packagecom.imooc.dao;importjava.io.IOException;importjava.util.ArrayList;importjava.util.List;importorg.apache.ibatis.session.SqlSession;importorg.apache.log4j.Logger;importcom.imooc.bean.Message;importcom.imooc.db.DBAccess;public classMessageDao {/*** 根据查询条件获取消息列表*/

public ListqueryMessageList(String command, String description) {

List messageList = new ArrayList<>();

DBAccess dbAccess= newDBAccess();

SqlSession sqlSession= null;try{

sqlSession=dbAccess.getSqlSession();//通过sqlSession执行SQL语句

Message message = newMessage();

message.setCommand(command);

message.setDescription(description);

messageList= sqlSession.selectList("Message.queryMessageList", message);

}catch(IOException e) {

e.printStackTrace();

}finally{//如果中间发生异常sqlSession可能是null

if (sqlSession != null) {

sqlSession.close();

}

}returnmessageList;

}/*** 单条删除*/

public void deletOne(intid) {

DBAccess dbAccess= newDBAccess();

SqlSession sqlSession= null;try{

sqlSession=dbAccess.getSqlSession();

sqlSession.delete("Message.deleteOne", id);

sqlSession.commit();//Mybatis不默认提交//JDBC默认自动提交，除非setAutoCommit(false)//这个时候姐需要conn.commit()提交事务//可以通过conn.rollback([Savepoint savepoint])回滚

} catch(IOException e) {

e.printStackTrace();

}finally{if (sqlSession != null) {

sqlSession.close();

}

}

}/*** 删除多条消息*/

public void deleteBatch(Listids) {

DBAccess dbAccess= newDBAccess();

SqlSession sqlSession= null;try{

sqlSession=dbAccess.getSqlSession();

sqlSession.delete("Message.deleteBatch", ids);

sqlSession.commit();

}catch(IOException e) {

e.printStackTrace();

}finally{if (sqlSession != null) {

sqlSession.close();

}

}

}public static voidmain(String[] args) {

MessageDao messageDao= newMessageDao();

messageDao.queryMessageList("", "");

}

}