自定义MVC增删改查

 

---

目录

1.将框架打成jar包，然后导入新工程，并且把框架的依赖jar包导入进去

2.将分页标签相关文件、及相关助手类导入

3.框架的配置文件添加、以及web.xml的配置-以后开源框架的使用从这一步开始

4.完成Book实体类及bookDao的编写

5.完成通用的增删改方法

6.完成BookAction

7.完成mvc.xml的配置

8.完成前台代码的编写

9.总结

---

1.将框架打成jar包，然后导入新工程，并且把框架的依赖jar包导入进去。

                        

                 

                 

    

                 

  

                                

 2.将分页标签相关文件、及相关助手类导入

 3.框架的配置文件添加、以及web.xml的配置-以后开源框架的使用从这一步开始

                                        

                                         

4.完成Book实体类及bookDao的编写

package com.ycx.entity;

public class Book {
	private int bid;
	private String bname;
	private float price;
	public Book() {
		// TODO Auto-generated constructor stub
	}
	public int getBid() {
		return bid;
	}
	public void setBid(int bid) {
		this.bid = bid;
	}
	public String getBname() {
		return bname;
	}
	public void setBname(String bname) {
		this.bname = bname;
	}
	public float getPrice() {
		return price;
	}
	public void setPrice(float price) {
		this.price = price;
	}
	public Book(int bid, String bname, float price) {
		super();
		this.bid = bid;
		this.bname = bname;
		this.price = price;
	}
	@Override
	public String toString() {
		return "Book [bid=" + bid + ", bname=" + bname + ", price=" + price + "]";
	}
	
}

package com.ycx.dao;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import com.ycx.entity.Book;
import com.ycx.util.BaseDao;
import com.ycx.util.DBAccess;
import com.ycx.util.PageBean;
import com.ycx.util.StringUtils;

public class BookDao extends BaseDao<Book>{
//	查询
	public List<Book> list(Book book,PageBean pageBean) throws Exception{
		String sql="select * from t_mvc_book where 1=1";
		String bname = book.getBname();
		if(StringUtils.isNotBlank(bname)) {
			sql+=" and bname like '%"+bname+"%'";
		}
		int bid = book.getBid();
//		前台jsp传递到后台，只要传了就有值，没穿就是默认值，默认值就是0
		if(bid!=0) {
			sql+=" and bid = "+bid;
		}
		return super.executeQuery(sql, pageBean, rs ->{
			List<Book> list=new ArrayList<>();
			try {
				while(rs.next()) {
					list.add(new Book(rs.getInt("bid"),rs.getString("bname"),rs.getFloat("price")));
				}
			} catch (Exception e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
			return list;
		});
	}
	
//	 增
	public int add(Book book) throws Exception {
		Connection con = DBAccess.getConnection();
		String sql="insert into t_mvc_book values (?,?,?)";
		PreparedStatement pst = con.prepareStatement(sql);
		pst.setObject(1, book.getBid());
		pst.setObject(2, book.getBname());
		pst.setObject(3, book.getPrice());
		return pst.executeUpdate();
	}
//	 删
	public int del(Book book) throws Exception {
		Connection con = DBAccess.getConnection();
		String sql="delete from t_mvc_book where bid= ?";
		PreparedStatement pst = con.prepareStatement(sql);
		pst.setObject(1, book.getBid());
		return pst.executeUpdate();
	}
	
	
//	 改
	public int edit(Book book) throws Exception {
		Connection con = DBAccess.getConnection();
		String sql="update t_mvc_book set bname=?,price=?, where bid=？";
		PreparedStatement pst = con.prepareStatement(sql);
		pst.setObject(3, book.getBid());
		pst.setObject(1, book.getBname());
		pst.setObject(2, book.getPrice());
		return pst.executeUpdate();
	}
	
	
}

然后用junit4去测试：

ctrl+n

 

 

 之后就自动生成了一个BookDaoTest:

package com.ycx.dao;

import static org.junit.Assert.*;

import java.util.List;

import org.junit.After;
import org.junit.Before;
import org.junit.Test;

import com.ycx.entity.Book;

public class BookDaoTest {
	private BookDao bookDao=new BookDao();
	@Before
	public void setUp() throws Exception {
	}

