Java example source code file (WindowsPreferences.java)
The WindowsPreferences.java Java example source code/*
* Copyright (c) 2000, 2002, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code 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
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package java.util.prefs;
import java.util.Map;
import java.util.TreeMap;
import java.util.StringTokenizer;
import java.io.ByteArrayOutputStream;
import sun.util.logging.PlatformLogger;
/**
* Windows registry based implementation of <tt>Preferences.
* <tt>Preferences' systemRoot and userRoot are stored in
* <tt>HKEY_LOCAL_MACHINE\SOFTWARE\JavaSoft\Prefs and
* <tt>HKEY_CURRENT_USER\Software\JavaSoft\Prefs correspondingly.
*
* @author Konstantin Kladko
* @see Preferences
* @see PreferencesFactory
* @since 1.4
*/
class WindowsPreferences extends AbstractPreferences{
/**
* Logger for error messages
*/
private static PlatformLogger logger;
/**
* Windows registry path to <tt>Preferences's root nodes.
*/
private static final byte[] WINDOWS_ROOT_PATH
= stringToByteArray("Software\\JavaSoft\\Prefs");
/**
* Windows handles to <tt>HKEY_CURRENT_USER and
* <tt>HKEY_LOCAL_MACHINE hives.
*/
private static final int HKEY_CURRENT_USER = 0x80000001;
private static final int HKEY_LOCAL_MACHINE = 0x80000002;
/**
* Mount point for <tt>Preferences' user root.
*/
private static final int USER_ROOT_NATIVE_HANDLE = HKEY_CURRENT_USER;
/**
* Mount point for <tt>Preferences' system root.
*/
private static final int SYSTEM_ROOT_NATIVE_HANDLE = HKEY_LOCAL_MACHINE;
/**
* Maximum byte-encoded path length for Windows native functions,
* ending <tt>null character not included.
*/
private static final int MAX_WINDOWS_PATH_LENGTH = 256;
/**
* User root node.
*/
static final Preferences userRoot =
new WindowsPreferences(USER_ROOT_NATIVE_HANDLE, WINDOWS_ROOT_PATH);
/**
* System root node.
*/
static final Preferences systemRoot =
new WindowsPreferences(SYSTEM_ROOT_NATIVE_HANDLE, WINDOWS_ROOT_PATH);
/* Windows error codes. */
private static final int ERROR_SUCCESS = 0;
private static final int ERROR_FILE_NOT_FOUND = 2;
private static final int ERROR_ACCESS_DENIED = 5;
/* Constants used to interpret returns of native functions */
private static final int NATIVE_HANDLE = 0;
private static final int ERROR_CODE = 1;
private static final int SUBKEYS_NUMBER = 0;
private static final int VALUES_NUMBER = 2;
private static final int MAX_KEY_LENGTH = 3;
private static final int MAX_VALUE_NAME_LENGTH = 4;
private static final int DISPOSITION = 2;
private static final int REG_CREATED_NEW_KEY = 1;
private static final int REG_OPENED_EXISTING_KEY = 2;
private static final int NULL_NATIVE_HANDLE = 0;
/* Windows security masks */
private static final int DELETE = 0x10000;
private static final int KEY_QUERY_VALUE = 1;
private static final int KEY_SET_VALUE = 2;
private static final int KEY_CREATE_SUB_KEY = 4;
private static final int KEY_ENUMERATE_SUB_KEYS = 8;
private static final int KEY_READ = 0x20019;
private static final int KEY_WRITE = 0x20006;
private static final int KEY_ALL_ACCESS = 0xf003f;
/**
* Initial time between registry access attempts, in ms. The time is doubled
* after each failing attempt (except the first).
*/
private static int INIT_SLEEP_TIME = 50;
/**
* Maximum number of registry access attempts.
*/
private static int MAX_ATTEMPTS = 5;
/**
* BackingStore availability flag.
*/
private boolean isBackingStoreAvailable = true;
/**
* Java wrapper for Windows registry API RegOpenKey()
*/
private static native int[] WindowsRegOpenKey(int hKey, byte[] subKey,
int securityMask);
/**
* Retries RegOpenKey() MAX_ATTEMPTS times before giving up.
