Java查询MySQL数据库指定数据库中所有表名、字段名、字段类型、字段长度、字段描述

public static List<Map<String, String>> getColumnInfoByTableName(String databaseName, String databaseUserName,
                                                                     String databaseUserPassword, String tableName){
         //指定表
//        String sql = "SELECT TABLE_NAME, column_name, DATA_TYPE, COLUMN_TYPE, column_comment FROM information_schema. COLUMNS WHERE TABLE_SCHEMA = '"+databaseName+"' and TABLE_NAME = '"+tableName+"'";
        //不指定表
        String sql = "SELECT TABLE_NAME, column_name, DATA_TYPE, COLUMN_TYPE, column_comment FROM information_schema. COLUMNS WHERE TABLE_SCHEMA = '"+databaseName+"'";
        List<Map<String, String>> columnNameList = getJdbcData("com.mysql.jdbc.Driver",
                "jdbc:mysql://IP:PORT/databaseName?useUnicode=true&characterEncoding=UTF8",
                databaseUserName, databaseUserPassword,
                sql,
                1, 5);
        //结果中的对应关系:column1 -- 表名; column2 -- 字段名; column3 -- 字段类型; column4 -- 字段类型长度; column5 -- 字段描述;
        return columnNameList;
    }