运行展示:
代码：
首先是项目的大包：
正常项目中JavaBean和DAO应该放在两个不同的包中，在这因为代码较少，放在一个包内
Books.java:
package Beans;
public class Books {
private int bookId;
private String bookName;
private double price;
public int getBookId() {
return bookId;
}
public void setBookId(int bookId) {
this.bookId = bookId;
}
public String getBookName() {
return bookName;
}
public void setBookName(String bookName) {
this.bookName = bookName;
}
public double getPrice() {
return price;
}
public void setPrice(double price) {
this.price = price;
}
}
DAO.java:
package Beans;
import java.util.List;
public interface DAO {
//查询书单
public List<Books> findAllBooks();
//find book by id
public Books findBookByName(String name);
//update book
public void updateBook(Books book);
//add a new book
public void addBook(Books book);
//delete a book by id
public void deleteBookByName(String name);
}
DAOImpl.java:
package Beans;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;
public class DAOImpl implements DAO {
public List<Books> findAllBooks(){
List<Books> list = new ArrayList();
Books book = null;
DBUtil util = new DBUtil();
Connection conn = util.getConnection();
String sql = "select * from Book";
try {
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery(sql);
while(rs.next()) {
book = new Books();
book.setBookId( rs.getInt("bookId"));
book.setBookName(rs.getString("bookName"));
book.setPrice(rs.getDouble("price"));
list.add(book);
}
rs.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally {
util.closeConnection(conn);
}
return list;
}
public Books findBookByName(String name) {
// TODO Auto-generated method stub
DBUtil util = new DBUtil();
Connection conn = util.getConnection();
Books b = null;
String sql = "select * from Book where bookName=? ";
try {
PreparedStatement pstmt=
conn.prepareStatement(sql);
pstmt.setString(1, name);
ResultSet rs = pstmt.executeQuery();
if(rs.next()) {
b = new Books();
b.setBookId(rs.getInt("bookId"));
b.setBookName(rs.getString("bookName"));
b.setPrice(rs.getInt("Price"));
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return b;
}
public void updateBook(Books book) {
// TODO Auto-generated method stub
DBUtil util = new DBUtil();
Connection conn = util.getConnection();
Books b = null;
String sql = "update Book set bookName=?,price=?,bookId=?";
try {
b=new Books();
PreparedStatement pstmt = conn.prepareStatement(sql);
pstmt.setString(1, b.getBookName());
pstmt.setDouble(2, b.getPrice());
pstmt.setInt(3, b.getBookId());
pstmt.executeUpdate();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void addBook(Books book) {
// TODO Auto-generated method stub
DBUtil util = new DBUtil();
Connection conn = util.getConnection();
System.out.println(conn);
String sql =
"insert into Book(bookId,bookName,price) values(?,?,?)";
try {
PreparedStatement pstmt = conn.prepareStatement(sql);
pstmt.setInt(1, book.getBookId());
pstmt.setString(2, book.getBookName());
pstmt.setDouble(3,book.getPrice());
pstmt.executeUpdate();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void deleteBookByName(String name) {
// TODO Auto-generated method stub
DBUtil util = new DBUtil();
Connection conn = util.getConnection();
String sql = "delete from Book where bookName = ? ";
try {
PreparedStatement pstmt = conn.prepareStatement(sql);
pstmt.setString(1, name);
pstmt.executeUpdate();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
DBUtil.java:(分享了两种常用的数据库连接方式，大家可以自行选用哦！）
多插一嘴：如果连接数据库老是报classnotfundException 可以查看我的另一篇博文寻找解决方法！
package Beans;
import java.io.IOException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.Properties;
public class DBUtil {
public Connection getConnection() {
try {
Class.forName("com.mysql.cj.jdbc.Driver");
return DriverManager.getConnection("jdbc:mysql://localhost:3306/demo?serverTimezone=UTC","root","zxc123456");
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
public void closeConnection(Connection conn) {
if(conn!=null)
try {
conn.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public Connection openConnection() {
Properties prop = new Properties();
String driver = null;
String url = null;
String username = null;
String password = null;
try {
prop.load(
this.getClass().getClassLoader().getResourceAsStream(
"DBconfig.properties"));
driver = prop.getProperty("driver");
url = prop.getProperty("url");
username = prop.getProperty("username");
password = prop.getProperty("password");
Class.forName(driver);
return DriverManager.getConnection(url,username,password);
} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}
return null;
}
}
home.jsp:
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ page import="Beans.DAOImpl"%>
<%@ page import="Beans.Books"%>
<%@ page import="java.util.ArrayList" %>
<%@ page import="java.util.List" %>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Operation</title>
<script>
function confirmDelete() {
if (confirm("确定删除吗？")) {
return true;
} else {
return false;
}
}
window.onload = initAll;
function initAll() {
//alert('init');
var delEl = document.getElementsByClassName("da");
