JDBC之修改数据

文件分布图：

在MySQL中设置表格：

Books:

package com.caiduping.entity;

public class Books {
    private int id;
    // 图书名称
    private String name;
    // 价格
    private double price;
    // 数量
    private int bookCount;
    // 作者
    private String author;
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public double getPrice() {
        return price;
    }
    public void setPrice(double price) {
        this.price = price;
    }
    public int getBookCount() {
        return bookCount;
    }
    public void setBookCount(int bookCount) {
        this.bookCount = bookCount;
    }
    public String getAuthor() {
        return author;
    }
    public void setAuthor(String author) {
        this.author = author;
    }
}

bookdao:

package com.caiduping.dao;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.Statement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;
import java.util.ArrayList;
import com.caiduping.dao.dataconn;
import com.caiduping.entity.Books;

public class bookdao {
    public int addBooks(Books b) throws ClassNotFoundException,SQLException{
        dataconn c=new dataconn();
        Connection conn=c.openconn();
        String sql = "insert into tb_books(name,price,bookCount,author) values(?,?,?,?)";
        // 获取PreparedStatement
         PreparedStatement ps = conn.prepareStatement(sql);
        // 对SQL语句中的第1个参数赋值
         ps.setString(, b.getName());
         System.out.println("name："+b.getName());
        // 对SQL语句中的第2个参数赋值
          ps.setDouble(, b.getPrice());
          // 对SQL语句中的第3个参数赋值
          ps.setInt(,b.getBookCount());
          // 对SQL语句中的第4个参数赋值
          ps.setString(, b.getAuthor());
          // 执行更新操作，返回所影响的行数
          int row = ps.executeUpdate();
          // 判断是否更新成功
          conn.close();
          return row;
    }
    public List<Books> Listbook() throws ClassNotFoundException, SQLException{
        List<Books> b=new ArrayList<Books>();
         dataconn c=new dataconn();
         Connection conn=c.openconn();
         Statement st=conn.createStatement();
          ResultSet rs=st.executeQuery("select * from tb_books");  //利用st执行语句,结果防到结果集.
          while(rs.next())
          {Books b1=new Books();
          b1.setId(rs.getInt("id"));
          b1.setName(rs.getString("name"));
          b1.setPrice(rs.getDouble("price"));
          b1.setBookCount(rs.getInt("bookCount"));
          b1.setAuthor(rs.getString("author"));
          b.add(b1);
          }
          rs.close();
          st.close();
          conn.close();
          return b;
    }
     public List<Books> Listbook(String a) throws ClassNotFoundException, SQLException  //查询书籍名称含有a串的书籍
      {List<Books> b=new ArrayList<Books>();
      dataconn c=new dataconn();
      Connection conn=c.openconn();
      Statement st=conn.createStatement();
      ResultSet rs=st.executeQuery("select * from tb_books where name like '%'+" + a + "+'%'");  //利用st执行语句,结果防到结果集.
      while(rs.next())
      {Books b1=new Books();
      b1.setId(rs.getInt("id"));
      b1.setName(rs.getString("name"));
      b1.setPrice(rs.getDouble("price"));
      b1.setBookCount(rs.getInt("bookCount"));
      b1.setAuthor(rs.getString("author"));
      b.add(b1);
      }
      rs.close();
      st.close();
      conn.close();
      return b;

      }
     public Books Listbook(int a) throws ClassNotFoundException, SQLException //参数a为书籍编号
      {Books b1=new Books();
      dataconn c=new dataconn();
      Connection conn=c.openconn();
      Statement st=conn.createStatement();
      ResultSet rs=st.executeQuery("select * from tb_books where id=" + a);  //利用st执行语句,结果防到结果集.
      if(rs.next())
      {
      b1.setId(rs.getInt("id"));
      b1.setName(rs.getString("name"));
      b1.setPrice(rs.getDouble("price"));
      b1.setBookCount(rs.getInt("bookCount"));
      b1.setAuthor(rs.getString("author"));

