JavaWeb——A case of adding, deleting, modifying and checking under MVC mode
Directory MVC mode Environment configuration pom.xml mybatis-config. xml Directory structure java directory： com directory： mapper directory： pojo directory： service directory： util directory： web directory： ; resources directory： com/mapper directory： BrandMapper.xml webapp directory&# xff1a; index.html brand.jsp addBrand.jsp updateBrand.jsp MVC mode Environment configuration pom.xml 4.0.0com.myprojectbrand-demo1.0-SNAPSHOTwarmysqlmysql-connector-java8.0.21org.mybatismybatis 3.4.6javax.servletjavax.servlet-api3.1.0provided org.apache.mavenmaven-plugin-api2.0 commons-iocommons-io2.6javax.servlet.jspjsp-api2.1providedjstljstl1.2 org.apache.tomcat.maventomcat7-maven-plugin2.2 mybatis-config.xml Directory structure java directory： com directory： mapper directory： package com.mapper;import com.pojo.Brand;import java.util.List;public interface BrandMapper {List selectAll();void add(Brand brand);Brand selectById(int id);void update(Brand brand);void deletet(int id);} pojo directory： package com.pojo;/*** Brand entity class*/public class Brand {// id primary key private Integer id; // Brand name private String brandName; // Company name private String companyName; // Sorting field private Integer ordered; // Description information private String description; // Status ：0：Disabled 1：Enable private Integer status;public Brand() {}public Brand(Integer id, String brandName, String companyName, String description) {this.id = id;this.brandName = brandName;this .companyName = companyName;this.description = description;} public Brand(Integer id, String brandName, String companyName, Integer ordered, String description, Integer status) {this.id = id;this .brandName = brandName;this.companyName = companyName;this.ordered = ordered;this.description = description;this.status = status;}public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getBrandName() {return brandName;}public void setBrandName(String brandName) {this.brandName = brandName;}public String getCompanyName() {return companyName;}public void setCompanyName(String companyName) {this.companyName = companyName;}public Integer getOrdered() {return ordered;}public…
![Java link database, as well as the toolkit for adding, deleting, checking and modifying --Source code [MySQL]](https://www.1024programmer.com/wp-content/uploads/2023/09/ff1bdf00f1686e9b-300x193.jpeg)
Java linked database, and toolkit for adding, deleting, checking and modifying – source code [MySQL]
Database | mysql tutorial Database-mysql tutorial comment page html source code, Ubuntu18efi, how to uninstall tomcat9 , the source code of the crawler, the source code of PHP playing Youku video, Shannan seo tutorial lzwpackage com.msit.util; web account recharge source code, how to use vscode git, automatic ip ubuntu, how to completely close tomcat, sqlite database suffix name, crawler text , php adds text to pictures, how much does Loudi seo optimization cost, thinkphp novel website template, electronic chapter template psdlzwimport java.sql.Connection;import java.sql.DriverManager;import java.sql.PreparedStatement; import java.sql.ResultSet;import java.sql.SQLException;import java.sql.Statement;asp read and write txt file source code, vscode plug-in logical symbols, create thread Ubuntu, tomcat Image mapping configuration, sqlite3 view table name, basic principles of web crawler courseware video, PHP syntax detection, Jiangjin District SEO optimization plan, what are the web template websites, how to modify the homepage template folder of Empire CMS lzw/** * Database Tool class links MySql database * * @author Administrator * */public class SqlHelper { // The data required for the link (these data Write directly to the encrypted data file). private static String url = “jdbc:mysql://127.0.0.1:3306/msitdb”; private static String user = “root”; private static String password = “root” ; private static String driverName = “com.mysql.jdbc.Driver”; //…
MVC design pattern ((javaWEB) implements operations of adding, deleting, modifying and checking data in the database under the database connection pool)…
Implementation of design function： —-There is no business layer，The DAO is directly called by the Servlet, so there is no transaction operation，So it is obtained directly from the DAO connection object —-Adopt MVC design pattern —-Adopt technology . MVC design pattern，JSP,Servlet，POJO . The database uses mysql . The database connection pool requires the use of C3P0 database connection pool . The prompts on the page require the use of jQuery —-Technical difficulties . How to use a Servlet for multiple requests . How to fuzzy query . How to “verify whether user information has been used” and give prompts when creating and modifying ——— ————————————————– —————————————- 1. First of all Some implementations of database connection pool C3P0 need to import five open source framework packages： c3p0-0.9.1.2.jar commons-dbcp-1.4.jar commons-dbutils-1.3.jar commons-pool-1.5.5.jar mysql-connector-java-5.1.6-bin.jar ————————————————- ————————– 2. The file to connect to the database connection pool is ： Create an XML file c3p0-config.xml in the src directory; root lxn123 com.mysql.jdbc.Driver jdbc:mysql:///test 5 10 10 50 20 5 ———————————————— ———————————- 3. Classes for connecting to the database connection pool&# xff1a;JdbcUtils public class JdbcUtils { //Release connection connection public static void releaseConnection(Connection connection){ try { if (connection!=null) { connection.close(); } } catch (Exception e) {…
JAVAWEB realizes the modification function of adding, deleting, checking and modifying (book information management)
First, click the modify button on the index.jsp page to get the id of the row: ↓ Secondly, jump to the updateBooks.jsp page to modify the information. The page code is as follows: ↓ 1 <%– 2 Created by IntelliJ IDEA. 3 User: NFS 4 Date: 2019-7-12 5 Time: 14:31 6 To change this template use File | Settings | File Templates. 7 –%> 8 9 10 11 12 13 14 15 <% 16 Books books = (Books) request.getAttribute(“update”);17 18 if (books != null) {19 %>20 21 22 23 24 Number:25 <input name="book_id" value="” readonly> 26 27 28 Book title:29 <input name="book_name" value="”>30 31 32 Author:33 <input name="author" value="”>34 35 36 Inventory:37 <input name="number" value= "”>38 39 40 Price:41 <input name=" price" value="”>42 43 44 Publisher:45 <input name="pub" value="”>46 47 48 49 50 51 <%52 } else {53 %>54 No relevant data was found for this ID, so it cannot be modified. 55 <%56 }57 %>58 59 60 61 /books/lst”>Return to homepage62 63 64 The servlet corresponding to updateBooks.jsp: updateBooks.java, the code is as follows: ↓ 1 package BookSystem.CRUD; 2 3 import BookSystem.Other.Books; 4 import BookSystem.Other.DButil; 5 6 import javax.servlet.ServletException; 7 import javax.servlet.annotation.WebServlet; 8 import javax.servlet.http.HttpServlet; 9 import javax.servlet.http.HttpServletRequest;…
