新手填坑 java.lang.Integer cannot be cast to java.lang.String

本文转载自： http://wwwblogs/zhengwanmeixiansen/archive/2017/08/17/7380666.html 作者：zhengwanmeixiansen 转载请注明该声明。

java连接mysql封装的获取集合的公用方法

public List<Map<String, String>> getSet(String sql){
        List<Map<String, String>> list = new ArrayList<Map<String,String>>();
        ResultSet rs = null;
        Statement sm = null;
        try {
            //1.加载驱动程序
            Class.forName(driver);
            con = DriverManager.getConnection(url, user, passwod);
            //2.创建statement类对象，用来执行SQL语句！！
            sm = con.createStatement();
            rs = sm.executeQuery(sql);
            //返回列的描述信息
            ResultSetMetaData rsmd = rs.getMetaData();
            while(rs.next()){
                Map map = new HashMap();
                for (int i = 1; i <= rsmd.getColumnCount(); i++) {
                    map.put(rsmd.getColumnName(i), rs.getObject(i));
                }
                list.add(map);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }finally {
            closeAll(rs,sm,con);
        }
        return list;
    }