Hi,
I've tried the quickstart tutorial and run into a small problem. When I
tried to modified the mail.apvr to allow null parameter and null value in
Message object,
{
"namespace": "example.proto",
"protocol": "Mail",
"types": [
{"name": "Message", "type": "record",
"fields": [
{"name": "to", "type": "string"},
{"name": "from", "type": "string"},
{"name": "body", "type": ["string", "null"]}
]
}
],
"messages": {
"send": {
"request": [{"name": "message", "type": ["Message", "null"]}],
"response": "string"
},
"receive": {
"request": [{"name": "query", "type": ["string", "null"]}],
"response": ["null", "Message"]
}
}
}
public class Main {
public static class MailImpl implements Mail {
// in this simple example just return details of the message
public Utf8 send(Message message) {
return new Utf8("Sent message to " + message.to.toString() + "
from "+ message.
from.toString() + " with body " + message.body);
}
public Message receive(Utf8 query) throws AvroRemoteException {
Message message = new Message();
message.to = new Utf8("user");
message.from = new Utf8("user");
//message.body = new Utf8("Hello Tuan");
return message;
}
}
public static void main(String[] args) throws Exception {
SocketServer server =
new SocketServer(new SpecificResponder(Mail.class, new MailImpl()),
new InetSocketAddress(0));
// client code - attach to the server and send a message
SocketTransceiver client = new
SocketTransceiver(newInetSocketAddress(server.getPort()));
SpecificRequestor requestor = new SpecificRequestor(Mail.class, client);
Mail proxy = (Mail) SpecificRequestor.getClient(Mail.class, requestor);
// fill in the Message record and send it
Message message = new Message();
message.to = new Utf8("tuan");
message.from = new Utf8("tuan");
message.body = new Utf8("Hello Tuan");
System.out.println("Send Result: " + proxy.send(null));
System.out.println("Receive Result: " + proxy.receive(new Utf8("query"
)));
// cleanup
client.close();
server.close();
System.out.println("Exist!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!");
}
}
I got the following exceptions when I tried to passed the null parrameter to
the receive method and return a message with the null body.
Exception in thread "Connection to /192.168.1.200:64182"
java.lang.NullPointerException
at
org.apache.avro.specific.SpecificDatumWriter.getField(SpecificDatumWriter.java:36)
at
org.apache.avro.generic.GenericDatumWriter.writeRecord(GenericDatumWriter.java:90)
at
org.apache.avro.generic.GenericDatumWriter.write(GenericDatumWriter.java:62)
at
org.apache.avro.generic.GenericDatumWriter.write(GenericDatumWriter.java:55)
at
org.apache.avro.reflect.ReflectResponder.writeResponse(ReflectResponder.java:69)
at org.apache.avro.ipc.Responder.respond(Responder.java:135)
at
org.apache.avro.ipc.SocketServer$Connection.run(SocketServer.java:91)
at java.lang.Thread.run(Thread.java:637)
java.lang.NullPointerException
at
org.apache.avro.io.BinaryEncoder.writeString(BinaryEncoder.java:131)
at
org.apache.avro.generic.GenericDatumWriter.writeString(GenericDatumWriter.java:171)
at
org.apache.avro.generic.GenericDatumWriter.write(GenericDatumWriter.java:72)
at
org.apache.avro.generic.GenericDatumWriter.write(GenericDatumWriter.java:55)
at
org.apache.avro.reflect.ReflectRequestor.writeRequest(ReflectRequestor.java:78)
at org.apache.avro.ipc.Requestor.request(Requestor.java:107)
at
org.apache.avro.reflect.ReflectRequestor.invoke(ReflectRequestor.java:62)
at $Proxy5.querySingle(Unknown Source)
I also try to to serialize/deserialize the Message object with the
SecificDatumWriter and there is no exception. Do I miss any thing here?
Thank for your help.
Tuan Nguyen!
