Appfuse：扩展自己的GenericManager

通过代码生成机制的appfuse访问数据都通过GenericManager来实现，GenericManager默认提供了以下几个方法：

package org.appfuse.service;

import java.io.Serializable;
import java.util.List;

/**
 * Generic Manager that talks to GenericDao to CRUD POJOs.
 *
 * <p>Extend this interface if you want typesafe (no casting necessary) managers
 * for your domain objects.
 *
 * @author <a href="mailto:matt@raibledesigns.com">Matt Raible</a>
 *  Updated by jgarcia: added full text search + reindexing
 * @param <T> a type variable
 * @param <PK> the primary key for that type
 */
public interface GenericManager<T, PK extends Serializable> {

    /**
     * Generic method used to get all objects of a particular type. This
     * is the same as lookup up all rows in a table.
     * @return List of populated objects
     */
    List<T> getAll();

    /**
     * Generic method to get an object based on class and identifier. An
     * ObjectRetrievalFailureException Runtime Exception is thrown if
     * nothing is found.
     *
     * @param id the identifier (primary key) of the object to get
     * @return a populated object
     * @see org.springframework.orm.ObjectRetrievalFailureException
     */
    T get(PK id);

    /**
     * Checks for existence of an object of type T using the id arg.
     * @param id the identifier (primary key) of the object to get
     * @return - true if it exists, false if it doesn't
     */
    boolean exists(PK id);

    /**
     * Generic method to save an object - handles both update and insert.
     * @param object the object to save
     * @return the updated object
     */
    T save(T object);

    /**
     * Generic method to delete an object
     * @param object the object to remove
     */
    void remove(T object);

    /**
     * Generic method to delete an object based on class and id
     * @param id the identifier (primary key) of the object to remove
     */
    void remove(PK id);

    /**
     * Generic method to search for an object.
     * @param searchTerm the search term
     * @param clazz type of class to search for.
     * @return a list of matched objects
     */
    List<T> search(String searchTerm, Class clazz);
    /**
     * Generic method to regenerate full text index of the persistent class T
     */
    void reindex();

    /**
     * Generic method to regenerate full text index of all indexed classes
     *
     * @param async
     *            true to perform the reindexing asynchronously
     */
    void reindexAll(boolean async);
}

通常我们用getAll()访问表中所有的数据，可惜无排序；用search(String searchTerm, Class clazz)来过滤数据，可惜不能自定义条件，只能全字段搜索。

下面是我在开发过程中扩展出来的几个方法，直接附上GenericDaoHibernate中的实现，各层的声明就没再累赘。

1. 自定义排序的getAll

 public List<T> getAll(String order) {
        Session sess = getSession();
        Criteria criteria = sess.createCriteria(persistentClass);
        criteria.addOrder(Order.desc(order));
        System.out.println(criteria);
        return criteria.list();
    }

2. 自定义HQL语句的查询

 public List<T> selectDataByHql(String hql) {
         Session session = getSession();
        Query query=session.createQuery(hql);
        //执行查询，返回对象集合  
        List<T> allClasses = query.list();
        return allClasses;
    }

3. 根据某一列字段精确匹配的数据，并可排序，比如State=1

public List<T> search(String property,Object value,String order) throws SearchException {
        Session sess = getSession();
        Criteria cri= sess.createCriteria(persistentClass); 
        if(StringUtils.isNotBlank(order)){
            cri.addOrder(Order.desc(order));
        }
        cri.add(Restrictions.eq(property,value));
        return cri.list();
    }

4. 自定义条件的查询

public List<T> search(Criterion query,String order) throws SearchException {
        Session sess = getSession();
        Criteria cri= sess.createCriteria(persistentClass); 
        if(StringUtils.isNotBlank(order)){
            cri.addOrder(Order.desc(order));
        }
        cri.add(query);
        return cri.list();
    }

 

有人可能疑问为啥定义了4，还要再定义2呢，只能说编码风格的问题，我喜欢用4的方式，但有人喜欢HQL语句，觉得更加直观。