将网络图片转化成base64格式

只需要传url即可

private static String strNetImageToBase64;
	private String NetImageToBase64(String netImagePath) {
		final ByteArrayOutputStream data = new ByteArrayOutputStream();
		String s = null;
		try {
			// 创建URL
			URL url = new URL(netImagePath);
			final byte[] by = new byte[1024];
			// 创建链接
			final HttpURLConnection conn = (HttpURLConnection) url.openConnection();
			conn.setRequestMethod("GET");
			conn.setConnectTimeout(5000);

			new Thread(new Runnable() {
				@Override
				public void run() {
					try {
						InputStream is = conn.getInputStream();
						// 将内容读取内存中
						int len = -1;
						while ((len = is.read(by)) != -1) {
							data.write(by, 0, len);
						}
						// 对字节数组Base64编码
						BASE64Encoder encoder = new BASE64Encoder();
						strNetImageToBase64 = encoder.encode(data.toByteArray());
						// 关闭流
						is.close();
					} catch (IOException e) {
						e.printStackTrace();
					}
				}
			}).start();

		} catch (IOException e) {
			e.printStackTrace();
		}
		return strNetImageToBase64;
	}