在公司需要一个线程池来管理图片的下载请各位帮忙 能提供例子是最好的
/**
@version 1.0
*/
public class ThreadPoolManager {
protected static Logger log = LoggerFactory
.getLogger(ThreadPoolManager.class);
private static ThreadPoolManager tpm = new ThreadPoolManager();
// 线程池维护线程的最少数量
private final static int CORE_POOL_SIZE = 4;
// 线程池维护线程的最大数量
private final static int MAX_POOL_SIZE = 10;
// 线程池维护线程所允许的空闲时间
private final static int KEEP_ALIVE_TIME = 0;
// 线程池所使用的缓冲队列大小
private final static int WORK_QUEUE_SIZE = 10;
// 图片缓冲队列
private Queue msgQueue = new LinkedList();
// 访问消息缓存的调度线程
final Runnable accessBufferThread = new Runnable() {
public void run() {
// 查看是否有待定请求，如果有，则创建一个新的Thread，并添加到线程池中
if (hasMoreAcquire()) {
ImageDO image = (ImageDO) msgQueue.poll();
Runnable task = new UploadThread(image);
threadPool.execute(task);
}
if (hasImagesInDB()) {
try {
BeanFactoryService beanFactory = (BeanFactoryService) BizServiceManager
.getInstance().getService(
BeanFactoryService.SERVICE_NAME);
ImageManager imageManager = (ImageManager) beanFactory
.getBean("imageManager");
List<ImageDO> images = imageManager
.getImages(ImageDO.STATE_READY);
for (int i = 0; i < images.size(); i++) {
ImageDO img = images.get(i);
img.setState(ImageDO.STATE_RUNNING);
img.setModifiedCount(img.getModifiedCount() + 1);
img.setLastModified(CalendarUtil.getCurrentDate()
.getTime());
imageManager.updateImage(img);
Runnable task = new UploadThread(img);
threadPool.execute(task);
}
} catch (Exception e) {
log.error("获取下载图片队列失败", e);
}
}
}
};
// 用于被拒绝任务的处理程序
final RejectedExecutionHandler handler = new RejectedExecutionHandler() {
public void rejectedExecution(Runnable r, ThreadPoolExecutor executor) {
log.error(((UploadThread) r).getImg() + " 放入队列中重新等待执行");
msgQueue.offer(((UploadThread) r).getImg());
}
};
// 管理数据库访问的线程池
final ThreadPoolExecutor threadPool = new ThreadPoolExecutor(
CORE_POOL_SIZE, MAX_POOL_SIZE, KEEP_ALIVE_TIME, TimeUnit.SECONDS,
new ArrayBlockingQueue(WORK_QUEUE_SIZE), this.handler);
// 调度线程池
final ScheduledExecutorService scheduler = Executors
.newScheduledThreadPool(1);
final ScheduledFuture taskHandler = scheduler.scheduleAtFixedRate(
accessBufferThread, 0, 5, TimeUnit.SECONDS);
public static ThreadPoolManager newInstance() {
return tpm;
}
private ThreadPoolManager() {
}
private boolean hasMoreAcquire() {
return !msgQueue.isEmpty();
}
private boolean hasImagesInDB() {
boolean result = false;
try {
BeanFactoryService beanFactory = (BeanFactoryService) BizServiceManager
.getInstance().getService(BeanFactoryService.SERVICE_NAME);
if (beanFactory == null)
return false;
ImageManager imageManager = (ImageManager) beanFactory
.getBean("imageManager");
if (imageManager == null)
return false;
int imagesCount = imageManager.getImagesCount(ImageDO.STATE_READY);
result = (imagesCount != 0);
} catch (Exception e) {
log.error("获取下载图片队列失败", e);
}
return result;
}
public void processImg(ImageDO img) {
Runnable task = new UploadThread(img);
threadPool.execute(task);
}
public long getCompleteTasksCount() {
return this.threadPool.getCompletedTaskCount();
}
public long getActiveTasksCount() {
return this.threadPool.getActiveCount();
}
public long getAllTasksCount() {
return this.threadPool.getTaskCount();
}
public long getQuequeCount() {
return this.msgQueue.size();
}
public boolean getRunningStatus() {
return !(this.threadPool.isShutdown());
}
public long getScheduledQuequeSize() {