	@After
	public void tearDown() throws Exception {
	}

	@Test
	public void testList() {
		try {
			List<Book> list = bookDao.list(new Book(), null);
			for (Book book : list) {
				System.out.println(book);
			}
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

	@Test
	public void testAdd() {
		fail("Not yet implemented");
	}

	@Test
	public void testDel() {
		fail("Not yet implemented");
	}

	@Test
	public void testEdit() {
		fail("Not yet implemented");
	}

}

测试查询所有：

打印结果如下

 

 测试分页查询：

@Test
	public void testList() {
		try {
			List<Book> list = bookDao.list(new Book(), new PageBean());
			for (Book book : list) {
				System.out.println(book);
			}
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

结果如下：

 测试新增数据：

@Test
	public void testAdd() {
		Book book = new Book(1234321, "1234321", 1234321);
		try {
			bookDao.add(book);
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

结果如下：

 测试修改：

@Test
	public void testEdit() {
		Book book = new Book(1234321, "123432100", 1234321);
		try {
			bookDao.edit(book);
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

结果如下：

 测试删除：

	@Test
	public void testDel() {
		Book book = new Book(1234321, "1234321", 1234321);
		try {
			bookDao.del(book);
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

5.完成通用的增删改方法

BaseDao:

	public int executeUpdate(String sql,T t,String [] attrs) throws Exception {
		Connection con = DBAccess.getConnection();
		PreparedStatement pst = con.prepareStatement(sql);
//		将T的某一个属性对应的值加到 pst 对象中
		for (int i = 0; i < attrs.length; i++) {
			Field f = t.getClass().getDeclaredField(attrs[i]);
			f.setAccessible(true);
			pst.setObject(i+1, f.get(t));
		}
		return pst.executeUpdate();
	}

BookDao:

package com.ycx.dao;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import com.ycx.entity.Book;
import com.ycx.util.BaseDao;
import com.ycx.util.DBAccess;
import com.ycx.util.PageBean;
import com.ycx.util.StringUtils;

public class BookDao extends BaseDao<Book>{
//	查询
	public List<Book> list(Book book,PageBean pageBean) throws Exception{
		String sql="select * from t_mvc_book where 1=1";
		String bname = book.getBname();
		if(StringUtils.isNotBlank(bname)) {
			sql+=" and bname like '%"+bname+"%'";
		}
		int bid = book.getBid();
//		前台jsp传递到后台，只要传了就有值，没穿就是默认值，默认值就是0
		if(bid!=0) {
			sql+=" and bid = "+bid;
		}
		return super.executeQuery(sql, pageBean, rs ->{
			List<Book> list=new ArrayList<>();
			try {
				while(rs.next()) {
					list.add(new Book(rs.getInt("bid"),rs.getString("bname"),rs.getFloat("price")));
				}
			} catch (Exception e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
			return list;
		});
	}
	
//	 增
	
	public int add(Book book) throws Exception {
		String sql="insert into t_mvc_book values (?,?,?)";
		return super.executeUpdate(sql, book, new String[] {"bid","bname","price"});
	}
//	 删
	
	public int del(Book book) throws Exception {
		String sql="delete from t_mvc_book where bid= ?";
		return super.executeUpdate(sql, book, new String[] {"bid"});
	}
	
//	 改
	
	public int edit(Book book) throws Exception {
		String sql="update t_mvc_book set bname=?,price=?, where bid=？";
		return super.executeUpdate(sql, book, new String[] {"bname","price","bid"});
	}
	
	
}

6.完成BookAction

package com.ycx.web;

import java.util.List;

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

import com.ycx.dao.BookDao;
import com.ycx.entity.Book;
import com.ycx.framework.ActionSupport;
import com.ycx.framework.ModelDriven;
import com.ycx.util.PageBean;

public class BookAction  extends ActionSupport implements ModelDriven<Book>{
	private Book book=new Book();
	private BookDao bookDao=new BookDao();
	
