SystemPropertiesReflection.java

/**   Copyright (C) 2013  Louis Teboul <louisteboul@gmail.com>
 *
 *     This program 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 of the License, or
 *     (at your option) any later version.
 *
 *     This program 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 this program; if not, write to the Free Software Foundation, Inc.,
 *     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 **/

package com.secupwn.aimsicd.utils;

import android.content.Context;

import java.io.File;
import java.lang.reflect.Method;

import dalvik.system.DexFile;
import io.freefair.android.util.logging.AndroidLogger;
import io.freefair.android.util.logging.Logger;

/**
 * Class using reflection to grant access to the private hidden
 * android.os.SystemProperties class
 */
public class SystemPropertiesReflection {

    private static final Logger log = AndroidLogger.forClass(SystemPropertiesReflection.class);

    /**
     * This class cannot be instantiated
     */
    private SystemPropertiesReflection() {

    }

    /**
     * Get the value for the given key.
     *
     * @return an empty string if the key isn't found
     * @throws IllegalArgumentException if the key exceeds 32 characters
     */
    public static String get(Context context, String key) throws IllegalArgumentException {

        String ret;

        try {
            ClassLoader cl = context.getClassLoader();
            Class<?> SystemProperties = cl.loadClass("android.os.SystemProperties");

            //Parameters Types
            @SuppressWarnings("rawtypes")
            Class[] paramTypes = new Class[1];
            paramTypes[0] = String.class;

            Method get = SystemProperties.getMethod("get", paramTypes);

            //Parameters
            Object[] params = new Object[1];
            params[0] = key;

            ret = (String) get.invoke(SystemProperties, params);

        } catch (IllegalArgumentException iae) {
            log.error(iae.getMessage(), iae);
            throw iae;
        } catch (Exception e) {
            log.error(e.getMessage(), e);
            ret = "";
        }

        return ret;

    }

    /**
     * Get the value for the given key.
     *
     * @return if the key isn't found, return def if it isn't null, or an empty string otherwise
     * @throws IllegalArgumentException if the key exceeds 32 characters
     */
    public static String get(Context context, String key, String def)
            throws IllegalArgumentException {

        String ret;

        try {
            ClassLoader cl = context.getClassLoader();
            Class<?> SystemProperties = cl.loadClass("android.os.SystemProperties");

            //Parameters Types
            @SuppressWarnings("rawtypes")
            Class[] paramTypes = new Class[2];
            paramTypes[0] = String.class;
            paramTypes[1] = String.class;

            Method get = SystemProperties.getMethod("get", paramTypes);

            //Parameters
            Object[] params = new Object[2];
            params[0] = key;
            params[1] = def;

            ret = (String) get.invoke(SystemProperties, params);

        } catch (IllegalArgumentException iae) {
            log.error(iae.getMessage(), iae);
            throw iae;
        } catch (Exception e) {
            log.error(e.getMessage(), e);
            ret = def;
        }

        return ret;
    }

    /**
     * Set the value for the given key.
     *
     * @throws IllegalArgumentException if the key exceeds 32 characters
     *                          OR      if the value exceeds 92 characters
     */
    public static void set(Context context, String key, String val)
            throws IllegalArgumentException {

        try {
            @SuppressWarnings("unused")
            DexFile df = new DexFile(new File("/system/app/Settings.apk"));
            @SuppressWarnings("unused")
            ClassLoader cl = context.getClassLoader();
            @SuppressWarnings("rawtypes")
            Class SystemProperties = Class.forName("android.os.SystemProperties");

            //Parameters Types
            @SuppressWarnings("rawtypes")
            Class[] paramTypes = new Class[2];
            paramTypes[0] = String.class;
            paramTypes[1] = String.class;

            Method set = SystemProperties.getMethod("set", paramTypes);

            //Parameters
            Object[] params = new Object[2];
            params[0] = key;
            params[1] = val;

            set.invoke(SystemProperties, params);

        } catch (IllegalArgumentException iae) {
            log.error(iae.getMessage(), iae);
            throw iae;
        } catch (Exception ignored) {
            log.debug(ignored.getMessage(), ignored);
        }

    }
}