MyBatis 实战

怼烎@ 2023-10-15 22:51 52阅读 0赞

## 一、MyBatis 代码生成器 ##

### 1.概述 ###

*  通过逆向的方式，通过已经建好的表，反向生成 mapper 接口，mapper.xml 文件，domain 实体
 *  官方文档：http://mybatis.org/generator/index.html

### 2.快速入门 ###

#### 2.1导入插件 ####

<plugin>
        <groupId>org.mybatis.generator</groupId>
        <artifactId>mybatis-generator-maven-plugin</artifactId>
        <version>1.4.1</version>
        <dependencies>
    
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <version>8.0.29</version>
            </dependency>
        </dependencies>
    </plugin>

#### 2.2添加配置文件 ####

*  名称：generatorConfig.xml

<!DOCTYPE generatorConfiguration PUBLIC
            "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
            "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">
    <generatorConfiguration>
        <context id="simple" targetRuntime="MyBatis3">
    
            <jdbcConnection driverClass="com.mysql.cj.jdbc.Driver"
                            connectionURL="jdbc:mysql://localhost:3306/mybatis"
                            userId="root"
                            password="123456"
            />
    
            <javaModelGenerator targetPackage="cn.sycoder.domain" targetProject="src/main/java"/>
    
            <sqlMapGenerator targetPackage="cn.sycoder.mapper" targetProject="src/main/resources"/>
    
            <javaClientGenerator type="XMLMAPPER" targetPackage="cn.sycoder.mapper" targetProject="src/main/java"/>
    
    
    
            <table tableName="generator"  />
        </context>
    </generatorConfiguration>

#### 2.3运行 ####

![image-20221024113229615][]

#### 2.4生成文件 ####

![在这里插入图片描述][3811bc5d008142acb1258808f9f28cdf.png]

## 二、JavaWEB 项目实战 ##

### 1.项目前期准备 ###

#### 1.1导入项目依赖 ####

<dependencies>
            <dependency>
                <groupId>junit</groupId>
                <artifactId>junit</artifactId>
                <version>4.11</version>
            </dependency>
    
            
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <version>8.0.29</version>
            </dependency>
            
            <dependency>
                <groupId>org.mybatis</groupId>
                <artifactId>mybatis</artifactId>
                <version>3.5.6</version>
            </dependency>
            
            <dependency>
                <groupId>log4j</groupId>
                <artifactId>log4j</artifactId>
                <version>1.2.17</version>
            </dependency>
    
            
            <dependency>
                <groupId>com.github.pagehelper</groupId>
                <artifactId>pagehelper</artifactId>
                <version>5.3.0</version>
            </dependency>
    
            <dependency>
                <groupId>javax.servlet</groupId>
                <artifactId>javax.servlet-api</artifactId>
                <version>3.1.0</version>
                <scope>provided</scope>
                
            </dependency>
            <dependency>
                <groupId>javax.servlet</groupId>
                <artifactId>jsp-api</artifactId>
                <version>2.0</version>
                <scope>provided</scope>
            </dependency>
        </dependencies>
    
        <build>
            <plugins>
    
                <plugin>
                    <groupId>org.mybatis.generator</groupId>
                    <artifactId>mybatis-generator-maven-plugin</artifactId>
                    <version>1.3.2</version>
                    <configuration>
                        <verbose>true</verbose>
                        <overwrite>false</overwrite>
                    </configuration>
                    <dependencies>
    
                        <dependency>
                            <groupId>mysql</groupId>
                            <artifactId>mysql-connector-java</artifactId>
                            <version>8.0.29</version>
                        </dependency>
                    </dependencies>
                </plugin>
            </plugins>
        </build>

#### 1.2新建用户表 ####

create table user
    (
    	id bigint auto_increment
    		primary key,
    	name varchar(64) null,
    	account varchar(64) null,
    	password varchar(128) null,
    	constraint user_account_uindex
    		unique (account)
    );

#### 1.3新建商品表 ####

create table product
    (
    	id bigint auto_increment
    		primary key,
    	name varchar(64) null,
    	price double null,
    	remark varchar(128) null,
    	create_time datetime null,
    	create_id bigint null,
    	update_time datetime null,
    	update_id bigint null
    );

#### 1.4搭建好的项目结构 ####

![在这里插入图片描述][224342d8374a430294ebdc6be52ba7e8.png]

