使用Maven搭建一个Web项目

设计需求

完成添加客户信息的操作

设计思路

1. 在页面点击保存，数据提交到服务器
2. 创建CustomerServlet，在CustomerServlet的doPost()方法里面
   1） 获得请求参数(封装成一个对象)
   2）调用业务，进行保存
   3）响应
3. 创建CustomerService，创建一个方法
4. 创建CustomerDao，使用DBUtils操作数据库(保存)

代码部分

pom.xml

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

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>com.byc</groupId>
  <artifactId>customer</artifactId>
  <version>1.0-SNAPSHOT</version>
  <packaging>war</packaging>

  <name>customer Maven Webapp</name>
  <!-- FIXME change it to the project's website -->
  <url>http://www.example.com</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <maven.compiler.source>1.8</maven.compiler.source>
    <maven.compiler.target>1.8</maven.compiler.target>
  </properties>

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.12</version>
      <scope>test</scope>
    </dependency>
    <!-- https://mvnrepository.com/artifact/junit/junit -->
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.12</version>
      <scope>test</scope>
    </dependency>
    <!--
    https://mvnrepository.com/artifact/javax.servlet/javax.servlet-api -->
    <dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>javax.servlet-api</artifactId>
      <version>3.1.0</version>
      <scope>provided</scope>
    </dependency>
    <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java
    -->
    <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>8.0.16</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/com.alibaba/druid -->
    <dependency>
      <groupId>com.alibaba</groupId>
      <artifactId>druid</artifactId>
      <version>1.1.23</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/commons-dbutils/commons-
    dbutils -->
    <dependency>
      <groupId>commons-dbutils</groupId>
      <artifactId>commons-dbutils</artifactId>
      <version>1.6</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/commons-beanutils/commons-
    beanutils -->
    <dependency>
    <groupId>commons-beanutils</groupId>
    <artifactId>commons-beanutils</artifactId>
    <version>1.9.3</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/javax.servlet.jsp/jsp-api
    -->
    <dependency>
      <groupId>javax.servlet.jsp</groupId>
      <artifactId>jsp-api</artifactId>
      <version>2.1</version>
      <scope>provided</scope>
    </dependency>
    <!-- https://mvnrepository.com/artifact/javax.servlet/jstl -->
    <dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>jstl</artifactId>
      <version>1.2</version>
    </dependency>
    <!--加入lombok依赖-->
    <!-- https://mvnrepository.com/artifact/org.projectlombok/lombok -->
    <dependency>
      <groupId>org.projectlombok</groupId>
      <artifactId>lombok</artifactId>
      <version>1.18.12</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/org.projectlombok/lombok -->
    <dependency>
      <groupId>org.projectlombok</groupId>
      <artifactId>lombok</artifactId>
      <version>1.18.12</version>
      <scope>provided</scope>
    </dependency>


  </dependencies>


  <build>
    <plugins>
  <plugin>
    <groupId>org.apache.tomcat.maven</groupId>
    <artifactId>tomcat7-maven-plugin</artifactId>
    <configuration>
      <!-- 指定端⼝ -->
      <port>8080</port>
      <!-- 请求路径 -->
      <path>/</path>
    </configuration>
  </plugin>
</plugins>
        </build>
</project>

创建数据库

CREATE TABLE `cst_customer` (
`cust_id` bigint(32) NOT NULL AUTO_INCREMENT COMMENT '客户编号(主键)',
`cust_name` varchar(32) NOT NULL COMMENT '客户名称(公司名称)',
`cust_source` varchar(32) DEFAULT NULL COMMENT '客户信息来源',
`cust_industry` varchar(32) DEFAULT NULL COMMENT '客户所属⾏业',
`cust_level` varchar(32) DEFAULT NULL COMMENT '客户级别',
`cust_phone` varchar(64) DEFAULT NULL COMMENT '固定电话',
`cust_mobile` varchar(16) DEFAULT NULL COMMENT '移动电话',
PRIMARY KEY (`cust_id`)
)

在IDEA中安装Lombok插件

Customer.java

package com.byc.pojo;

import lombok.Data;

