README.md

Compiler Plugin SPI

Thrifty exposes a post-processing interface here called TypeProcessor. Using the standard Java SPI, you can modify the classes generated from Thrift IDL by implementing this interface and making it available in the compiler's classpath.

Example

Thrifty generated classes are not Serializable by default. If you wanted to change that, you could modify the compiler - or, you could implement a TypeProcessor to do it for you, much more easily:

public class SerializableTypeProcessor implements TypeProcessor {
    @Override
    public TypeSpec process(TypeSpec type) {
        TypeSpec.Builder builder = type.toBuilder();

        builder.addSuperinterface(Serializable.class);
        builder.addField(FieldSpec.builder(long.class, "serialVersionUID")
                .addModifiers(Modifier.PRIVATE, Modifier.STATIC, Modifier.FINAL)
                .initializer("$L", -1)
                .build());

        return builder.build();
    }
}

Usage

The minimal project to implement this processor looks like the following:

src/

• main/
  • java/
    • com/
      • corp/
        • SerializableTypeProcessor.java
  • resources/
    • META-INF/
      • services/
        • com.microsoft.thrifty.compiler.spi.TypeProcessor

The file under META-INF is how Java services are identified. The file should contain the full name of your processor class, in this example:

com.corp.SerializableTypeProcessor

Once this project is built into a JAR, you can include it in the classpath on the command line like so:

java -cp thrifty-compiler.jar:your-processor.jar com.microsoft.thrifty.compiler.ThriftyCompiler # compiler args as usual

This is a little wordy. An easier but less-flexible approach could be to build an uberjar including the compiler along with your processor. See thrifty-example-postprocessor/build.gradle for one way to do it.