### 2.注册功能实现 ###

*  注册流程分析
    
    ![在这里插入图片描述][8bfbd833a6534f4cbf5ce9c2107652c4.png]
    
     *  servlet
        
            @WebServlet("/register")
            public class RegisterController extends HttpServlet {
                    
            
            
                @Override
                protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
                    
                    String account = req.getParameter("account");
                    IRegisterService service = new RegisterServiceImpl();
                    boolean check = service.checkAccount(account);
                    String ret = check ? "yes" : "no";
                    resp.getWriter().write(ret);
                }
            
                @Override
                protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
                    
                    //获取请求数据
                    String account = req.getParameter("account");
                    String password = req.getParameter("password");
                    //直接插入用户
                    IRegisterService service = new RegisterServiceImpl();
                    int insertCount = service.insert(account, password);
                    req.getRequestDispatcher("/login.html").forward(req,resp);
                }
            
            
            }
     *  异步检测是否注册用户
        
            // 定义失去焦点事件发送异步请求去检验账户是否存在
                document.getElementById("account").οnblur=function () {
                    console.log(this.value);
                    //发送到后端进行account 检验
                    axios({
                        method:'get',
                        url:'/register',
                        params:{
                            account:this.value
                        }
                    }).then(function (response) {
                        if("no" == response.data){
                            document.getElementById("account_err").style.display='none'
                        }else{
                            document.getElementById("account_err").style.display=''
                        }
                    })
                }
     *  检验与注册 service
        
            @Override
                public boolean checkAccount(String account) {
                    
                    try(SqlSession sqlSession = MyBatisUtils.getSqlSession()){
                    
                        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
                        //查询用户是否存在
                        User user = mapper.selectByAccount(account);
                        return user != null;
                    }catch (Exception e){
                    
                        e.printStackTrace();
                    }
                    return false;
                }
            
                @Override
                public int insert(String account, String password) {
                    
                    try(SqlSession sqlSession = MyBatisUtils.getSqlSession()){
                    
                        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
                        //查询用户是否存在
                        User user1 = new User();
                        user1.setAccount(account);
                        user1.setPassword(password);
                        int insert = mapper.insert(user1);
                        return insert;
                    }catch (Exception e){
                    
                        e.printStackTrace();
                    }
                    return 0;
                }

### 3.登录功能实现 ###

*  流程图分析
    
    ![外链图片转存失败,源站可能有防盗链机制,建议将图片保存下来直接上传][125c3c07238446efa203355e26eaec11.png]

### 4.列表查询功能实现 ###

*  功能分析
    
    ![image-20221024143020580][]
 *  添加 fasterjson 依赖
    
        <dependency>
                    <groupId>com.alibaba</groupId>
                    <artifactId>fastjson</artifactId>
                    <version>1.2.79</version>
                </dependency>
 *  通过序列化的方式输出

### 5.商品新增 ###

*  新增前端
    
        insert(){
              
                        let _this = this;
                        //关掉弹框
                        _this.dialogVisible=false,
                        axios({
              
                            method:'post',
                            url:'/product',
                            params:_this.insertForm
                        }).then(function (response) {
              
        
                            if("no" == response.data){
              
                                alert("新增失败")
                            }else{
              
                                _this.listProduct();
                            }
                        })
        
                        _this.insertForm = {
              
                            name:'',
                            price:'',
                            remark:''
                        }
                    },

### 6.商品修改 ###

*  修改前端
    
        // 编辑商品
                    updateSubmit(){
              
                        let _this = this;
                        //关掉弹框
                        _this.updateDialogVisible=false,
                            axios({
              
                                method:'put',
                                url:'/product',
                                params:_this.updateForm
                            }).then(function (response) {
              
                                if("no" == response.data){
              
                                    alert("更新失败")
                                }else{
              
                                    _this.listProduct();
                                }
                            })
                    },

### 7.批量删除 ###

*  删除前端
    
        //删除方法
                    del(row){
              
                        console.log(row.id);
                        let _this = this;
                            axios({
              
                                method:'delete',
                                url:'/product',
                                params:{
              
                                    ids:row.id
                                }
                            }).then(function (response) {
              
