Avrohugger Maven Plugin

October 3, 2021 · View on GitHub

Maven plugin for generating Scala case classes and ADTs from Apache Avro schemas, datafiles, and protocols.

Usage

The plugin currently supports one goal:

generate-scala-sources: This generates the Scala sources for the Avro schema

<plugin>
    <groupId>at.makubi.maven.plugin</groupId>
    <artifactId>avrohugger-maven-plugin</artifactId>
    <version>1.7</version>
    <executions>
        <execution>
            <phase>generate-sources</phase>
            <goals>
                <goal>generate-scala-sources</goal>
            </goals>
        </execution>
    </executions>
</plugin>

Usage in conjunction with the scala-maven-plugin

This plugin can be used in conjunction with the scala-maven-plugin to add the generated Scala sources to your Scala build.

<plugins>
    <plugin>
        <groupId>at.makubi.maven.plugin</groupId>
        <artifactId>avrohugger-maven-plugin</artifactId>
        <executions>
            <execution>
                <phase>generate-sources</phase>
                <goals>
                    <goal>generate-scala-sources</goal>
                </goals>
            </execution>
        </executions>
    </plugin>

    <plugin>
        <groupId>net.alchim31.maven</groupId>
        <artifactId>scala-maven-plugin</artifactId>
        <executions>
            <execution>
                <id>add-generated-sources</id>
                <phase>generate-sources</phase>
                <goals>
                    <goal>add-source</goal>
                </goals>
                <configuration>
                    <sourceDir>${project.build.directory}/generated-sources/avro</sourceDir>
                </configuration>
            </execution>
            <execution>
                <goals>
                    <goal>compile</goal>
                    <goal>testCompile</goal>
                </goals>
            </execution>
        </executions>
        ...
    </plugin>
</plugins>

Override variables

You can override the following variables in the plugin configuration:

sourceDirectory

Path to the directory containing the Avro schema files
Defaults to ${basedir}/src/main/avro

outputDirectory

Path to the output directory for the generated Scala sources
Defaults to ${project.build.directory}/generated-sources/avro

recursive

Boolean to allow recursion over the specified sourceDirectory
Defaults to false

limitedNumberOfFieldsInCaseClasses

Boolean to restrict case class generation for compatibility with scala 2.10
Defaults to false

sourceGenerationFormat

Format for source code generation
Possible values are SCAVRO, SPECIFIC_RECORD and STANDARD
Defaults to SPECIFIC_RECORD

namespaceMapping

Map namespace in Avro files to custom package name in generated scala files
Defaults to Empty List (Namespace is not modified)

fileIncludes

List of paths to be included in generation
fileInclude elements consist of
- path: The path to be included
- matchSyntax: STRING, GLOB or REGEX
Paths are relative to the sourceDirectory
An empty list is overwritten with the default setting
For GLOB see https://docs.oracle.com/javase/7/docs/api/java/nio/file/FileSystem.html#getPathMatcher(java.lang.String)
Defaults to FileInclude("**", GLOB) which includes all files

typeOverrides

Override for types for generation
Possible elements
- Complex
  - arrayType
  - enumType
  - fixedType
  - mapType
  - protocolType
  - recordType
  - unionType
- Primitive
  - booleanType
  - bytesType
  - doubleType
  - floatType
  - intType
  - longType
  - nullType
  - stringType
- Logical
  - timestampMillisType - possible values are JavaTimeInstant or JavaSqlTimestamp
Defaults to no overrides

Example

To override the sourceDirectory and outputDirectory, use

<plugins>
    <plugin>
        <groupId>at.makubi.maven.plugin</groupId>
        <artifactId>avrohugger-maven-plugin</artifactId>
        <executions>
            <execution>
                <phase>generate-sources</phase>
                <goals>
                    <goal>generate-scala-sources</goal>
                </goals>
            </execution>
        </executions>
        <configuration>
            <sourceDirectory>src/main/resources/avro</sourceDirectory>
            <outputDirectory>target/generated-sources</outputDirectory>
        </configuration>
    </plugin>
</plugins>

To override the sourceDirectory, outputDirectory, recurse over sourceDirectory, and restrict generated class fields to be compatible with Scala 2.10 use

<plugins>
    <plugin>
        <groupId>at.makubi.maven.plugin</groupId>
        <artifactId>avrohugger-maven-plugin</artifactId>
        <executions>
            <execution>
                <phase>generate-sources</phase>
                <goals>
                    <goal>generate-scala-sources</goal>
                </goals>
            </execution>
        </executions>
        <configuration>
            <sourceDirectory>src/main/resources/avro</sourceDirectory>
            <outputDirectory>target/generated-sources</outputDirectory>
            <recursive>true</recursive>
            <limitedNumberOfFieldsInCaseClasses>true</limitedNumberOfFieldsInCaseClasses>>
        </configuration>
    </plugin>
</plugins>

To override the namespaceMapping of Avro protocols under the com.example.packagename namespace to com.example.packagenamechanged and include all files in a subdirectory and its subdirectories named subdir, use

<plugins>
    <plugin>
        <groupId>at.makubi.maven.plugin</groupId>
        <artifactId>avrohugger-maven-plugin</artifactId>
        <executions>
            <execution>
                <phase>generate-sources</phase>
                <goals>
                    <goal>generate-scala-sources</goal>
                </goals>
            </execution>
        </executions>
        <configuration>
            <namespaceMapping>
                <mapping>
                    <from>com.example.packagename</from>
                    <to>com.example.packagenamenew.subchange</to>
                </mapping>
            </namespaceMapping>
            <fileIncludes>
                <fileInclude>
                    <path>subdir/**</path>
                    <matchSyntax>GLOB</matchSyntax>
                </fileInclude>
            </fileIncludes>
        </configuration>
    </plugin>
</plugins>