Connection对象一直没有被释放

以下这个方法的目的是
1.先更新表sys_enterprise 里的一条记录
2.在到sys_staffs插入一条记录
3.然后 执行存储过程建里俩个表

问题是 为什么我执行成功后？到sql 2000 的查询分析器里运行

select * from sys_staffs 觉得表里的锁一直没释放呢?
难道每个 con 都要写一个 con.commit()函数

public boolean checkEnterprise(String id)
	{
		boolean flag = false;
		EnterpriseEntity enterprise = this.getEnterpriseById(id);
		String sql = "update sys_enterprise set e_isallowed = 1 where e_id = ?";
		Connection con = dbc.getConnection();
		
		CallableStatement cst = null;
		PreparedStatement pst = null;
		ResultSet rs = null;
		try {
			
			con.setAutoCommit(false);
			pst = con.prepareStatement(sql);
			pst.setString(1, id);
			pst.executeUpdate();
			
			con = null;
			con = dbc.getConnection();
			con.setAutoCommit(false);
			sql = "insert into sys_staffs(s_name,s_pwd,s_enterprisename) values(?,?,?)";
			pst = con.prepareStatement(sql);
			pst.setString(1, enterprise.getEname());
			pst.setString(2, Secret.getMD5(enterprise.getEname()));
			pst.setString(3, enterprise.getEname());
			pst.executeUpdate();
			
			con = null;
			con = dbc.getConnection();
			con.setAutoCommit(false);
			sql = "{call proc_create_enterprise '"+enterprise.getEname()+"'}";
			cst = con.prepareCall(sql);
			cst.execute();
			
			con.commit();
			flag = true;
		} catch (Exception e) {
			flag = false;
			try {
				con.rollback();
			} catch (SQLException e1) {
				e1.printStackTrace();
			}
			e.printStackTrace();
		}finally{
			dbc.close(rs, pst, con);
		}
		return flag;
	}