                                if("no" == response.data){
              
                                    alert("删除失败")
                                }else{
              
                                    _this.listProduct();
                                }
                            })
                    },
                    // 批量删除
                    batchDelete(){
              
                        _this = this;
                        let param ='';
                        let arr = this.multipleSelection;
                        for (let i = 0; i <arr.length ; i++) {
              
                            if(i ==0){
              
                                param = arr[i].id
                            }else{
              
                                param = param + ','+arr[i].id
                            }
        
                        }
                        console.log(param);
                        axios({
              
                            method:'delete',
                            url:'/product',
                            params:{
              
                                ids:param
                            }
                        }).then(function (response) {
              
                            if("no" == response.data){
              
                                alert("删除失败")
                            }else{
              
                                _this.listProduct();
                            }
                        })
                    },

### 8.优化 ###

*  修改日期显示
    
        @JSONField(format = "yyyy-MM-dd MM:hh:ss")
 *  新增结束数据还在
    
        _this.insertForm = {
                            name:'',
                            price:'',
                            remark:''
                        }
 *  页码显示不对
    
        handleSizeChange(val) {
            console.log(`每页 ${val} 条`);
            this.queryParam.pageSize = val;
            this.queryParam.currentPage = 1;
            this.listProduct();
        },
        handleCurrentChange(val) {
            console.log(`当前页: ${val}`);
            this.queryParam.currentPage = val;
            this.listProduct();
        
        },

## 三、项目部署上线(知识点补充) ##

*  不用去纠结 axios 没有定义的问题，后面学习完 vue 脚手架， npm 等之后，安装一下就好了

### 1.修改数据库连接配置 ###

*  修改数据库配置
    
    ![在这里插入图片描述][076b918ae98f4606a785a92641f996dd.png]

### 2.检查maven 打包方式 ###

*  需要 war 包打包方式
    
    ![image-20221025130810465][]

### 3.打包 ###

*  使用 maven 插件打包 mvn package
    
    ![外链图片转存失败,源站可能有防盗链机制,建议将图片保存下来直接上传][33440c77a7c34f54afe252c32d19ed46.png]

### 4.上传war包到linux 服务器 ###

*  rz 命令，上传war 文件到服务器
 *  备份 webapps 文件夹
    
        mv webapps ./webapps_back
 *  新建webapps 目录
    
        mkdir webapps
 *  将上传的 war 包移动到 webapps 目录下并且重命名
    
        mv WebProject-04-1.0-SNAPSHOT.war ./apache-tomcat-9.0.68/webapps/ROOT.war
 *  重启tomcat
    
        sh ./bin/startup.sh
 *  查看日志
    
        tail -n 500 -f logs/catalina.out

### 5.linux mysql 新建 mybatis 库 ###

mvn package

\[外链图片转存中…(img-PLQJ0zIX-1694683657050)\]

### 4.上传war包到linux 服务器 ###

### 5.linux mysql 新建 mybatis 库 ###

*  新建数据表 user 和 product

[image-20221024113229615]: https://img-blog.csdnimg.cn/img_convert/4bfdaf0ffb279424d72a0de6b985967e.png
[3811bc5d008142acb1258808f9f28cdf.png]: https://img-blog.csdnimg.cn/3811bc5d008142acb1258808f9f28cdf.png
[224342d8374a430294ebdc6be52ba7e8.png]: https://img-blog.csdnimg.cn/224342d8374a430294ebdc6be52ba7e8.png
[8bfbd833a6534f4cbf5ce9c2107652c4.png]: https://img-blog.csdnimg.cn/8bfbd833a6534f4cbf5ce9c2107652c4.png
[125c3c07238446efa203355e26eaec11.png]: https://img-blog.csdnimg.cn/125c3c07238446efa203355e26eaec11.png
[image-20221024143020580]: https://img-blog.csdnimg.cn/img_convert/bf12017044071d215d3aca4031de369e.png
[076b918ae98f4606a785a92641f996dd.png]: https://img-blog.csdnimg.cn/076b918ae98f4606a785a92641f996dd.png
[image-20221025130810465]: https://img-blog.csdnimg.cn/img_convert/c4a9e4848879320c6892675384ca6062.png
[33440c77a7c34f54afe252c32d19ed46.png]: https://img-blog.csdnimg.cn/33440c77a7c34f54afe252c32d19ed46.png