java - Serializing/Deserializing a standalone integer using protocol buffers -

up now, i've been using protocol buffers serialize , deserialize objects using code-generated classes.

now attempting serialize , deserialize single 64-bit integer. problem is, i'm getting different results in java , c#.

here's how i'm doing in java....

private static byte[] convertlongtobytearray(long value) throws ioexception {     int size = codedoutputstream.computeint64sizenotag(value);     byte[] buffer = new byte[size];     codedoutputstream codedoutputstream = codedoutputstream.newinstance(buffer);     codedoutputstream.writeint64notag(value);     codedoutputstream.flush();     codedoutputstream.checknospaceleft();     return buffer; } 

and here's how i'm doing in c#, using protobuf.net:

public void serializelongvalue() {     long n = 9876;     byte[] memorybuffer = null;     using (memorystream destination = new memorystream())     {         protobuf.serializer.serialize(destination, n);         destination.flush();         memorybuffer = destination.toarray();     }      using (memorystream source = new memorystream(memorybuffer))     {         long result = protobuf.serializer.deserialize<long>(source);         assert.areequal(n, result);     } } 

the java code converted number 9876 [0x94, 0x4d]

the c# code converted number 9876 [0x08, 0x94, 0x4d]

how do both com.google.protobuf , protobuf.net produce identical outputs?

the protobuf.net method protobuf.serializer.serialize forces field header (field number=1) stream. that's way can perform serialization; method invokes number of internal methods not publicly available.

the solution i'm using change java code include field header.

here new java code.

private static byte[] convertlongtobytearray(long value) throws ioexception {     int size = codedoutputstream.computetagsize(1) + codedoutputstream.computeint64sizenotag(value);     byte[] buffer = new byte[size];     codedoutputstream codedoutputstream = codedoutputstream.newinstance(buffer);     codedoutputstream.writeint64(1, value);     codedoutputstream.flush();     codedoutputstream.checknospaceleft();     return buffer; }  public static long convertbytearraytolong(byte[] bytearray) throws ioexception {     codedinputstream codedinputstream = codedinputstream.newinstance(bytearray);     codedinputstream.readtag();     return codedinputstream.readint64(); } 

the changes i've made are:

• when computing required buffer size, include tag size
• instead of codedoutputstream.writeint64notag, call codedoutputstream.writeint64
• when reading back, call codedoutputstream.readtag before calling codedoutputstream.readint64