return ((ScheduledThreadPoolExecutor)this.scheduler).getQueue().size();
}
}
public class UploadThread implements Runnable {
private ImageDO img;
protected Logger log = LoggerFactory.getLogger(UploadThread.class);
public ImageDO getImg() {
return img;
}
public void setImg(ImageDO img) {
this.img = img;
}
public UploadThread() {
super();
}
public UploadThread(ImageDO img) {
this.img = img;
}
public void run() {
BeanFactoryService beanFactory = (BeanFactoryService) BizServiceManager
.getInstance().getService(BeanFactoryService.SERVICE_NAME);
ImageManager imageManager = (ImageManager) beanFactory
.getBean("imageManager");
if (UploadUtil.upload(img)) {
try {
log.debug("下載圖片成功:"+ img);
imageManager.deleteImageByid(img.getId());
} catch (ManagerException e) {
log.error("删除图片记录失败:"+ img.getId(), e);
}
} else {
img.setState(ImageDO.STATE_FAIL);
try {
imageManager.updateImage(img);
} catch (ManagerException e) {
log.error("设置图片下载状态失败:"+ img.getId(), e);
}
}
}
}
public class UploadUtil {
private static Logger logger = Logger.getLogger(UploadUtil.class);
private static FileStorage attachmentFileStorage;
private static String imgServer;
/**
* @param imgServer
* the imgServer to set
*/
public void setImgServer(String imgServer) {
UploadUtil.imgServer = imgServer;
}
public static String getUrlPrefix() {
return imgServer;
}
public static boolean upload(ImageDO image) {
String url = image.getWsrc();
try {
// yahoo相册的图片链接如果被处理过，需要替换&为&
if (url.toLowerCase().indexOf("yahoo") != -1
&& url.toLowerCase().indexOf("&") != -1) {
url = url.replaceAll("&", "&");
}
HttpMethod httpMethod = getHttpMethod(url);
ByteArrayDataSource ds = new ByteArrayDataSource(httpMethod
.getResponseBodyAsStream(), "image/jpeg");
ds.setName("upload.jpg");
boolean result = attachmentFileStorage.save(ds, image.getLsrc());
httpMethod.releaseConnection();
return result;
} catch (Exception e) {
logger.error("upload image fail:" + url, e);
}
return false;
}
private static HttpMethod getHttpMethod(String url) throws IOException {
HttpMethod httpMethod = new GetMethod(url);
httpMethod.setRequestHeader("Cache-Control", "no-cache");
httpMethod.setRequestHeader("Accept-Language", "zh-cn");
HttpClient clientTemp = new HttpClient(); // HttpClient创建
HttpClientParams clientParams = clientTemp.getParams();
clientParams.setParameter("http.socket.timeout", 5000); // 5秒socket等待数据
clientParams.setParameter("http.connection.timeout", 5000); // 5秒http
// connection建立超时
clientParams.setParameter("http.connection-manager.timeout", 5000L); // 5秒从http
// yahoo相册的图片需要设置Referer头
if (url.toLowerCase().indexOf("yahoo") != -1) {
httpMethod.addRequestHeader("Referer", "http://forum.taobao.com/");
}
// connection
// manager获取可用的Http
// connection超时
clientParams.setParameter("http.method.retry-handler",
new DefaultHttpMethodRetryHandler()); // 如果Http出错，三次重试
clientTemp.executeMethod(httpMethod);
return httpMethod;
}
public void setAttachmentFileStorage(FileStorage attachmentFileStorage) {
UploadUtil.attachmentFileStorage = attachmentFileStorage;
}
public static void main(String[] args) throws Exception {
HttpMethod httpMethod = getHttpMethod("http://cn.photos.yahoo.com/users/47df51c0z8a48b60a/255c/__sr_/dbce.jpg?wa86dTAyD7Rq05sklm3fMQ--&F18");
InputStream inputStream = httpMethod.getResponseBodyAsStream();
FileOutputStream os = new FileOutputStream("c:/test.jpg");
IOUtils.copy(inputStream, os);
os.close();
httpMethod.releaseConnection();
}
}