日期:2014-05-16 浏览次数:20572 次
//db2数据库 public class PostJdbcDao extends JdbcDaoSupport implements PostDao { private LobHandler lobHandler; private DataFieldMaxValueIncrementer incre; public LobHandler getLobHandler() { return lobHandler; } public void setLobHandler(LobHandler lobHandler) { this.lobHandler = lobHandler; } public void addPost(final Post post) { String sql = " INSERT INTO t_post(post_id,user_id,post_text,post_attach)" + " VALUES(?,?,?,?)"; getJdbcTemplate().execute( sql, new AbstractLobCreatingPreparedStatementCallback( this.lobHandler) { protected void setValues(PreparedStatement ps, LobCreator lobCreator) throws SQLException { ps.setInt(1, incre.nextIntValue()); ps.setInt(2, post.getUserId()); lobCreator.setClobAsString(ps, 3, post.getPostText()); lobCreator.setBlobAsBytes(ps, 4, post.getPostAttach()); } }); } } 设置相对应的配置文件(Oracle 9i版本),Oracle的数据库最喜欢搞搞特别的东西啦: <bean id="nativeJdbcExtractor" class="org.springframework.jdbc.support.nativejdbc.CommonsDbcpNativeJdbcExtractor" lazy-init="true" /> <bean id="oracleLobHandler" class="org.springframework.jdbc.support.lob.OracleLobHandler" lazy-init="true"> <property name="nativeJdbcExtractor" ref="nativeJdbcExtractor" /> </bean> <bean id="dao" abstract="true"> <property name="jdbcTemplate" ref="jdbcTemplate" /> </bean> <bean id="postDao" parent="dao" class="com.baobaotao.dao.jdbc.PostJdbcDao"> <property name="lobHandler" ref="oracleLobHandler" /> </bean> Oracle 10g或其他数据库如下设置: <bean id="defaultLobHandler" class="org.springframework.jdbc.support.lob.DefaultLobHandler" lazy-init="true" /> <bean id="dao" abstract="true"> <property name="jdbcTemplate" ref="jdbcTemplate" /> </bean> <bean id="postDao" parent="dao" class="com.baobaotao.dao.jdbc.PostJdbcDao"> <property name="lobHandler" ref="defaultLobHandler" /> </bean> 读取BLOB/CLOB块,举例: public List getAttachs(final int userId){ String sql = "SELECT post_id,post_attach FROM t_post where user_id =? and post_attach is not null"; return getJdbcTemplate().query( sql,new Object[] {userId}, new RowMapper() { public Object mapRow(ResultSet rs, int rowNum) throws SQLException { Post post = new Post(); int postId = rs.getInt(1); byte[] attach = lobHandler.getBlobAsBytes(rs, 2); post.setPostId(postId); post.setPostAttach(attach); return post; } }); }