JAVAWeb | SMBMS 项目实战（一）

数据库

项目如何搭建？
考虑使不使用 maven？不使用则需要导入 jar 包，使用则需要导入依赖

搭建项目准备工作

1. 搭建一个maven web 项目

删除 pom.xml 中无关紧要的内容，留下如图所示的内容：

将 web.xml 的内容用如下替换掉（因为下面这个是最新的，好用，一般不会有问题，在 tomcat 的文件夹下也可以找到这个配置信息）

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee
                      http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
         version="4.0"
         metadata-complete="true">
    
</web-app>

并将 maven 结构的文件夹补全，如下图：

2. 配置 Tomcat，其中 Application context 为 /smbms，相当于我们访问初始时的 /smbms，就会进入 index.jsp 页面

3. 测试项目是否能够跑起来

4. 导入项目中需要的 jar 包：jsp，Servlet，mysql 驱动 jstl，stand…

  <dependencies>

    <dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>javax.servlet-api</artifactId>
      <version>4.0.1</version>
    </dependency>

    <dependency>
      <groupId>javax.servlet.jsp</groupId>
      <artifactId>javax.servlet.jsp-api</artifactId>
      <version>2.3.3</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/tomcat/jasper-runtime -->
    <dependency>
      <groupId>tomcat</groupId>
      <artifactId>jasper-runtime</artifactId>
      <version>5.5.23</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/javax.servlet.jsp.jstl/jstl -->
    <dependency>
      <groupId>javax.servlet.jsp.jstl</groupId>
      <artifactId>jstl</artifactId>
      <version>1.2</version>
    </dependency>

    <dependency>
      <groupId>taglibs</groupId>
      <artifactId>standard</artifactId>
      <version>1.1.2</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/com.mysql/mysql-connector-j -->
    <dependency>
      <groupId>com.mysql</groupId>
      <artifactId>mysql-connector-j</artifactId>
      <version>8.0.33</version>
    </dependency>

  </dependencies>

5. 构建项目包结构：基本需要如下，更具需要，还可以构建其他的包

pojo 放实体类
dao：操作数据库的
service：业务层
servlet：
filter：过滤器
utils：工具类

连接数据库

下一步通过 mysql 可视化界面，执行 sql 文件创建数据库 smbms 以及一系列表格

smbms.sql文件

USE `smbms`;
 
DROP TABLE IF EXISTS `smbms_address`;
 
CREATE TABLE `smbms_address` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT COMMENT '主键ID',
  `contact` varchar(15) COLLATE utf8_unicode_ci DEFAULT NULL COMMENT '联系人姓名',
  `addressDesc` varchar(50) COLLATE utf8_unicode_ci DEFAULT NULL COMMENT '收货地址明细',
  `postCode` varchar(15) COLLATE utf8_unicode_ci DEFAULT NULL COMMENT '邮编',
  `tel` varchar(20) COLLATE utf8_unicode_ci DEFAULT NULL COMMENT '联系人电话',
  `createdBy` bigint(20) DEFAULT NULL COMMENT '创建者',
  `creationDate` datetime DEFAULT NULL COMMENT '创建时间',
  `modifyBy` bigint(20) DEFAULT NULL COMMENT '修改者',
  `modifyDate` datetime DEFAULT NULL COMMENT '修改时间',
  `userId` bigint(20) DEFAULT NULL COMMENT '用户ID',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=7 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
 
insert  into `smbms_address`(`id`,`contact`,`addressDesc`,`postCode`,`tel`,`createdBy`,`creationDate`,`modifyBy`,`modifyDate`,`userId`) values (1,'王丽','北京市东城区东交民巷44号','100010','13678789999',1,'2016-04-13 00:00:00',NULL,NULL,1),(2,'张红丽','北京市海淀区丹棱街3号','100000','18567672312',1,'2016-04-13 00:00:00',NULL,NULL,1),(3,'任志强','北京市东城区美术馆后街23号','100021','13387906742',1,'2016-04-13 00:00:00',NULL,NULL,1),(4,'曹颖','北京市朝阳区朝阳门南大街14号','100053','13568902323',1,'2016-04-13 00:00:00',NULL,NULL,2),(5,'李慧','北京市西城区三里河路南三巷3号','100032','18032356666',1,'2016-04-13 00:00:00',NULL,NULL,3),(6,'王国强','北京市顺义区高丽营镇金马工业区18号','100061','13787882222',1,'2016-04-13 00:00:00',NULL,NULL,3);
 
