根據url地址，下載圖片【IO流】

package com.bonc.wechat.common.util;

import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URL;

/**
 * 根據URL下載圖片到本地指定目錄！
 * 
 * @author Administrator
 * 
 */
public class DownLodeImgsUtil {

	/**
	 * 傳遞圖片的url，將圖片下載在對應的文件中
	 * 
	 * @param urlString
	 *            圖片連接
	 * @param localAdd
	 *            下載到硬盤位置
	 * @param imgname
	 *            下載的圖片重命名名字
	 * @author xvk
	 * @throws Exception
	 */

	public static void downloadPhotos(String urlString, String localAdd,
			String imgname) throws Exception {
		File dir = new File(localAdd);
		if (!dir.exists()) {
			dir.mkdirs();
		}
		try {
			File file = new File(localAdd + "/" + imgname);
			OutputStream os = new FileOutputStream(file);
			// 創建一個url對象
			URL url = new URL(urlString);
			InputStream is = url.openStream();
			byte[] buff = new byte[1024];
			while (true) {
				int readed = is.read(buff);
				if (readed == -1) {
					break;
				}
				byte[] temp = new byte[readed];
				System.arraycopy(buff, 0, temp, 0, readed);
				// 寫入文件
				os.write(temp);
			}
			is.close();
			os.close();
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}

@Test
	public void testDownLodeImgsUnit() throws MalformedURLException{
		String imgURL = "https://img.alicdn.com/bao/uploaded/i4/TB1.BpXOFXXXXbzXFXXXXXXXXXX_!!0-item_pic.jpg_430x430q90.jpg";
		String imgname = "aaaaaaaaaa.jpg";
		String localAdd = "D:\\imgs\\";
		try {
			DownLodeImgsUtil.downloadPhotos(imgURL, localAdd, imgname);
		} catch (Exception e) {
			e.printStackTrace();
		}
	}