On Jul 7 2008, Ted Ross wrote:
[EMAIL PROTECTED] wrote:
> Hello Ted/Anybody,
>
> Could you please correct me about the schema request (AM1S) which I am
> sending to broker to get the schema response for particular class?
>
> Could you please let me know what is wrong here. I think schema
> request is not healthy. Please guide me here. I am not receiving the
> schema response with this schema request
>
> Here is the code snippet of Schema request and Schema response.
> // Code snippet for Schema Request (AM1S)
> ....
>
> p.opcode="AM1S";
> p.sequenceNo=500;
> p.packageName="qpid";
> p.classname="vhost";
>
> message.clear();
> try {
> // encode the opcode
> message.put(p.opcode.getBytes("UTF-8"));
> message.putInt( p.sequenceNo);
> // encode the package name
> encoder.writeStr8(p.packageName);
> message.putShort((byte) p.packageName.length());
> message.put(p.packageName.getBytes("UTF-8"));
> // encode the class name
> encoder.writeStr8(p.classname);
> message.putShort((byte) p.classname.length());
> message.put(p.classname.getBytes("UTF-8"));
> // encode the schema hash
> // *** schema has contents which it got from // byte[]
> schemaHash=decoder.readBin128(); something like [EMAIL PROTECTED] ***
>
> encoder.writeBin128(schemaHash);
> message.put((byte) schemaHash.length);
> message.put(schemaHash);
> } catch (UnsupportedEncodingException e) {
> e.printStackTrace();
> }
> ........
> ........
>
> ------
>
> //Start Code snippet Schema Response (AM1s)
>
> String packname = decoder.readStr8();
> System.out.println("Package Name: " + packname);
> String clasnam = decoder.readStr8();
> System.out.println("Class Name: " + clasnam);
>
> // get the decoded schema hash
> decoder.readBin128();
> // get the decoded properties contents
> int propCnt = decoder.readUint16();
> System.out.println("Property content: " + propCnt);
> long statCnt = decoder.readUint16();
> System.out.println("Statistic content: " + statCnt);
> int methodCnt = decoder.readUint16();
> System.out.println("Method content: " + methodCnt);
> int eventCnt = decoder.readUint16();
> System.out.println("Event content: " + eventCnt);
>
> for( int i = 0; i < propCnt; i++ )
> { // decode the MAP
> Map<String,Object> map = decoder.readMap();
> }
>
> for( int i = 0; i < statCnt; i++ )
> {
> // decode the MAP
> Map<String,Object> map = decoder.readMap();
> }
>
> for( int i = 0; i < methodCnt; i++ )
> { // decode the MAP
> Map<String,Object> map = decoder.readMap();
> }
>
> for( int i = 0; i < eventCnt; i++ )
> { // decode the MAP
> Map<String,Object> map = decoder.readMap();
> }
> ---------
> End of the Code
>
> Thank you.
>
> Best Regards,
> Rahul
>
Rahul,
There's a problem with the encoding of the bin128 for the hash value.
If you look at the AMQP 0-10 specification for the proper encoding for a
bin128 value, you will see that it is encoded as 16 octets (no length
field). Your code prepends a one-byte length which causes the value to
be incorrect/unmatched from the viewpoint of the management broker.
In looking at your code fragment, I am unclear as to what "encoder" is
and why you use it. In the following section, you invoke "writeStr8" on
"encoder" but then you manually encode the string into "message".
// encode the package name
encoder.writeStr8(p.packageName);
message.putShort((byte) p.packageName.length());
message.put(p.packageName.getBytes("UTF-8"));
Regards,
-Ted
Hello Ted,
encoder is an instance of AbstractEncoder class under
org.apache.qpidity.transport.codec.Encoder. And thanks for pointing the
duplication.
Yes, you are correct i checked the spec. and it (bin128) is encoded as 16
octets. I added the following method for encoding the 128 bin schema hash
with help of Rafael. so you mean this will not help to encode the schema...
/* public void writeBin128(byte[] s) { if (s == null) { s = new byte[16]; }
else if (s.length != 16) { throw new IllegalArgumentException("" + s); }
put(s);
}
*/
could you please let me know which method can encode this schema or is
there any method in AbstractEncoder which can do this OR How can i encode
this.
Thanks in advance.
BR,
Rahul
