package com.googlecode.righettod.cip.util;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.prefs.BackingStoreException;
import java.util.prefs.Preferences;
/**
* Very evil class to read from the Windows registry by breaking into the WindowsPreference class methods and forcing them to be accessible.
* <p/>
* N.B. All access to WindowsPreferences (rather than just Preferences) must be through introspection, as this class only exists on Windows platforms.
*
* @author David Croft (<a href="http://www.davidc.net">www.davidc.net</a>)
* @version $Id: WindowsRegistry.java 285 2009-06-18 17:48:28Z david $
* @see "http://www.davidc.net/programming/java/reading-windows-registry-java-without-jni"
*/
public class WindowsRegistry {
/* Windows hives */
public static final int HKEY_CURRENT_USER = 0x80000001;
public static final int HKEY_LOCAL_MACHINE = 0x80000002;
/* Windows security masks */
private static final int KEY_READ = 0x20019;
/* Constants used to interpret returns of native functions */
private static final int NATIVE_HANDLE = 0;
private static final int ERROR_CODE = 1;
/* Windows error codes. */
private static final int ERROR_SUCCESS = 0;
private static final int ERROR_FILE_NOT_FOUND = 2;
public static String getKeySz(int hive, String keyName, String valueName) throws BackingStoreException {
if ((hive != HKEY_CURRENT_USER) && (hive != HKEY_LOCAL_MACHINE)) {
throw new IllegalArgumentException("Invalid hive " + hive);
}
final Class clazz = Preferences.userRoot().getClass();
try {
final Method openKeyMethod = clazz.getDeclaredMethod("WindowsRegOpenKey", int.class, byte[].class, int.class);
openKeyMethod.setAccessible(true);
final Method closeKeyMethod = clazz.getDeclaredMethod("WindowsRegCloseKey", int.class);
closeKeyMethod.setAccessible(true);
final Method queryValueMethod = clazz.getDeclaredMethod("WindowsRegQueryValueEx", int.class, byte[].class);
queryValueMethod.setAccessible(true);
int[] result = (int[]) openKeyMethod.invoke(null, hive, stringToByteArray(keyName), KEY_READ);
if (result[ERROR_CODE] != ERROR_SUCCESS) {
if (result[ERROR_CODE] == ERROR_FILE_NOT_FOUND) {
throw new BackingStoreException("Not Found error opening key " + keyName);
} else {
throw new BackingStoreException("Error " + result[ERROR_CODE] + " opening key " + keyName);
}
}
int hKey = result[NATIVE_HANDLE];
byte[] b = (byte[]) queryValueMethod.invoke(null, hKey, stringToByteArray(valueName));
closeKeyMethod.invoke(null, hKey);
if (b == null)
return null;
else
return byteArrayToString(b);
}
catch (InvocationTargetException e) {
throw new BackingStoreException(e.getCause());
}
catch (NoSuchMethodException e) {
throw new BackingStoreException(e);
}
catch (IllegalAccessException e) {
throw new BackingStoreException(e);
}
}
/**
* Returns this java string as a null-terminated byte array
*
* @param str The string to convert
* @return The resulting 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
*
* @param array The null-terminated byte array to convert
* @return The resulting string
*/
private static String byteArrayToString(byte[] array) {
StringBuilder result = new StringBuilder();
for (int i = 0; i < (array.length - 1); i++) {
result.append((char) array[i]);
}
return result.toString();
}
@SuppressWarnings({ "UseOfSystemOutOrSystemErr", "HardcodedFileSeparator" })
private static void testKey(int hive, String keyName, String valueName) {
String s;
if (hive == HKEY_CURRENT_USER)
System.out.print("HKCU\\");
if (hive == HKEY_LOCAL_MACHINE)
System.out.print("HKLM\\");
System.out.println(keyName);
System.out.println(" Reading: " + valueName);
try {
s = getKeySz(hive, keyName, valueName);
System.out.println(" >>" + s + "<<");
}
catch (BackingStoreException e) {
System.out.println(" !!" + e.getMessage());
}
}
public static void main(String args[]) {
testKey(HKEY_LOCAL_MACHINE, "SOFTWARE\\Valve\\Steam", "InstallPath");
testKey(HKEY_LOCAL_MACHINE, "SOFTWARE\\Valve\\Steam\\Apps\\15660", "");
testKey(HKEY_LOCAL_MACHINE, "SOFTWARE\\Valve\\Steam\\Apps\\22000", "");
testKey(HKEY_LOCAL_MACHINE, "SOFTWARE\\Valve\\Steam\\Apps\\22010", "");
}
}