用JSP+JavaBean开发模式实现一个销售额的查询
数据库使用mysql,如下: vo包的Sales类: package com.vo; public class Sales { public String salestime; public float salesnum; public String getSalestime() { return salestime; } public void setSalestime(String salestime) { this.salestime = salestime; } public float getSalesnum() { return salesnum; } public void setSalesnum(float salesnum) { this.salesnum = salesnum; } } dao包中的DBManager类: package com.dao; import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; public class DbManager { private static String URL = "jdbc:mysql