((pl == 2) && (f.getPath().charAt(0) == slash))
		|| (pl == 3));
    
private booleanisLetter(char c)

	return ((c >= 'a") && (c <= 'z")) || ((c >= 'A") && (c <= 'Z"));
    
private booleanisSlash(char c)

	return (c == '\\") || (c == '/");
    
public native java.lang.String[]list(java.io.File f)

public java.io.File[]listRoots()

	int ds = listRoots0();
	int n = 0;
	for (int i = 0; i < 26; i++) {
	    if (((ds >> i) & 1) != 0) {
		if (!access((char)('A" + i) + ":" + slash))
		    ds &= ~(1 << i);
		else
		    n++;
	    }
	}
	File[] fs = new File[n];
	int j = 0;
	char slash = this.slash;
	for (int i = 0; i < 26; i++) {
	    if (((ds >> i) & 1) != 0)
		fs[j++] = new File((char)('A" + i) + ":" + slash);
	}
	return fs;
    
private static native intlistRoots0()

private java.lang.Stringnormalize(java.lang.String path, int len, int off)

	if (len == 0) return path;
	if (off < 3) off = 0;	/* Avoid fencepost cases with UNC pathnames */
	int src;
	char slash = this.slash;
	StringBuffer sb = new StringBuffer(len);

	if (off == 0) {
	    /* Complete normalization, including prefix */
	    src = normalizePrefix(path, len, sb);
	} else {
	    /* Partial normalization */
	    src = off;
	    sb.append(path.substring(0, off));
	}

	/* Remove redundant slashes from the remainder of the path, forcing all
	   slashes into the preferred slash */
	while (src < len) {
	    char c = path.charAt(src++);
	    if (isSlash(c)) {
		while ((src < len) && isSlash(path.charAt(src))) src++;
		if (src == len) {
		    /* Check for trailing separator */
		    int sn = sb.length();
		    if ((sn == 2) && (sb.charAt(1) == ':")) {
			/* "z:\\" */
			sb.append(slash);
			break;
		    }
		    if (sn == 0) {
			/* "\\" */
			sb.append(slash);
			break;
		    }
		    if ((sn == 1) && (isSlash(sb.charAt(0)))) {
			/* "\\\\" is not collapsed to "\\" because "\\\\" marks
		           the beginning of a UNC pathname.  Even though it is
		           not, by itself, a valid UNC pathname, we leave it as
		           is in order to be consistent with the win32 APIs,
		           which treat this case as an invalid UNC pathname
		           rather than as an alias for the root directory of
		           the current drive. */
			sb.append(slash);
			break;
		    }
		    /* Path does not denote a root directory, so do not append
		       trailing slash */
		    break;
		} else {
		    sb.append(slash);
		}
	    } else {
		sb.append(c);
	    }
	}

	String rv = sb.toString();
	return rv;
    
public java.lang.Stringnormalize(java.lang.String path)

	int n = path.length();
	char slash = this.slash;
	char altSlash = this.altSlash;
	char prev = 0;
	for (int i = 0; i < n; i++) {
	    char c = path.charAt(i);
	    if (c == altSlash)
		return normalize(path, n, (prev == slash) ? i - 1 : i);
	    if ((c == slash) && (prev == slash) && (i > 1))
		return normalize(path, n, i - 1);
	    if ((c == ':") && (i > 1))
		return normalize(path, n, 0);
	    prev = c;
	}
	if (prev == slash) return normalize(path, n, n - 1);
	return path;
    
private intnormalizePrefix(java.lang.String path, int len, java.lang.StringBuffer sb)

	int src = 0;
	while ((src < len) && isSlash(path.charAt(src))) src++;
	char c;
	if ((len - src >= 2)
	    && isLetter(c = path.charAt(src))
	    && path.charAt(src + 1) == ':") {
	    /* Remove leading slashes if followed by drive specifier.
	       This hack is necessary to support file URLs containing drive
	       specifiers (e.g., "file://c:/path").  As a side effect,
	       "/c:/path" can be used as an alternative to "c:/path". */
	    sb.append(c);
	    sb.append(':");
	    src += 2;
	} else {
	    src = 0;
	    if ((len >= 2)
		&& isSlash(path.charAt(0))
		&& isSlash(path.charAt(1))) {
		/* UNC pathname: Retain first slash; leave src pointed at
		   second slash so that further slashes will be collapsed
		   into the second slash.  The result will be a pathname
		   beginning with "\\\\" followed (most likely) by a host
		   name. */
		src = 1;
		sb.append(slash);
	    }
	}
	return src;
    
static java.lang.StringparentOrNull(java.lang.String path)

