sevlet代码实现
package com.zzxtit.system.servlet;
import java.io.IOException;
import java.sql.SQLException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.ScalarHandler;
import com.zzxtit.util.DBUtil;
@WebServlet("/getTotalIncome.action")
public class getTotalIncome extends HttpServlet{
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doPost(request,response);
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
request.setCharacterEncoding("utf-8");
response.setContentType("text/html; charset=utf-8");
String idCard = request.getParameter("idCard");
//System.out.println("进入servlet");
String sql = "select sum(consume_money) as sum_consume_money from t_order";
QueryRunner qr = new QueryRunner(DBUtil.getDS());
try {
Object obj = qr.query(sql, new ScalarHandler());
String totalMoney = String.valueOf(obj);
//System.out.println(totalMoney);
response.getWriter().write(totalMoney);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
注 :
(1) sql求和语句 select sum(consume_money) as sum_consume_money from t_order
(2)注意ScalarHandler的使用
(3)前台 使用的ajax进入的servlet 所出使用response.getWriter().write(totalMoney);返回数据
(4)读取出来的数据是BigDecimal的格式,无法转为int格式的数据, 我们先将其转为String格式的数据,直接通过String类型的数据进行传递,直接将String类型的数据放到html的代码中。
前台ajax代码实现 :
$(function(){
var sumMoney = 0;
$.ajax({
url : "${ctxpath}/getTotalIncome.action",
type : "post",
//dataType : "String",
success : function(data){
//alert("测试成功");
//alert(data);
//sumMoney = Number(data);
//alert(sumMoney);
//alert(data);
document.getElementById("ordersum").innerHTML = data;
},
error : function(data){
parseInt(data);
alert(data);
}
})
});