最新SpringBoot整合Druid连接池+MybatisPlus+逆向代码生成器

前一段时间一直在整合MybatisPlus和他的代码生成器，当时一直不成功。一直都放着没有搞。
今天正好有机会搭建一个小demo，又重新搞了一下，才发现是以前的连接池问题导致了Mybatis整合失败，同时逆向工程也成功了。
版本：SpringBoot 版本2.1.6，MybatisPlus版本3.1.2，Druid版本1.1.18

引入依赖：pom文件如下：

	<dependencies>
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-webartifactId>
        dependency>
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-devtoolsartifactId>
            <scope>runtimescope>
            <optional>trueoptional>
        dependency>
        <dependency>
            <groupId>mysqlgroupId>
            <artifactId>mysql-connector-javaartifactId>
            <scope>runtimescope>
        dependency>
        <dependency>
            <groupId>org.projectlombokgroupId>
            <artifactId>lombokartifactId>
            <optional>trueoptional>
        dependency>
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-testartifactId>
            <scope>testscope>
        dependency>
        
        <dependency>
            <groupId>com.baomidougroupId>
            <artifactId>mybatis-plus-boot-starterartifactId>
            <version>3.1.2version>
        dependency>

        
        <dependency>
            <groupId>com.alibabagroupId>
            <artifactId>druidartifactId>
            <version>1.1.18version>
        dependency>
        
        <dependency>
            <groupId>com.alibabagroupId>
            <artifactId>fastjsonartifactId>
            <version>1.2.58version>
        dependency>

        
        <dependency>
            <groupId>org.apache.commonsgroupId>
            <artifactId>commons-lang3artifactId>
            <version>3.9version>
        dependency>

        
        <dependency>
            <groupId>com.baomidougroupId>
            <artifactId>mybatis-plus-generatorartifactId>
            <version>3.1.2version>
        dependency>
        <dependency>
            <groupId>org.freemarkergroupId>
            <artifactId>freemarkerartifactId>
            <version>2.3.28version>
        dependency>
    dependencies>

设置application.yml（整合MybatisPlus）

server:
  port: 8080

#database
spring:
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource
    url: jdbc:mysql://127.0.0.1:3306/xunyou?useUnicode=true&characterEncoding=UTF-8&serverTimezone=GMT%2B8&useSSL=false&allowMultiQueries=true
    username: root
    password: 123456
    driver-class-name: com.mysql.cj.jdbc.Driver
    initialSize: 5
    minIdle: 5
    maxActive: 20
    maxWait: 6000
    timeBetweenEvictionRunsMillis: 60000
    minEvictableIdleTimeMillis: 300000
    validationQuery: SELECT 1 FROM DUAL
    testWhileIdle: true
    testOnBorrow: false
    testOnReturn: false
    filters: stat,wall
    logSlowSql: true

#显示sql语句
logging:
  level:
    com:
      wanmait:
        tmallm:
          mapper: debug
# 配置mybatis-plus
# 配置扫描xml
mybatis-plus:
  mapper-locations: classpath*:mapper/*.xml
  type-aliases-package: com.xxn.backstage.entity

整合Druid连接池

详细的可以看一下我以前写的文章，我也是照着以前复制的
新建一个config包，新建DruidConfig

package com.xxn.backstage.config;

import com.alibaba.druid.pool.DruidDataSource;
import com.alibaba.druid.support.http.StatViewServlet;
import com.alibaba.druid.support.http.WebStatFilter;
import com.baomidou.mybatisplus.autoconfigure.SpringBootVFS;
import com.baomidou.mybatisplus.extension.spring.MybatisSqlSessionFactoryBean;
import lombok.extern.slf4j.Slf4j;
import org.apache.ibatis.io.VFS;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.boot.web.servlet.ServletRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;
import org.springframework.transaction.PlatformTransactionManager;
import org.springframework.transaction.annotation.EnableTransactionManagement;

import javax.sql.DataSource;
import java.sql.SQLException;

