java 通过url取得文件返回InputStream类型数据的工具类

/**
 * 通过url取得文件返回InputStream类型数据
 * @author gugf
 *
 */
public class HttpUtils {

	/**
	 * 通过图片url返回图片Bitmap
	 * @param url
	 * @return
	 */
	public static InputStream returnBitMap(String path) {
		URL url = null;
		InputStream is =null;
		try {
			url = new URL(path);
		} catch (MalformedURLException e) {
			e.printStackTrace();
		}
		try {
			HttpURLConnection conn = (HttpURLConnection) url.openConnection();//利用HttpURLConnection对象,我们可以从网络中获取网页数据.
			conn.setDoInput(true);
			conn.connect();
			is = conn.getInputStream();	//得到网络返回的输入流
			
		} catch (IOException e) {
			e.printStackTrace();
		}
		return is;
	}
}

在android的4.0中会报异常，在主线程中加入以下代码可解决

		StrictMode.setThreadPolicy(new StrictMode.ThreadPolicy.Builder()
				.detectDiskReads().detectDiskWrites().detectNetwork() 
				.penaltyLog().build());
		StrictMode.setVmPolicy(new StrictMode.VmPolicy.Builder()
				.detectLeakedSqlLiteObjects().penaltyLog().penaltyDeath()
				.build());