DROP TABLE IF EXISTS `smbms_bill`;
 
CREATE TABLE `smbms_bill` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT COMMENT '主键ID',
  `billCode` varchar(20) COLLATE utf8_unicode_ci DEFAULT NULL COMMENT '账单编码',
  `productName` varchar(20) COLLATE utf8_unicode_ci DEFAULT NULL COMMENT '商品名称',
  `productDesc` varchar(50) COLLATE utf8_unicode_ci DEFAULT NULL COMMENT '商品描述',
  `productUnit` varchar(10) COLLATE utf8_unicode_ci DEFAULT NULL COMMENT '商品单位',
  `productCount` decimal(20,2) DEFAULT NULL COMMENT '商品数量',
  `totalPrice` decimal(20,2) DEFAULT NULL COMMENT '商品总额',
  `isPayment` int(10) DEFAULT NULL COMMENT '是否支付（1：未支付 2：已支付）',
  `createdBy` bigint(20) DEFAULT NULL COMMENT '创建者（userId）',
  `creationDate` datetime DEFAULT NULL COMMENT '创建时间',
  `modifyBy` bigint(20) DEFAULT NULL COMMENT '更新者（userId）',
  `modifyDate` datetime DEFAULT NULL COMMENT '更新时间',
  `providerId` bigint(20) DEFAULT NULL COMMENT '供应商ID',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=19 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
 
insert  into `smbms_bill`(`id`,`billCode`,`productName`,`productDesc`,`productUnit`,`productCount`,`totalPrice`,`isPayment`,`createdBy`,`creationDate`,`modifyBy`,`modifyDate`,`providerId`) values (2,'BILL2016_002','香皂、肥皂、药皂','日用品-皂类','块','1000.00','10000.00',2,1,'2016-03-23 04:20:40',NULL,NULL,13),(3,'BILL2016_003','大豆油','食品-食用油','斤','300.00','5890.00',2,1,'2014-12-14 13:02:03',NULL,NULL,6),(4,'BILL2016_004','橄榄油','食品-进口食用油','斤','200.00','9800.00',2,1,'2013-10-10 03:12:13',NULL,NULL,7),(5,'BILL2016_005','洗洁精','日用品-厨房清洁','瓶','500.00','7000.00',2,1,'2014-12-14 13:02:03',NULL,NULL,9),(6,'BILL2016_006','美国大杏仁','食品-坚果','袋','300.00','5000.00',2,1,'2016-04-14 06:08:09',NULL,NULL,4),(7,'BILL2016_007','沐浴液、精油','日用品-沐浴类','瓶','500.00','23000.00',1,1,'2016-07-22 10:10:22',NULL,NULL,14),(8,'BILL2016_008','不锈钢盘碗','日用品-厨房用具','个','600.00','6000.00',2,1,'2016-04-14 05:12:13',NULL,NULL,14),(9,'BILL2016_009','塑料杯','日用品-杯子','个','350.00','1750.00',2,1,'2016-02-04 11:40:20',NULL,NULL,14),(10,'BILL2016_010','豆瓣酱','食品-调料','瓶','200.00','2000.00',2,1,'2013-10-29 05:07:03',NULL,NULL,8),(11,'BILL2016_011','海之蓝','饮料-国酒','瓶','50.00','10000.00',1,1,'2016-04-14 16:16:00',NULL,NULL,1),(12,'BILL2016_012','芝华士','饮料-洋酒','瓶','20.00','6000.00',1,1,'2016-09-09 17:00:00',NULL,NULL,1),(13,'BILL2016_013','长城红葡萄酒','饮料-红酒','瓶','60.00','800.00',2,1,'2016-11-14 15:23:00',NULL,NULL,1),(14,'BILL2016_014','泰国香米','食品-大米','斤','400.00','5000.00',2,1,'2016-10-09 15:20:00',NULL,NULL,3),(15,'BILL2016_015','东北大米','食品-大米','斤','600.00','4000.00',2,1,'2016-11-14 14:00:00',NULL,NULL,3),(16,'BILL2016_016','可口可乐','饮料','瓶','2000.00','6000.00',2,1,'2012-03-27 13:03:01',NULL,NULL,2),(17,'BILL2016_017','脉动','饮料','瓶','1500.00','4500.00',2,1,'2016-05-10 12:00:00',NULL,NULL,2),(18,'BILL2016_018','哇哈哈','饮料','瓶','2000.00','4000.00',2,1,'2015-11-24 15:12:03',NULL,NULL,2);
 
