android自带的内存储器memory和第三方外部存储disk管理

/**  * @author [email protected]  * @time 20140606  */ package com.intbird.utils;import java.io.File;import com.yilake.store.FileHelper;import android.graphics.Bitmap;import android.os.Environment;import android.util.LruCache;public class CacheManager {	//单例	private static CacheManager cacheInstance;		//内存缓存大小	private final int MEMO_CACHE_SIZE=((int)(Runtime.getRuntime().maxMemory()/1024));	//文件缓存大小	private final int DISK_CACHE_SIZE=1024*1024*100;	//内存缓存	private LruCache<String,Bitmap> mMemoryCache;	//文件缓存	private DiskLruCache mDiskLruCache;	private String cacheUrl="";		public CacheManager() {		//内存缓存		mMemoryCache=new LruCache<String, Bitmap>(MEMO_CACHE_SIZE){			protected int sizeOf(String key, Bitmap bitmap) {				return bitmap.getByteCount()/1024;			};		};		//文件缓存		setBitmapFileCacheDir(FileHelper.DISK_CACHE_FILEDIR);	}		/**	 * 获取单例	 * @return	 */	public static CacheManager getInstance() {		if(cacheInstance==null){			cacheInstance=new CacheManager();		}		return cacheInstance;	}		/**	 * 设置缓存目录;	 * @param cacheDir	 */	public void setBitmapFileCacheDir(String cacheDir){		File cacheFile=	getDiskFileCache(cacheDir);		cacheUrl=cacheFile.getAbsolutePath();		mDiskLruCache=DiskLruCache.openCache(cacheFile, DISK_CACHE_SIZE);	}	/**	 * 返回缓存目录路径	 * @return	 */	public String getBitmapFileCacheDir(){		return cacheUrl;	}		//通用外部调用	public void addBitmapToCache(String fileUrl, Bitmap bitmap) {		addBitmapToMemory(fileUrl,bitmap);		addBitmapToDisk(fileUrl,bitmap);	}	public Bitmap getBitmapFromCache(String key){		Bitmap bmp=null;		bmp=getBitmapFromMemory(key);		if(bmp==null){			bmp=getBitmapFromDisk(key);		}		return bmp;	}	/**	 * 图片加入内存缓存	 * @param key	 * @param bitmap	 */	private void addBitmapToMemory(String key,Bitmap bitmap){		if(getBitmapFromMemory(key)==null){			mMemoryCache.put(key, bitmap);		}	}	/**	 * 获取内存缓存图片	 * @param key	 * @return	 */	private Bitmap getBitmapFromMemory(String key){		return mMemoryCache.get(key);	}	/**		 * 将图片加入文件缓存	 * @param key	 * @param bitmap	 */	private void addBitmapToDisk(String key,Bitmap bitmap){        if (mDiskLruCache != null && mDiskLruCache.get(key) == null) {            mDiskLruCache.put(key, bitmap);        }	}	/**	 * 从文件缓存中获取图片	 * @param key	 * @return	 */	private Bitmap getBitmapFromDisk(String key){        if (mDiskLruCache != null) {            return mDiskLruCache.get(key);        }	    return null;	}		/**	 * 获取缓存目录	 * @return	 */	public static File getDiskFileCache(String cacheDir){		String cachePath =Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState()) ||	                    !Environment.isExternalStorageRemovable() ? 	                    		Environment.getExternalStorageDirectory().getPath():	                    		Environment.getDataDirectory().getPath();	    File file =new File(cachePath + File.separator + cacheDir);	    if(!file.exists()) file.mkdir();	    return file;	}}