利用DetachedCriteria構建HQL參數動態匹配，detachedcriteria

利用DetachedCriteria構建HQL參數動態匹配，detachedcriteria

此文章是基於 搭建SpringMVC+Spring+Hibernate平台

1. DetachedCriteria構建類：CriteriaBuilder.java

package com.ims.persistence.base;

import java.math.BigDecimal;
import java.sql.Types;
import java.util.Map;

import org.apache.commons.lang3.StringUtils;
import org.hibernate.criterion.Criterion;
import org.hibernate.criterion.DetachedCriteria;
import org.hibernate.criterion.MatchMode;
import org.hibernate.criterion.Restrictions;

import com.ims.common.DateUtil;

public class CriteriaBuilder {
    private DetachedCriteria detachedCriteria;
    private Map<String, ?> parmasMap;
    
    public CriteriaBuilder(DetachedCriteria detachedCriteria, Map<String, ?> parmasMap){
        this.detachedCriteria = detachedCriteria;
        this.parmasMap = parmasMap;
    }
    
    public DetachedCriteria addCriterion(String propertyName,String paramName){
        return addCriterion(propertyName,paramName,Expression.EQ);
    }
    
    public DetachedCriteria addCriterion(String propertyName,String paramName,Expression expression){
        return addCriterion(propertyName, paramName, Types.VARCHAR, expression);
    }
    
    public DetachedCriteria addCriterion(String propertyName,String paramName, Integer propertyType){
        return addCriterion(propertyName,paramName,propertyType,Expression.EQ);
    }
    
    public DetachedCriteria addCriterion(String propertyName,String paramName, Integer propertyType, Expression expression){
        if(parmasMap!=null){
            Criterion criterion = buildCriterion(propertyName,paramName,propertyType,expression);
            if(null!=criterion){
                detachedCriteria.add(criterion);
            }
        }        
        return detachedCriteria;
    }
    
    private Criterion buildCriterion(String propertyName,String paramName,Integer propertyType,Expression expression){
        boolean propertyBlank = true;
        Object paramValue = parmasMap.get(paramName);
        if(paramValue!=null && StringUtils.isNotBlank(paramValue.toString())){
            propertyBlank = false;
        }
        
        Criterion criterion = null;
        if(!propertyBlank){
            switch(propertyType){
                case Types.INTEGER:
                    paramValue = Integer.valueOf(paramValue.toString());
                    break;
                case Types.VARCHAR:
                    paramValue = paramValue.toString();
                    break;
                case Types.DATE:
                    paramValue = DateUtil.stringToDate(paramValue.toString());
                    break;
                case Types.DECIMAL:
                    paramValue = new BigDecimal(paramValue.toString());
                    break;
            }
            switch(expression){
                case EQ:
                    criterion = Restrictions.eq(propertyName, paramValue);
                    break;
                case NE:
                    criterion = Restrictions.ne(propertyName, paramValue);
                    break;
                case GT:
                    criterion = Restrictions.gt(propertyName, paramValue);
                    break;
                case GE:
                    criterion = Restrictions.ge(propertyName, paramValue);
                    break;
                case LT:
                    criterion = Restrictions.lt(propertyName, paramValue);
                    break;
                case LE:
                    criterion = Restrictions.le(propertyName, paramValue);
                    break;
            }
        }
        return criterion;
    }

    public DetachedCriteria addLikeCriterion(String propertyName,String paramName){
        return addLikeCriterion(propertyName,paramName,MatchMode.ANYWHERE);
    }
    
    public DetachedCriteria addLikeCriterion(String propertyName,String paramName,MatchMode matchMode){
        if(parmasMap!=null){
            Criterion criterion = buildLikeCriterion(propertyName,paramName,matchMode);
            if(null!=criterion){
                detachedCriteria.add(criterion);
            }
        }
        return detachedCriteria;
    }
    
    public Criterion buildLikeCriterion(String propertyName,String paramName,MatchMode matchMode){
        Criterion criterion = null;
        Object paramValue = parmasMap.get(paramName);
        if(paramValue!=null && StringUtils.isNotBlank(paramValue.toString())){
            criterion = Restrictions.like(propertyName, paramValue.toString(), matchMode);
        }    
        return criterion;
    }
}

2. 比較運算符枚舉類：Expression.java

package com.ims.persistence.base;

public enum Expression {
    /** 等於  */
    EQ,
    /** 不等於 */
    NE,
    /** 大於 */
    GT,
    /** 大於等於 */
    GE,
    /** 小於 */
    LT,
    /** 小於等於 */
    LE;
}

3. 使用如類：WarehouseBSImpl.java

package com.ims.service.xxx.impl;

import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.hibernate.criterion.DetachedCriteria;
import org.hibernate.criterion.ProjectionList;
import org.hibernate.criterion.Projections;
import org.hibernate.transform.Transformers;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import com.ims.persistence.base.CriteriaBuilder;
import com.ims.persistence.dao.xxx.WarehouseDao;
import com.ims.persistence.model.xxx.Warehouse;
import com.ims.service.xxx.WarehouseBS;

@Service("warehouseBS")
public class WarehouseBSImpl implements WarehouseBS{
    @Autowired
    private WarehouseDao warehouseDao;
    
    private DetachedCriteria buildCriteria(DetachedCriteria detachedCriteria, Map<String, Object> params){
        CriteriaBuilder criteriaBuilder = new CriteriaBuilder(detachedCriteria, params);
        criteriaBuilder.addCriterion("warehouse.projectCode", "projectCode");
        return detachedCriteria;
    }
    
    @Override
    public List<Map<String, Object>> getWarehouses(String projectCode) {
        Map<String, Object> params = new HashMap<String, Object>();
        params.put("projectCode", projectCode);
        DetachedCriteria detachedCriteria = DetachedCriteria.forClass(Warehouse.class, "warehouse");
        buildCriteria(detachedCriteria, params);
        
        ProjectionList pList = Projections.projectionList();           
        pList.add(Projections.property("warehouse.warehouseCode").as("value"));           
        pList.add(Projections.property("warehouse.warehouseName").as("text")); 
        detachedCriteria.setProjection(pList);        
        detachedCriteria.setResultTransformer(Transformers.ALIAS_TO_ENTITY_MAP);
        
        return warehouseDao.findByCriteria(detachedCriteria);
    }

}