DROP TABLE IF EXISTS `smbms_provider`;
 
CREATE TABLE `smbms_provider` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT COMMENT '主键ID',
  `proCode` varchar(20) COLLATE utf8_unicode_ci DEFAULT NULL COMMENT '供应商编码',
  `proName` varchar(20) COLLATE utf8_unicode_ci DEFAULT NULL COMMENT '供应商名称',
  `proDesc` varchar(50) COLLATE utf8_unicode_ci DEFAULT NULL COMMENT '供应商详细描述',
  `proContact` varchar(20) COLLATE utf8_unicode_ci DEFAULT NULL COMMENT '供应商联系人',
  `proPhone` varchar(20) COLLATE utf8_unicode_ci DEFAULT NULL COMMENT '联系电话',
  `proAddress` varchar(50) COLLATE utf8_unicode_ci DEFAULT NULL COMMENT '地址',
  `proFax` varchar(20) COLLATE utf8_unicode_ci DEFAULT NULL COMMENT '传真',
  `createdBy` bigint(20) DEFAULT NULL COMMENT '创建者（userId）',
  `creationDate` datetime DEFAULT NULL COMMENT '创建时间',
  `modifyDate` datetime DEFAULT NULL COMMENT '更新时间',
  `modifyBy` bigint(20) DEFAULT NULL COMMENT '更新者（userId）',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=16 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
 
insert  into `smbms_provider`(`id`,`proCode`,`proName`,`proDesc`,`proContact`,`proPhone`,`proAddress`,`proFax`,`createdBy`,`creationDate`,`modifyDate`,`modifyBy`) values (1,'BJ_GYS001','北京三木堂商贸有限公司','长期合作伙伴，主营产品:茅台、五粮液、郎酒、酒鬼酒、泸州老窖、赖茅酒、法国红酒等','张国强','13566667777','北京市丰台区育芳园北路','010-58858787',1,'2013-03-21 16:52:07',NULL,NULL),(2,'HB_GYS001','石家庄帅益食品贸易有限公司','长期合作伙伴，主营产品:饮料、水饮料、植物蛋白饮料、休闲食品、果汁饮料、功能饮料等','王军','13309094212','河北省石家庄新华区','0311-67738876',1,'2016-04-13 04:20:40',NULL,NULL),(3,'GZ_GYS001','深圳市泰香米业有限公司','初次合作伙伴，主营产品：良记金轮米,龙轮香米等','郑程瀚','13402013312','广东省深圳市福田区深南大道6006华丰大厦','0755-67776212',1,'2014-03-21 16:56:07',NULL,NULL),(4,'GZ_GYS002','深圳市喜来客商贸有限公司','长期合作伙伴，主营产品：坚果炒货.果脯蜜饯.天然花茶.营养豆豆.特色美食.进口食品.海味零食.肉脯肉','林妮','18599897645','广东省深圳市福龙工业区B2栋3楼西','0755-67772341',1,'2013-03-22 16:52:07',NULL,NULL),(5,'JS_GYS001','兴化佳美调味品厂','长期合作伙伴，主营产品：天然香辛料、鸡精、复合调味料','徐国洋','13754444221','江苏省兴化市林湖工业区','0523-21299098',1,'2015-11-22 16:52:07',NULL,NULL),(6,'BJ_GYS002','北京纳福尔食用油有限公司','长期合作伙伴，主营产品：山茶油、大豆油、花生油、橄榄油等','马莺','13422235678','北京市朝阳区珠江帝景1号楼','010-588634233',1,'2012-03-21 17:52:07',NULL,NULL),(7,'BJ_GYS003','北京国粮食用油有限公司','初次合作伙伴，主营产品：花生油、大豆油、小磨油等','王驰','13344441135','北京大兴青云店开发区','010-588134111',1,'2016-04-13 00:00:00',NULL,NULL),(8,'ZJ_GYS001','慈溪市广和绿色食品厂','长期合作伙伴，主营产品：豆瓣酱、黄豆酱、甜面酱，辣椒，大蒜等农产品','薛圣丹','18099953223','浙江省宁波市慈溪周巷小安村','0574-34449090',1,'2013-11-21 06:02:07',NULL,NULL),(9,'GX_GYS001','优百商贸有限公司','长期合作伙伴，主营产品：日化产品','李立国','13323566543','广西南宁市秀厢大道42-1号','0771-98861134',1,'2013-03-21 19:52:07',NULL,NULL),(10,'JS_GYS002','南京火头军信息技术有限公司','长期合作伙伴，主营产品：不锈钢厨具等','陈女士','13098992113','江苏省南京市浦口区浦口大道1号新城总部大厦A座903室','025-86223345',1,'2013-03-25 16:52:07',NULL,NULL),(11,'GZ_GYS003','广州市白云区美星五金制品厂','长期合作伙伴，主营产品：海绵床垫、坐垫、靠垫、海绵枕头、头枕等','梁天','13562276775','广州市白云区钟落潭镇福龙路20号','020-85542231',1,'2016-12-21 06:12:17',NULL,NULL),(12,'BJ_GYS004','北京隆盛日化科技','长期合作伙伴，主营产品：日化环保清洗剂，家居洗涤专卖、洗涤用品网、墙体除霉剂、墙面霉菌清除剂等','孙欣','13689865678','北京市大兴区旧宫','010-35576786',1,'2014-11-21 12:51:11',NULL,NULL),(13,'SD_GYS001','山东豪克华光联合发展有限公司','长期合作伙伴，主营产品：洗衣皂、洗衣粉、洗衣液、洗洁精、消杀类、香皂等','吴洪转','13245468787','山东济阳济北工业区仁和街21号','0531-53362445',1,'2015-01-28 10:52:07',NULL,NULL),(14,'JS_GYS003','无锡喜源坤商行','长期合作伙伴，主营产品：日化品批销','周一清','18567674532','江苏无锡盛岸西路','0510-32274422',1,'2016-04-23 11:11:11',NULL,NULL),(15,'ZJ_GYS002','乐摆日用品厂','长期合作伙伴，主营产品：各种中、高档塑料杯，塑料乐扣水杯（密封杯）、保鲜杯（保鲜盒）、广告杯、礼品杯','王世杰','13212331567','浙江省金华市义乌市义东路','0579-34452321',1,'2016-08-22 10:01:30',NULL,NULL);
 
