1.Map作为parameterClass

映射文件：

Xml代码

1. <!--use Map type as parameterClass-->
2. < select   id = "getProduct-Map"   parameterClass = "java.util.Map"   resultMap = "get-product-result" >
3. <![CDATA[
4. select * from t_product
5. where prd_id=#id# and prd_description=#description#
6. ]]>
7. </ select >

<!--use Map type as parameterClass--><select id="getProduct-Map" parameterClass="java.util.Map" resultMap="get-product-result"><![CDATA[select * from t_productwhere prd_id=#id# and prd_description=#description#]]></select>

DAO层：

Java代码

1. /**
2. * java.util.Map作为parameterClass
3. */
4. public  Product getProductMap(Map map)  throws  SQLException {
5. init();
6. Product product = (Product)sqlMapClient.queryForObject( "getProduct-Map" , map);
7. return  product;
8. }

/*** java.util.Map作为parameterClass*/public Product getProductMap(Map map) throws SQLException {init();Product product = (Product)sqlMapClient.queryForObject("getProduct-Map", map);return product;}

 Test类：

Java代码

1. public   void  getProductMap()  throws  SQLException{
2. Map map =  new  HashMap();
3. map.put( "id" ,  new  Integer( 1 ));
4. map.put( "description" ,  "basketball" );
5. Product product = productDao.getProductMap(map);
6. System.out.println(product);
7. }

public void getProductMap() throws SQLException{Map map = new HashMap();map.put("id", new Integer(1));map.put("description", "basketball");Product product = productDao.getProductMap(map);System.out.println(product);}

结果：

id:1
description:basketball
price206.99

2.Map作为resultClass

映射文件：

Xml代码

1. < resultMap   id = "get-product-map"   class = "java.util.HashMap" >
2. < result   property = "id"   column = "prd_id" />
3. < result   property = "description"   column = "prd_description" />
4. < result   property = "price"   column = "prd_price" />
5. </ resultMap >
6. <!--START  use Map type as resultClass,MUST use java.util.HashMap instead java.util.Map-->
7. < select   id = "getProdcut-MapResult"   resultClass =" java.util.HashMap " >
8. <![CDATA[
9. select * from t_product
10. ]]>
11. </ select >
12. < select   id = "getProductUseMap-resultMap"   resultMap = "get-product-map" >
13. <![CDATA[
14. select * from t_product
15. ]]>
16. </ select >
17. <!-- END  -->

<resultMap id="get-product-map" class="java.util.HashMap"><result property="id" column="prd_id"/><result property="description" column="prd_description"/><result property="price" column="prd_price"/></resultMap><!--START  use Map type as resultClass,MUST use java.util.HashMap instead java.util.Map--><select id="getProdcut-MapResult" resultClass=" java.util.HashMap"><![CDATA[select * from t_product]]></select><select id="getProductUseMap-resultMap" resultMap="get-product-map"><![CDATA[select * from t_product]]></select><!-- END  -->

 DAO层：

Java代码

1. /**
2. * java.util.Map作为resultClass
3. */
4. public  List getProductMapResult()  throws  SQLException {
5. init();
6. List list = sqlMapClient.queryForList( "getProdcut-MapResult" );
7. return  list;
8. }
9. public  List getProductUseMapByResultMap()  throws  SQLException {
10. init();
11. List list = sqlMapClient.queryForList( "getProductUseMap-resultMap" );
12. return  list;
13. }

/*** java.util.Map作为resultClass*/public List getProductMapResult() throws SQLException {init();List list = sqlMapClient.queryForList("getProdcut-MapResult");return list;}public List getProductUseMapByResultMap() throws SQLException {init();List list = sqlMapClient.queryForList("getProductUseMap-resultMap");return list;}

 Test类：

Java代码

1. public   void  getProductMapResult()  throws  SQLException{
2. Map map =  null ;
3. List list = productDao.getProductMapResult();
4. for (Iterator it=list.iterator(); it.hasNext();) {
5. //List里存放的是java.util.Map类型
6. Object obj = (Object)it.next();
7. System.out.println(obj.getClass());
8. System.out.println(obj);
9. }
10. }
11. public   void  getProductUseMapByResultMap()  throws  SQLException {
12. Map map =  null ;
13. List list = productDao.getProductUseMapByResultMap();
14. for (Iterator it=list.iterator(); it.hasNext();) {
15. //List里存放的是java.util.Map类型
16. Object obj = (Object)it.next();
17. System.out.println(obj.getClass());
18. System.out.println(obj);
19. }
20. }

public void getProductMapResult() throws SQLException{Map map = null;List list = productDao.getProductMapResult();for(Iterator it=list.iterator(); it.hasNext();) {//List里存放的是java.util.Map类型Object obj = (Object)it.next();System.out.println(obj.getClass());System.out.println(obj);}}public void getProductUseMapByResultMap() throws SQLException {Map map = null;List list = productDao.getProductUseMapByResultMap();for(Iterator it=list.iterator(); it.hasNext();) {//List里存放的是java.util.Map类型Object obj = (Object)it.next();System.out.println(obj.getClass());System.out.println(obj);}}

结果：

class java.util.HashMap
{prd_id=1, prd_price=206.99, prd_description=basketball}
class java.util.HashMap
{prd_id=2, prd_price=106.99, prd_description=football}
class java.util.HashMap
{price=206.99, description=basketball, id=1}
class java.util.HashMap
{price=106.99, description=football, id=2}

注意： Map作为resultClass时，必须指定具体的实现类，比如java.util.HashMap,否则会报错

Caused by: java.lang.RuntimeException: JavaBeansDataExchange could not instantiate result class.  Cause: java.lang.InstantiationException: java.util.Map

转自：http://xulongfa.iteye.com/blog/429616