根据url获取文件信息

代码：
String downloadUrl = request.getUrl();//获取文件的原始下载地址
URL url = null;
try {
    url = new URL(request.getUrl());
    try {
        // 忽略所有证书
        HostnameVerifier hv = new HostnameVerifier() {
            public boolean verify(String urlHostName, SSLSession session) {
                logger.warn("Warning: URL Host: " + urlHostName + " vs. " + session.getPeerHost());
                return true;
            }
        };
        trustAllHttpsCertificates();
        HttpsURLConnection.setDefaultHostnameVerifier(hv);
    } catch (Exception e) {

    }
    conn = (HttpURLConnection) url.openConnection();
    conn.setRequestProperty("User-Agent", "Mozilla/4.0 (compatible; MSIE 5.0; Windows NT; DigExt)");
    conn.setConnectTimeout(3 * 1000);
    //获取文件字节流
    InputStream inputStream = conn.getInputStream();    
    //获取文件大小
    long fileSize = (long) conn.getContentLength();
    //获取到byte[]参数
    byte[] getData = readInputStream(inputStream);
}

/**
 * 从输入流中获取字节数组
 */
private byte[] readInputStream(InputStream inputStream) throws IOException {
    byte[] buffer = new byte[1024];
    int len = 0;
    ByteArrayOutputStream bos = new ByteArrayOutputStream();
    while ((len = inputStream.read(buffer)) != -1) {
        bos.write(buffer, 0, len);
    }
    bos.close();
    return bos.toByteArray();
}
/**
* 信任所有证书
*/
private static void trustAllHttpsCertificates() throws Exception {
    javax.net.ssl.TrustManager[] trustAllCerts = new javax.net.ssl.TrustManager[1];
    javax.net.ssl.TrustManager tm = new miTM();
    trustAllCerts[0] = tm;
    javax.net.ssl.SSLContext sc = javax.net.ssl.SSLContext.getInstance("SSL");
    sc.init(null, trustAllCerts, null);
    HttpsURLConnection.setDefaultSSLSocketFactory(sc.getSocketFactory());
}