starters/karaf-boot-starter-blueprint/src/main/java/org/apache/karaf/boot/blueprint/impl/BlueprintProcessor.java

package org.apache.karaf.boot.blueprint.impl;

import java.io.File;
import java.io.IOException;
import java.io.OutputStream;
import java.lang.annotation.Annotation;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.aries.blueprint.annotation.Bean;
import org.apache.karaf.boot.plugin.api.BootPlugin;
import org.apache.karaf.boot.plugin.api.StreamFactory;

public class BlueprintProcessor implements BootPlugin {
    
    @Override
    public Class<? extends Annotation> getAnnotation() {
        return Bean.class;
    }

    @Override
    public Map<String, List<String>> enhance(List<Class<?>> annotated, File generatedDir,
                                             StreamFactory streamFactory) {
        OutputStream beansOS = streamFactory.create(new File (generatedDir, "META-INF/beans.xml"));
        try {
            beansOS.close();
        } catch (IOException e) {
            throw new RuntimeException("Error closing stream", e);
        }
        Map<String, List<String>> headers = new HashMap<>();
        headers.put("Bundle-Blueprint-Annotation", Arrays.asList("true"));
        return headers;
    }

}