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  • MVC (jsp + servlet + javabean) 以及jdbc

    前端: 

    <%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
    <%@ page import = "java.util.ArrayList" %>
    <!DOCTYPE html>
    <html>
    <head>
    <meta charset="UTF-8">
    <title>Insert title here</title>
    </head>
    <body>
    <%!
    int size;
    ArrayList temp = new ArrayList();
    %>
    <%
    ArrayList result = (ArrayList)request.getAttribute("result");
    size = result.size();
    %>
    <table>
    <tr>
    <th>ID</th>
    <th>品牌</th>
    <th>价格</th>
    <th>保质期</th>
    </tr>
    <%
    for(int j = 0; j <size; j++){
    temp.clear();
    temp = (ArrayList)result.get(j); %>
    <tr>
    <th><a href = "change?id=<%=temp.get(0)%>"><%=temp.get(0)%></a></th>
    <th><%= temp.get(1)%></th>
    <th><%= temp.get(2)%></th>
    <th><%= temp.get(3)%></th>
    </tr>
    <%}
    %>
    </table>
    <a href = "add.jsp"> 增加 </a>

    </body>
    </html>

    后端: 

    @WebServlet("/show")
    public class show extends HttpServlet {
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    service service = new service();
    ArrayList result = service.queryAll();
    //将传递数据放入到request里面
    request.setAttribute("result", result);
    request.getRequestDispatcher( "show.jsp").forward(request,response);
    }

    /**
    * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
    */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    // TODO Auto-generated method stub
    doGet(request, response);
    }

    }

    实体类:

    package dao;

    //专门用于数据的传递
    public class entity {
    private int id;
    private String name;
    private int price;
    private int date;

    public String getName() {
    return name;
    }
    public void setName(String name) {
    this.name = name;
    }
    public int getPrice() {
    return price;
    }
    public void setPrice(int price) {
    this.price = price;
    }
    public int getDate() {
    return date;
    }
    public void setDate(int date) {
    this.date = date;
    }
    }

     数据库jdbc:JDBC的工作量大:需要先注册驱动和数据库信息、操作Connection、通过statement对象执行SQL,将结果返回给resultSet,然后从resultSet中读取数据并转换为pojo对象,最后需要关闭数据库相关资源。

    jdbc实例:

      public class add {
        public static boolean add(int Id, String Name, int Price, int Data) {
          String dbDriver = "com.microsoft.sqlserver.jdbc.SQLServerDriver";
          String dbURL = "jdbc:sqlserver://localhost:1433;DatabaseName = test";
          String userName = "sa";
          String userPwd = "123456";
          try {
            Class.forName(dbDriver);
            Connection connection = DriverManager.getConnection(dbURL, userName, userPwd);
            Statement state = connection.createStatement();
            String sql = "use test";
            state.execute(sql);
            sql = "insert into dbo.car(id,name,price,data)values(" + Id +"," + "'Name'" +"," + Price +"," + Data +")";
            System.out.println("检查传入的字段");
            System.out.println(sql);
            boolean result = state.execute(sql);
            System.out.println(result);
            return result;
          }
        catch(Exception e) {
            e.printStackTrace();
          }
        return false;
        }
      }

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  • 原文地址:https://www.cnblogs.com/helloqiufei/p/10730345.html
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