BitmapManager

package com.snda.lottery.common;


import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.lang.ref.SoftReference;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.WeakHashMap;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;


import com.snda.lottery.app.api.ApiClient;
import com.snda.lottery.util.FileUtils;


import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Bitmap.CompressFormat;
import android.os.Environment;
import android.os.Handler;
import android.os.Message;
import android.widget.ImageView;
/**
 * 异步线程加载图片工具类
 * 使用说明：
 * BitmapManager bmpManager;
 * bmpManager = new BitmapManager(BitmapFactory.decodeResource(context.getResources(), R.drawable.loading));
 * bmpManager.loadBitmap(imageURL, imageView);
 * @author wulianghuan
 * @version 1.0
 * @created 2014-06-08
 */
public class BitmapManager {  
 
    private static HashMap<String, SoftReference<Bitmap>> cache;  
    private static ExecutorService pool;  
    private static Map<ImageView, String> imageViews;  
    private Bitmap defaultBmp;
    // SD卡上图片储存地址  
    private final static String SAVE_PATH = Environment.getExternalStorageDirectory().getPath() + "/snda_lottery/";
    
    static {  
        cache = new HashMap<String, SoftReference<Bitmap>>();  
        pool = Executors.newFixedThreadPool(5);  //固定线程池
        imageViews = Collections.synchronizedMap(new WeakHashMap<ImageView, String>());
    }  
    
    public BitmapManager(){}
    
    public BitmapManager(Bitmap def) {
    this.defaultBmp = def;
    }
    
    /**
     * 设置默认图片
     * @param bmp
     */
    public void setDefaultBmp(Bitmap bmp) {  
    defaultBmp = bmp;  
    }   
  
    /**
     * 加载图片
     * @param url
     * @param imageView
     */
    public void loadBitmap(String url, ImageView imageView) {  
    loadBitmap(url, imageView, this.defaultBmp, 0, 0);
    }

    /**
     * 加载图片-可设置加载失败后显示的默认图片
     * @param url
     * @param imageView
     * @param defaultBmp
     */
    public void loadBitmap(String url, ImageView imageView, Bitmap defaultBmp) {  
    loadBitmap(url, imageView, defaultBmp, 0, 0);
    }
    
    /**
     * 加载图片-可指定显示图片的高宽
     * @param url
     * @param imageView
     * @param width
     * @param height
     */
    public void loadBitmap(String url, ImageView imageView, Bitmap defaultBmp, int width, int height) {  
        imageViews.put(imageView, url);  
        Bitmap bitmap = getBitmapFromCache(url);  
   
        if (bitmap != null) {  
//显示缓存图片
            imageView.setImageBitmap(bitmap);  
        } else {  
        //加载SD卡中的图片缓存
        String filename = FileUtils.getFileName(url);
        String filepath = imageView.getContext().getFilesDir() + File.separator + filename;
    File file = new File(filepath);
    if(file.exists()){
//显示SD卡中的图片缓存
    Bitmap bmp = getBitmap(imageView.getContext(), filename);
        imageView.setImageBitmap(bmp);
        }else{
//线程加载网络图片
        imageView.setImageBitmap(defaultBmp);
        queueJob(url, imageView, width, height);
        }
        }  
    }  
  
    /**
     * 从缓存中获取图片
     * @param url
     */
    public Bitmap getBitmapFromCache(String url) {  
    Bitmap bitmap = null;
        if (cache.containsKey(url)) {  
            bitmap = cache.get(url).get();  
        }  
        return bitmap;  
    }  
    
    /**
     * 从网络中加载图片
     * @param url
     * @param imageView
     * @param width
     * @param height
     */
    public void queueJob(final String url, final ImageView imageView, final int width, final int height) {  
        /* Create handler in UI thread. */  
        final Handler handler = new Handler() {  
            public void handleMessage(Message msg) {  
                String tag = imageViews.get(imageView);  
                if (tag != null && tag.equals(url)) {  
                    if (msg.obj != null) {  
                        imageView.setImageBitmap((Bitmap) msg.obj);  
                        try {
                        //向SD卡中写入图片缓存
saveImage(FileUtils.getFileName(url), (Bitmap) msg.obj);
} catch (IOException e) {
e.printStackTrace();
}
                    } 
                }  
            }  
        };  
  
        pool.execute(new Runnable() {   
            public void run() {  
                Message message = Message.obtain();  
                message.obj = downloadBitmap(url, width, height);  
                handler.sendMessage(message);  
            }  
        });  
    } 
  
    /**
     * 下载图片-可指定显示图片的高宽
     * @param url
     * @param width
     * @param height
     */
    private Bitmap downloadBitmap(String url, int width, int height) {   
        Bitmap bitmap = null;
        try {
//http加载图片
bitmap = ApiClient.getNetBitmap(url);
if(width > 0 && height > 0) {
//指定显示图片的高宽
bitmap = Bitmap.createScaledBitmap(bitmap, width, height, true);
} 
//放入缓存
cache.put(url, new SoftReference<Bitmap>(bitmap));
} catch (Exception e) {
e.printStackTrace();
}
        return bitmap;  
    }
    
    /**
* 获取bitmap
* @param context
* @param fileName
* @return
*/
public static Bitmap getBitmap(Context context,String fileName) {
FileInputStream fis = null;
Bitmap bitmap = null;
try {
fis = context.openFileInput(fileName);
bitmap = BitmapFactory.decodeStream(fis);
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (OutOfMemoryError e) {
e.printStackTrace();
}finally{
try {
fis.close();
} catch (Exception e) {}
}
return bitmap;
}


// private void saveBitmap() {
// FileOutputStream outStream = new FileOutputStream(localFile);
// InputStream inputStream = conn.getInputStream();
// byte[] buffer = new byte[1024];
// int len = 0;
// while( (len = inputStream.read(buffer)) != -1){
// outStream.write(buffer, 0, len);
// }
// inputStream.close();
// outStream.close();
// }
/**
* 写图片文件
* 在Android系统中，文件保存在 /data/data/PACKAGE_NAME/files 目录下
* @throws IOException 
*/
public static void saveImage(String fileName, Bitmap bitmap) throws IOException 
{ 
saveImage(fileName, bitmap, 100);
}
public static void saveImage(String fileName, Bitmap bitmap, int quality) throws IOException 
{ 
if(bitmap==null || fileName==null) return;
// 保存的文件路径
File file = new File(SAVE_PATH+fileName);
FileOutputStream fos = new FileOutputStream(file);
ByteArrayOutputStream stream = new ByteArrayOutputStream();
bitmap.compress(CompressFormat.JPEG, quality, stream);
byte[] bytes = stream.toByteArray();
fos.write(bytes);
fos.close();
}
}