      }
      rs.close();
      st.close();
      conn.close();
      return b1;
}
     public int modiBooks(Books b) throws SQLException, ClassNotFoundException
      {int a=;
      dataconn c=new dataconn();
      Connection conn=c.openconn();
      String sql="update tb_books set name=?,price=?,bookCount=?,author=? where id=?";
      PreparedStatement ps=conn.prepareStatement(sql);
      ps.setString(,b.getName());
      ps.setDouble(, b.getPrice());
      ps.setInt(,b.getBookCount());
      ps.setString(, b.getAuthor());
      ps.setInt(,b.getId());
      a=ps.executeUpdate();
      ps.close();
      conn.close();

      return a;
      }}

dataconn:

package com.caiduping.dao;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class dataconn {
    public Connection openconn()throws ClassNotFoundException,SQLException {
        // TODO Auto-generated method stub
        Connection conn=null;
        Class.forName("com.mysql.jdbc.Driver");
        conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/db_database10","user2","");
        return conn;
    }
}

Booklist:

package com.caiduping.servlet;

import java.io.IOException;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.caiduping.dao.bookdao;
import com.caiduping.entity.Books;

public class Booklist extends HttpServlet {

    /**
     * Constructor of the object.
     */
    public Booklist() {
        super();
    }

    /**
     * Destruction of the servlet. <br>
     */
    public void destroy() {
        super.destroy(); // Just puts "destroy" string in log
        // Put your code here
    }

    /**
     * The doGet method of the servlet. <br>
     *
     * This method is called when a form has its tag value method equals to get.
     *
     * @param request the request send by the client to the server
     * @param response the response send by the server to the client
     * @throws ServletException if an error occurred
     * @throws IOException if an error occurred
     */
    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
            bookdao b=new bookdao();
            List<Books> b1=new ArrayList<Books>();
            try{
                try {
                    b1=b.Listbook();
                } catch (SQLException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }catch(ClassNotFoundException e){
                e.printStackTrace();
            }
    }

    /**
     * The doPost method of the servlet. <br>
     *
     * This method is called when a form has its tag value method equals to post.
     *
     * @param request the request send by the client to the server
     * @param response the response send by the server to the client
     * @throws ServletException if an error occurred
     * @throws IOException if an error occurred
     */
    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doGet(request, response);
    }

    /**
     * Initialization of the servlet. <br>
     *
     * @throws ServletException if an error occurs
     */
    public void init() throws ServletException {
        // Put your code here
    }

}

modibooks1:

package com.caiduping.servlet;

import java.io.IOException;
import java.io.PrintWriter;
import java.sql.SQLException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.caiduping.dao.bookdao;
import com.caiduping.entity.Books;

public class modibooks1 extends HttpServlet {

    /**
     * Constructor of the object.
     */
    public modibooks1() {
        super();
    }

    /**
     * Destruction of the servlet. <br>
     */
    public void destroy() {
        super.destroy(); // Just puts "destroy" string in log
        // Put your code here
    }

    /**
     * The doGet method of the servlet. <br>
     *
     * This method is called when a form has its tag value method equals to get.
     *
     * @param request the request send by the client to the server
     * @param response the response send by the server to the client
     * @throws ServletException if an error occurred
     * @throws IOException if an error occurred
     */
    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        int a=Integer.parseInt(request.getParameter("ID"));
        bookdao b=new bookdao();
        Books b1=new Books();
        try{
            try {
                b1=b.Listbook(a);
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }catch(ClassNotFoundException e){
            e.printStackTrace();
        }
        request.setAttribute("book", b1);
        request.getRequestDispatcher("modi1.jsp").forward(request, response);
    }

    /**
     * The doPost method of the servlet. <br>
     *
     * This method is called when a form has its tag value method equals to post.
     *
     * @param request the request send by the client to the server
     * @param response the response send by the server to the client
     * @throws ServletException if an error occurred
     * @throws IOException if an error occurred
     */
    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        doGet(request, response);
    }

    /**
     * Initialization of the servlet. <br>
     *
     * @throws ServletException if an error occurs
     */
    public void init() throws ServletException {
        // Put your code here
    }

}

modibooks2:

package com.caiduping.servlet;

import java.io.IOException;
import java.io.PrintWriter;
import java.sql.SQLException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.caiduping.dao.bookdao;
import com.caiduping.entity.Books;

public class modibooks2 extends HttpServlet {

    /**
     * Constructor of the object.
     */
    public modibooks2() {
        super();
    }

    /**
     * Destruction of the servlet. <br>
     */
    public void destroy() {
        super.destroy(); // Just puts "destroy" string in log
        // Put your code here
    }

