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-异步渲染页面的文字和图片信息

* @author lufang

public abstract class PageRenderer {

private final ExecutorService executor = createExecutorService();

* 渲染页面

* @param source

* 页面源码

public void renderPage(CharSequence source) {

final List<String> imagePaths = scanForImagePaths(source);

Callable<List<ImageData>> task = new Callable<List<ImageData>>() {

public List<ImageData> call() {

List<ImageData> result = new ArrayList<ImageData>();

for (String path : imagePaths)

result.add(downloadImage(path));

return result;

Future<List<ImageData>> future = executor.submit(task);

renderText(source);

try {

List<ImageData> imageData = future.get();

for (ImageData data : imageData)

renderImage(data);

} catch (InterruptedException e) {

// 因为在得到这个异常的同时,线程的中断状态已经被清除了,需要保留线程的中断状态,则需要调用Thread.currentThread().interrupt()

Thread.currentThread().interrupt();

// 取消任务

future.cancel(true);

} catch (ExecutionException e) {

launderThrowable(e.getCause());

} finally {http://www.huiyi8.com/moban/

afterRender(); 

* 简单的抛出异常, 子类可覆盖并提供自己的实现

* @param cause

* 接收到的异常

* @return Throwable 经检查后的异

protected Throwable launderThrowable(Throwable cause) {

return new Throwable(cause);*

* 渲染结束动作, 默认无操作, 子类可覆盖并提供自己的实现

protected void afterRender() {

// do nothing

* 交由子类决定如何构造线程池

*

* @return ExecutorService 线程池

*/

protected abstract ExecutorService createExecutorService();

* 交由子类决定如何提取图片地址

* @param source

* 页面源码

* @return 图片地址列表

protected abstract List<String> scanForImagePaths(CharSequence source);

* 交由子类决定如何下载文字

* @param source

* 页面源码

protected abstract void renderText(CharSequence source);

* 交由子类决定如何渲染图片

*

* @param data

* 图片信息

protected abstract void renderImage(ImageData data);

* 交由子类决定如何下载图片

* @param path

* 路径

* @return ImageData 图片信息

*/

protected abstract ImageData downloadImage(String path);

* 图片基本信息

* @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;