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Use of custom MVC

2022-06-30 03:05:00 【An Li Jiu Ge】

Catalog

Preface

One 、 Build custom mvc Framework environment

Two 、 Basic addition, deletion and modification

3、 ... and 、 General addition, deletion and modification

Four 、 Query delete

5、 ... and 、 New and modified front-end implementation

Preface

One 、 Build custom mvc Framework environment

First of all, we will customize mvc become involved jar package

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You can see it on my desktop jar It's packed

Create a new project , Import dependence

In a new project , Import the paging label and related helper classes into
Add configuration file 、web.xml To configure

Two 、 Basic addition, deletion and modification

The code is as follows ：

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>{
	// Inquire about 
	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();
		// The front desk jsp Pass it to the background , As long as it's passed, it's worth it , No transmission is the default value , The default value is 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;
		});
	}
	
//	 increase 
	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();
	}
	
	
//	 Delete 
	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();
	}
	
//	 modify 
	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();
	}
}

The test code is as follows ：

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");
	}

}

Query all

increase

First, check whether the book exists in the database

@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();
		}
	}

Call the added method

Query the database again to see if the data exists

modify


	@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();
		}
	}

Database query , Is the modification successful

Delete

@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();
		}
	}

Enter the database to see if the deletion is successful