DROP TABLE IF EXISTS `smbms_role`;
 
CREATE TABLE `smbms_role` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT COMMENT '主键ID',
  `roleCode` varchar(15) COLLATE utf8_unicode_ci DEFAULT NULL COMMENT '角色编码',
  `roleName` varchar(15) COLLATE utf8_unicode_ci DEFAULT NULL COMMENT '角色名称',
  `createdBy` bigint(20) DEFAULT NULL COMMENT '创建者',
  `creationDate` datetime DEFAULT NULL COMMENT '创建时间',
  `modifyBy` bigint(20) DEFAULT NULL COMMENT '修改者',
  `modifyDate` datetime DEFAULT NULL COMMENT '修改时间',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
 
insert  into `smbms_role`(`id`,`roleCode`,`roleName`,`createdBy`,`creationDate`,`modifyBy`,`modifyDate`) values (1,'SMBMS_ADMIN','系统管理员',1,'2016-04-13 00:00:00',NULL,NULL),(2,'SMBMS_MANAGER','经理',1,'2016-04-13 00:00:00',NULL,NULL),(3,'SMBMS_EMPLOYEE','普通员工',1,'2016-04-13 00:00:00',NULL,NULL);
 
DROP TABLE IF EXISTS `smbms_user`;
 
CREATE TABLE `smbms_user` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT COMMENT '主键ID',
  `userCode` varchar(15) COLLATE utf8_unicode_ci DEFAULT NULL COMMENT '用户编码',
  `userName` varchar(15) COLLATE utf8_unicode_ci DEFAULT NULL COMMENT '用户名称',
  `userPassword` varchar(15) COLLATE utf8_unicode_ci DEFAULT NULL COMMENT '用户密码',
  `gender` int(10) DEFAULT NULL COMMENT '性别（1:女、 2:男）',
  `birthday` date DEFAULT NULL COMMENT '出生日期',
  `phone` varchar(15) COLLATE utf8_unicode_ci DEFAULT NULL COMMENT '手机',
  `address` varchar(30) COLLATE utf8_unicode_ci DEFAULT NULL COMMENT '地址',
  `userRole` bigint(20) DEFAULT NULL COMMENT '用户角色（取自角色表-角色id）',
  `createdBy` bigint(20) DEFAULT NULL COMMENT '创建者（userId）',
  `creationDate` datetime DEFAULT NULL COMMENT '创建时间',
  `modifyBy` bigint(20) DEFAULT NULL COMMENT '更新者（userId）',
  `modifyDate` datetime DEFAULT NULL COMMENT '更新时间',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=16 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
 
