签名在REST API中不匹配

Question

我已经使用代码在亚马逊上创建了一个存储桶。我不想使用Amazon SDK，因为它使我的android代码非常繁重，因此尝试编写REST API。

我在这里找到了代码REST API

我使用了真正的密钥。但是我得到了这个错误

403
Error: AccessDenied

SignatureDoesNotMatch. The request signature we calculated does not match the signature you provided. Check your key and signing method.

请帮忙。

代码

  public class Operation {

private javax.crypto.spec.SecretKeySpec signingKey = null;
private javax.crypto.Mac mac = null;
private String keyId = null;

public static void main(String[] args) {
    Operation t = new Operation();
    try {
        t.setKeyId("YourAWSAccessKeyIDHere");
        t.setKey("YourAWSSecretKeyHere");
        t.createBucket();
    } catch (Exception e) {
        e.printStackTrace();
    }
}

public void createBucket() throws Exception
{
    // S3 timestamp pattern.
    String fmt = "EEE, dd MMM yyyy HH:mm:ss ";
    SimpleDateFormat df = new SimpleDateFormat(fmt, Locale.US);
    df.setTimeZone(TimeZone.getTimeZone("GMT"));

    // Data needed for signature
    String method = "PUT";
    String contentMD5 = "";
    String contentType = "";
    String date = df.format(new Date()) + "GMT";
    String bucket = "/onjava";

    // Generate signature
    StringBuffer buf = new StringBuffer();
    buf.append(method).append("\n");
    buf.append(contentMD5).append("\n");
    buf.append(contentType).append("\n");
    buf.append(date).append("\n");
    buf.append(bucket);
    String signature = sign(buf.toString());

    // Connection to s3.amazonaws.com
    HttpURLConnection httpConn = null;
    URL url = new URL("http","s3.amazonaws.com",80,bucket);
    httpConn = (HttpURLConnection) url.openConnection();
    httpConn.setDoInput(true);
    httpConn.setDoOutput(true);
    httpConn.setUseCaches(false);
    httpConn.setDefaultUseCaches(false);
    httpConn.setAllowUserInteraction(true);
    httpConn.setRequestMethod(method);
    httpConn.setRequestProperty("Date", date);
    httpConn.setRequestProperty("Content-Length", "0");
    String AWSAuth = "AWS " + keyId + ":" + signature;
    httpConn.setRequestProperty("Authorization", AWSAuth);
    // Send the HTTP PUT request.
    int statusCode = httpConn.getResponseCode();
    if ((statusCode/100) != 2)
    {
        // Deal with S3 error stream.
        InputStream in = httpConn.getErrorStream();
        String errorStr = getS3ErrorCode(in);
        System.out.println("Error: "+errorStr);
    }
      else
      {
        System.out.println("Bucket created successfully");
      }
   }

  public void setKeyId(String id)
  {
    this.keyId = id;
  }

  // This method converts AWSSecretKey into crypto instance.
  public void setKey(String AWSSecretKey) throws Exception
    {
    mac = Mac.getInstance("HmacSHA1");
    byte[] keyBytes = AWSSecretKey.getBytes("UTF8");
    signingKey = new SecretKeySpec(keyBytes, "HmacSHA1");
    mac.init(signingKey);
  }

// This method creates S3 signature for a given String.
  public String sign(String data) throws Exception
  {
  // Signed String must be BASE64 encoded.
  byte[] signBytes = mac.doFinal(data.getBytes("UTF8"));
  String signature = encodeBase64(signBytes);
  return signature;
  }

  public String encodeBase64(byte[] data)
  {
    String base64 =  new sun.misc.BASE64Encoder().encodeBuffer(data);
    if (base64.endsWith("\r\n")) base64 = base64.substring(0,base64.length()-2);
    return base64;
  }

  public String getS3ErrorCode(InputStream doc) throws Exception
  {
    String code = null;
    SAXParserFactory parserfactory = SAXParserFactory.newInstance();
    parserfactory.setNamespaceAware(false);
    parserfactory.setValidating(false);
    SAXParser xmlparser = parserfactory.newSAXParser();
    S3ErrorHandler handler = new S3ErrorHandler();
    xmlparser.parse(doc, handler);
    code = handler.getErrorCode();
    return code;
  }

// This inner class implements a SAX handler.
class S3ErrorHandler extends DefaultHandler
{
    private StringBuffer code = new StringBuffer();
    private boolean append = false;

    public void startElement(String uri, String ln, String qn, Attributes atts)
    {
        if (qn.equalsIgnoreCase("Code")) append = true;
    }

    public void endElement(String url, String ln, String qn)
    {
        if (qn.equalsIgnoreCase("Code")) append = false;
    }

    public void characters(char[] ch, int s, int length)
    {
        if (append) code.append(new String(ch, s, length));
    }

    public String getErrorCode()
    {
        return code.toString();
    }


 }