SSH电力项目三 - Dao层、service层查询实现（HQL）

底层方法封装：模糊查询，姓张的人

查询思路：select * from elec_text o           #Dao层 

　　　　    where o.textName like '%张%'     #Service层

　　　　　 and o.textRemark like '%张%'  #Service层   

　　　　    order by o.textDate ASC, o.textName DESC ;  #Service层

为了在业务层对称，采用如下写法：

　　　　select * from elec_text o where 1=1　　#Dao层

　　　　and o.textName like '%张%'　　　　　　 #Service层

　　　　and o.textRemark like '%张%'　　　　    #Service层

　　　　order by o.textDate ASC, textName DESC  #Service层

TestService.java

package junit;
public class TestService {

    @Test
    public void save(){
    ApplicationContext ac = new ClassPathXmlApplicationContext("beans.xml");
    IElecTextService elecTextService = (IElecTextService) ac.getBean(IElecTextService.SERVICE_NAME);

    ElecText e = new ElecText();
    e.setTextName("abbbc");
    e.setTextDate(new Date());
    e.setTextRemark("deeef");
    elecTextService.saveElecText(e);

    }
//
    @Test
    public void  findCollectionByConditionNopage(){
        ApplicationContext ac = new ClassPathXmlApplicationContext("beans.xml");
        IElecTextService elecTextService = (IElecTextService) ac.getBean(IElecTextService.SERVICE_NAME);

        ElecText elecText = new ElecText();
        elecText.setTextName("张");
        elecText.setTextRemark("张");
        List<ElecText> list = elecTextService.findCollectionByConditionNopage(elecText);

        if(list != null && list.size() > 0){
            for(ElecText text:list){
                System.out.println(text.getTextName() + "+"+ text.getTextRemark());
            }
        }
    }
}

ElecTextService.java  接口：

package com.itheima.elec.service;public interface IElecTextService {

    public static final String SERVICE_NAME="com.itheima.elec.service.impl.ElecTextServiceImpl";
    void saveElecText(ElecText elecText);
    List<ElecText> findCollectionByConditionNopage(ElecText elecText);
}

ElecTextServiceImpl.java 接口

package com.itheima.elec.service.impl;
//事务控制：spring的声明事务处理,在service层添加@Transactional
@Service(IElecTextService.SERVICE_NAME)
@Transactional(readOnly=true)
public class ElecTextServiceImpl implements IElecTextService {

    @Resource(name=IElecTextDao.SERVICE_NAME)
    IElecTextDao elecTextDao;

    @Transactional(readOnly=false)
    public void saveElecText(ElecText elecText) {
        // TODO Auto-generated method stub
            elecTextDao.save(elecText);
    }

    @Override
    public List<ElecText> findCollectionByConditionNopage(ElecText elecText) {
        //查询条件
        String condition = "";
        //查询条件对应的参数
        List<Object> paramsList = new ArrayList<Object>();
//        if(elecText.getTextName() != null && !elecText.getTextName().equals("")){
//                condition += " and o.textName like ?";
//        }
        if(StringUtils.isNotBlank(elecText.getTextName())){
            condition += "  and o.textName like  ?";
            paramsList.add("%" + elecText.getTextName() + "%");
        }

        if(StringUtils.isNotBlank(elecText.getTextRemark())){
            condition += "  and o.textRemark like  ?";
            paramsList.add("%" + elecText.getTextRemark() + "%");
        }
        //传递可变参数
        Object [] params = paramsList.toArray();
        //排序
        Map<String, String> orderby = new LinkedHashMap<String,String>();
                orderby.put("o.textDate", "asc");
                orderby.put("o.textName", "desc");
      //查询
      List<ElecText> list = elecTextDao.findCollectionByConditionNoPage(condition,params,orderby);
      return list;
    }

}

ICommonDao.java

package com.itheima.elec.dao;public interface ICommonDao<T> {

    void save(T entity);
    void update(T entity);
    T findObjectById(Serializable id);
    void deleteObjectByIds(Serializable... ids);
    void deleteObjectByCollection(List<T> list);
    List<T> findCollectionByConditionNoPage(String condition, Object[] params, Map<String, String> orderby    );
}

ICommonDaoImpl.java

package com.itheima.elec.dao.impl;public class CommonDaoImpl<T>  extends HibernateDaoSupport implements ICommonDao<T> {

