AlipayClient alipayClient = new DefaultAlipayClient("https://openapi.alipay.com/gateway.do", APP_ID, APP_PRIVATE_KEY, "json", CHARSET, ALIPAY_PUBLIC_KEY, "RSA2");//获得初始化的AlipayClient
AlipayDataDataserviceBillDownloadurlQueryRequest request = new AlipayDataDataserviceBillDownloadurlQueryRequest();//创建API对应的request类
request.setBizContent("{" +
"    \"bill_type\":\"trade\"," +
"    \"bill_date\":\"2016-04-05\"}"); //设置业务参数
AlipayDataDataserviceBillDownloadurlQueryResponse response = alipayClient.execute(request);//通过alipayClient调用API，获得对应的response类
System.out.print(response.getbody());
//根据response中的结果继续业务逻辑处理

//将接口返回的对账单下载地址传入urlStr
String urlStr = "http://dwbillcenter.alipay.com/downloadBillFile.resource?bizType=X&userId=X&fileType=X&bizDates=X&downloadFileName=X&fileId=X";
//指定希望保存的文件路径
String filePath = "/Users/fund_bill_20160405.zip";
URL url = null;
HttpURLConnection httpUrlConnection = null;
InputStream fis = null;
FileOutputStream fos = null;
try {
    url = new URL(urlStr);
    httpUrlConnection = (HttpURLConnection) url.openConnection();
    httpUrlConnection.setConnectTimeout(5 * 1000);
    httpUrlConnection.setDoInput(true);
    httpUrlConnection.setDoOutput(true);
    httpUrlConnection.setUseCaches(false);
    httpUrlConnection.setRequestMethod("GET");
    httpUrlConnection.setRequestProperty("Charsert", "UTF-8");
    httpUrlConnection.connect();
    fis = httpUrlConnection.getInputStream();
    byte[] temp = new byte[1024];
    int b;
    fos = new FileOutputStream(new File(filePath));
    while ((b = fis.read(temp)) != -1) {
        fos.write(temp, 0, b);
        fos.flush();
    }
} catch (MalformedURLException e) {
    e.printStackTrace();
} catch (IOException e) {
    e.printStackTrace();
} finally {
    try {
        if(fis!=null) fis.close();
        if(fos!=null) fos.close();
        if(httpUrlConnection!=null) httpUrlConnection.disconnect();
    } catch (IOException e) {
        e.printStackTrace();
    }
}