自定义MVC的使用

前言

一、搭建自定义mvc框架环境

二、基础增删改

三、通用增删改

四、查询删除

五、新增修改的前端实现

前言

一、搭建自定义mvc框架环境

首先我们将自定义的mvc打成jar包

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可以在我的桌面看到jar包了

创建一个新项目，导入依赖

在新建的项目中，将分页标签以及相关的助手类导入

添加配置文件、web.xml配置

二、基础增删改

代码如下：


package com.zhw.dao;
 
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
 
import com.zhw.entity.Book;
import com.zhw.util.BaseDao;
import com.zhw.util.DBAccess;
import com.zhw.util.PageBean;
import com.zhw.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，没传就是默认值，默认值为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 (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
			return list;
		});
	}
	
//	增加
	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();
	}
	
	
//	删除
	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();
	}
	
//	修改
	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(1, book.getBname());
		pst.setObject(2, book.getPrice());
		pst.setObject(3, book.getBid());
		return pst.executeUpdate();
	}
}

测试代码如下：


package com.zhw.dao;
 
import static org.junit.Assert.*;
 
import java.util.List;
 
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
 
import com.zhw.entity.Book;
 
public class BookDaoTest {
 
	private BookDao bd = new BookDao();
	@Before
	public void setUp() throws Exception {
	}
 
	@After
	public void tearDown() throws Exception {
	}
 
	@Test
	public void testList() {
		try {
			List<Book> list = bd.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() {
		Book book = new Book(111234321, "1234321" , 1234321);
		try {
			bd.add(book);
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
 
	@Test
	public void testDel() {
		Book book = new Book(111234321, "12343212222" , 1234321);
		try {
			bd.edit(book);
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
 
	@Test
	public void testEdit() {
		fail("Not yet implemented");
	}
 
}

查询全部

增加

先查询看一下数据库中是否存在该书籍


@Test
	public void testAdd() {
		Book book = new Book(111234321, "1234321" , 1234321);
		try {
			bd.add(book);
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

调用增加的方法

再次查询数据库是否存在该数据

修改


 
	@Test
	public void testEdit() {
		Book book = new Book(111234321, "12343212222" , 1234321);
		try {
			bd.edit(book);
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

数据库查询，是否修改成功

删除


@Test
	public void testDel() {
		Book book = new Book(111234321, "12343212222" , 1234321);
		try {
			bd.del(book);
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

进数据库看是否删除成功