使用demo下载自己配置的服务器上的文件，提示SignatureDoesNotMatch

求助啊我现在是要测试从我们的地址中下载一个文件，我们的实际文件存放路径是  bucket.endpoint/访问用户的id/jay.jpg


OSSCredentialProvider credetialProvider = new OSSFederationCredentialProvider() {
            @Override
            public OSSFederationToken getFederationToken() {
                try {
                    String ak = accessKeyId;
                    String sk = accessKeySecret;
                    String token = accessToken;
                    String expiration = time[size=; font-size: 14pt,14pt] ;
                    return new OSSFederationToken(ak , sk , token , expiration) ;
                 } catch (Exception e) {
                    e.printStackTrace() ;
                 }
                 return null;
             }
        } ;



download.setOnClickListener( new View.OnClickListener() {
     @Override
     public void onClick(View v) {
         new Thread( new Runnable() {
             @Override
             public void run() {
                 new GetObjectSamples( oss , testBucket , downloadObject).asyncGetObjectSample() ;
            }
        }).start() ;
    }
}) ;
这里的downloadObject = "/访问用户的id/jay.jpg"
就报这个错误
E/ErrorCode: SignatureDoesNotMatch
12-09 15:49:47.012 8150-9000/com.alibaba.sdk.android.oss.app E/RequestId: 5667DD180C0F571621A1B688
12-09 15:49:47.012 8150-9000/com.alibaba.sdk.android.oss.app E/HostId: healthd-pic-store.oss-cn-beijing.aliyuncs.com
12-09 15:49:47.012 8150-9000/com.alibaba.sdk.android.oss.app E/RawMessage: <?xml version="1.0" encoding="UTF-8"?>
12-09 15:49:47.012 8150-9000/com.alibaba.sdk.android.oss.app E/RawMessage: <Error>
12-09 15:49:47.012 8150-9000/com.alibaba.sdk.android.oss.app E/RawMessage:   <Code>SignatureDoesNotMatch</Code>
12-09 15:49:47.012 8150-9000/com.alibaba.sdk.android.oss.app E/RawMessage:   <Message>The request signature we calculated does not match the signature you provided. Check your key and signing method.</Message>
12-09 15:49:47.012 8150-9000/com.alibaba.sdk.android.oss.app E/RawMessage:   <RequestId>5667DD180C0F571621A1B688</RequestId>
12-09 15:49:47.012 8150-9000/com.alibaba.sdk.android.oss.app E/RawMessage:   <HostId>healthd-pic-store.oss-cn-beijing.aliyuncs.com</HostId>
12-09 15:49:47.012 8150-9000/com.alibaba.sdk.android.oss.app E/RawMessage:   <OSSAccessKeyId>已省略</OSSAccessKeyId>
12-09 15:49:47.012 8150-9000/com.alibaba.sdk.android.oss.app E/RawMessage:   <SignatureProvided>y/bYh+AYpo7pa12VsBunJk/Mh7s=</SignatureProvided>
12-09 15:49:47.012 8150-9000/com.alibaba.sdk.android.oss.app E/RawMessage:   <StringToSign>GET

将downloadObject修改成“97/jay.jpg”时，就返回

com.alibaba.sdk.android.oss.app E/ErrorCode: AccessDenied
12-09 16:40:14.235 17338-17505/com.alibaba.sdk.android.oss.app E/RequestId: 5667E8EFA9929D396CD40026
12-09 16:40:14.235 17338-17505/com.alibaba.sdk.android.oss.app E/HostId: healthd-pic-store.oss-cn-beijing.aliyuncs.com
12-09 16:40:14.236 17338-17505/com.alibaba.sdk.android.oss.app E/RawMessage: <?xml version="1.0" encoding="UTF-8"?>
12-09 16:40:14.236 17338-17505/com.alibaba.sdk.android.oss.app E/RawMessage: <Error>
12-09 16:40:14.236 17338-17505/com.alibaba.sdk.android.oss.app E/RawMessage:   <Code>AccessDenied</Code>
12-09 16:40:14.236 17338-17505/com.alibaba.sdk.android.oss.app E/RawMessage:   <Message>Access denied by authorizer's policy.</Message>
12-09 16:40:14.236 17338-17505/com.alibaba.sdk.android.oss.app E/RawMessage:   <RequestId>5667E8EFA9929D396CD40026</RequestId>
12-09 16:40:14.236 17338-17505/com.alibaba.sdk.android.oss.app E/RawMessage:   <HostId>healthd-pic-store.oss-cn-beijing.aliyuncs.com</HostId>
12-09 16:40:14.236 17338-17505/com.alibaba.sdk.android.oss.app E/RawMessage: </Error>


这到底是什么原因啊