CrudResolver.java

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package org.glassfish.config.support;

import org.jvnet.hk2.annotations.Optional;
import org.jvnet.hk2.annotations.Contract;
import org.jvnet.hk2.annotations.Service;
import org.jvnet.hk2.config.ConfigBeanProxy;
import org.glassfish.api.admin.AdminCommandContext;

import javax.inject.Inject;
import javax.inject.Named;
import java.lang.annotation.Annotation;

/**
 * A config resolver is responsible for finding the target object of a specified
 * type on which a creation command invocation will be processed.
 *
 * Implementation of these interfaces can be injected with the command invocation
 * parameters in order to determine which object should be returned
 *
 * @author Jerome Dochez
 */
@Contract
public interface CrudResolver {

    /**
     * Retrieves the existing configuration object a command invocation is intented to mutate.
     *
     * @param context the command invocation context
     * @param type the type of the expected instance
     * @return the instance or null if not found 
     */
    <T extends ConfigBeanProxy> T resolve(AdminCommandContext context, Class<T> type);

    @Service
    public static final class DefaultResolver implements CrudResolver {
        
        @Inject
        @Named("type")
        @Optional
        CrudResolver defaultResolver=null;

        @Override
        public <T extends ConfigBeanProxy> T resolve(AdminCommandContext context, Class<T> type) {
            if (defaultResolver!=null) {
                return defaultResolver.resolve(context, type);
            }
            return null;
        }
    }
}