*/
private static int[] WindowsRegOpenKey1(int hKey, byte[] subKey,
int securityMask) {
int[] result = WindowsRegOpenKey(hKey, subKey, securityMask);
if (result[ERROR_CODE] == ERROR_SUCCESS) {
return result;
} else if (result[ERROR_CODE] == ERROR_FILE_NOT_FOUND) {
logger().warning("Trying to recreate Windows registry node " +
byteArrayToString(subKey) + " at root 0x" +
Integer.toHexString(hKey) + ".");
// Try recreation
int handle = WindowsRegCreateKeyEx(hKey, subKey)[NATIVE_HANDLE];
WindowsRegCloseKey(handle);
return WindowsRegOpenKey(hKey, subKey, securityMask);
} else if (result[ERROR_CODE] != ERROR_ACCESS_DENIED) {
long sleepTime = INIT_SLEEP_TIME;
for (int i = 0; i < MAX_ATTEMPTS; i++) {
try {
Thread.sleep(sleepTime);
} catch(InterruptedException e) {
return result;
}
sleepTime *= 2;
result = WindowsRegOpenKey(hKey, subKey, securityMask);
if (result[ERROR_CODE] == ERROR_SUCCESS) {
return result;
}
}
}
return result;
}
/**
* Java wrapper for Windows registry API RegCloseKey()
*/
private static native int WindowsRegCloseKey(int hKey);
/**
* Java wrapper for Windows registry API RegCreateKeyEx()
*/
private static native int[] WindowsRegCreateKeyEx(int hKey, byte[] subKey);
/**
* Retries RegCreateKeyEx() MAX_ATTEMPTS times before giving up.
*/
private static int[] WindowsRegCreateKeyEx1(int hKey, byte[] subKey) {
int[] result = WindowsRegCreateKeyEx(hKey, subKey);
if (result[ERROR_CODE] == ERROR_SUCCESS) {
return result;
} else {
long sleepTime = INIT_SLEEP_TIME;
for (int i = 0; i < MAX_ATTEMPTS; i++) {
try {
Thread.sleep(sleepTime);
} catch(InterruptedException e) {
return result;
}
sleepTime *= 2;
result = WindowsRegCreateKeyEx(hKey, subKey);
if (result[ERROR_CODE] == ERROR_SUCCESS) {
return result;
}
}
}
return result;
}
/**
* Java wrapper for Windows registry API RegDeleteKey()
*/
private static native int WindowsRegDeleteKey(int hKey, byte[] subKey);
/**
* Java wrapper for Windows registry API RegFlushKey()
*/
private static native int WindowsRegFlushKey(int hKey);
/**
* Retries RegFlushKey() MAX_ATTEMPTS times before giving up.
*/
private static int WindowsRegFlushKey1(int hKey) {
int result = WindowsRegFlushKey(hKey);
if (result == ERROR_SUCCESS) {
return result;
} else {
long sleepTime = INIT_SLEEP_TIME;
for (int i = 0; i < MAX_ATTEMPTS; i++) {
try {
Thread.sleep(sleepTime);
} catch(InterruptedException e) {
return result;
}
sleepTime *= 2;
result = WindowsRegFlushKey(hKey);
if (result == ERROR_SUCCESS) {
return result;
}
}
}
return result;
}
/**
* Java wrapper for Windows registry API RegQueryValueEx()
*/
private static native byte[] WindowsRegQueryValueEx(int hKey,
byte[] valueName);
/**
* Java wrapper for Windows registry API RegSetValueEx()
*/
private static native int WindowsRegSetValueEx(int hKey, byte[] valueName,
byte[] value);
/**
* Retries RegSetValueEx() MAX_ATTEMPTS times before giving up.
*/
private static int WindowsRegSetValueEx1(int hKey, byte[] valueName,
byte[] value) {
int result = WindowsRegSetValueEx(hKey, valueName, value);
if (result == ERROR_SUCCESS) {
return result;
} else {
long sleepTime = INIT_SLEEP_TIME;
for (int i = 0; i < MAX_ATTEMPTS; i++) {
try {
Thread.sleep(sleepTime);
} catch(InterruptedException e) {
return result;
}
sleepTime *= 2;
result = WindowsRegSetValueEx(hKey, valueName, value);
if (result == ERROR_SUCCESS) {
return result;
}
}
}
return result;
}
/**
* Java wrapper for Windows registry API RegDeleteValue()
*/
private static native int WindowsRegDeleteValue(int hKey, byte[] valueName);
/**
* Java wrapper for Windows registry API RegQueryInfoKey()
*/
private static native int[] WindowsRegQueryInfoKey(int hKey);
/**
* Retries RegQueryInfoKey() MAX_ATTEMPTS times before giving up.
*/
private static int[] WindowsRegQueryInfoKey1(int hKey) {
int[] result = WindowsRegQueryInfoKey(hKey);
if (result[ERROR_CODE] == ERROR_SUCCESS) {
return result;
} else {
long sleepTime = INIT_SLEEP_TIME;
for (int i = 0; i < MAX_ATTEMPTS; i++) {
try {
Thread.sleep(sleepTime);
} catch(InterruptedException e) {
return result;
}
sleepTime *= 2;
result = WindowsRegQueryInfoKey(hKey);
if (result[ERROR_CODE] == ERROR_SUCCESS) {
return result;
}
}
}
return result;
}
/**
* Java wrapper for Windows registry API RegEnumKeyEx()
*/
private static native byte[] WindowsRegEnumKeyEx(int hKey, int subKeyIndex,
int maxKeyLength);
/**
* Retries RegEnumKeyEx() MAX_ATTEMPTS times before giving up.