insert  into `smbms_user`(`id`,`userCode`,`userName`,`userPassword`,`gender`,`birthday`,`phone`,`address`,`userRole`,`createdBy`,`creationDate`,`modifyBy`,`modifyDate`) values (1,'admin','系统管理员','1234567',1,'1983-10-10','13688889999','北京市海淀区成府路207号',1,1,'2013-03-21 16:52:07',NULL,NULL),(2,'liming','李明','0000000',2,'1983-12-10','13688884457','北京市东城区前门东大街9号',2,1,'2014-12-31 19:52:09',NULL,NULL),(5,'hanlubiao','韩路彪','0000000',2,'1984-06-05','18567542321','北京市朝阳区北辰中心12号',2,1,'2014-12-31 19:52:09',NULL,NULL),(6,'zhanghua','张华','0000000',1,'1983-06-15','13544561111','北京市海淀区学院路61号',3,1,'2013-02-11 10:51:17',NULL,NULL),(7,'wangyang','王洋','0000000',2,'1982-12-31','13444561124','北京市海淀区西二旗辉煌国际16层',3,1,'2014-06-11 19:09:07',NULL,NULL),(8,'zhaoyan','赵燕','0000000',1,'1986-03-07','18098764545','北京市海淀区回龙观小区10号楼',3,1,'2016-04-21 13:54:07',NULL,NULL),(10,'sunlei','孙磊','0000000',2,'1981-01-04','13387676765','北京市朝阳区管庄新月小区12楼',3,1,'2015-05-06 10:52:07',NULL,NULL),(11,'sunxing','孙兴','0000000',2,'1978-03-12','13367890900','北京市朝阳区建国门南大街10号',3,1,'2016-11-09 16:51:17',NULL,NULL),(12,'zhangchen','张晨','0000000',1,'1986-03-28','18098765434','朝阳区管庄路口北柏林爱乐三期13号楼',3,1,'2016-08-09 05:52:37',1,'2016-04-14 14:15:36'),(13,'dengchao','邓超','0000000',2,'1981-11-04','13689674534','北京市海淀区北航家属院10号楼',3,1,'2016-07-11 08:02:47',NULL,NULL),(14,'yangguo','杨过','0000000',2,'1980-01-01','13388886623','北京市朝阳区北苑家园茉莉园20号楼',3,1,'2015-02-01 03:52:07',NULL,NULL),(15,'zhaomin','赵敏','0000000',1,'1987-12-04','18099897657','北京市昌平区天通苑3区12号楼',2,1,'2015-09-12 12:02:12',NULL,NULL);

先新建数据库，再执行 sql 语句

6. 编写实体类

ORM 映射：表 $\to$ 类，如下一一对应，并建立每个属性的 get，set 方法

User 表对应的实体类

package com.uestc.pojo;

import java.util.Date;

public class User {
    //静态属性
    /*id*/
    private Integer id;
    //用户编码
    private String userCode;
    //用户名称
    private String userName;
    //用户密码
    private String userPassword;
    //性别
    private Integer gender;
    //出生日期
    private Date birthday;
    //电话
    private String phone;
    //地址
    private String address;
    //用户角色
    private Integer userRole;
    //创建者
    private Integer createdBy;
    //创建时间
    private Date creationDate;
    //更新者
    private Integer modifyBy;
    //更新时间
    private Date modifyDate;

    //年龄
    private Integer age;

    //用户角色名称
    private String userRoleName;

    //getter和setter方法

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getUserCode() {
        return userCode;
    }

    public void setUserCode(String userCode) {
        this.userCode = userCode;
    }

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    public String getUserPassword() {
        return userPassword;
    }

    public void setUserPassword(String userPassword) {
        this.userPassword = userPassword;
    }

    public Integer getGender() {
        return gender;
    }

    public void setGender(Integer gender) {
        this.gender = gender;
    }

    public Date getBirthday() {
        return birthday;
    }

    public void setBirthday(Date birthday) {
        this.birthday = birthday;
    }

    public String getPhone() {
        return phone;
    }

    public void setPhone(String phone) {
        this.phone = phone;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    public Integer getUserRole() {
        return userRole;
    }

    public void setUserRole(Integer userRole) {
        this.userRole = userRole;
    }

    public Integer getCreatedBy() {
        return createdBy;
    }

    public void setCreatedBy(Integer createdBy) {
        this.createdBy = createdBy;
    }

