Source Code Cross Referenced for DAOSupport.java in  » J2EE » jfox » org » jfox » entity » dao » Java Source Code / Java DocumentationJava Source Code and Java Documentation

01:        /*
02:         * JFox - The most lightweight Java EE Application Server!
03:         * more details please visit http://www.huihoo.org/jfox or http://www.jfox.org.cn.
04:         *
05:         * JFox is licenced and re-distributable under GNU LGPL.
06:         */
07:        package org.jfox.entity.dao;
08:
09:        import java.util.HashMap;
10:        import java.util.Map;
11:        import javax.persistence.EntityManager;
12:
13:        import org.jfox.entity.EntityFactory;
14:        import org.jfox.entity.MappedEntity;
15:        import org.jfox.entity.QueryExt;
16:
17:        /**
18:         * DAOSupport，�装了 DAO 的基本�作
19:         * 需è¦?ç”±å­?ç±»æ??ä¾›EntityManager，在 getEntityManager方法中返回
20:         *
21:         * DAO 应该都从 DAOSupport 继承，并且实现为 Stateless Local SessionBean
22:         *
23:         * DAO �以脱离容器�行，此时�能使用@PersistenceContext注入，
24:         * 而�能通过javax.persistence.Persistence的��方法�构造
25:         *
26:         * @author <a href="mailto:jfox.young@gmail.com">Yang Yong</a>
27:         */
28:        public abstract class DAOSupport implements  DataAccessObject {
29:
30:            /**
31:             * 返回 EntityManager，由�类使用 @PersistenceContext 注入
32:             */
33:            protected abstract EntityManager getEntityManager();
34:
35:            /**
36:             * 根� Entity Class生� Entity对象
37:             *
38:             * @param entityClass entity class
39:             */
40:            public static <T> T newEntityObject(Class<T> entityClass) {
41:                return newEntityObject(entityClass,
42:                        new HashMap<String, Object>());
43:            }
44:
45:            /**
46:             * 使用数� Map，生� Entity对象，Map的key和Entity的Column对应
47:             *
48:             * @param entityClass entity class
49:             * @param dataMap data dataMap
50:             */
51:            public static <T> T newEntityObject(final Class<T> entityClass,
52:                    final Map<String, Object> dataMap) {
53:                return EntityFactory.newEntityObject(entityClass, dataMap);
54:            }
55:
56:            /**
57:             * 给定query name 创建 NamedNativeQeury
58:             * @param queryName query name
59:             */
60:            public QueryExt createNamedNativeQuery(String queryName) {
61:                return (QueryExt) getEntityManager()
62:                        .createNamedQuery(queryName);
63:            }
64:
65:            /**
66:             * 给定 sql 构造 Qeury，Result类型为MappedEntity
67:             * @param sql native sql template
68:             */
69:            public QueryExt createNativeQuery(String sql) {
70:                return createNativeQuery(sql, MappedEntity.class);
71:            }
72:
73:            /**
74:             * 给定 sql 构造 Qeury，Result类型为resultClass
75:             * @param sql native sql template
76:             * @param resultClass 返回的结果对象类型
77:             */
78:            public QueryExt createNativeQuery(String sql, Class<?> resultClass) {
79:                return (QueryExt) getEntityManager().createNativeQuery(sql,
80:                        resultClass);
81:            }
82:
83:            /**
84:             * 生�19的PK，比如：2006080816404856650
85:             * PK ���唯一，�包�任何业务�义，比如：对于 ID 连续性的�求
86:             */
87:            public long nextPK() {
88:                return PKGenerator.getInstance().nextPK();
89:            }
90:
91:        }