*/
private static byte[] WindowsRegEnumKeyEx1(int hKey, int subKeyIndex,
int maxKeyLength) {
byte[] result = WindowsRegEnumKeyEx(hKey, subKeyIndex, maxKeyLength);
if (result != null) {
return result;
} else {
long sleepTime = INIT_SLEEP_TIME;
for (int i = 0; i < MAX_ATTEMPTS; i++) {
try {
Thread.sleep(sleepTime);
} catch(InterruptedException e) {
return result;
}
sleepTime *= 2;
result = WindowsRegEnumKeyEx(hKey, subKeyIndex, maxKeyLength);
if (result != null) {
return result;
}
}
}
return result;
}
/**
* Java wrapper for Windows registry API RegEnumValue()
*/
private static native byte[] WindowsRegEnumValue(int hKey, int valueIndex,
int maxValueNameLength);
/**
* Retries RegEnumValueEx() MAX_ATTEMPTS times before giving up.
*/
private static byte[] WindowsRegEnumValue1(int hKey, int valueIndex,
int maxValueNameLength) {
byte[] result = WindowsRegEnumValue(hKey, valueIndex,
maxValueNameLength);
if (result != null) {
return result;
} else {
long sleepTime = INIT_SLEEP_TIME;
for (int i = 0; i < MAX_ATTEMPTS; i++) {
try {
Thread.sleep(sleepTime);
} catch(InterruptedException e) {
return result;
}
sleepTime *= 2;
result = WindowsRegEnumValue(hKey, valueIndex,
maxValueNameLength);
if (result != null) {
return result;
}
}
}
return result;
}
/**
* Constructs a <tt>WindowsPreferences node, creating underlying
* Windows registry node and all its Windows parents, if they are not yet
* created.
* Logs a warning message, if Windows Registry is unavailable.
*/
private WindowsPreferences(WindowsPreferences parent, String name) {
super(parent, name);
int parentNativeHandle = parent.openKey(KEY_CREATE_SUB_KEY, KEY_READ);
if (parentNativeHandle == NULL_NATIVE_HANDLE) {
// if here, openKey failed and logged
isBackingStoreAvailable = false;
return;
}
int[] result =
WindowsRegCreateKeyEx1(parentNativeHandle, toWindowsName(name));
if (result[ERROR_CODE] != ERROR_SUCCESS) {
logger().warning("Could not create windows registry "
+ "node " + byteArrayToString(windowsAbsolutePath()) +
" at root 0x" + Integer.toHexString(rootNativeHandle()) +
". Windows RegCreateKeyEx(...) returned error code " +
result[ERROR_CODE] + ".");
isBackingStoreAvailable = false;
return;
}
newNode = (result[DISPOSITION] == REG_CREATED_NEW_KEY);
closeKey(parentNativeHandle);
closeKey(result[NATIVE_HANDLE]);
}
/**
* Constructs a root node creating the underlying
* Windows registry node and all of its parents, if they have not yet been
* created.
* Logs a warning message, if Windows Registry is unavailable.
* @param rootNativeHandle Native handle to one of Windows top level keys.
* @param rootDirectory Path to root directory, as a byte-encoded string.
*/
private WindowsPreferences(int rootNativeHandle, byte[] rootDirectory) {
super(null,"");
int[] result =
WindowsRegCreateKeyEx1(rootNativeHandle, rootDirectory);
if (result[ERROR_CODE] != ERROR_SUCCESS) {
logger().warning("Could not open/create prefs root node " +
byteArrayToString(windowsAbsolutePath()) + " at root 0x" +
Integer.toHexString(rootNativeHandle()) +
". Windows RegCreateKeyEx(...) returned error code " +
result[ERROR_CODE] + ".");
isBackingStoreAvailable = false;
return;
}
// Check if a new node
newNode = (result[DISPOSITION] == REG_CREATED_NEW_KEY);
closeKey(result[NATIVE_HANDLE]);
}
/**
* Returns Windows absolute path of the current node as a byte array.
* Java "/" separator is transformed into Windows "\".
