ReplicaCatalogQueryGenerator.java

/**
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.airavata.registry.core.replica.catalog.utils;

import org.apache.airavata.registry.cpi.ResultOrderType;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.persistence.EntityManager;
import javax.persistence.Query;
import java.util.HashMap;
import java.util.Map;

public class ReplicaCatalogQueryGenerator {

    private final static Logger logger = LoggerFactory.getLogger(ReplicaCatalogQueryGenerator.class);
	private String tableName;
	private Map<String,Object> matches=new HashMap<String, Object>();
	private static final String SELECT_OBJ="p";
	private static final String DELETE_OBJ="p";
	private static final String TABLE_OBJ="p";

	public ReplicaCatalogQueryGenerator(String tableName, Object[]... params) {
		setTableName(tableName);
		for (Object[] param : params) {
			addMatch(param[0].toString(), param[1]);
		}
	}
	
	public String getTableName() {
		return tableName;
	}

    public void setTableName(String tableName) {
		this.tableName = tableName;
	}

    public void addMatch(String colName, Object matchValue){
		matches.put(colName, matchValue);
	}
	
	public void setParameter(String colName, Object matchValue){
		addMatch(colName, matchValue);
	}

    public Query selectQuery(EntityManager entityManager){
        String queryString="SELECT "+ SELECT_OBJ + " FROM " +getTableName()+" "+TABLE_OBJ;
        return generateQueryWithParameters(entityManager, queryString);
    }

    public Query selectQuery(EntityManager entityManager, String orderByColumn,
                             ResultOrderType resultOrderType){
        String order = (resultOrderType == ResultOrderType.ASC) ? "ASC" : "DESC";
        String orderByClause = " ORDER BY " + SELECT_OBJ + "." + orderByColumn + " " + order;
        String queryString="SELECT "+ SELECT_OBJ + " FROM " +getTableName()+" "+TABLE_OBJ;
        return generateQueryWithParameters(entityManager, queryString, orderByClause);
    }

	public Query deleteQuery(EntityManager entityManager){
		String queryString="Delete FROM "+getTableName()+" "+TABLE_OBJ;
		return generateQueryWithParameters(entityManager, queryString);
	}

	private Query generateQueryWithParameters(EntityManager entityManager, String queryString) {
		return generateQueryWithParameters(entityManager, queryString, "");
	}

    private Query generateQueryWithParameters(EntityManager entityManager,
                                              String queryString, String orderByClause) {
        Map<String,Object> queryParameters=new HashMap<String, Object>();
        if (matches.size()>0){
            String matchString = "";
            int paramCount=0;
            for (String colName : matches.keySet()) {
                String paramName="param"+paramCount;
                queryParameters.put(paramName, matches.get(colName));
                if (!matchString.equals("")){
                    matchString+=" AND ";
                }
                matchString+=TABLE_OBJ+"."+colName+" =:"+paramName;
                paramCount++;
            }
            queryString+=" WHERE "+matchString;
        }
        queryString += orderByClause;
        Query query = entityManager.createQuery(queryString);
        for (String paramName : queryParameters.keySet()) {
            query.setParameter(paramName, queryParameters.get(paramName));
        }
        return query;
    }
}