@Configuration
@EnableTransactionManagement
@Slf4j
public class DruidConfig {

    @Value("${spring.datasource.url}")
    private String dbUrl;

    @Value("${spring.datasource.username}")
    private String username;

    @Value("${spring.datasource.password}")
    private String password;

    @Value("${spring.datasource.driver-class-name}")
    private String driverClassName;

    @Value("${spring.datasource.initialSize}")
    private int initialSize;

    @Value("${spring.datasource.minIdle}")
    private int minIdle;

    @Value("${spring.datasource.maxActive}")
    private int maxActive;

    @Value("${spring.datasource.maxWait}")
    private int maxWait;

    @Value("${spring.datasource.timeBetweenEvictionRunsMillis}")
    private int timeBetweenEvictionRunsMillis;

    @Value("${spring.datasource.minEvictableIdleTimeMillis}")
    private int minEvictableIdleTimeMillis;

    @Value("${spring.datasource.validationQuery}")
    private String validationQuery;

    @Value("${spring.datasource.testWhileIdle}")
    private boolean testWhileIdle;

    @Value("${spring.datasource.testOnBorrow}")
    private boolean testOnBorrow;

    @Value("${spring.datasource.testOnReturn}")
    private boolean testOnReturn;

    @Value("${spring.datasource.filters}")
    private String filters;

    @Value("${spring.datasource.logSlowSql}")
    private String logSlowSql;

    @Bean
    public ServletRegistrationBean druidServlet(){
        ServletRegistrationBean reg = new ServletRegistrationBean();
        reg.setServlet(new StatViewServlet());
        reg.addUrlMappings("/druid/*");
        reg.addInitParameter("loginUserName",username);
        reg.addInitParameter("loginPassWord",password);
        reg.addInitParameter("logSlowSql",logSlowSql);
        return reg;
    }

    @Bean
    public FilterRegistrationBean filterRegistrationBean(){
        FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean();
        filterRegistrationBean.setFilter(new WebStatFilter());
        filterRegistrationBean.addUrlPatterns("/*");
        filterRegistrationBean.addInitParameter("exclusions", "*.js,*.gif,*.jpg,*.png,*.css,*.ico,/druid/*");
        filterRegistrationBean.addInitParameter("profileEnable", "true");
        return filterRegistrationBean;
    }

    @Bean
    public DataSource druidDataSource(){
        DruidDataSource datasource = new DruidDataSource();
        datasource.setUrl(dbUrl);
        datasource.setUsername(username);
        datasource.setPassword(password);
        datasource.setDriverClassName(driverClassName);
        datasource.setInitialSize(initialSize);
        datasource.setMinIdle(minIdle);
        datasource.setMaxActive(maxActive);
        datasource.setMaxWait(maxWait);
        datasource.setTimeBetweenEvictionRunsMillis(timeBetweenEvictionRunsMillis);
        datasource.setMinEvictableIdleTimeMillis(minEvictableIdleTimeMillis);
        datasource.setValidationQuery(validationQuery);
        datasource.setTestWhileIdle(testWhileIdle);
        datasource.setTestOnBorrow(testOnBorrow);
        datasource.setTestOnReturn(testOnReturn);
        try{
            datasource.setFilters(filters);
        }catch(SQLException e){
            log.error("druid configuration initialization filter", e);
        }
        return datasource;
    }
    /* 注意这里，这是整合不上MybatisPlus的罪魁祸首
    @Bean
    public SqlSessionFactory sqlSessionFactory() throws Exception{
        SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
        sqlSessionFactoryBean.setDataSource(druidDataSource());

        VFS.addImplClass(SpringBootVFS.class);
        PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
        sqlSessionFactoryBean.setMapperLocations(resolver.getResources("classpath*:/mapper/*.xml"));
        log.info("dao层扫描层为：/mapper/*.xml");
        return sqlSessionFactoryBean.getObject();
    }
    */
    