* @see Preferences#absolutePath()
*/
private byte[] windowsAbsolutePath() {
ByteArrayOutputStream bstream = new ByteArrayOutputStream();
bstream.write(WINDOWS_ROOT_PATH, 0, WINDOWS_ROOT_PATH.length-1);
StringTokenizer tokenizer = new StringTokenizer(absolutePath(),"/");
while (tokenizer.hasMoreTokens()) {
bstream.write((byte)'\\');
String nextName = tokenizer.nextToken();
byte[] windowsNextName = toWindowsName(nextName);
bstream.write(windowsNextName, 0, windowsNextName.length-1);
}
bstream.write(0);
return bstream.toByteArray();
}
/**
* Opens current node's underlying Windows registry key using a
* given security mask.
* @param securityMask Windows security mask.
* @return Windows registry key's handle.
* @see #openKey(byte[], int)
* @see #openKey(int, byte[], int)
* @see #closeKey(int)
*/
private int openKey(int securityMask) {
return openKey(securityMask, securityMask);
}
/**
* Opens current node's underlying Windows registry key using a
* given security mask.
* @param mask1 Preferred Windows security mask.
* @param mask2 Alternate Windows security mask.
* @return Windows registry key's handle.
* @see #openKey(byte[], int)
* @see #openKey(int, byte[], int)
* @see #closeKey(int)
*/
private int openKey(int mask1, int mask2) {
return openKey(windowsAbsolutePath(), mask1, mask2);
}
/**
* Opens Windows registry key at a given absolute path using a given
* security mask.
* @param windowsAbsolutePath Windows absolute path of the
* key as a byte-encoded string.
* @param mask1 Preferred Windows security mask.
* @param mask2 Alternate Windows security mask.
* @return Windows registry key's handle.
* @see #openKey(int)
* @see #openKey(int, byte[],int)
* @see #closeKey(int)
*/
private int openKey(byte[] windowsAbsolutePath, int mask1, int mask2) {
/* Check if key's path is short enough be opened at once
otherwise use a path-splitting procedure */
if (windowsAbsolutePath.length <= MAX_WINDOWS_PATH_LENGTH + 1) {
int[] result = WindowsRegOpenKey1(rootNativeHandle(),
windowsAbsolutePath, mask1);
if (result[ERROR_CODE] == ERROR_ACCESS_DENIED && mask2 != mask1)
result = WindowsRegOpenKey1(rootNativeHandle(),
windowsAbsolutePath, mask2);
if (result[ERROR_CODE] != ERROR_SUCCESS) {
logger().warning("Could not open windows "
+ "registry node " + byteArrayToString(windowsAbsolutePath()) +
" at root 0x" + Integer.toHexString(rootNativeHandle()) +
". Windows RegOpenKey(...) returned error code " +
result[ERROR_CODE] + ".");
result[NATIVE_HANDLE] = NULL_NATIVE_HANDLE;
if (result[ERROR_CODE] == ERROR_ACCESS_DENIED) {
throw new SecurityException("Could not open windows "
+ "registry node " + byteArrayToString(windowsAbsolutePath()) +
" at root 0x" + Integer.toHexString(rootNativeHandle()) +
": Access denied");
}
}
return result[NATIVE_HANDLE];
} else {
return openKey(rootNativeHandle(), windowsAbsolutePath, mask1, mask2);
}
}
/**
* Opens Windows registry key at a given relative path
* with respect to a given Windows registry key.
* @param windowsAbsolutePath Windows relative path of the
* key as a byte-encoded string.
* @param nativeHandle handle to the base Windows key.
* @param mask1 Preferred Windows security mask.
* @param mask2 Alternate Windows security mask.
* @return Windows registry key's handle.
* @see #openKey(int)
* @see #openKey(byte[],int)
* @see #closeKey(int)
*/
private int openKey(int nativeHandle, byte[] windowsRelativePath,
int mask1, int mask2) {
/* If the path is short enough open at once. Otherwise split the path */
if (windowsRelativePath.length <= MAX_WINDOWS_PATH_LENGTH + 1 ) {
int[] result = WindowsRegOpenKey1(nativeHandle,
windowsRelativePath, mask1);
if (result[ERROR_CODE] == ERROR_ACCESS_DENIED && mask2 != mask1)
result = WindowsRegOpenKey1(nativeHandle,
windowsRelativePath, mask2);
if (result[ERROR_CODE] != ERROR_SUCCESS) {
logger().warning("Could not open windows "
+ "registry node " + byteArrayToString(windowsAbsolutePath()) +
" at root 0x" + Integer.toHexString(nativeHandle) +
". Windows RegOpenKey(...) returned error code " +
result[ERROR_CODE] + ".");
result[NATIVE_HANDLE] = NULL_NATIVE_HANDLE;
}
return result[NATIVE_HANDLE];
} else {
int separatorPosition = -1;
// Be greedy - open the longest possible path
for (int i = MAX_WINDOWS_PATH_LENGTH; i > 0; i--) {
if (windowsRelativePath[i] == ((byte)'\\')) {
separatorPosition = i;
break;
}
}
// Split the path and do the recursion
byte[] nextRelativeRoot = new byte[separatorPosition+1];
System.arraycopy(windowsRelativePath, 0, nextRelativeRoot,0,
separatorPosition);
nextRelativeRoot[separatorPosition] = 0;
byte[] nextRelativePath = new byte[windowsRelativePath.length -
separatorPosition - 1];
System.arraycopy(windowsRelativePath, separatorPosition+1,
nextRelativePath, 0, nextRelativePath.length);
int nextNativeHandle = openKey(nativeHandle, nextRelativeRoot,
mask1, mask2);
if (nextNativeHandle == NULL_NATIVE_HANDLE) {
return NULL_NATIVE_HANDLE;
}
int result = openKey(nextNativeHandle, nextRelativePath,
mask1,mask2);
closeKey(nextNativeHandle);
return result;
}
}
/**
* Closes Windows registry key.