    //泛型转化
    Class entityClass = TUtils.getActualType(this.getClass());
    /**
     * 如何来实现这个save方法：通过HibernateDaoSupport 来实现，需要注入sessionFactory
     */
    @Resource
    public void setDi(SessionFactory sessionFactory){
        this.setSessionFactory(sessionFactory);
    }
    @Override
    public void save(T entity) {
        this.getHibernateTemplate().save(entity);
    }

    public void update(T entity){
        this.getHibernateTemplate().update(entity);
    }
    @Override
    public T findObjectById(Serializable id) {
//        Class entityClass = TUtils.getActualType(this.getClass());
        return (T) this.getHibernateTemplate().get(entityClass, id);   //entityClass 此处需要类型
    }
    @Override
    public void deleteObjectByIds(Serializable... ids) {
        if(ids != null && ids.length > 0){
            for(Serializable id:ids){
                Object entity = this.findObjectById(id);
                this.getHibernateTemplate().delete(entity);
            }
        }
//        this.getHibernateTemplate().delete(entity);
    }
    @Override
    public void deleteObjectByCollection(List<T> list) {
            this.getHibernateTemplate().deleteAll(list);
    }
    @Override
    /**
    这里1=1的目的是方便在Service层拼装sql或者hql语句，连接统一使用and
     * SELECT o FROM ElecText o WHERE 1=1             #Dao层填写
            AND o.textName LIKE '%张%'                  #Service拼装
            AND o.textRemark LIKE '%张%'                #Service拼装
            ORDER BY o.textDate ASC,o.textName desc   #Service拼装
     */
    public List<T> findCollectionByConditionNoPage(String condition, Object[] params, Map<String, String> orderby) {
        //hql语句
        String hql = "from " + entityClass.getSimpleName() + "  o where 1 = 1";
        //将Map集合中存放的字段排序，组织成ORDER BY o.textDate ASC, o.textName Desc
        String orderByCondition = this.orderByHql(orderby);
        //添加查询条件
        String finalHql = hql + condition + orderByCondition;
        //查询，执行sql语句
        //方法一：
        List<T> list = this.getHibernateTemplate().find(finalHql, params);

/*

//方案三

List<T> list = (List<T>) this.getHibernateTemplate().execute(new HibernateCallback() {

@Override
public Object doInHibernate(Session session) throws HibernateException, SQLException {
//回调session
Query query = session.createQuery(finalHql);
if(params!=null && params.length > 0){ //params报错，将传递的参数强转为final 类型
for(int i=0;i<params.length;i++){
query.setParameter(i, params[i]);
}
}
return query.list();
}
});

*/

        return list;
    }
    private String orderByHql(Map<String, String> orderby) {
        StringBuffer buffer = new StringBuffer("");
        if(orderby != null && orderby.size() > 0){
            buffer.append(" ORDER BY ");  //这个地方一定要加空格，否则拼接字符串会报错
            for(Map.Entry<String, String> map:orderby.entrySet()){
                buffer.append(map.getKey() + " " + map.getValue() + ",");
            }
            //删除最后一个逗号
            buffer.deleteCharAt(buffer.length() - 1);
        }
        return buffer.toString();
    }
}

方案三：

 @Override
     public List<T> findCollectionByConditionNoPage(String condition, final Object[] params, Map<String, String> orderby) {
         //hql语句   面向对象
         String hql="from "+ entityClass.getSimpleName() +" o where 1=1";
         //添加查询条件
         //将map集合中存放的字段排序组织成字符串 order by o.textDate asc, o.textName desc
         String orderbyCondition = this.orderbyHql(orderby);
         final String finalHql = hql + condition + orderbyCondition;
         //方案一：使用模板调用
 //        List<T> list = this.getHibernateTemplate().find(finalHql, params);
 //        return list;

         //方案三：
         List<T> list = this.getHibernateTemplate().execute(new HibernateCallback() {

             @Override
             public Object doInHibernate(Session session) throws HibernateException, SQLException {
                 Query query = session.createQuery(finalHql);
                 if(params != null && params.length > 0){
                     for (int i = 0; i < params.length; i++) {
                         query.setParameter(i, params[i]);
                     }
                 }
                 return query.list();
             }

         });
         return list;
     }

2017.1.11  11:58

第一次回顾 2017.5.14 kangjie