    public Date getCreationDate() {
        return creationDate;
    }

    public void setCreationDate(Date creationDate) {
        this.creationDate = creationDate;
    }

    public Integer getModifyBy() {
        return modifyBy;
    }

    public void setModifyBy(Integer modifyBy) {
        this.modifyBy = modifyBy;
    }

    public Date getModifyDate() {
        return modifyDate;
    }

    public void setModifyDate(Date modifyDate) {
        this.modifyDate = modifyDate;
    }

    public Integer getAge() {
        Date date = new Date();
        Integer age = date.getYear() - birthday.getYear(); // 当前时间 - 生日时间计算出年龄
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

    public String getUserRoleName() {
        return userRoleName;
    }

    public void setUserRoleName(String userRoleName) {
        this.userRoleName = userRoleName;
    }
}

role 表对应的实体类

package com.uestc.pojo;

import java.util.Date;

public class Role {
    /**
     * id
     */
    private Integer id;
    //角色编码
    private String roleCode;
    //角色名称
    private String roleName;
    //创建者
    private Integer createdBy;
    //创建时间
    private Date creationDate;
    //更新者
    private Integer modifyBy;
    //更新时间
    private Date modifyDate;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getRoleCode() {
        return roleCode;
    }

    public void setRoleCode(String roleCode) {
        this.roleCode = roleCode;
    }

    public String getRoleName() {
        return roleName;
    }

    public void setRoleName(String roleName) {
        this.roleName = roleName;
    }

    public Integer getCreatedBy() {
        return createdBy;
    }

    public void setCreatedBy(Integer createdBy) {
        this.createdBy = createdBy;
    }

    public Date getCreationDate() {
        return creationDate;
    }

    public void setCreationDate(Date creationDate) {
        this.creationDate = creationDate;
    }

    public Integer getModifyBy() {
        return modifyBy;
    }

    public void setModifyBy(Integer modifyBy) {
        this.modifyBy = modifyBy;
    }

    public Date getModifyDate() {
        return modifyDate;
    }

    public void setModifyDate(Date modifyDate) {
        this.modifyDate = modifyDate;
    }
}

provider 表对应的实体类

package com.uestc.pojo;

import java.util.Date;

public class Provider {
    /**
     * id
     */
    private Integer id;
    //供应商编码
    private String proCode;
    //供应商名称
    private String proName;
    //供应商描述
    private String proDesc;
    //供应商联系人
    private String proContact;
    //供应商电话
    private String proPhone;
    //供应商地址
    private String proAddress;
    //供应商传真
    private String proFax;
    //创建者
    private Integer createdBy;
    //创建时间
    private Date creationDate;
    //更新者
    private Integer modifyBy;
    //更新时间
    private Date modifyDate;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getProCode() {
        return proCode;
    }

    public void setProCode(String proCode) {
        this.proCode = proCode;
    }

    public String getProName() {
        return proName;
    }

    public void setProName(String proName) {
        this.proName = proName;
    }

    public String getProDesc() {
        return proDesc;
    }

    public void setProDesc(String proDesc) {
        this.proDesc = proDesc;
    }

    public String getProContact() {
        return proContact;
    }

    public void setProContact(String proContact) {
        this.proContact = proContact;
    }

    public String getProPhone() {
        return proPhone;
    }

    public void setProPhone(String proPhone) {
        this.proPhone = proPhone;
    }

    public String getProAddress() {
        return proAddress;
    }

    public void setProAddress(String proAddress) {
        this.proAddress = proAddress;
    }

    public String getProFax() {
        return proFax;
    }

    public void setProFax(String proFax) {
        this.proFax = proFax;
    }

    public Integer getCreatedBy() {
        return createdBy;
    }

    public void setCreatedBy(Integer createdBy) {
        this.createdBy = createdBy;
    }

    public Date getCreationDate() {
        return creationDate;
    }

    public void setCreationDate(Date creationDate) {
        this.creationDate = creationDate;
    }

    public Integer getModifyBy() {
        return modifyBy;
    }

    public void setModifyBy(Integer modifyBy) {
        this.modifyBy = modifyBy;
    }

    public Date getModifyDate() {
        return modifyDate;
    }

    public void setModifyDate(Date modifyDate) {
        this.modifyDate = modifyDate;
    }