* Logs a warning if Windows registry is unavailable.
* @param key's Windows registry handle.
* @see #openKey(int)
* @see #openKey(byte[],int)
* @see #openKey(int, byte[],int)
*/
private void closeKey(int nativeHandle) {
int result = WindowsRegCloseKey(nativeHandle);
if (result != ERROR_SUCCESS) {
logger().warning("Could not close windows "
+ "registry node " + byteArrayToString(windowsAbsolutePath()) +
" at root 0x" + Integer.toHexString(rootNativeHandle()) +
". Windows RegCloseKey(...) returned error code " + result + ".");
}
}
/**
* Implements <tt>AbstractPreferences putSpi() method.
* Puts name-value pair into the underlying Windows registry node.
* Logs a warning, if Windows registry is unavailable.
* @see #getSpi(String)
*/
protected void putSpi(String javaName, String value) {
int nativeHandle = openKey(KEY_SET_VALUE);
if (nativeHandle == NULL_NATIVE_HANDLE) {
isBackingStoreAvailable = false;
return;
}
int result = WindowsRegSetValueEx1(nativeHandle,
toWindowsName(javaName), toWindowsValueString(value));
if (result != ERROR_SUCCESS) {
logger().warning("Could not assign value to key " +
byteArrayToString(toWindowsName(javaName))+ " at Windows registry node "
+ byteArrayToString(windowsAbsolutePath()) + " at root 0x"
+ Integer.toHexString(rootNativeHandle()) +
". Windows RegSetValueEx(...) returned error code " + result + ".");
isBackingStoreAvailable = false;
}
closeKey(nativeHandle);
}
/**
* Implements <tt>AbstractPreferences getSpi() method.
* Gets a string value from the underlying Windows registry node.
* Logs a warning, if Windows registry is unavailable.
* @see #putSpi(String, String)
*/
protected String getSpi(String javaName) {
int nativeHandle = openKey(KEY_QUERY_VALUE);
if (nativeHandle == NULL_NATIVE_HANDLE) {
return null;
}
Object resultObject = WindowsRegQueryValueEx(nativeHandle,
toWindowsName(javaName));
if (resultObject == null) {
closeKey(nativeHandle);
return null;
}
closeKey(nativeHandle);
return toJavaValueString((byte[]) resultObject);
}
/**
* Implements <tt>AbstractPreferences removeSpi() method.
* Deletes a string name-value pair from the underlying Windows registry
* node, if this value still exists.
* Logs a warning, if Windows registry is unavailable or key has already
* been deleted.
*/
protected void removeSpi(String key) {
int nativeHandle = openKey(KEY_SET_VALUE);
if (nativeHandle == NULL_NATIVE_HANDLE) {
return;
}
int result =
WindowsRegDeleteValue(nativeHandle, toWindowsName(key));
if (result != ERROR_SUCCESS && result != ERROR_FILE_NOT_FOUND) {
logger().warning("Could not delete windows registry "
+ "value " + byteArrayToString(windowsAbsolutePath())+ "\\" +
toWindowsName(key) + " at root 0x" +
Integer.toHexString(rootNativeHandle()) +
". Windows RegDeleteValue(...) returned error code " +
result + ".");
isBackingStoreAvailable = false;
}
closeKey(nativeHandle);
}
/**
* Implements <tt>AbstractPreferences keysSpi() method.
* Gets value names from the underlying Windows registry node.
* Throws a BackingStoreException and logs a warning, if
* Windows registry is unavailable.
