com.siberhus.ngai.EntityQueryMap.java Source code

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Here is the source code for com.siberhus.ngai.EntityQueryMap.java

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/* Copyright 2009 Hussachai Puripunpinyo
 *
 * Licensed 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 com.siberhus.ngai;

import java.util.Collection;
import java.util.List;
import java.util.Map;
import java.util.Set;

import javax.persistence.EntityManager;
import javax.persistence.Query;
import javax.servlet.http.HttpServletRequest;

import org.apache.commons.lang.StringUtils;

import com.siberhus.ngai.core.Ngai;

/**
 * <p>
 * This map is not for use in business logic that need some key-value pair feature.<br/>
 * It's just the simple map that has special {@link EntityListMap#get(Object)} method.
 * </p>
 * <p> 
 * This map alone has nothing special but when combine it with EL (Expression Language) - <br/>
 * the magic will happen.
 * </p>
 * @see com.siberhus.ngai.service.DefaultDirectQueryService
 * @author hussachai
 * @since 0.9
 */
public class EntityQueryMap implements Map<String, List<Object>> {

    private HttpServletRequest request;

    /**
     * 
     */
    public EntityQueryMap(HttpServletRequest request) {
        this.request = request;
    }

    /**
     * 
     * @return
     */
    public EntityManager getEntityManager() {
        return Ngai.getEntityManager();
    }

    /**
     * 
     * <p>
     * Pass query string as parameter then this method will create {@link javax.persistence.Query} <br/>
     * object from that query, execute the query and return the entity list as the result.
     * </p>
     * 
     * @param queryString (JPQL)
     * @return List of entity
     * @since 0.9
     */
    @SuppressWarnings("unchecked")
    @Override
    public List<Object> get(Object q) {

        String queryStr = q + " ";
        Query query = getEntityManager().createQuery(queryStr);
        String paramNames[] = StringUtils.substringsBetween(queryStr, ":", " ");
        if (paramNames != null) {
            for (String paramName : paramNames) {
                query.setParameter(paramName, findAttribute(paramName));
            }
        }
        return query.getResultList();
    }

    protected Object findAttribute(String name) {
        Object value = null;
        value = request.getAttribute(name);
        if (value != null)
            return value;
        value = request.getSession().getAttribute(name);
        if (value != null)
            return value;
        value = request.getSession().getServletContext().getAttribute(name);
        if (value != null)
            return value;
        return null;
    }

    @Override
    public void clear() {
    }

    @Override
    public boolean containsKey(Object key) {
        return false;
    }

    @Override
    public boolean containsValue(Object value) {
        return false;
    }

    @Override
    public Set<java.util.Map.Entry<String, List<Object>>> entrySet() {
        return null;
    }

    @Override
    public boolean isEmpty() {
        return false;
    }

    @Override
    public Set<String> keySet() {
        return null;
    }

    @Override
    public List<Object> put(String key, List<Object> value) {
        return null;
    }

    @Override
    public void putAll(Map<? extends String, ? extends List<Object>> m) {
    }

    @Override
    public List<Object> remove(Object key) {
        return null;
    }

    @Override
    public int size() {
        return 0;
    }

    @Override
    public Collection<List<Object>> values() {
        return null;
    }

}