java根据URL下载图片。如果URL中有中文,会报错

Question

public void download(String urlString, String filename) throws Exception{
// 构造URL
URL url = new URL(urlString);
// 打开连接
URLConnection con = url.openConnection();
// 输入流
InputStream is = con.getInputStream();
// 1K的数据缓冲
byte[] bs = new byte[1024];
// 读取到的数据长度
int len;
// 输出的文件流
OutputStream os = new FileOutputStream(filename);
// 开始读取
while ((len = is.read(bs)) != -1) {
os.write(bs, 0, len);
}
// 完毕，关闭所有链接
os.close();
is.close();
}

Answer 1

异常：
java.io.IOException: Server returned HTTP response code: 400 for URL