IMAGEloader
package com.zxsc.cook_dishes_cy.framework.utils;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.graphics.Bitmap;
import android.os.Build;
import android.util.Log;
import android.util.LruCache;
import android.widget.ImageView;
@SuppressLint(“NewApi”)
public class ImageLoader {
/**线程池**/
private ExecutorService mExecutorService;
/**用于缓存图片**/
private LruCache<String, Bitmap> mLrcCache;
public ImageLoader() {
mExecutorService = Executors.newFixedThreadPool(3);
// mLrcCache = new LruCache<String, Bitmap>(maxSize);
initLrcCache();
}
private boolean mIsBusy = false;
public void setmIsBusy(boolean mIsBusy) {
this.mIsBusy = mIsBusy;
}
private void initLrcCache() {
//获取系统分配给每个应用程序的最大内存，每个应用系统分配64M
int maxMemory = (int) Runtime.getRuntime().maxMemory();
log(“maxMemory=”+maxMemory);
// int mCacheSize = maxMemory / 8;
int mCacheSize = 5000 * 1024;
mLrcCache = new LruCache<String, Bitmap>(mCacheSize){
@Override
protected int sizeOf(String key, Bitmap value) {
int size = 0;
if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB_MR1){
size = value.getByteCount();
//3.1版本之后，使用的是这个方法获取bitmap的内存大小
log(“size = ” + size);
return size;
}
//3.1版本之前，使用的是这个方法获取bitmap的内存大小
size = value.getRowBytes() * value.getHeight();
log(“size = ” + size);
return size;
}
};
}
public void displayImg(String imgUrl,ImageView imageView){
imageView.setTag(imgUrl);
log(“进入 displayImg”);
//首先从lrc缓存中获取bitmap
Bitmap bitmap = getBitmapFromCache(imgUrl);
if(bitmap != null){
//直接为ImageView设置Bitmap
showBitmap(imageView, bitmap,imgUrl);
log(“来自lru缓存中”);
return;
}
log(“lru缓存中不存在bitmap，开始从本地获取”);
//向线程池提交线程任务
if(!mIsBusy){
LoadBitmapRunnable runnable = new LoadBitmapRunnable(imageView, imgUrl);
mExecutorService.submit(runnable);
log(“提交一个网络请求”);
}
}
/**
* 加载显示bitmap的线程
* @author Administrator
*
*/
private class LoadBitmapRunnable implements Runnable{
private ImageView imageView;
private String imgUrl;
public LoadBitmapRunnable(ImageView imageView, String imgUrl) {
super();
this.imageView = imageView;
this.imgUrl = imgUrl;
}
@Override
public void run() {
//从本地获取Bitmap
Bitmap bitmap = getBitmapFromLocal(imgUrl);
log(“run–bitmap=”+bitmap);
if(bitmap != null){
//为ImageView显示Bitmap
showBitmap(imageView, bitmap,imgUrl);
log(“来自本地”);
return;
}
log(“本地不存在bitmap，开始从网络获取”);
//从网络获取Bitmap
bitmap = getBitmapFromNetwork(imgUrl);
if(bitmap != null){
//为ImageView显示Bitmap
showBitmap(imageView, bitmap,imgUrl);
log(“来自网络“);
}
}
}
/**
* 为ImageView显示Bitmap
* @param imageView
* @param bitmap
*/
private void showBitmap(ImageView imageView,Bitmap bitmap,String imgUrl){
//防止图片错乱显示
if(!imgUrl.equals(imageView.getTag().toString())){
return;
}
DisplayImgRunnable runnable = new DisplayImgRunnable(imageView, bitmap);
Activity aty = (Activity) imageView.getContext();
aty.runOnUiThread(runnable);
}
class DisplayImgRunnable implements Runnable{
private ImageView imageView;
private Bitmap bitmap;
public DisplayImgRunnable(ImageView imageView, Bitmap bitmap) {
super();
this.imageView = imageView;
this.bitmap = bitmap;
}
@Override
public void run() {
imageView.setImageBitmap(bitmap);
}
}
/**
* 将bitmap放入lrc缓存
* @param bitmap
* @param urlStr
*/
private void addBitmapToCache(Bitmap bitmap,String urlStr){
mLrcCache.put(urlStr, bitmap);
}
/**
* 从lrc缓存中获取bitmap
* @param imgUrl
* @return
*/
private Bitmap getBitmapFromCache(String imgUrl){
return mLrcCache.get(imgUrl);
}
/**
* 从本地获取Bitmap
* @param imgUrl
* @return
*/
public Bitmap getBitmapFromLocal(String imgUrl) {
//TODO
Bitmap bitmap = BitmapUtil.getBitmapFromSDCard(imgUrl);
if(bitmap != null){
addBitmapToCache(bitmap, imgUrl);
}
return bitmap;
}
/**
* 从网络获取Bitmap
* @param imgUrl
* @return
*/
public Bitmap getBitmapFromNetwork(String imgUrl){
Bitmap bitmap = null;
try {
URL url = new URL(imgUrl);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setConnectTimeout(8 * 1000);
conn.setReadTimeout(8 * 1000);
InputStream is = conn.getInputStream();
//将文件保存到本地SD卡
BitmapUtil.saveBitmap(is, imgUrl);
bitmap = BitmapUtil.getBitmapFromSDCard(imgUrl);
//加入lrc缓存
addBitmapToCache(bitmap, imgUrl);
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return bitmap;
}
public void log(Object o){
Log.d(“ImageLoader”, o+””);
}
}