*/
protected String[] keysSpi() throws BackingStoreException{
// Find out the number of values
int nativeHandle = openKey(KEY_QUERY_VALUE);
if (nativeHandle == NULL_NATIVE_HANDLE) {
throw new BackingStoreException("Could not open windows"
+ "registry node " + byteArrayToString(windowsAbsolutePath()) +
" at root 0x" + Integer.toHexString(rootNativeHandle()) + ".");
}
int[] result = WindowsRegQueryInfoKey1(nativeHandle);
if (result[ERROR_CODE] != ERROR_SUCCESS) {
String info = "Could not query windows"
+ "registry node " + byteArrayToString(windowsAbsolutePath()) +
" at root 0x" + Integer.toHexString(rootNativeHandle()) +
". Windows RegQueryInfoKeyEx(...) returned error code " +
result[ERROR_CODE] + ".";
logger().warning(info);
throw new BackingStoreException(info);
}
int maxValueNameLength = result[MAX_VALUE_NAME_LENGTH];
int valuesNumber = result[VALUES_NUMBER];
if (valuesNumber == 0) {
closeKey(nativeHandle);
return new String[0];
}
// Get the values
String[] valueNames = new String[valuesNumber];
for (int i = 0; i < valuesNumber; i++) {
byte[] windowsName = WindowsRegEnumValue1(nativeHandle, i,
maxValueNameLength+1);
if (windowsName == null) {
String info =
"Could not enumerate value #" + i + " of windows node " +
byteArrayToString(windowsAbsolutePath()) + " at root 0x" +
Integer.toHexString(rootNativeHandle()) + ".";
logger().warning(info);
throw new BackingStoreException(info);
}
valueNames[i] = toJavaName(windowsName);
}
closeKey(nativeHandle);
return valueNames;
}
/**
* Implements <tt>AbstractPreferences childrenNamesSpi() method.
* Calls Windows registry to retrive children of this node.
* Throws a BackingStoreException and logs a warning message,
* if Windows registry is not available.
*/
protected String[] childrenNamesSpi() throws BackingStoreException {
// Open key
int nativeHandle = openKey(KEY_ENUMERATE_SUB_KEYS| KEY_QUERY_VALUE);
if (nativeHandle == NULL_NATIVE_HANDLE) {
throw new BackingStoreException("Could not open windows"
+ "registry node " + byteArrayToString(windowsAbsolutePath()) +
" at root 0x" + Integer.toHexString(rootNativeHandle()) + ".");
}
// Get number of children
int[] result = WindowsRegQueryInfoKey1(nativeHandle);
if (result[ERROR_CODE] != ERROR_SUCCESS) {
String info = "Could not query windows"
+ "registry node " + byteArrayToString(windowsAbsolutePath()) +
" at root 0x" + Integer.toHexString(rootNativeHandle()) +
". Windows RegQueryInfoKeyEx(...) returned error code " +
result[ERROR_CODE] + ".";
logger().warning(info);
throw new BackingStoreException(info);
}
int maxKeyLength = result[MAX_KEY_LENGTH];
int subKeysNumber = result[SUBKEYS_NUMBER];
if (subKeysNumber == 0) {
closeKey(nativeHandle);
return new String[0];
}
String[] subkeys = new String[subKeysNumber];
String[] children = new String[subKeysNumber];
// Get children
for (int i = 0; i < subKeysNumber; i++) {
byte[] windowsName = WindowsRegEnumKeyEx1(nativeHandle, i,
maxKeyLength+1);
if (windowsName == null) {
String info =
"Could not enumerate key #" + i + " of windows node " +
byteArrayToString(windowsAbsolutePath()) + " at root 0x" +
Integer.toHexString(rootNativeHandle()) + ". ";
logger().warning(info);
throw new BackingStoreException(info);
}
String javaName = toJavaName(windowsName);
children[i] = javaName;
}
closeKey(nativeHandle);
return children;
}
/**
* Implements <tt>Preferences flush() method.
* Flushes Windows registry changes to disk.
* Throws a BackingStoreException and logs a warning message if Windows
* registry is not available.
*/
public void flush() throws BackingStoreException{
if (isRemoved()) {
parent.flush();
return;
}
if (!isBackingStoreAvailable) {
throw new BackingStoreException(
"flush(): Backing store not available.");
}
int nativeHandle = openKey(KEY_READ);
if (nativeHandle == NULL_NATIVE_HANDLE) {
throw new BackingStoreException("Could not open windows"
+ "registry node " + byteArrayToString(windowsAbsolutePath()) +
" at root 0x" + Integer.toHexString(rootNativeHandle()) + ".");
}
int result = WindowsRegFlushKey1(nativeHandle);
if (result != ERROR_SUCCESS) {
String info = "Could not flush windows "
+ "registry node " + byteArrayToString(windowsAbsolutePath())
+ " at root 0x" + Integer.toHexString(rootNativeHandle()) +
". Windows RegFlushKey(...) returned error code " + result + ".";
logger().warning(info);
throw new BackingStoreException(info);
}
closeKey(nativeHandle);
}
/**
* Implements <tt>Preferences sync() method.
