android.os.SystemProperties反射帮助类

package com.viking;import java.lang.reflect.Method;import android.content.Context;/** * @author Viking.Den * * @email [e-mail] * * @time 2014-7-17 */public class SystemPropertiesProxy{/** * This class cannot be instantiated */private SystemPropertiesProxy(){}    /**     * 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();           @SuppressWarnings("rawtypes")          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]= new String(key);          ret= (String) get.invoke(SystemProperties, params);        }catch( IllegalArgumentException iAE ){            throw iAE;        }catch( Exception 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= def;        try{          ClassLoader cl = context.getClassLoader();           @SuppressWarnings("rawtypes")          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]= new String(key);          params[1]= new String(def);          ret= (String) get.invoke(SystemProperties, params);        }catch( IllegalArgumentException iAE ){            throw iAE;        }catch( Exception e ){            ret= def;        }        return ret;    }    /**     * Get the value for the given key, and return as an integer.     * @param key the key to lookup     * @param def a default value to return     * @return the key parsed as an integer, or def if the key isn't found or     *         cannot be parsed     * @throws IllegalArgumentException if the key exceeds 32 characters     */    public static Integer getInt(Context context, String key, int def) throws IllegalArgumentException {        Integer ret= def;        try{          ClassLoader cl = context.getClassLoader();           @SuppressWarnings("rawtypes")          Class SystemProperties = cl.loadClass("android.os.SystemProperties");          //Parameters Types          @SuppressWarnings("rawtypes")          Class[] paramTypes= new Class[2];          paramTypes[0]= String.class;          paramTypes[1]= int.class;            Method getInt = SystemProperties.getMethod("getInt", paramTypes);          //Parameters          Object[] params= new Object[2];          params[0]= new String(key);          params[1]= new Integer(def);          ret= (Integer) getInt.invoke(SystemProperties, params);        }catch( IllegalArgumentException iAE ){            throw iAE;        }catch( Exception e ){            ret= def;        }        return ret;    }    /**     * Get the value for the given key, and return as a long.     * @param key the key to lookup     * @param def a default value to return     * @return the key parsed as a long, or def if the key isn't found or     *         cannot be parsed     * @throws IllegalArgumentException if the key exceeds 32 characters     */    public static Long getLong(Context context, String key, long def) throws IllegalArgumentException {        Long ret= def;        try{          ClassLoader cl = context.getClassLoader();          @SuppressWarnings("rawtypes")          Class SystemProperties= cl.loadClass("android.os.SystemProperties");          //Parameters Types          @SuppressWarnings("rawtypes")          Class[] paramTypes= new Class[2];          paramTypes[0]= String.class;          paramTypes[1]= long.class;            Method getLong = SystemProperties.getMethod("getLong", paramTypes);          //Parameters          Object[] params= new Object[2];          params[0]= new String(key);          params[1]= new Long(def);          ret= (Long) getLong.invoke(SystemProperties, params);        }catch( IllegalArgumentException iAE ){            throw iAE;        }catch( Exception e ){            ret= def;        }        return ret;    }    /**     * Get the value for the given key, returned as a boolean.     * Values 'n', 'no', '0', 'false' or 'off' are considered false.     * Values 'y', 'yes', '1', 'true' or 'on' are considered true.     * (case insensitive).     * If the key does not exist, or has any other value, then the default     * result is returned.     * @param key the key to lookup     * @param def a default value to return     * @return the key parsed as a boolean, or def if the key isn't found or is     *         not able to be parsed as a boolean.     * @throws IllegalArgumentException if the key exceeds 32 characters     */    public static Boolean getBoolean(Context context, String key, boolean def) throws IllegalArgumentException {        Boolean ret= def;        try{          ClassLoader cl = context.getClassLoader();           @SuppressWarnings("rawtypes")          Class SystemProperties = cl.loadClass("android.os.SystemProperties");          //Parameters Types          @SuppressWarnings("rawtypes")          Class[] paramTypes= new Class[2];          paramTypes[0]= String.class;          paramTypes[1]= boolean.class;            Method getBoolean = SystemProperties.getMethod("getBoolean", paramTypes);          //Parameters                   Object[] params= new Object[2];          params[0]= new String(key);          params[1]= new Boolean(def);          ret= (Boolean) getBoolean.invoke(SystemProperties, params);        }catch( IllegalArgumentException iAE ){            throw iAE;        }catch( Exception e ){            ret= def;        }        return ret;    }    /**     * Set the value for the given key.     * @throws IllegalArgumentException if the key exceeds 32 characters     * @throws IllegalArgumentException if the value exceeds 92 characters     */    public static void set(Context context, String key, String val) throws IllegalArgumentException {        try{          @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]= new String(key);          params[1]= new String(val);          set.invoke(SystemProperties, params);        }catch( IllegalArgumentException iAE ){            throw iAE;        }catch( Exception e ){}    }}