for (var i = 0; i < delEl.length; i++) {
delEl[i].onclick = confirmDelete;
}
}
</script>
</head>
<body>
<h2>书籍信息管理</h2>
<%
DAOImpl dao = new DAOImpl();
List<Books> list = new ArrayList();
list=dao.findAllBooks();
%>
<form action="doselect.jsp" method="post">
<div>
<input type="text" name="inputName">
<input type="submit" value="查询">
</div>
<hr border="1">
</form>
<jsp:useBean id="book" class="Beans.Books"/>
<table border="1">
<tr>
<th>书籍编号</th>
<th>名称</th>
<th>价格</th>
<th>操作</th>
</tr>
<%
for(Books b:list){
%>
<tr align="center">
<td><%=b.getBookId() %></td>
<td><%=b.getBookName() %></td>
<td><%=b.getPrice() %></td>
<td><a href="update.jsp?id=<%=b.getBookId()%>">修改</a> | <a class="da" href="dodelete.jsp?name=<%=b.getBookName()%>">删除</a></td>
</tr>
<%
}
%>
</table>
<br>
<a href="insert.jsp">添加书籍</a>
</body>
</html>insert.jsp:
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert</title>
</head>
<h2>添加书籍！</h2>
<body>
<%request.setCharacterEncoding("utf-8"); %>
<form action="doInsert.jsp" method="post">
<div>
<label for="">编号:</label>
<input type="number" name="bookId" id="id">
</div>
<div>
<label for="">书名:</label>
<input type="text" name="bookName" id="book">
</div>
<div>
<label for="">价格:</label>
<input type="number" name="price" id="price">
</div>
<div>
<input type="submit" name="s" value="提交">
</div>
</form>
</body>
</html>doInsert.jsp:
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ page import="Beans.DAOImpl"%>
<%@ page import="Beans.Books"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
<%
int id=Integer.parseInt(request.getParameter("bookId").toString());
String name=request.getParameter("bookName").toString();
double price = Double.valueOf(request.getParameter("price").toString());
%>
<%request.setCharacterEncoding("utf-8"); %>
<jsp:useBean id="book" class="Beans.Books" scope="page">
<jsp:setProperty name="book" property="bookId" value="<%=id%>" />
<jsp:setProperty name="book" property="bookName" value="<%=name%>" />
<jsp:setProperty name="book" property="price" value="<%=price%>" />
</jsp:useBean>
<%
DAOImpl dao = new DAOImpl();
dao.addBook(book);
%>
<jsp:forward page="insert.jsp"/>
</body>
</html>update.jsp:
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>update</title>
</head>
<body>
<h2>修改书籍信息</h2>
<form action="doUpdate.jsp" method="post">
<div>
<label for="">编号：</label>
<input type="number" name="id" value="<%=Integer.parseInt(request.getParameter("id").toString()) %>" >
</div>
<div>
<label for="">书名：</label>
<input type="text" name="book">
</div>
<div>
<label for="">价格：</label>
<input type="number" name="price">
</div>
<div>
<input type="submit" value="提交">
</div>
</form>
</body>
</html>doUpdate.jsp:
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ page import="Beans.DAOImpl"%>
<%@ page import="Beans.Books"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
<%
int id = Integer.parseInt(request.getParameter("id").toString());
String name= request.getParameter("book").toString();
double price = Double.valueOf(request.getParameter("price"));
%>
<jsp:useBean id="book" class="Beans.Books"/>
<jsp:setProperty name="book" property="bookId" value="<%=id%>"/>
<jsp:setProperty name="book" property="bookName" value="<%=name %>"/>
<jsp:setProperty name="book" property="price" value="<%=price %>"/>
<%
DAOImpl dao = new DAOImpl();
dao.updateBook(book);
%>
<jsp:forward page="update.jsp"/>
</body>
</html>doselect.jsp:
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ page import="Beans.DAOImpl"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>select</title>
</head>
<body>
<jsp:useBean id="b" class="Beans.Books"/>
<%
String bookname=request.getParameter("inputName").toString();
DAOImpl dao = new DAOImpl();
b=dao.findBookByName(bookname);
%>
<jsp:setProperty property="bookId" name="b" value="<%=b.getBookId() %>"/>
<jsp:setProperty property="bookName" name="b" value="<%=b.getBookName() %>"/>
<jsp:setProperty property="price" name="b" value="<%=b.getPrice() %>"/>
<table border="1">
<tr>
<th>书籍编号</th>
<th>书名</th>
<th>价格</th>
<th>操作</th>
</tr>
<%
if(b!=null){
%>
<tr align="center">
<td>
<jsp:getProperty property="bookId" name="b"/>
</td>
<td>
<jsp:getProperty property="bookName" name="b"/>
</td>
<td>
<jsp:getProperty property="price" name="b"/>
</td>
<td><a href="update.jsp">修改</a>|<a href="delete.jsp">删除</a></td>
</tr>
<%
}
%>
</table>
</body>
</html>dodelete.jsp:
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<%@ page import="Beans.DAOImpl"%>
<%@ page import="Beans.Books"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="ISO-8859-1">
<title>delete</title>
</head>
<body>
<%
DAOImpl dao = new DAOImpl();
dao.deleteBookByName(request.getParameter("name"));
%>
<jsp:forward page="home.jsp"/>
</body>
</html>写给自己：
- <a href="update.jsp?id=<%=b.getBookId()%>">修改</a>中可以设id,name 等各种根据需要的，这里面的id也是一个页面传递，相当于一层过滤了，在另一页面也是使用request.getParameter("id")来获取。同时，这个页面传值应该是get请求（URL中会显示？id=）
- <jsp:useBean id="book" class="Beans.Books"/>相当于新建了一个对象实例，同时这个对象book也可以在页面中使用
- 表单传值乱码的问题还没有有效解决。。。（或许是浏览器不同吧）
掉坑也要弧线！！！！