    /**
     * The doGet method of the servlet. <br>
     *
     * This method is called when a form has its tag value method equals to get.
     *
     * @param request the request send by the client to the server
     * @param response the response send by the server to the client
     * @throws ServletException if an error occurred
     * @throws IOException if an error occurred
     */
    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
            Books b=new Books();
            b.setId(Integer.parseInt(request.getParameter("id").toString()));
            b.setName(request.getParameter("name"));
            b.setPrice(Double.parseDouble(request.getParameter("price").toString()));
            b.setAuthor(request.getParameter("author"));
            bookdao b1=new bookdao();
            int n=;
            try{
                try {
                    n=b1.modiBooks(b);
                } catch (ClassNotFoundException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }catch(SQLException e){
                e.printStackTrace();
            }
            request.getRequestDispatcher("b").forward(request, response);
    }

    /**
     * The doPost method of the servlet. <br>
     *
     * This method is called when a form has its tag value method equals to post.
     *
     * @param request the request send by the client to the server
     * @param response the response send by the server to the client
     * @throws ServletException if an error occurred
     * @throws IOException if an error occurred
     */
    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doGet(request, response);
    }

    /**
     * Initialization of the servlet. <br>
     *
     * @throws ServletException if an error occurs
     */
    public void init() throws ServletException {
        // Put your code here
    }

}

book_list.jsp:

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ page import="com.caiduping.entity.Books" %>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">

    <title>My JSP 'book_list.jsp' starting page</title>

    <meta http-equiv="pragma" content="no-cache">
    <meta http-equiv="cache-control" content="no-cache">
    <meta http-equiv="expires" content="">
    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    <meta http-equiv="description" content="This is my page">
    <!--
    <link rel="stylesheet" type="text/css" href="styles.css">
    -->

  </head>

  <body>
   <table width="" border="" align="center">
  <tr>
    <td>编号</td>
    <td>名称</td>
    <td>单价</td>
    <td>数量</td>
    <td>作者</td><td>操作</td>
  </tr>
  <%
  List<Books> list=(List<Books>)request.getAttribute("list");
  if(list==null||list.size()<){
  out.print("没有数据！");
  }else{
  %>
  <%for(Books b:list){ %>
<tr>
    <td><%=b.getId() %></td>
    <td><%=b.getName() %></td>
    <td><%=b.getPrice() %></td>
    <td><%=b.getBookCount() %></td>
    <td><%=b.getAuthor() %></td>
    <td><a href="modi?ID=%=b.getId() %>">修改</a></td>
  </tr>
  <%
  }
  } %>
  </table>
  </body>
</html>

modi1.jsp:

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ page  import="com.caiduping.entity.Books" %>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">

    <title>My JSP 'modi1.jsp' starting page</title>

    <meta http-equiv="pragma" content="no-cache">
    <meta http-equiv="cache-control" content="no-cache">
    <meta http-equiv="expires" content="">
    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    <meta http-equiv="description" content="This is my page">
    <!--
    <link rel="stylesheet" type="text/css" href="styles.css">
    -->

  </head>

  <body>
   <%
  Books b=(Books)request.getAttribute("books"); %>
    <form id="form1" name="form1" method="post" action="modi2">
    <input type="hidden" name="id" value="<%=b.getId()%>" />
  <table width="" border="" align="center">
    <tr>
      <td colspan=""><div align="center" class="STYLE1">书籍修改</div></td>
    </tr>

    <tr>
      <td>书名</td>
      <td><label>
        <input name="name" type="text" id="name" value="<%=b.getName()%>"/>
      </label></td>
    </tr>
    <tr>
      <td>单价</td>
      <td><label>
        <input name="price" type="text" id="price" value="<%=b.getPrice()%>"/>
      </label></td>
    </tr>
    <tr>
      <td>数量</td>
      <td><label>
        <input name="bookCount" type="text" id="bookCount" value="<%=b.getBookCount()%>"/>
      </label></td>
    </tr>
    <tr>
      <td>作者</td>
      <td><label>
        <input name="author" type="text" id="author" value="<%=b.getAuthor()%>"/>
      </label></td>
    </tr>
    <tr>
      <td colspan=""><label>
        <div align="center">
          <input type="submit" name="Submit" value="修改" />
          </div>
      </label></td>
    </tr>
  </table>
</form>
  </body>
</html>