Ian Lewis' Blog

A few days ago Protocol Buffers was released by Google as an open source project. Protocol Buffers is a way to generate code for objects that can be serialized to and de-serialized from the protocol buffers binary format. An implementation of the protocol buffers compiler which reads a "proto" and can output Java, Python, and C++ code. Because the format is a binary format and the compiler can output in several languages, this would allow for fast message passing between applications that may or may not be implemented in the same language.

I went ahead and created two simple Java and Python applications that test protocol buffers by simply creating a simple User object, prompting the user for a nickname and e-mail and then serializing the result. I also added a command to de-serialize the output and show the contents of the reconstituted object.

Here I ran the Java program to write the protocol buffers data to a file and then I run the python program to read it.

ian@laptop:~/src/protocol-buffers-test$ make javawrite
mkdir -p java
protoc --java_out=java/ prototest.proto
javac -classpath "java/:protobuf-java-2.0.0beta.jar" java/test.java java/prototest/Prototest.java
java -cp ".:java/:protobuf-java-2.0.0beta.jar" test write test.out
Nickname: Ian <- this is input
Email: test@test.com <- this is input
土 7月 12 19:09:28
ian@laptop:~/src/protocol-buffers-test$ make javaread
java -cp ".:java/:protobuf-java-2.0.0beta.jar" test read test.out
User
Nickname: Ian <- this is output
Email: test@test.com <- this is output
土 7月 12 19:09:33
ian@laptop:~/src/protocol-buffers-test$

Code available here. Code listing follows.

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