JAVA-EE不使用MVC的情况下完成银行转账业务------计算机网络经典

深碍√TFBOYSˉ_ 2024-02-20 08:44 19阅读 0赞

>     package com.bjpowernode.Bank.web.servlet;
>     
>     import com.bjpowernode.Bank.exception.AppException;
>     import com.bjpowernode.Bank.exception.MoneyNotEnoughException;
>     import com.bjpowernode.oa.utils.DBUtil;
>     import jakarta.servlet.ServletException;
>     import jakarta.servlet.annotation.WebServlet;
>     import jakarta.servlet.http.HttpServlet;
>     import jakarta.servlet.http.HttpServletRequest;
>     import jakarta.servlet.http.HttpServletResponse;
>     
>     import java.io.IOException;
>     import java.io.PrintWriter;
>     import java.sql.Connection;
>     import java.sql.PreparedStatement;
>     import java.sql.ResultSet;
>     import java.sql.SQLException;
>     
>     @WebServlet("/bank/transfer")
>     public class AccountTransferServlet extends HttpServlet
>     {
>         @Override
>         protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
>             request.setCharacterEncoding("UTF-8");
>             response.setContentType("text/html;charset=UTF-8");
>             PrintWriter out = response.getWriter();
>             String fromActno = request.getParameter("fromActno");
>             String toActno = request.getParameter("toActno");
>             Double value = Double.parseDouble(request.getParameter("Value"));
>             Connection connection = null;
>             PreparedStatement statement = null;
>             ResultSet resultSet = null;
>             PreparedStatement statement1 = null;
>             PreparedStatement statement2 = null;
>             try
>             {
>                 connection = DBUtil.getConnection();
>                 connection.setAutoCommit(false);
>                 String sql = "select * from t_act where actno = ?";
>                 statement = connection.prepareStatement(sql);
>                 statement.setString(1,fromActno);
>                 resultSet = statement.executeQuery();
>                 if(resultSet.next())
>                 {
>                     System.out.println("我在这");
>                     double balance = resultSet.getDouble("balance");
>                     System.out.println(balance);
>                     if(balance < value)
>                     {
>                         //余额不足
>                         throw new MoneyNotEnoughException("余额不足");
>                     }
>                     else
>                     {
>                         String newSql = "update t_act set balance = balance - ? where actno = ?";
>                         statement1 = connection.prepareStatement(newSql);
>                         statement1.setDouble(1,value);
>                         statement1.setString(2,fromActno);
>                         int count = statement1.executeUpdate();
>                         String sql2 = "update t_act set balance = balance + ? where actno = ?";
>                         statement2 = connection.prepareStatement(sql2);
>                         statement2.setDouble(1,value);
>                         statement2.setString(2,toActno);
>                         count = count + statement2.executeUpdate();
>                         if(count != 2)
>                         {
>                             throw new AppException("App异常请联系管理员");
>                         }
>                         else
>                         {
>                             connection.commit();
>                             out.println("转账成功");
>                         }
>                     }
>                 }
>             }
>             catch (Exception e)
>             {
>                 if (connection != null)
>                 {
>                     try
>                     {
>                         connection.rollback();
>                     }
>                     catch (SQLException ex)
>                     {
>                         throw new RuntimeException(ex);
>                     }
>                 }
>                 //传的一定是构造方法我们传的值
>                 out.println(e.getMessage());
>             }
>             finally
>             {
>                 DBUtil.close(connection,statement,resultSet);
>                 DBUtil.close(null,statement1,null);
>                 DBUtil.close(null,statement2,null);
>             }
>         }
>     }
> 
>     package com.bjpowernode.Bank.web.servlet;
>     
>     import com.bjpowernode.Bank.exception.AppException;
>     import com.bjpowernode.Bank.exception.MoneyNotEnoughException;
>     import com.bjpowernode.oa.utils.DBUtil;
>     import jakarta.servlet.ServletException;
>     import jakarta.servlet.annotation.WebServlet;
>     import jakarta.servlet.http.HttpServlet;
>     import jakarta.servlet.http.HttpServletRequest;
>     import jakarta.servlet.http.HttpServletResponse;
>     
>     import java.io.IOException;
>     import java.io.PrintWriter;
>     import java.sql.Connection;
>     import java.sql.PreparedStatement;
>     import java.sql.ResultSet;
>     import java.sql.SQLException;
>     
>     @WebServlet("/bank/transfer")
>     public class AccountTransferServlet extends HttpServlet
>     {
>         @Override
>         protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
>             request.setCharacterEncoding("UTF-8");
>             response.setContentType("text/html;charset=UTF-8");
>             PrintWriter out = response.getWriter();
>             String fromActno = request.getParameter("fromActno");
>             String toActno = request.getParameter("toActno");
>             Double value = Double.parseDouble(request.getParameter("Value"));
>             Connection connection = null;
>             PreparedStatement statement = null;
>             ResultSet resultSet = null;
>             PreparedStatement statement1 = null;
>             PreparedStatement statement2 = null;
>             try
>             {
>                 connection = DBUtil.getConnection();
>                 connection.setAutoCommit(false);
>                 String sql = "select * from t_act where actno = ?";
>                 statement = connection.prepareStatement(sql);
>                 statement.setString(1,fromActno);
>                 resultSet = statement.executeQuery();
>                 if(resultSet.next())
>                 {
>                     System.out.println("我在这");
>                     double balance = resultSet.getDouble("balance");
>                     System.out.println(balance);
>                     if(balance < value)
>                     {
>                         //余额不足
>                         throw new MoneyNotEnoughException("余额不足");
>                     }
>                     else
>                     {
>                         String newSql = "update t_act set balance = balance - ? where actno = ?";
>                         statement1 = connection.prepareStatement(newSql);
>                         statement1.setDouble(1,value);
>                         statement1.setString(2,fromActno);
>                         int count = statement1.executeUpdate();
>                         String sql2 = "update t_act set balance = balance + ? where actno = ?";
>                         statement2 = connection.prepareStatement(sql2);
>                         statement2.setDouble(1,value);
>                         statement2.setString(2,toActno);
>                         count = count + statement2.executeUpdate();
>                         if(count != 2)
>                         {
>                             throw new AppException("App异常请联系管理员");
>                         }
>                         else
>                         {
>                             connection.commit();
>                             out.println("转账成功");
>                         }
>                     }
>                 }
>             }
>             catch (Exception e)
>             {
>                 if (connection != null)
>                 {
>                     try
>                     {
>                         connection.rollback();
>                     }
>                     catch (SQLException ex)
>                     {
>                         throw new RuntimeException(ex);
>                     }
>                 }
>                 //传的一定是构造方法我们传的值
>                 out.println(e.getMessage());
>             }
>             finally
>             {
>                 DBUtil.close(connection,statement,resultSet);
>                 DBUtil.close(null,statement1,null);
>                 DBUtil.close(null,statement2,null);
>             }
>         }
>     }