ibatis 简单示例

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㈠ 加载iBatis 配置文件与映射文件：

加载配置文件：
① String resource = "sqlMapConfig.xml";
?????Reader?reader =?Resources.getResourceAsReader(reader);?
?????SqlMapClient?sqlMapClient =?SqlMapClientBuilder.buildSqlMap(reader);

② String resource = "sqlMapConfig.properties";
?????Properties?props =?Resources.getResourceAsProperties(resource);
?????SqlMapClient?sqlMapClient =?SqlMapClientBuilder.buildSqlMap(props);

③ String resource = "sqlMapConfig.xml";
?????Stream?stream =?Resources.getResourceAsStream(resource);
?????SqlMapClient?sqlMapClient =?SqlMapClientBuilder.buildSqlMap(stream);

④ String resource = "sqlMapConfig.xml";
?????File?file =?Resources.getResourceAsFile(resource);
?????SqlMapClient?sqlMapClient =?SqlMapClientBuilder.buildSqlMap(file);

㈡ 数据更新：
插入：public int?insert(String statementName,Object parameterObject)?throws?SQLException.
更新：public int?update(String statementName,Object parameterObject)?throws?SQLException.
删除：public int?delete(String statementName,Object parameterObject)?throws?SQLException.

例：sqlMapClient.startTransaction();
?????? User user =?new?User();
?????? user.setId(100);
?????? user.setUsername("joe");
???????user.setPassword("123");
?????? user.setEmail("joe@163.com");
???????int?rows = sqlMapClient.insert("users.insertUser",user);//users映射文件namespace值，insertUser映射文件insert的id值
?????? sqlMapClient.commitTransaction();

㈢ 数据查询：
① 查询结果返回一个对象
public?Object?queryForObject(String statementName,Object parameterObject)?throws?SQLException.
public?Object?queryForObject(String statementName,Object parameterObject,Object resultObject)?throws?SQLException
例：sqlMapClient.startTransaction();
?????? Integer id =?new?Integer(100);
?????? User user = (User)sqlMapClient.queryForObject("users.getUser",id);
?????? sqlMapClient.commitTransaction();
② 查询结果放入List中
public?List?queryForList(String statementName,Object parameterObject)?throws?SQLException.
public?List?queryForList(String statementName,Object parameterObject,int?skipResults,int?maxResults)?throws?SQLException.
public?List?queryForList(String statementName,Object parameterObject,RowHandler rowHandler)?throws?SQLException.
例：sqlMapClient.startTransaction();
?????? List list = sqlMapClient.queryForList("users.getUserList",null);
?????? sqlMapList.commitTransaction();
例：sqlMapClient.startTransaction();
?????? List list = sqlMapClient.queryForList("users.getUserList",null,0,40);
?????? sqlMapList.commitTransaction();
例：sqlMapClient.startTransaction();
???????Rowhandler?rowhandler =?new?MyRowHandler();
?????? List list = sqlMapClient.queryForList("users.getUserList",null,rowhandler );
?????? sqlMapList.commitTransaction();
???????public class?MyRowHandler?implements?RowHandler{
?????????????public void?handlerRow(Object obj,List list)?throws?SQLException{
????????????????????? User user = (User)obj;
???????????????????? ?user.setPassword("123");
???????????????????? ?sqlMapClient.update("users.updateUser",user);
??????????? }
????? }
③ 分页查询
public?PaginatedList?queryForPaginatedList(String statementName,Object parameterObject,int?pageSize)?throws?SQLException.
例：PaginatedList?list = sqlMapClient.queryForPaginatedList("users.getUserList",null,10);
????? ?list.nextPage();?? //下一页
????? ?list.previous();?? //前一页
?????? list.isFirstPage();? //是否是首页
?????? list.isMiddlePage(); //是否是中间页
????? ?list.isLastPage();?? //是否是最后一页
?????? list.isPreviousPageAvaliable();? //是否有前一页
?????? list.getPageIndex();? //获得当前页码
????? ?list.getPageSize();?? //获得页面大小。
④ 查询结果放入Map中
public?Map?queryForMap(String statementName,Object parameterObject,String?keyProperty)?thorws?SQLException.
public?Map?queryForMap(String statementName,Object parameterObject,String?keyProperty,String?valueProperty)?thorwsSQLException.
例：sqlMapClient.startTransaction();
????? ?Map?map = sqlMapClient.queryForMap("users.getUserList",null,"id");
?????? sqlMapClient.commitTransaction();
?????? ?User user = (User)map.get(100);
⑤ 批量处理（insert/update/delete）
sqlMapClient.startBatch();
? //...execute statements
sqlMapClient.executeBatch();

事务管理
public void?startTransaction()?throws?SQLException? //开始事务
public void?commitTransaction()?throws?SQLException? //提交事务
public void?rollbackTransaction()?throws?SQLException? //回滚事务
public void?endTransaction()?throws?SQLException? //结束事务
注：对每个SqlMapClient实例，一个线程最多只能打开一个事务。

使用自动事务
如果没有使用startTransaction()、commitTransaction()、rollbackTransaction()方法明确地划分事务范围，事务将自动执行。不建议使用。
使用全局事务
全局事务也叫分布式事务，它可以允许在同一事务中更新多个数据库，即同时成功或失败。全局事务即可以手工管理，也可以有框架来管理。
使用手工来管理全局事务，必须在配置文件中设定<transactionManager>的type的属性值设为EXTERNAL。
使用框架来管理全局事务，必须在配置文件中设定<transactionManager>的type的属性值设为JTA。
例：try{
????????????sqlMapClient.startTransaction();
????????????sqlMapClient0.startTransaction();
????????????sqlMapClient.insert(...);
??????????? sqlMapClient0.update(...);
????????????sqlMapClient0.commitTransaction();
????????????sqlMapClient.commitTransaction();
?????? }finally{
????????????????try{
?????????????????????????sqlMapClient0.endTransaction();
??????????????? }finally{
?????????????????????????sqlMapClient.endTransaction();
??????????????? }
?????? }

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