SQL extension

config.xml

<bean id="newsfeedMetadataManager" class="com.fg.metadata.business.MetadataManagerFactory">
        <property name="metadataConfiguration" value="classpath:/META-INF/lib_newsfeed/metadata/metadataDescriptor.xml"/>
        <property name="dataSource" ref="dataSource"/>
        <property name="additionalConstraintTranslators">
            <list>
                <bean class="com.fg.newsfeed.model.query.ExclusionTranslator"/>
            </list>
        </property>
        <property name="sqlQueryInterceptors">
            <list>
                <bean class="com.fg.newsfeed.dao.CustomNewsfeedExclusionSqlQuery"/>
                <bean class="com.fg.newsfeed.dao.CustomNewsfeedCommentExclusionSqlQuery"/>
            </list>
        </property>
    </bean>

CustomNewsfeedCommentExclusionSqlQuery.java

package com.fg.newsfeed.dao;

import com.fg.metadata.business.SqlContainerQueryInterceptor;
import com.fg.metadata.business.SqlOneToManyBundleQueryInterceptor;
import com.fg.metadata.business.dto.ContainerId;
import com.fg.metadata.model.config.MetadataBundleDefinition;
import com.fg.metadata.model.config.MetadataContainerDefinition;
import com.fg.metadata.model.query.AdamQuery;
import com.fg.metadata.storage.model.Join;
import com.fg.metadata.storage.model.QueryDecomposition;
import com.fg.metadata.storage.model.WhereClausule;
import com.fg.newsfeed.model.NewsfeedItem;
import com.fg.newsfeed.model.query.ExceptExcluded;
import com.fg.query.util.QueryUtils;

import java.util.Arrays;
import java.util.List;

import static com.fg.metadata.storage.model.Join.JoinType.LEFT_JOIN;
import static com.fg.metadata.storage.model.WhereClausule.AppendAsType.AND;

/**
 * This interceptor will add specific virtual join that excludes newsfeed items comments set by specified user.
 *
 * @author Jan Novotný, FG Forrest a.s. (c) 2007
 * @version $Id: CustomNewsfeedCommentExclusionSqlQuery.java,v 1.4 2011/04/20 15:21:06 u_novoj Exp $
 */
public class CustomNewsfeedCommentExclusionSqlQuery implements SqlOneToManyBundleQueryInterceptor, SqlContainerQueryInterceptor {

	/**
	 * This method could analyze and alter query to a 1:N metadata bundle if business logic requires.
	 *
	 * @param sqlQuery
	 * @param bundleDefinition
	 * @param containerIds
	 * @param query
	 */
	public QueryDecomposition intercept(QueryDecomposition sqlQuery, MetadataBundleDefinition bundleDefinition, List<ContainerId> containerIds, AdamQuery query) {
		MetadataContainerDefinition containerDefinition = bundleDefinition.getParent();
		if ("newsfeed".equals(containerDefinition.getContainerType())) {
			ExceptExcluded except = QueryUtils.findSpecificConstraint(
					query.getFilteringForBundle(NewsfeedItem.BUNDLE_COMMENTS), 
					ExceptExcluded.class
			);
			if (except != null) {
                addCommentExcludeJoin(sqlQuery, except, bundleDefinition);
			}
		}
		return sqlQuery;
	}

    public QueryDecomposition intercept(QueryDecomposition sqlQuery, MetadataContainerDefinition containerDefinition, AdamQuery query) {
		if ("newsfeedComment".equals(containerDefinition.getContainerType())) {
            MetadataBundleDefinition bundleDefinition = containerDefinition.getPropertyBundle(containerDefinition.getDefaultBundle());
			ExceptExcluded except = QueryUtils.findSpecificConstraint(
					query.getUnboundFiltering(),
					ExceptExcluded.class
			);
            if (except == null) {
                except = QueryUtils.findSpecificConstraint(
                    query.getFilteringForBundle(bundleDefinition.getName()),
                    ExceptExcluded.class
                );
            }
			if (except != null) {
                addCommentExcludeJoin(sqlQuery, except, bundleDefinition);
			}
		}
		return sqlQuery;
    }

