sell2.java

jsp超市管理系统系统,是用经典的MVC设计模式开发的非常适合初学者学习。

package com.myservlet.sell;

import java.io.*;
import java.sql.*;
import javax.servlet.*;	
import javax.servlet.http.*;

import com.dbconn.*;

public class Sell2 extends HttpServlet{
	
	/**
	 * 
	 */
	private static final long serialVersionUID = 4235684279698135867L;

	public void doPost(HttpServletRequest request, HttpServletResponse response)
		throws ServletException, IOException {
		performTask(request, response);
	}

	public void doGet(HttpServletRequest request, HttpServletResponse response)
		throws ServletException, IOException {
		performTask(request, response);
	}

	private synchronized void performTask(HttpServletRequest request, HttpServletResponse response)
		throws ServletException, IOException{
		
		String opname = (String)request.getSession(true).getAttribute("opname");
		String kamount = request.getParameter("kamount");
		String goodsid = request.getParameter("id");		//商品ID
		String opid = request.getParameter("op");			//员工编号
		String samount = request.getParameter("samount");	//进货数量
		String remark = request.getParameter("bremark");	//进货备注
		String time = request.getParameter("time");			//进货时间

		ConnManager connManager = new ConnManager();
		Connection conn = connManager.getConnection("market");
		PreparedStatement ps = null;	
		
		if(Integer.parseInt(samount) > Integer.parseInt(kamount)){
			request.getSession(true).setAttribute("message8", "库存不足，请重新操作！");
		}
		else{
			try{
				String sql = "UPDATE goods SET amount=amount-'"+samount+"' WHERE id='"+goodsid+"'";
				sql = new String(sql.getBytes("ISO8859-1"), "gbk");
				System.out.println(sql);
				ps = conn.prepareStatement(sql);
				int m = ps.executeUpdate();
				if(m != 0){
					String sql2 = "INSERT INTO sell (id, goodsid, amount, time, opid, opname, remark) VALUES (sellseq.NEXTVAL, '"+goodsid+"', '"+samount+"', '"+time+"', '"+opid+"', '"+opname+"', '"+remark+"')";
					sql2 = new String(sql2.getBytes("ISO8859-1"), "gbk");
					System.out.println(sql2);
					ps = conn.prepareStatement(sql2);
					int n = ps.executeUpdate();
					if(n != 0){				
						request.getSession(true).setAttribute("message8", "销售成功！");
					}
				}
				else{
					request.getSession(true).setAttribute("message8", "销售失败，请重新操作！");
				}
			}
			catch(SQLException e){
				System.out.println(e);
				request.getSession(true).setAttribute("message8", "销售失败，输入数据格式错误！");
			}
			finally{
				try{
					ps.close();
					conn.close();
				}
				catch(SQLException e){
					System.out.println(e);
				}
				connManager.releaseConnection("market",conn);
			}
		}
	
		RequestDispatcher dispatcher= request.getRequestDispatcher("sell/result4.jsp");
		dispatcher.forward(request, response);
	}
}