    @Override
    public String toString() {
        return "Provider{" +
                "id=" + id +
                ", proCode='" + proCode + '\'' +
                ", proName='" + proName + '\'' +
                ", proDesc='" + proDesc + '\'' +
                ", proContact='" + proContact + '\'' +
                ", proPhone='" + proPhone + '\'' +
                ", proAddress='" + proAddress + '\'' +
                ", proFax='" + proFax + '\'' +
                ", createdBy=" + createdBy +
                ", creationDate=" + creationDate +
                ", modifyBy=" + modifyBy +
                ", modifyDate=" + modifyDate +
                '}';
    }
}

bill 表对应的实体类

package com.uestc.pojo;

import java.math.BigDecimal;
import java.util.Date;

public class Bill {
    /**
     * id
     */
    private Integer id;
    //账单编码
    private String billCode;
    //商品名称
    private String productName;
    //商品描述
    private String productDesc;
    //商品单位
    private String productUnit;
    //商品数量
    private BigDecimal productCount;
    //总金额
    private BigDecimal totalPrice;
    //是否支付
    private Integer isPayment;
    //创建者
    private Integer createdBy;
    //创建时间
    private Date creationDate;
    //更新者
    private Integer modifyBy;
    //更新时间
    private Date modifyDate;
    //供应商ID
    private Integer providerId;

    private String providerName;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getBillCode() {
        return billCode;
    }

    public void setBillCode(String billCode) {
        this.billCode = billCode;
    }

    public String getProductName() {
        return productName;
    }

    public void setProductName(String productName) {
        this.productName = productName;
    }

    public String getProductDesc() {
        return productDesc;
    }

    public void setProductDesc(String productDesc) {
        this.productDesc = productDesc;
    }

    public String getProductUnit() {
        return productUnit;
    }

    public void setProductUnit(String productUnit) {
        this.productUnit = productUnit;
    }

    public BigDecimal getProductCount() {
        return productCount;
    }

    public void setProductCount(BigDecimal productCount) {
        this.productCount = productCount;
    }

    public BigDecimal getTotalPrice() {
        return totalPrice;
    }

    public void setTotalPrice(BigDecimal totalPrice) {
        this.totalPrice = totalPrice;
    }

    public Integer getIsPayment() {
        return isPayment;
    }

    public void setIsPayment(Integer isPayment) {
        this.isPayment = isPayment;
    }

    public Integer getCreatedBy() {
        return createdBy;
    }

    public void setCreatedBy(Integer createdBy) {
        this.createdBy = createdBy;
    }

    public Date getCreationDate() {
        return creationDate;
    }

    public void setCreationDate(Date creationDate) {
        this.creationDate = creationDate;
    }

    public Integer getModifyBy() {
        return modifyBy;
    }

    public void setModifyBy(Integer modifyBy) {
        this.modifyBy = modifyBy;
    }

    public Date getModifyDate() {
        return modifyDate;
    }

    public void setModifyDate(Date modifyDate) {
        this.modifyDate = modifyDate;
    }

    public Integer getProviderId() {
        return providerId;
    }

    public void setProviderId(Integer providerId) {
        this.providerId = providerId;
    }

    public String getProviderName() {
        return providerName;
    }

    public void setProviderName(String providerName) {
        this.providerName = providerName;
    }

    @Override
    public String toString() {
        return "Bill{" +
                "id=" + id +
                ", billCode='" + billCode + '\'' +
                ", productName='" + productName + '\'' +
                ", productDesc='" + productDesc + '\'' +
                ", productUnit='" + productUnit + '\'' +
                ", productCount=" + productCount +
                ", totalPrice=" + totalPrice +
                ", isPayment=" + isPayment +
                ", createdBy=" + createdBy +
                ", creationDate=" + creationDate +
                ", modifyBy=" + modifyBy +
                ", modifyDate=" + modifyDate +
                ", providerId=" + providerId +
                ", providerName='" + providerName + '\'' +
                '}';
    }
}

7. 编写基本公共类

1、数据库配置文件（mysql5.xx和8.xx的编写有差异），在 resources 下新建 db.properties

driver=com.mysql.cj.jdbc.Driver
url=jdbc:mysql://112.124.60.179:3310/smbms?useUnicode=true&characterEncoding=utf8&useSSL=true
username=root
password=123456

• useUnicode=true&characterEncoding=utf8：这句话是为了安全而加入的
  url 可以通过如下获取
  

2. 编写数据库的公共类（BaseDao）

package com.uestc.dao;

import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Properties;