    private void addCommentExcludeJoin(QueryDecomposition sqlQuery, ExceptExcluded except, MetadataBundleDefinition bundleDefinition) {
        sqlQuery.addJoin(
                bundleDefinition,
            new Join(
				sqlQuery.getPlatform(),
                sqlQuery.getContainerTable(),
				sqlQuery.getContainerPrimaryKeyColumn(),
                "T_NF_FEED_COMMENT_EXCLUDE",
				"p",
                "idNewsfeedComment",
                LEFT_JOIN,
                Arrays.asList(
                        new WhereClausule(
                                AND,
                                "p.`idUser` = ?",
                                Arrays.asList(except.getIdUser())
                        )
                )
            )
        );
        sqlQuery.addFiltering(
            new WhereClausule(
                AND,
                "p.`id` IS NULL"
            )
        );
    }

}

CustomNewsfeedExclusionSqlQuery.java

package com.fg.newsfeed.dao;

import com.fg.metadata.business.SqlContainerQueryInterceptor;
import com.fg.metadata.model.config.MetadataBundleDefinition;
import com.fg.metadata.model.config.MetadataContainerDefinition;
import com.fg.metadata.model.query.AdamQuery;
import com.fg.metadata.storage.model.Join;
import com.fg.metadata.storage.model.QueryDecomposition;
import com.fg.metadata.storage.model.WhereClausule;
import com.fg.newsfeed.model.query.ExceptExcluded;
import com.fg.query.util.QueryUtils;

import java.util.Arrays;

import static com.fg.metadata.storage.model.Join.JoinType.LEFT_JOIN;
import static com.fg.metadata.storage.model.WhereClausule.AppendAsType.AND;

/**
 * This interceptor will add specific virtual join that excludes newsfeed items set by specified user.
 *
 * @author Jan Novotný, FG Forrest a.s. (c) 2007
 * @version $Id: CustomNewsfeedExclusionSqlQuery.java,v 1.2 2011/04/20 15:21:06 u_novoj Exp $
 */
public class CustomNewsfeedExclusionSqlQuery implements SqlContainerQueryInterceptor {

	/**
	 * This method could analyze and alter query if business logic requires.
	 *
	 * @param sqlQuery
	 * @param containerDefinition
	 */
	public QueryDecomposition intercept(QueryDecomposition sqlQuery, MetadataContainerDefinition containerDefinition, AdamQuery query) {
		if ("newsfeed".equals(containerDefinition.getContainerType())) {
			MetadataBundleDefinition defaultBundle = containerDefinition.getPropertyBundle(containerDefinition.getDefaultBundle());
			ExceptExcluded except = QueryUtils.findSpecificConstraint(
					query.getFilteringForBundle(defaultBundle.getName()),
					ExceptExcluded.class
			);
			if (except != null) {
				sqlQuery.addJoin(
					defaultBundle,
					new Join(
						sqlQuery.getPlatform(),
						sqlQuery.getContainerTable(),
						sqlQuery.getContainerPrimaryKeyColumn(),
						"T_NF_FEED_EXCLUDE",
						"o",
						"idNewsfeed",
						LEFT_JOIN,
						Arrays.asList(
							new WhereClausule(
									AND,
									"o.`idUser` = ?",
									Arrays.asList(except.getIdUser())
							)
						)
					)
				);
				sqlQuery.addFiltering(
					new WhereClausule(
						AND,
						"o.`id` IS NULL"
					)
				);				
			}
		}
		return sqlQuery;
	}
	
}

ExclusionTranslator.java

package com.fg.newsfeed.model.query;

import com.fg.query.constraint.*;
import com.fg.query.exception.*;
import com.fg.query.extractor.database.*;

/**
 * Description
 *
 * @author Jan Novotný, FG Forrest a.s. (c) 2007
 * @version $Id: ExclusionTranslator.java,v 1.1 2010/10/13 11:40:30 u_novoj Exp $
 */
public class ExclusionTranslator implements DatabaseConstraintTranslator {

	/**
	 * Returns true if this translator is able to process specified constraint.
	 *
	 * @return
	 */
	public boolean canTranslate(Constraint constraint) {
		return constraint instanceof ExceptExcluded;
	}

	/**
	 * Returns true if filter constraint is valid for object in context.
	 *
	 * @param constraint
	 * @return
	 */
	public void translate(Constraint constraint, DatabaseConstraintExtractor databaseConstraintExtractor) throws QueryComposeException {
		//donothing
	}
}