GeneralTypeListener.java

package ru.vyarus.guice.ext.core.type;

import com.google.inject.TypeLiteral;
import com.google.inject.spi.InjectionListener;
import com.google.inject.spi.TypeEncounter;
import com.google.inject.spi.TypeListener;
import ru.vyarus.guice.ext.core.util.Utils;

/**
 * Generic type listener for bean types (exact class, by base class or beans annotating interface).
 *
 * @param <T> bean type
 * @author Vyacheslav Rusakov
 * @since 30.06.2014
 */
public class GeneralTypeListener<T> implements TypeListener {

    private final Class<T> typeClass;
    private final TypePostProcessor<T> postProcessor;

    public GeneralTypeListener(final Class<T> typeClass, final TypePostProcessor<T> postProcessor) {
        this.typeClass = typeClass;
        this.postProcessor = postProcessor;
    }

    @Override
    @SuppressWarnings("unchecked")
    public <I> void hear(final TypeLiteral<I> type, final TypeEncounter<I> encounter) {
        final Class<? super I> actualType = type.getRawType();
        if (!Utils.isPackageValid(actualType)) {
            return;
        }
        if (typeClass.isAssignableFrom(actualType)) {
            encounter.register(new InjectionListener<I>() {
                @Override
                public void afterInjection(final I injectee) {
                    try {
                        postProcessor.process((T) injectee);
                    } catch (Exception ex) {
                        throw new IllegalStateException(
                                String.format("Failed to process type %s of class %s",
                                        typeClass.getSimpleName(), injectee.getClass().getSimpleName()), ex);
                    }
                }
            });
        }
    }
}