        if (path == null) return null;
        char sep = File.separatorChar;
        char altSep = '/";
        int last = path.length() - 1;
        int idx = last;
        int adjacentDots = 0;
        int nonDotCount = 0;
        while (idx > 0) {
            char c = path.charAt(idx);
            if (c == '.") {
                if (++adjacentDots >= 2) {
                    // Punt on pathnames containing . and ..
                    return null;
                }
                if (nonDotCount == 0) {
                    // Punt on pathnames ending in a .
                    return null;
                }
            } else if (c == sep) {
                if (adjacentDots == 1 && nonDotCount == 0) {
                    // Punt on pathnames containing . and ..
                    return null;
                }
                if (idx == 0 ||
                    idx >= last - 1 ||
                    path.charAt(idx - 1) == sep ||
                    path.charAt(idx - 1) == altSep) {
                    // Punt on pathnames containing adjacent slashes
                    // toward the end
                    return null;
                }
                return path.substring(0, idx);
            } else if (c == altSep) {
                // Punt on pathnames containing both backward and
                // forward slashes
                return null;
            } else if (c == '*" || c == '?") {
                // Punt on pathnames containing wildcards
                return null;
            } else {
                ++nonDotCount;
                adjacentDots = 0;
            }
            --idx;
        }
        return null;
    
public intprefixLength(java.lang.String path)

	char slash = this.slash;
	int n = path.length();
	if (n == 0) return 0;
	char c0 = path.charAt(0);
	char c1 = (n > 1) ? path.charAt(1) : 0;
	if (c0 == slash) {
	    if (c1 == slash) return 2;	/* Absolute UNC pathname "\\\\foo" */
	    return 1;			/* Drive-relative "\\foo" */
	}
	if (isLetter(c0) && (c1 == ':")) {
	    if ((n > 2) && (path.charAt(2) == slash))
		return 3;		/* Absolute local pathname "z:\\foo" */
	    return 2;			/* Directory-relative "z:foo" */
	}
	return 0;			/* Completely relative */
    
public booleanrename(java.io.File f1, java.io.File f2)

        // Keep canonicalization caches in sync after file deletion
        // and renaming operations. Could be more clever than this
        // (i.e., only remove/update affected entries) but probably
        // not worth it since these entries expire after 30 seconds
        // anyway.
        cache.clear();
        prefixCache.clear();
        return rename0(f1, f2);
    
protected native booleanrename0(java.io.File f1, java.io.File f2)

public java.lang.Stringresolve(java.lang.String parent, java.lang.String child)

        int pn = parent.length();
        if (pn == 0) return child;
        int cn = child.length();
        if (cn == 0) return parent;

        String c = child;
        int childStart = 0;
        int parentEnd = pn;

        if ((cn > 1) && (c.charAt(0) == slash)) {
            if (c.charAt(1) == slash) {
                /* Drop prefix when child is a UNC pathname */
                childStart = 2;
            } else {
                /* Drop prefix when child is drive-relative */
                childStart = 1;

            }
            if (cn == childStart) { // Child is double slash
                if (parent.charAt(pn - 1) == slash)
                    return parent.substring(0, pn - 1);
                return parent;
            }
        }

        if (parent.charAt(pn - 1) == slash)
            parentEnd--;

        int strlen = parentEnd + cn - childStart;
        char[] theChars = null;
        if (child.charAt(childStart) == slash) {
            theChars = new char[strlen];
            parent.getChars(0, parentEnd, theChars, 0);
            child.getChars(childStart, cn, theChars, parentEnd);
        } else {
            theChars = new char[strlen + 1];
            parent.getChars(0, parentEnd, theChars, 0);
            theChars[parentEnd] = slash;
            child.getChars(childStart, cn, theChars, parentEnd + 1);
        }
        return new String(theChars);
    
public java.lang.Stringresolve(java.io.File f)

	String path = f.getPath();
	int pl = f.getPrefixLength();
	if ((pl == 2) && (path.charAt(0) == slash))
	    return path;			/* UNC */
	if (pl == 3)
	    return path;			/* Absolute local */
	if (pl == 0)
	    return getUserPath() + slashify(path); /* Completely relative */
	if (pl == 1) {				/* Drive-relative */
	    String up = getUserPath();
	    String ud = getDrive(up);
	    if (ud != null) return ud + path;
	    return up + path;			/* User dir is a UNC path */
	}
	if (pl == 2) {				/* Directory-relative */
	    String up = getUserPath();
	    String ud = getDrive(up);
	    if ((ud != null) && path.startsWith(ud))
		return up + slashify(path.substring(2));
	    char drive = path.charAt(0);
	    String dir = getDriveDirectory(drive);
	    String np;
	    if (dir != null) {
		/* When resolving a directory-relative path that refers to a
		   drive other than the current drive, insist that the caller
		   have read permission on the result */
		String p = drive + (':" + dir + slashify(path.substring(2)));
		SecurityManager security = System.getSecurityManager();
		try {
		    if (security != null) security.checkRead(p);
		} catch (SecurityException x) {
		    /* Don't disclose the drive's directory in the exception */
		    throw new SecurityException("Cannot resolve path " + path);
		}
		return p;
	    }
	    return drive + ":" + slashify(path.substring(2)); /* fake it */
	}
	throw new InternalError("Unresolvable path: " + path);
    
public native booleansetLastModifiedTime(java.io.File f, long time)

public native booleansetPermission(java.io.File f, int access, boolean enable, boolean owneronly)

public native booleansetReadOnly(java.io.File f)

private java.lang.Stringslashify(java.lang.String p)

	if ((p.length() > 0) && (p.charAt(0) != slash)) return slash + p;
	else return p;