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這幾天仔細(xì)看了一下ibatis的文檔，發(fā)現(xiàn)2.2后，ibatis的改變還是挺大的。對于自定義類型支持的也不錯(cuò)，這樣對于blob和clob數(shù)據(jù)的處理也就簡單多了。 不過在spring 中已經(jīng)提供了很好的實(shí)現(xiàn)，所以這又省去了很多的功夫，接下來看看ibatis是如何支持clob和blob的。 ibatis提供了TypeHandler接口，用于處理數(shù)據(jù)類型，基本的實(shí)現(xiàn)類為BaseTypeHandler 在spring 中，提供了AbstractLobTypeHandler作為基礎(chǔ)類，并且提供了相應(yīng)的模版方法，所有的工作由LobHandler處理。 BlobByteArrayTypeHandler 主要用于處理blob類型數(shù)據(jù)，使用byte[]來映射相應(yīng)的blob ClobStringTypeHandler 用于處理clob類型數(shù)據(jù)，使用字符串來映射Clob 有一點(diǎn)需要注意的是，AbstractLobTypeHandler中實(shí)現(xiàn)了事務(wù)支持，需要用來釋放相應(yīng)的資源，所以一定需要在事務(wù)環(huán)境中進(jìn)行。 下面是一個(gè)簡單的例子： public class Food { private String content; private String id; private byte[] image; private String name; ... } xml如下：說明一下，在resultMap中可以通過typeHandler來指定具體的handler.在inline變量中，可以通過handler來定義相應(yīng)的typeHandler <sqlMap namespace="Food"> <typeAlias alias="Food" type="org.esoft.hdb.bo.Food"/> <resultMap id="foodResult" class="Food"> <result property="id" column="C_ID"/> <result property="name" column="C_NAME"/> <result property="content" column="C_content" typeHandler="org.springframework.orm.ibatis.support.ClobStringTypeHandler"/> <result property="image" column="C_image" typeHandler="org.springframework.orm.ibatis.support.BlobByteArrayTypeHandler"/> </resultMap> <sql id="foodFragment">select C_ID,C_NAME,C_CONTENT,C_IMAGE from T_FOOD</sql> <select id="getAll" resultMap="foodResult"> <include refid="foodFragment"/> </select> <select id="selectById" parameterClass="string" resultMap="foodResult"> <include refid="foodFragment"/> where C_ID=#id#</select> <insert id="insert" parameterClass="Food"> insert into T_FOOD ( C_ID, C_NAME,C_CONTENT, C_IMAGE) values ( #id#, #name#,#content,handler=org.springframework.orm.ibatis.support.ClobStringTypeHandler#, #image,handler=org.springframework.orm.ibatis.support.BlobByteArrayTypeHandler#) </insert> <update id="update" parameterClass="Food"> update T_FOOD set C_NAME = #name#, C_CONTENT = #content,handler=org.springframework.orm.ibatis.support.ClobStringTypeHandler#, C_IMAGE = #image,handler=org.springframework.orm.ibatis.support.BlobByteArrayTypeHandler# where C_ID = #id# </update> <delete id="deleteById" parameterClass="string"> delete from T_FOOD where C_ID = #id# </delete> </sqlMap> public interface FoodService { void save(Food food); Food get(String id); /** * @param food */ void update(Food food); } public class FoodServiceImpl implements FoodService { private FoodDAO foodDAO; private DaoCreator creator; public void setCreator(DaoCreator creator) { this.creator = creator; } protected FoodDAO getFoodDAO() { if (foodDAO == null) { foodDAO = (FoodDAO) creator.createDao(FoodDAO.class, Food.class); } return foodDAO; } public Food get(String id) { return getFoodDAO().get(id); } public void save(Food food) { getFoodDAO().save(food); } public void update(Food food) { getFoodDAO().update(food); } } spring xml 配置： 。。。 <bean id="lobHandler" class="org.springframework.jdbc.support.lob.DefaultLobHandler"/> <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"> <property name="dataSource" ref="dataSource"/> </bean> <bean id="sqlMapClient" class="org.springframework.orm.ibatis.SqlMapClientFactoryBean"> <property name="dataSource" ref="dataSource"/> <property name="configLocation"> <value>SqlMapConfig.xml</value> </property> <property name="lobHandler" ref="lobHandler"/> </bean> <bean id="daoCreate" class="org.esoft.hdb.ibatis.IbatisDaoCreator"> <property name="sqlMapClient" ref="sqlMapClient"/> </bean> <bean id="foodService" class="org.esoft.hdb.service.FoodServiceImpl"> <property name="creator" ref="daoCreate"/> </bean> <aop:config> <aop:pointcut id="foodServiceMethods" expression="execution(* org.esoft.hdb.service.FoodService.*(..))"/> <aop:advisor advice-ref="txAdvice" pointcut-ref="foodServiceMethods"/> </aop:config> <tx:advice id="txAdvice" transaction-manager="transactionManager"> <tx:attributes> <tx:method name="*" propagation="REQUIRED"/> </tx:attributes> </tx:advice> 簡單的測試： save : Food food = new Food(); food.setPk("1"); food.setName("food1"); BufferedInputStream in = new BufferedInputStream(getClass() .getResourceAsStream("/1.gif")); byte[] b = FileCopyUtils.copyToByteArray(in); food.setImage(b); in = new BufferedInputStream(getClass().getResourceAsStream( "/hibernate.cfg.xml")); b = FileCopyUtils.copyToByteArray(in); food.setContent(new String(b)); foodService.save(food); update: Food food = foodService.get("1"); BufferedInputStream in = new BufferedInputStream(getClass() .getResourceAsStream("/jdbc.properties")); byte[] b = FileCopyUtils.copyToByteArray(in); food.setContent(new String(b)); foodService.update(food); food = foodService.get("1"); assertNotNull(food.getImage()); |
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