zxing二维码识别3

/*
 * Copyright (C) 2010 ZXing authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.ejoyshop.android;

import android.os.IBinder;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

/**
 * This class is used to activate the weak light on some camera phones (not
 * flash) in order to illuminate surfaces for scanning. There is no official way
 * to do this, but, classes which allow access to this function still exist on
 * some devices. This therefore proceeds through a great deal of reflection.
 * 
 * See <a href=
 * "https://almondmendoza.com/2009/01/05/changing-the-screen-brightness-programatically/"
 * > https://almondmendoza.com/2009/01/05/changing-the-screen-brightness-
 * programatically/</a> and <a href=
 * "https://code.google.com/p/droidled/source/browse/trunk/src/com/droidled/demo/DroidLED.java"
 * > https://code.google.com/p/droidled/source/browse/trunk/src/com/droidled/demo
 * /DroidLED.java</a>. Thanks to Ryan Alford for pointing out the availability
 * of this class.
 */
final class FlashlightManager {
	private static final Object iHardwareService;
	private static final Method setFlashEnabledMethod;
	static {
		iHardwareService = getHardwareService();
		setFlashEnabledMethod = getSetFlashEnabledMethod(iHardwareService);

	}

	private FlashlightManager() {
	}

	private static Object getHardwareService() {
		Class<?> serviceManagerClass = maybeForName("android.os.ServiceManager");
		if (serviceManagerClass == null) {
			return null;
		}

		Method getServiceMethod = maybeGetMethod(serviceManagerClass,
				"getService", String.class);
		if (getServiceMethod == null) {
			return null;
		}

		Object hardwareService = invoke(getServiceMethod, null, "hardware");
		if (hardwareService == null) {
			return null;
		}

		Class<?> iHardwareServiceStubClass = maybeForName("android.os.IHardwareService$Stub");
		if (iHardwareServiceStubClass == null) {
			return null;
		}

		Method asInterfaceMethod = maybeGetMethod(iHardwareServiceStubClass,
				"asInterface", IBinder.class);
		if (asInterfaceMethod == null) {
			return null;
		}

		return invoke(asInterfaceMethod, null, hardwareService);
	}

	private static Method getSetFlashEnabledMethod(Object iHardwareService) {
		if (iHardwareService == null) {
			return null;
		}
		Class<?> proxyClass = iHardwareService.getClass();
		return maybeGetMethod(proxyClass, "setFlashlightEnabled", boolean.class);
	}

	private static Class<?> maybeForName(String name) {
		try {
			return Class.forName(name);
		} catch (ClassNotFoundException cnfe) {
			// OK
			return null;
		} catch (RuntimeException re) {

			return null;
		}
	}

	private static Method maybeGetMethod(Class<?> clazz, String name,
			Class<?>... argClasses) {
		try {
			return clazz.getMethod(name, argClasses);
		} catch (NoSuchMethodException nsme) {
			// OK
			return null;
		} catch (RuntimeException re) {
			return null;
		}
	}

	private static Object invoke(Method method, Object instance, Object... args) {
		try {
			return method.invoke(instance, args);
		} catch (IllegalAccessException e) {

			return null;
		} catch (InvocationTargetException e) {

			return null;
		} catch (RuntimeException re) {

			return null;
		}
	}

	static void enableFlashlight() {
		setFlashlight(true);
	}

	static void disableFlashlight() {
		setFlashlight(false);
	}

	private static void setFlashlight(boolean active) {
		if (iHardwareService != null) {
			invoke(setFlashEnabledMethod, iHardwareService, active);
		}
	}

}
/*
 * Copyright (C) 2010 ZXing authors
 *
 * Li