import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Future;
* 示例-異步渲染頁面的文字和圖檔資訊
* @author lufang
public abstract class PageRenderer {
private final ExecutorService executor = createExecutorService();
* 渲染頁面
* @param source
* 頁面源碼
public void renderPage(CharSequence source) {
final List<String> p_w_picpathPaths = scanForImagePaths(source);
Callable<List<ImageData>> task = new Callable<List<ImageData>>() {
public List<ImageData> call() {
List<ImageData> result = new ArrayList<ImageData>();
for (String path : p_w_picpathPaths)
result.add(downloadImage(path));
return result;
Future<List<ImageData>> future = executor.submit(task);
renderText(source);
try {
List<ImageData> p_w_picpathData = future.get();
for (ImageData data : p_w_picpathData)
renderImage(data);
} catch (InterruptedException e) {
// 因為在得到這個異常的同時,線程的中斷狀态已經被清除了,需要保留線程的中斷狀态,則需要調用Thread.currentThread().interrupt()
Thread.currentThread().interrupt();
// 取消任務
future.cancel(true);
} catch (ExecutionException e) {
launderThrowable(e.getCause());
} finally {http://www.huiyi8.com/moban/ 模闆
afterRender()
* 簡單的抛出異常, 子類可覆寫并提供自己的實作
* @param cause
* 接收到的異常
* @return Throwable 經檢查後的異
protected Throwable launderThrowable(Throwable cause) {
return new Throwable(cause);*
* 渲染結束動作, 預設無操作, 子類可覆寫并提供自己的實作
protected void afterRender() {
// do nothing
* 交由子類決定如何構造線程池
*
* @return ExecutorService 線程池
*/
protected abstract ExecutorService createExecutorService();
* 交由子類決定如何提取圖檔位址
* @return 圖檔位址清單
protected abstract List<String> scanForImagePaths(CharSequence source);
* 交由子類決定如何下載下傳文字
protected abstract void renderText(CharSequence source);
* 交由子類決定如何渲染圖檔
* @param data
* 圖檔資訊
protected abstract void renderImage(ImageData data);
* 交由子類決定如何下載下傳圖檔
* @param path
* 路徑
* @return ImageData 圖檔資訊
protected abstract ImageData downloadImage(String path);
* 圖檔基本資訊
* @author lufang
public static class ImageData {
private long height;
private long width;
private String uri;
public long getHeight() {
return height;
public void setHeight(long height) {
this.height = height;
public long getWidth() {
return width;
public void setWidth(long width) {
public String getUri() {
return uri;
public void setUri(String uri) {
this.uri = uri;