/**
 * 操作数据库的基类--静态类
 * @author Administrator
 *
 */
public class BaseDao {

    static{//静态代码块,在类加载的时候执行
        init();
    }

    private static String driver;
    private static String url;
    private static String username;
    private static String password;

    //初始化连接参数, 从配置文件里获得, 静态代码块，类加载的时候就初始化了
    public static void init(){
        Properties params=new Properties();

        // 通过类加载块读取静态的资源
        String configFile = "db.properties";
        InputStream is = BaseDao.class.getClassLoader().getResourceAsStream(configFile);
        try {
            params.load(is);
        } catch (IOException e) {
            e.printStackTrace();
        }
        driver=params.getProperty("driver");
        url=params.getProperty("url");
        username=params.getProperty("username");
        password=params.getProperty("password");

    }


    /**
     * 获取数据库连接
     * @return
     */
    public static Connection getConnection(){
        Connection connection = null;
        try {
            Class.forName(driver);
            connection = DriverManager.getConnection(url, username, password);
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        return connection;
    }


    /**
     * 查询操作
     * @param connection
     * @param preparedStatement
     * @param resultSet
     * @param sql
     * @param params
     * @return
     */
    public static ResultSet execute(Connection connection,PreparedStatement preparedStatement, ResultSet resultSet,
                                    String sql, Object[] params) throws Exception{

        // 预编译的 sql，在后面直接执行就可以了
        preparedStatement = connection.prepareStatement(sql);

        // params 是拿到参数
        for(int i = 0; i < params.length; i++){
            // setObject 占位符从 1 开始，但是数组是从 0 开始
            preparedStatement.setObject(i+1, params[i]); // 不知道具体类型都用 set Object
        }
        resultSet = preparedStatement.executeQuery(); // 获取结果
        return resultSet;
    }


    /**
     * 更新操作
     * @param connection
     * @param prepareStatement
     * @param sql
     * @param params
     * @return
     * @throws Exception
     */
    public static int execute(Connection connection,PreparedStatement prepareStatement,
                              String sql,Object[] params) throws Exception{
        int updateRows = 0;
        prepareStatement = connection.prepareStatement(sql);
        for(int i = 0; i < params.length; i++){
            prepareStatement.setObject(i+1, params[i]);
        }
        updateRows = prepareStatement.executeUpdate();
        return updateRows;
    }

    /**
     * 释放资源
     * @param connection
     * @param prepareStatement
     * @param resultSet
     * @return
     */
    public static boolean closeResource(Connection connection,PreparedStatement prepareStatement,ResultSet resultSet){
        boolean flag = true; // 都释放成功返回 true
        if(resultSet != null){
            try {
                resultSet.close();
                resultSet = null; //GC回收
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
                flag = false;
            }
        }
        if(prepareStatement != null){
            try {
                prepareStatement.close();
                prepareStatement = null; //GC回收
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
                flag = false;
            }
        }
        if(connection != null){
            try {
                connection.close();
                connection = null;//GC回收
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
                flag = false;
            }
        }
        return flag;
    }
}

3. 编写字符编码过滤器（防止中文乱码）

package com.threepure.filter;

import javax.servlet.*;
import java.io.IOException;

/**
 * @author ThreePure
 * @date 20/11/30 9:27
 * @description:过滤器
 * @since 1.8
 */
public class CharacterEncodingFilter implements Filter {

    //初始化：web服务器启动，就初始化了，随时等待过滤对象出现！
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        //FilterChain：链
        /*过滤中的所有代码，在过滤特定请求的时候会执行
         * 必须让过滤器继续运行，因为可能还有其他过滤器*/
        servletRequest.setCharacterEncoding("utf-8");
        servletResponse.setCharacterEncoding("utf-8");
        servletResponse.setContentType("text/html;charset=UTF-8");

        //filterChain是让我们的请求继续执行下去，如果不写，程序到这里就会被停止
        //匹配过滤器后每次请求都会执行一次
        filterChain.doFilter(servletRequest, servletResponse);
    }

    //web服务器关闭的时候会被销毁
    @Override
    public void destroy() {
    }
}

配置 web.xml
所有的请求都会通过下面的过滤器，因为使用的 /*

<!--    字符串过滤器-->
    <filter>
        <filter-name>CharacterEncodingFilter</filter-name>
        <filter-class>com.uestc.filter.CharacterEncodingFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>CharacterEncodingFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

8. 导入静态资源

• calendar：日期
• css：样式
• images：图片数据
• js

---

以上便是准备工作

References

B站视频