    @Bean
    public MybatisSqlSessionFactoryBean sqlSessionFactory() throws Exception{
        MybatisSqlSessionFactoryBean sqlSessionFactoryBean = new MybatisSqlSessionFactoryBean();
        sqlSessionFactoryBean.setDataSource(druidDataSource());
        VFS.addImplClass(SpringBootVFS.class);
        PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
        sqlSessionFactoryBean.setMapperLocations(resolver.getResources("classpath*:/mapper/*.xml"));
        log.info("dao层扫描层为：/mapper/*.xml");
        return sqlSessionFactoryBean;
    }

    @Bean
    public PlatformTransactionManager transactionManager() throws  SQLException{
        return new DataSourceTransactionManager(druidDataSource());
    }

}

这里注释的部分详细解释一下，在我以前整合Druid连接池的过程中，都是按照注释里面的方法，生成SqlSessionFactory，导致在整合Mybatis-Plus的时候在运行自带方法时，总是报异常，mybatis-plus官网上也对这个异常有特殊说明

Invalid bound statement (not found)

https://mp.baomidou.com/guide/faq.html#出现-invalid-bound-statement-not-found-异常
其中写到

• 检查是否指定了主键？如未指定，则会导致 selectById 相关 ID 无法操作，请用注解 @TableId 注解表 ID 主键。当然 @TableId 注解可以没有！但是你的主键必须叫 id（忽略大小写）
• SqlSessionFactory不要使用原生的，请使用MybatisSqlSessionFactory
• 检查是否自定义了SqlInjector，是否复写了getMethodList()方法，该方法里是否注入了你需要的方法(可参考DefaultSqlInjector)

我们这里问题出现在第二条，所以新的方法里没有生成原生的SqlSessionFactory，而是用了MybatisSqlSessionFactory。

MybatisPlus代码生成器（超级好用，比MybatisGenerator还好用）

前面我们已经添加过依赖了
所以直接在test下新建一个MybatisPlusGenerator的生成类，官网有现成的代码，我按照正常的习惯修改了一下，修改一下数据库源就可以直接用，修改的地方我加了注释

package com.xxn.backstage;

import com.baomidou.mybatisplus.core.exceptions.MybatisPlusException;
import com.baomidou.mybatisplus.core.toolkit.StringPool;
import com.baomidou.mybatisplus.core.toolkit.StringUtils;
import com.baomidou.mybatisplus.generator.AutoGenerator;
import com.baomidou.mybatisplus.generator.InjectionConfig;
import com.baomidou.mybatisplus.generator.config.*;
import com.baomidou.mybatisplus.generator.config.po.TableInfo;
import com.baomidou.mybatisplus.generator.config.rules.NamingStrategy;
import com.baomidou.mybatisplus.generator.engine.FreemarkerTemplateEngine;

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

public class MybatisPlusGenerator {

    /**
     * 

     * 读取控制台内容
     * 
     */
    public static String scanner(String tip) {
        Scanner scanner = new Scanner(System.in);
        StringBuilder help = new StringBuilder();
        help.append("请输入" + tip + "：");
        System.out.println(help.toString());
        if (scanner.hasNext()) {
            String ipt = scanner.next();
            if (StringUtils.isNotEmpty(ipt)) {
                return ipt;
            }
        }
        throw new MybatisPlusException("请输入正确的" + tip + "！");
    }

    public static void main(String[] args) {
        // 代码生成器
        AutoGenerator mpg = new AutoGenerator();

        // 全局配置
        GlobalConfig gc = new GlobalConfig();
        String projectPath = System.getProperty("user.dir");
        gc.setOutputDir(projectPath + "/src/main/java");
        gc.setAuthor("xxn");
        gc.setOpen(false);
        // gc.setSwagger2(true); 实体属性 Swagger2 注解
        mpg.setGlobalConfig(gc);

        // 数据源配置:这里注意修改
        DataSourceConfig dsc = new DataSourceConfig();
        dsc.setUrl("jdbc:mysql://127.0.0.1:3306/xunyou?useUnicode=true&characterEncoding=UTF-8&serverTimezone=GMT%2B8&useSSL=false&allowMultiQueries=true");
        // dsc.setSchemaName("public");
        dsc.setDriverName("com.mysql.cj.jdbc.Driver");
        dsc.setUsername("root");
        dsc.setPassword("123456");
        mpg.setDataSource(dsc);