* Flushes Windows registry changes to disk. Equivalent to flush().
* @see flush()
*/
public void sync() throws BackingStoreException{
if (isRemoved())
throw new IllegalStateException("Node has been removed");
flush();
}
/**
* Implements <tt>AbstractPreferences childSpi() method.
* Constructs a child node with a
* given name and creates its underlying Windows registry node,
* if it does not exist.
* Logs a warning message, if Windows Registry is unavailable.
*/
protected AbstractPreferences childSpi(String name) {
return new WindowsPreferences(this, name);
}
/**
* Implements <tt>AbstractPreferences removeNodeSpi() method.
* Deletes underlying Windows registry node.
* Throws a BackingStoreException and logs a warning, if Windows registry
* is not available.
*/
public void removeNodeSpi() throws BackingStoreException {
int parentNativeHandle =
((WindowsPreferences)parent()).openKey(DELETE);
if (parentNativeHandle == NULL_NATIVE_HANDLE) {
throw new BackingStoreException("Could not open parent windows"
+ "registry node of " + byteArrayToString(windowsAbsolutePath()) +
" at root 0x" + Integer.toHexString(rootNativeHandle()) + ".");
}
int result =
WindowsRegDeleteKey(parentNativeHandle, toWindowsName(name()));
if (result != ERROR_SUCCESS) {
String info = "Could not delete windows "
+ "registry node " + byteArrayToString(windowsAbsolutePath()) +
" at root 0x" + Integer.toHexString(rootNativeHandle()) +
". Windows RegDeleteKeyEx(...) returned error code " +
result + ".";
logger().warning(info);
throw new BackingStoreException(info);
}
closeKey(parentNativeHandle);
}
/**
* Converts value's or node's name from its byte array representation to
* java string. Two encodings, simple and altBase64 are used. See
* {@link #toWindowsName(String) toWindowsName()} for a detailed
* description of encoding conventions.
* @param windowsNameArray Null-terminated byte array.
*/
private static String toJavaName(byte[] windowsNameArray) {
String windowsName = byteArrayToString(windowsNameArray);
// check if Alt64
if ((windowsName.length()>1) &&
(windowsName.substring(0,2).equals("/!"))) {
return toJavaAlt64Name(windowsName);
}
StringBuffer javaName = new StringBuffer();
char ch;
// Decode from simple encoding
for (int i = 0; i < windowsName.length(); i++){
if ((ch = windowsName.charAt(i)) == '/') {
char next = ' ';
if ((windowsName.length() > i + 1) &&
((next = windowsName.charAt(i+1)) >= 'A') && (next <= 'Z')) {
ch = next;
i++;
} else if ((windowsName.length() > i + 1) && (next == '/')) {
ch = '\\';
i++;
}
} else if (ch == '\\') {
ch = '/';
}
javaName.append(ch);
}
return javaName.toString();
}
/**
* Converts value's or node's name from its Windows representation to java
* string, using altBase64 encoding. See
* {@link #toWindowsName(String) toWindowsName()} for a detailed
* description of encoding conventions.
*/
private static String toJavaAlt64Name(String windowsName) {
byte[] byteBuffer =
Base64.altBase64ToByteArray(windowsName.substring(2));
StringBuffer result = new StringBuffer();
for (int i = 0; i < byteBuffer.length; i++) {
int firstbyte = (byteBuffer[i++] & 0xff);
int secondbyte = (byteBuffer[i] & 0xff);
result.append((char)((firstbyte << 8) + secondbyte));
}
return result.toString();
}
/**
* Converts value's or node's name to its Windows representation
* as a byte-encoded string.
* Two encodings, simple and altBase64 are used.
* <p>
* <i>Simple encoding is used, if java string does not contain
* any characters less, than 0x0020, or greater, than 0x007f.
* Simple encoding adds "/" character to capital letters, i.e.
* "A" is encoded as "/A". Character '\' is encoded as '//',
* '/' is encoded as '\'.
* The constructed string is converted to byte array by truncating the
* highest byte and adding the terminating <tt>null character.
* <p>
* <i>altBase64 encoding is used, if java string does contain at least
* one character less, than 0x0020, or greater, than 0x007f.
* This encoding is marked by setting first two bytes of the
* Windows string to '/!'. The java name is then encoded using
* byteArrayToAltBase64() method from
* Base64 class.
