Sometimes one needs to derive a Google Protocol Buffers schema from an XML schema .. e.g. from an Enterprise Architect Export.

Tool used here: schema2proto (GitLab project)

Steps

  1. Download schema2proto-lib from the global Maven repository: https://search.maven.org/search?q=schema2proto

  2. Run Schema2Proto against a give XSD schema file and with a given output directory:

java -jar schema2proto-lib-1.53.jar Schema2Proto --outputDirectory=src/main/protobuf input.xsd

A yaml config file may be given instead of cli parameters:

java -jar schema2proto-lib-1.53.jar Schema2Proto ----configFile=config.yaml input.xsd

A sample config can be found here

Using as a Maven plugin is also an option and worked for me better:

<plugin>
        <groupId>no.entur</groupId>
        <artifactId>schema2proto-maven-plugin</artifactId>
        <version>1.53</version>
        <configuration>
            <configFile>config.yaml</configFile>
            <xsdFile>schema.xsd</xsdFile>
        </configuration>
        <executions>
            <execution>
                <id>generate-resources</id>
                <goals>
                    <goal>generate</goal>
                </goals>
            </execution>
        </executions>
    </plugin>

Alternative

Not maintained and pretty old: https://github.com/tranchis/xsd2thrift

As the download link is dead, we need to clone the sources and build them by ourselves:

  1. Clone https://github.com/tranchis/xsd2thrift

  2. Edit the pom.xml and change the source/target level to 1.7 (when using an environment where source level 6 is not supported any more)

  3. Build with maven package .. that’s it

Now we may generate our protobuf schemata like this:

java xsd2thrift-1.0.jar --protobuf --output=out.proto filename.xsd

Resources