        // 包配置
        PackageConfig pc = new PackageConfig();
        //这一句可以注释
        //pc.setModuleName(scanner("模块名"));
        pc.setParent("com.xxn.backstage");
        mpg.setPackageInfo(pc);

        // 自定义配置
        InjectionConfig cfg = new InjectionConfig() {
            @Override
            public void initMap() {
                // to do nothing
            }
        };

        // 如果模板引擎是 freemarker
        String templatePath = "/templates/mapper.xml.ftl";
        // 如果模板引擎是 velocity
        // String templatePath = "/templates/mapper.xml.vm";

        // 自定义输出配置
        List<FileOutConfig> focList = new ArrayList<>();
        // 自定义配置会被优先输出
        focList.add(new FileOutConfig(templatePath) {
            @Override
            public String outputFile(TableInfo tableInfo) {
                // 自定义输出文件名 ， 如果你 Entity 设置了前后缀、此处注意 xml 的名称会跟着发生变化！！
                //此处与官网有区别，官网多生成一层目录
                return projectPath + "/src/main/resources/mapper/" + tableInfo.getEntityName() + "Mapper" + StringPool.DOT_XML;
            }
        });
        /*
        cfg.setFileCreate(new IFileCreate() {
            @Override
            public boolean isCreate(ConfigBuilder configBuilder, FileType fileType, String filePath) {
                // 判断自定义文件夹是否需要创建
                checkDir("调用默认方法创建的目录");
                return false;
            }
        });
        */
        cfg.setFileOutConfigList(focList);
        mpg.setCfg(cfg);

        // 配置模板
        TemplateConfig templateConfig = new TemplateConfig();

        // 配置自定义输出模板
        //指定自定义模板路径，注意不要带上.ftl/.vm, 会根据使用的模板引擎自动识别
        // templateConfig.setEntity("templates/entity2.java");
        // templateConfig.setService();
        // templateConfig.setController();

        templateConfig.setXml(null);
        mpg.setTemplate(templateConfig);

        // 策略配置
        StrategyConfig strategy = new StrategyConfig();
        strategy.setNaming(NamingStrategy.underline_to_camel);
        strategy.setColumnNaming(NamingStrategy.underline_to_camel);
        //strategy.setSuperEntityClass("com.xxn.mybatisplusgenerator.common.BaseEntity");
        strategy.setEntityLombokModel(true);
        strategy.setRestControllerStyle(true);
        // 公共父类
        //没有公共父类的，注释这一句
        //strategy.setSuperControllerClass("com.xxn.mybatisplusgenerator.BaseController");
        // 写于父类中的公共字段，一定要把这一句注释，否则不会生成主键很麻烦
        //strategy.setSuperEntityColumns("id");
        strategy.setInclude(scanner("表名，多个英文逗号分割").split(","));
        strategy.setControllerMappingHyphenStyle(true);
        //注意这一句是去除前缀
        strategy.setTablePrefix(pc.getModuleName() + "_");
        mpg.setStrategy(strategy);
        mpg.setTemplateEngine(new FreemarkerTemplateEngine());
        mpg.execute();
    }
}

去除前缀还是要说一下，如果你要手动输入前缀，需要把上面

pc.setModuleName(scanner("模块名"));

这一句注释打开
比方说数据库的表名为 sys_user，你生成的时候又不想要sys_的前缀，你就可以打开注释，在输入模块名的地方输入sys，会自动加_（源码很简单，一看就懂）
然后直接运行这个类里的main方法就会生成
可以看一下目录结构

水印挡了一部分，应该能看懂
运用逆向工程最大的好处就是namespace肯定是对的，运行出问题基本上可以排除mapper类与xml对应的问题，而且超级便捷
项目上传gitee，不会的同学可以下载参考一下。
https://gitee.com/heheyixiao/SpringBootDemo.git