系统学习hibernate之十一：set、list、map、array集合

系统学习hibernate之十一：set、list、map、array集合

hibernate中的集合的使用还是比较多，跟普通的string、int等字段处理的方式不一样，下面介绍 set、list、map、array集合在hibernate中的应用。

例子：
1、 CollectionMapping的POJO类

 1 import  java.util.List;
 2 import  java.util.Map;
 3 import  java.util.Set;
 4
 5 public   class  CollectionMapping  {
 6    private int id;
 7    
 8    private String name;
 9    
10    private Set setValue;
11    
12    private List listValue;
13    
14    private String[] arrayValue;
15    
16    private Map mapValue;
17//省略setter、getter方法
18}

2、CollectionMapping.hbm.xml映射文件

 1 <? xml version="1.0" ?>
 2 <! DOCTYPE hibernate-mapping PUBLIC 
 3     "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
 4     "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd" >
 5 < hibernate-mapping  package ="org.apple.hibernate" >
 6      < class  name ="CollectionMapping"  table ="t_collectionMapping" >
 7          < id  name ="id" >
 8              < generator  class ="native" />
 9          </ id >
10          < property  name ="name" />
11          < set  name ="setValue"  table ="t_set_value" >
12              < key  column ="set_id" />
13              < element  type ="string"  column ="set_value" />
14          </ set >
15          < list  name ="listValue"  table ="t_list_value" >
16              < key  column ="list_id" />
17              < list-index  column ="list_index" />
18              < element  type ="string"  column ="list_value" />
19          </ list >
20          < array  name ="arrayValue"  table ="t_array_value" >
21              < key  column ="array_id" />
22              < list-index  column ="array_index" />
23              < element  type ="string"  column ="array_value" />
24          </ array >
25          < map  name ="mapValue"  table ="t_map_value" >
26              < key  column ="map_id" />
27              < map-key  type ="string"  column ="map_key" />
28              < element  type ="string"  column ="map_value" />
29          </ map >
30      </ class >
31 </ hibernate-mapping >

3、利用SchemaExport生成数据库表

mysql> desc t_array_value;
+-------------+--------------+------+-----+---------+-------+
| Field       | Type         | Null | Key | Default | Extra |
+-------------+--------------+------+-----+---------+-------+
| array_id    | int(11)      | NO   | PRI |         |       |
| array_value | varchar(255) | YES  |     | NULL    |       |
| array_index | int(11)      | NO   | PRI |         |       |
+-------------+--------------+------+-----+---------+-------+
3 rows in set (0.03 sec)

mysql> desc t_array_value;
+-------------+--------------+------+-----+---------+-------+
| Field       | Type         | Null | Key | Default | Extra |
+-------------+--------------+------+-----+---------+-------+
| array_id    | int(11)      | NO   | PRI |         |       |
| array_value | varchar(255) | YES  |     | NULL    |       |
| array_index | int(11)      | NO   | PRI |         |       |
+-------------+--------------+------+-----+---------+-------+
3 rows in set (0.03 sec)

mysql> desc t_list_value;
+------------+--------------+------+-----+---------+-------+
| Field      | Type         | Null | Key | Default | Extra |
+------------+--------------+------+-----+---------+-------+
| list_id    | int(11)      | NO   | PRI |         |       |
| list_value | varchar(255) | YES  |     | NULL    |       |
| list_index | int(11)      | NO   | PRI |         |       |
+------------+--------------+------+-----+---------+-------+
3 rows in set (0.03 sec)
mysql> desc t_map_value;
+-----------+--------------+------+-----+---------+-------+
| Field     | Type         | Null | Key | Default | Extra |
+-----------+--------------+------+-----+---------+-------+
| map_id      | int(11)      | NO   | PRI |         |       |
| map_value | varchar(255) | YES  |     | NULL    |       |
| map_key   | varchar(255) | NO   | PRI |         |       |
+-----------+--------------+------+-----+---------+-------+
3 rows in set (0.03 sec)
mysql> desc t_set_value;
+-----------+--------------+------+-----+---------+-------+
| Field     | Type         | Null | Key | Default | Extra |
+-----------+--------------+------+-----+---------+-------+
| set_id    | int(11)      | NO   | MUL |         |       |
| set_value | varchar(255) | YES  |     | NULL    |       |
+-----------+--------------+------+-----+---------+-------+
2 rows in set (0.03 sec)

4、测试方法：

 1 public   void  testSave1()
 2      {
 3        Session session = null;
 4        CollectionMapping c = new CollectionMapping();
 5        
 6        c.setName("xxx");
 7        
 8        Set setValue = new HashSet();
 9        setValue.add("a");
10        setValue.add("b");
11        c.setSetValue(setValue);
12        
13        List listValue = new ArrayList();
14        listValue.add("c");
15        listValue.add("d");
16        c.setListValue(listValue);
17        
18        String[] arrayValue = new String[]{"e", "f"};
19        c.setArrayValue(arrayValue);
20        
21        Map mapValue = new HashMap();
22        mapValue.put("k1", "v1");
23        mapValue.put("k2", "v2");
24        c.setMapValue(mapValue);        
25        try {
26            session = HibernateUtil.getSession();
27            session.beginTransaction();
28            session.save(c);
29            session.getTransaction().commit();
30            
31        } catch (Exception e) {
32            // TODO: handle exception
33            session.beginTransaction().rollback();
34        }finally{
35            session.close();
36        }
37    }

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