*/
private static byte[] toWindowsName(String javaName) {
StringBuffer windowsName = new StringBuffer();
for (int i = 0; i < javaName.length(); i++) {
char ch =javaName.charAt(i);
if ((ch < 0x0020)||(ch > 0x007f)) {
// If a non-trivial character encountered, use altBase64
return toWindowsAlt64Name(javaName);
}
if (ch == '\\') {
windowsName.append("//");
} else if (ch == '/') {
windowsName.append('\\');
} else if ((ch >= 'A') && (ch <='Z')) {
windowsName.append("/" + ch);
} else {
windowsName.append(ch);
}
}
return stringToByteArray(windowsName.toString());
}
/**
* Converts value's or node's name to its Windows representation
* as a byte-encoded string, using altBase64 encoding. See
* {@link #toWindowsName(String) toWindowsName()} for a detailed
* description of encoding conventions.
*/
private static byte[] toWindowsAlt64Name(String javaName) {
byte[] javaNameArray = new byte[2*javaName.length()];
// Convert to byte pairs
int counter = 0;
for (int i = 0; i < javaName.length();i++) {
int ch = javaName.charAt(i);
javaNameArray[counter++] = (byte)(ch >>> 8);
javaNameArray[counter++] = (byte)ch;
}
return stringToByteArray(
"/!" + Base64.byteArrayToAltBase64(javaNameArray));
}
/**
* Converts value string from its Windows representation
* to java string. See
* {@link #toWindowsValueString(String) toWindowsValueString()} for the
* description of the encoding algorithm.
*/
private static String toJavaValueString(byte[] windowsNameArray) {
// Use modified native2ascii algorithm
String windowsName = byteArrayToString(windowsNameArray);
StringBuffer javaName = new StringBuffer();
char ch;
for (int i = 0; i < windowsName.length(); i++){
if ((ch = windowsName.charAt(i)) == '/') {
char next = ' ';
if (windowsName.length() > i + 1 &&
(next = windowsName.charAt(i + 1)) == 'u') {
if (windowsName.length() < i + 6){
break;
} else {
ch = (char)Integer.parseInt
(windowsName.substring(i + 2, i + 6), 16);
i += 5;
}
} else
if ((windowsName.length() > i + 1) &&
((windowsName.charAt(i+1)) >= 'A') && (next <= 'Z')) {
ch = next;
i++;
} else if ((windowsName.length() > i + 1) &&
(next == '/')) {
ch = '\\';
i++;
}
} else if (ch == '\\') {
ch = '/';
}
javaName.append(ch);
}
return javaName.toString();
}
/**
* Converts value string to it Windows representation.
* as a byte-encoded string.
* Encoding algorithm adds "/" character to capital letters, i.e.
* "A" is encoded as "/A". Character '\' is encoded as '//',
* '/' is encoded as '\'.
* Then encoding scheme similar to jdk's native2ascii converter is used
* to convert java string to a byte array of ASCII characters.
*/
private static byte[] toWindowsValueString(String javaName) {
StringBuffer windowsName = new StringBuffer();
for (int i = 0; i < javaName.length(); i++) {
char ch =javaName.charAt(i);
if ((ch < 0x0020)||(ch > 0x007f)){
// write \udddd
windowsName.append("/u");
String hex = Integer.toHexString(javaName.charAt(i));
StringBuffer hex4 = new StringBuffer(hex);
hex4.reverse();
int len = 4 - hex4.length();
for (int j = 0; j < len; j++){
hex4.append('0');
}
for (int j = 0; j < 4; j++){
windowsName.append(hex4.charAt(3 - j));
}
} else if (ch == '\\') {
windowsName.append("//");
} else if (ch == '/') {
windowsName.append('\\');
} else if ((ch >= 'A') && (ch <='Z')) {
windowsName.append("/" + ch);
} else {
windowsName.append(ch);
}
}
return stringToByteArray(windowsName.toString());
}
/**
* Returns native handle for the top Windows node for this node.
*/
private int rootNativeHandle() {
return (isUserNode()? USER_ROOT_NATIVE_HANDLE :
SYSTEM_ROOT_NATIVE_HANDLE);
}
/**
* Returns this java string as a null-terminated byte array
*/
private static byte[] stringToByteArray(String str) {
byte[] result = new byte[str.length()+1];
for (int i = 0; i < str.length(); i++) {
result[i] = (byte) str.charAt(i);
}
result[str.length()] = 0;
return result;
}
/**
* Converts a null-terminated byte array to java string
*/
private static String byteArrayToString(byte[] array) {
StringBuffer result = new StringBuffer();
for (int i = 0; i < array.length - 1; i++) {
result.append((char)array[i]);
}
return result.toString();
}
/**
* Empty, never used implementation of AbstractPreferences.flushSpi().
*/
protected void flushSpi() throws BackingStoreException {
// assert false;
}
/**
* Empty, never used implementation of AbstractPreferences.flushSpi().
*/
protected void syncSpi() throws BackingStoreException {
// assert false;
}
private static synchronized PlatformLogger logger() {
if (logger == null) {
logger = PlatformLogger.getLogger("java.util.prefs");
}
return logger;
}
}
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