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:
1 package org.appfuse.service; 2 3 import java.io.Serializable; 4 import java.util.List; 5 6 /** 7 * Generic Manager that talks to GenericDao to CRUD POJOs. 8 * 9 * <p>Extend this interface if you want typesafe (no casting necessary) managers 10 * for your domain objects. 11 * 12 * @author <a href="mailto:matt@raibledesigns.com">Matt Raible</a> 13 * Updated by jgarcia: added full text search + reindexing 14 * @param <T> a type variable 15 * @param <PK> the primary key for that type 16 */ 17 public interface GenericManager<T, PK extends Serializable> { 18 19 /** 20 * Generic method used to get all objects of a particular type. This 21 * is the same as lookup up all rows in a table. 22 * @return List of populated objects 23 */ 24 List<T> getAll(); 25 26 /** 27 * Generic method to get an object based on class and identifier. An 28 * ObjectRetrievalFailureException Runtime Exception is thrown if 29 * nothing is found. 30 * 31 * @param id the identifier (primary key) of the object to get 32 * @return a populated object 33 * @see org.springframework.orm.ObjectRetrievalFailureException 34 */ 35 T get(PK id); 36 37 /** 38 * Checks for existence of an object of type T using the id arg. 39 * @param id the identifier (primary key) of the object to get 40 * @return - true if it exists, false if it doesn't 41 */ 42 boolean exists(PK id); 43 44 /** 45 * Generic method to save an object - handles both update and insert. 46 * @param object the object to save 47 * @return the updated object 48 */ 49 T save(T object); 50 51 /** 52 * Generic method to delete an object 53 * @param object the object to remove 54 */ 55 void remove(T object); 56 57 /** 58 * Generic method to delete an object based on class and id 59 * @param id the identifier (primary key) of the object to remove 60 */ 61 void remove(PK id); 62 63 /** 64 * Generic method to search for an object. 65 * @param searchTerm the search term 66 * @param clazz type of class to search for. 67 * @return a list of matched objects 68 */ 69 List<T> search(String searchTerm, Class clazz); 70 /** 71 * Generic method to regenerate full text index of the persistent class T 72 */ 73 void reindex(); 74 75 /** 76 * Generic method to regenerate full text index of all indexed classes 77 * 78 * @param async 79 * true to perform the reindexing asynchronously 80 */ 81 void reindexAll(boolean async); 82 }
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
1 public List<T> getAll(String order) { 2 Session sess = getSession(); 3 Criteria criteria = sess.createCriteria(persistentClass); 4 criteria.addOrder(Order.desc(order)); 5 System.out.println(criteria); 6 return criteria.list(); 7 }
2. 自定义HQL语句的查询
1 public List<T> selectDataByHql(String hql) { 2 Session session = getSession(); 3 Query query=session.createQuery(hql); 4 //执行查询,返回对象集合 5 List<T> allClasses = query.list(); 6 return allClasses; 7 }
3. 根据某一列字段精确匹配的数据,并可排序,比如State=1
1 public List<T> search(String property,Object value,String order) throws SearchException { 2 Session sess = getSession(); 3 Criteria cri= sess.createCriteria(persistentClass); 4 if(StringUtils.isNotBlank(order)){ 5 cri.addOrder(Order.desc(order)); 6 } 7 cri.add(Restrictions.eq(property,value)); 8 return cri.list(); 9 }
4. 自定义条件的查询
1 public List<T> search(Criterion query,String order) throws SearchException { 2 Session sess = getSession(); 3 Criteria cri= sess.createCriteria(persistentClass); 4 if(StringUtils.isNotBlank(order)){ 5 cri.addOrder(Order.desc(order)); 6 } 7 cri.add(query); 8 return cri.list(); 9 }
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。