从输入的SQL参数中获取表名及字段名的操作教程

工具类

package com.isoft.mongo;/*
 * @Author: Create by Achun
 *@Time: 2018/6/3 23:20
 *
 */

import java.util.ArrayList;
import java.util.List;

public class SQLUtils {

    public List getColumns(String querysql){
        List column = new ArrayList();
        String tmp = querysql.substring(querysql.indexOf("select") + 6,
                querysql.indexOf("from")).trim();
        if (tmp.indexOf("*") == -1){
            String cols[] = tmp.split(",");
            for (String c:cols){
                column.add(c);
            }
        }
        return column;
    }

    public String getTBname(String querysql){
        String tmp = querysql.substring(querysql.indexOf("from")+4).trim();
        int sx = tmp.indexOf(" ");
        if(sx == -1){
            return tmp;
        }else {
            return tmp.substring(0,sx);
        }
    }

}

测试：

package com.isoft.mongo;
/*
 * @Author: Create by Achun
 *@Time: 2018/6/3 23:32
 *
 */

import java.util.List;

public class SQLUtilsTest {
    public static void main(String[] args) {
        String querysql = "select id,name,age,exent_month from mg";
        SQLUtils utils = new SQLUtils();
        String tablename = utils.getTBname(querysql);
        List columns = utils.getColumns(querysql);
        System.out.println("tablename:" + tablename);
        System.out.println("columns:" + columns);
        System.out.println("frist column:"+columns.get(0));

    }
}