@Data
public class Customer  {
    
    
    private Long cust_id;
    private String cust_name;
    private String cust_source;
    private String cust_industry;
    private String cust_level;
    private String cust_phone;
    private String cust_mobile;
}

index.jsp文件

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<form action="/register"
      method="post">
    客户名称：<input type="text" name="cust_name"/><br/>
    客户来源：<input type="text" name="cust_source"/><br/>
    客户行业：<input type="text" name="cust_industry"/><br/>
    客户级别：<input type="text" name="cust_level"/><br/>
    客户手机：<input type="text" name="cust_phone"/><br/>
    客户电话：<input type="text" name="cust_mobile"/><br/>
    <input type="submit" value="保存"/><br/>
</form>
</body>
</html>

resourses

driverClassName=com.mysql.cj.jdbc.Driver
url=jdbc:mysql://localhost:3306/mydb?characterEncoding=utf8&useSSL=false&serverTimezone=UTC&rewriteBatchedStatements=true
username=root
password=root

用户注册

package com.byc;

import com.byc.pojo.Customer;
import com.byc.service.CustomerService;
import org.apache.commons.beanutils.BeanUtils;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.sql.SQLException;
import java.util.Map;

@WebServlet("/register")
public class RegisterCustomerServlet extends HttpServlet {
    
    
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    
    

        //1.处理中文
        request.setCharacterEncoding("utf-8");
        response.setContentType("text/html;charset=utf-8");

        //2.获取浏览器发来的数据
        Map<String, String[]> map = request.getParameterMap();

        //3.封装数据到客户Bean中
        Customer customer = new Customer();
        try {
    
    
            BeanUtils.populate(customer,map);
        }catch (Exception e){
    
    
            e.printStackTrace();
        }

        //4.调用service层方法，保存客户
        CustomerService service = new CustomerService();
        try {
    
    
            service.save(customer);
        } catch (SQLException e) {
    
    
            e.printStackTrace();
        }

        //5.响应结果返回给页面
        response.getWriter().print("保存成功！！！");

    }

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    
    
        doGet(request, response);
    }
}

DruidUtils.java

package com.byc.util;

import com.alibaba.druid.pool.DruidDataSourceFactory;

import javax.sql.DataSource;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.Properties;

/**
 * 阿⾥巴巴的连接池 Druid ⼯具类
 */
public class DruidUtils {
    
    
    /*
    1. 加载 druid.properties 配置⽂件
    2. 创建 Druid 连接池对象
    3. 提供 获得 连接池对象的⽅法
    4. 提供 从连接池中 获取连接对象Connection的 ⽅法
    */
    public static DataSource ds = null;

    static {
    
    
        try {
    
    
//1. 加载 druid.properties 配置⽂件
            InputStream is =
                    DruidUtils.class.getClassLoader().getResourceAsStream("db.properties");
            Properties prop = new Properties();
            prop.load(is);
//2. 创建 Druid 连接池对象
            ds = DruidDataSourceFactory.createDataSource(prop);
        } catch (Exception e) {
    
    
            e.printStackTrace();
        }
    }

    /*
    3. 提供 获得 连接池对象的⽅法
    */
    public static DataSource getDataSource() {
    
    
        return ds;
    }

    /*
    4. 提供 从连接池中 获取连接对象Connection的 ⽅法
    */
    public static Connection getConnetion() throws SQLException {
    
    
        Connection conn = ds.getConnection();
        return conn;
    }
}

CustomerService.java

package com.byc.service;

import com.byc.dao.CustomerDao;
import com.byc.pojo.Customer;

import java.sql.SQLException;

public class CustomerService {
    
    
    /**
     * 保存客户
     * @param c
     */
    public void save(Customer c) throws SQLException {
    
    
        //调用dao层的方法，保存客户
        CustomerDao customerDao = new CustomerDao();
        customerDao.save(c);
    }
}

CustomerDao.java

package com.byc.dao;

import com.byc.pojo.Customer;
import com.byc.util.DruidUtils;
import org.apache.commons.dbutils.QueryRunner;

import java.sql.SQLException;

public class CustomerDao {
    
    

    private QueryRunner queryRunner = new QueryRunner(DruidUtils.getDataSource());
    /**
     * 保存客户
     * @param c
     */
    public void save(Customer c) throws SQLException {
    
    
        String sql = "insert into cst_customer values(?,?,?,?,?,?,?)";
        Object[] params = {
    
    
                c.getCust_id(), c.getCust_name(),c.getCust_source(),c.getCust_industry(),
                c.getCust_level(), c.getCust_phone(), c.getCust_mobile()
        };
        queryRunner.update(sql,params);
    }
}

目录结构

页面截图

常见错误解决办法