	
	@Override
	public Book getModel() {
		return null;
	}
//	增
	public String add(HttpServletRequest req, HttpServletResponse resp) {
		try {
			bookDao.add(book);
		} catch (Exception e) {
			e.printStackTrace();
		}
//		toList代表跳到查询界面
		return "toList";
	}
	
//	删
	public String del(HttpServletRequest req, HttpServletResponse resp) {
		try {
			bookDao.del(book);
		} catch (Exception e) {
			e.printStackTrace();
		}
//		toList代表跳到查询界面
		return "toList";
	}	
//	修改	
		public String edit(HttpServletRequest req, HttpServletResponse resp) {
			try {
				bookDao.edit(book);
			} catch (Exception e) {
				e.printStackTrace();
			}
//			toList代表跳到查询界面
			return "toList";
		}
//		查询所有
		public String list(HttpServletRequest req, HttpServletResponse resp) {
			try {
				PageBean pageBean=new PageBean();
				pageBean.setRequest(req);
				List<Book> list = bookDao.list(book, pageBean);
				req.setAttribute("list", list);
				req.setAttribute("pageBean", pageBean);
			} catch (Exception e) {
				e.printStackTrace();
			}
//			执行查询展示
			return "list";
		}	
		
//		跳转到新增或者修改界面
		public String preEdit(HttpServletRequest req, HttpServletResponse resp) {
			try {
				int bid = book.getBid();
				if(bid != 0) {
//					传递bid到后台，有且只能查出一条数据，那也就意味着list集合中只有一条
					List<Book> list = bookDao.list(book, null);
					req.setAttribute("b", list.get(0));
				}
			} catch (Exception e) {
				e.printStackTrace();
			}
//			代表跳到编辑界面
			return "toEdit";
		}	
		
		
		
		
}

7.完成mvc.xml的配置

<?xml version="1.0" encoding="UTF-8"?>
<config>

	<action path="/book" type="com.ycx.web.BookAction">
		<forward name="list" path="/bookList.jsp" redirect="true" />
		<forward name="toEdit" path="/bookEdit.jsp" redirect="false" />
		<forward name="toList" path="/book.action?methodName=list" redirect="false" />
	</action>
	
</config>

8.完成前台代码的编写

<%@ page language="java" contentType="text/html; charset=UTF-8"
	pageEncoding="UTF-8"%>
	<%@taglib uri="http://ycx.com" prefix="y" %>
	<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<link
	href="https://cdn.bootcdn.net/ajax/libs/twitter-bootstrap/4.5.0/css/bootstrap.css"
	rel="stylesheet">
<script
	src="https://cdn.bootcdn.net/ajax/libs/twitter-bootstrap/4.5.0/js/bootstrap.js"></script>
<title>书籍列表</title>
<style type="text/css">
.page-item input {
	padding: 0;
	width: 40px;
	height: 100%;
	text-align: center;
	margin: 0 6px;
}

.page-item input, .page-item b {
	line-height: 38px;
	float: left;
	font-weight: 400;
}

.page-item.go-input {
	margin: 0 10px;
}
</style>
</head>
<body>
	<form class="form-inline"
		action="${pageContext.request.contextPath }/book.action?methodName=list" method="post">
		<div class="form-group mb-2">
			<input type="text" class="form-control-plaintext" name="bname"
				placeholder="请输入书籍名称">
		</div>
		<button type="submit" class="btn btn-primary mb-2">查询</button>
	</form>

	<table class="table table-striped ">
		<thead>
			<tr>
				<th scope="col">书籍ID</th>
				<th scope="col">书籍名</th>
				<th scope="col">价格</th>
			</tr>
		</thead>
		<tbody>
			<c:forEach items="${list }" var="b">
			<tr>
				<td>${b.bid }</td>
				<td>${b.bname }</td>
				<td>${b.price }</td>
			</tr>
			</c:forEach>
		</tbody>
	</table>
	
	<y:page pageBean="${pageBean }"></y:page>
	

</body>
</html>

 

9.总结

自定义MVC框架应用中最为关键的是要把自定义MVC框架打造好，其中在应用是也要注意细节，比如：改造.xml文件时要跳转的目的类。