AssetsUtils.java

package com.banking.xc.utils;

import java.io.File;
import java.io.InputStream;

import skytv_com.banking.enjoymovie.MyApplication;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.BitmapFactory.Options;
import android.graphics.drawable.BitmapDrawable;

import com.banking.xc.utils.ImageUtil.InputWay;

public class AssetsUtils {

	private static final String TAG = "AssetsCacheUtils";

	/**
	 * 从assets目录下读取缓存图片，例如：可读取/assets/jdcache/000343742987434c8f20cfafb007583a.image
	 * 
	 * @param name
	 *            缓存图片名称
	 * @param width
	 *            读取图片的宽度
	 * @param height
	 *            读取图片的高度
	 * @return
	 */
	public static BitmapDrawable readImage(String name, int width, int height) {
		name = name + ".image";
		Bitmap bitmap = null;
		try {
			if (Log.D) {
				Log.d(TAG, " readImage() -->> name" + name + " width:" + width + " height:" + height);
			}
			InputStream inputStream = MyApplication.getInstance().getResources().getAssets().open("" + File.separator + name);
			if (null != inputStream) {
				byte[] inBytes = IOUtil.readAsBytes(inputStream, null);
				
				InputWay inputWay = new InputWay();
				inputWay.setByteArray(inBytes);
				
				bitmap = ImageUtil.createBitmap(inputWay , width, height);

				if (Log.D) {
					Log.d(TAG, " AssetsCacheUtils readImage() -->> succeed!");
				}
				return new BitmapDrawable(bitmap);
			}
		} catch (Exception e) {
			if (Log.D) {
				Log.d(TAG, " readImage() -->> " + e.getMessage());
				e.printStackTrace();
			}
		}

		return null;
	}
	
	/**
	 * 得到/jdcache/打包缓存中的文件输入流
	 * 
	 * @param name
	 *            文件名
	 * @param extName
	 *            扩展名
	 * @return
	 */
	public static InputStream open(String name, String extName) {
		name = name + extName;
		try {
			if (Log.D) {
				Log.d(TAG, " open() -->> name:" + name + ", extName:" + extName);
			}
			return MyApplication.getInstance().getResources().getAssets().open("" + File.separator + name);

		} catch (Exception e) {
			if (Log.D) {
				Log.d(TAG, " open() -->> " + e.getMessage());
				e.printStackTrace();
			}
		}
		return null;
	}

	private static Options getBitmapOpt(int length) {
		BitmapFactory.Options opt = new BitmapFactory.Options();
		opt.inPurgeable = true;
		opt.inInputShareable = true;
		if (length > 1024 * 64) {
			opt.inSampleSize = 2;
		}
		return opt;
	}

}