https://github.com/FasterXML/jackson-dataformats-binary/issues/87

MessageResolutionTest.java

package com.fasterxml.jackson.dataformat.protobuf.schema;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.ObjectWriter;
import com.fasterxml.jackson.dataformat.protobuf.ProtobufFactory;
import com.fasterxml.jackson.dataformat.protobuf.ProtobufTestBase;

import java.io.IOException;
import java.io.StringReader;


public class MessageResolutionTest extends ProtobufTestBase
{
    static String proto1 =
        "syntax = \"proto2\";\n"
        + "package mypackage;\n"
        + "\n"
        + "message Main {\n"
        + "    required Other o = 1;\n"
        + "}\n"
        + "\n"
        + "message Other {\n"
        + "    required int32 f = 1;\n"
        + "}\n";

    static String proto2 =
        "syntax = \"proto2\";\n"
        + "package mypackage;\n"
        + "\n"
        + "message Other {\n"
        + "    required int32 f = 1;\n"
        + "}\n"
        + "\n"
        + "message Main {\n"
        + "    required Other o = 1;\n"
        + "}\n";

    static class Main
    {
        public Other o;

        protected Main() { }

        public Main(Other o)
        {
            this.o = o;
        }
    }


    static class Other
    {
        public int f;

        protected Other() { }

        public Other(int f)
        {
            this.f = f;
        }
    }

    private final ObjectMapper MAPPER = new ObjectMapper(new ProtobufFactory());

    public void testParsing1() throws Exception
    {
        byte[] bytes = serializeTest(proto1);
        assertNotNull(bytes);
    }

    public void testParsing2() throws Exception
    {
        byte[] bytes = serializeTest(proto2);
        assertNotNull(bytes);
    }

    private byte[] serializeTest(String proto) throws IOException
    {
        // create PB binary from known .proto schema
        ProtobufSchema schema = ProtobufSchemaLoader.std.load(new StringReader(proto));
        System.out.println(schema.toString());
        final ObjectWriter w = MAPPER.writerFor(Main.class).with(schema);
        Other o = new Other(123);
        Main m = new Main(o);
        return w.writeValueAsBytes(m);
    }
}