Spring-Boot 整合MyBatis 添加pageHelper 开启事务逆向工程

冷不防 2021-11-27 04:28 362阅读 0赞

### 1、整合MyBatis ###

在`pom.xml`中配置数据库驱动、连接池

<dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-jdbc</artifactId>
            </dependency>
            
            <dependency>
                <groupId>org.mybatis.spring.boot</groupId>
                <artifactId>mybatis-spring-boot-starter</artifactId>
                <version>1.3.2</version>
            </dependency>
            
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <scope>Compile</scope>
            </dependency>
            
            <dependency>
                <groupId>com.alibaba</groupId>
                <artifactId>druid-spring-boot-starter</artifactId>
                <version>1.1.10</version>
            </dependency>

在`application.yml`配置数据源

spring:
    # 数据源配置
      datasource:
        name: mysql_test
        type: com.alibaba.druid.pool.DruidDataSource
        #druid相关配置
        druid:
          #监控统计拦截的filters
          filters: stat
          driver-class-name: com.mysql.jdbc.Driver
          #基本属性
          url: jdbc:mysql://localhost:3306/数据库名?useUnicode=true&characterEncoding=UTF-8&allowMultiQueries=true&serverTimezone=GMT%2B8&useSSL=false
          username: root
          password: root
          #配置初始化大小/最小/最大
          initial-size: 1
          min-idle: 1
          max-active: 20
          #获取连接等待超时时间
          max-wait: 60000
          #间隔多久进行一次检测，检测需要关闭的空闲连接
          time-between-eviction-runs-millis: 60000
          #一个连接在池中最小生存的时间
          min-evictable-idle-time-millis: 300000
          validation-query: SELECT 'x'
          #空闲连接是否被回收
          test-while-idle: true
          #申请连接时是否检测有效性
          test-on-borrow: false
          #归还连接时是否检测有效性
          test-on-return: false

### 1.2配置mybatis映射文件 ###

在`application.yml`配置映射文件的路径以及自身配置文件的路径；  
如果在mybatis的配置文件中设置了别名包路径，这里就不用再次设置了；

#mybatis的配置
    mybatis:
      config-location: classpath:mybatis/mybatis-config.xml
      mapper-locations: classpath:com/example/test/mapper/*.xml
    # type-aliases-package: com.javasm.boot

`mybatis-config.xml`配置文件  
基本都在`application.yml`中配置了，这里就配置一下延迟加载之类的。

<?xml version="1.0" encoding="UTF-8" ?>
    
    <!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd">
    
    <configuration>
    	<settings>
       		<setting name="lazyLoadingEnabled" value="true"/>
        	<setting name="aggressiveLazyLoading" value="false"/>
        	<setting name="lazyLoadTriggerMethods" value=""/>
    		<setting name="logImpl" value="log4j2"/>
    		<setting name="cacheEnabled" value="true"/>
    	</settings>
    	
    	<typeAliases>
    		<package name="com.example"/>
    	</typeAliases>
    </configuration>

这里设置了别名，所以`application.yml`不用再配置了。

### 1.3、mapper类生成代理对象 ###

@Mapper注解用来注解dao层的接口，使它的实现类可以被自动注入；

@Mapper
    public interface SysuserMapper { 
        int deleteByPrimaryKey(Integer uid);
    
        int insert(Sysuser record);
    
        int insertSelective(Sysuser record);
    
        Sysuser selectByPrimaryKey(Integer uid);
    
        int updateByPrimaryKeySelective(Sysuser record);
    
        int updateByPrimaryKey(Sysuser record);
    }

除了使用@Mapper注解每一个dao接口，还可以在主程序类上加@MapperScan注解，扫描mapper包下的所有接口；  
`Application`主程序

@SpringBootApplication
    @MapperScan("com.java.boot.*.mapper")		//扫描mapper包下的所有注解
    @EnableTransactionManagement			//开启注解式事务 
    public class Application extends SpringBootServletInitializer { 
        @Override
        protected SpringApplicationBuilder configure(SpringApplicationBuilder builder) { 
            return builder.sources(Application.class);
        }
    
        public static void main(String[] args) { 
            SpringApplication a = new SpringApplication(Application.class);
            a.setBannerMode(Banner.Mode.OFF);//关闭banner
            a.run(args);
    // SpringApplication.run(Application.class, args);
        }
    
    }

### 2、使用事务 ###

在主程序类上加@EnableTransactionManagement开启注解式事务；（见3中的Application主程序代码）
        在服务层方法上加Transactional注解即可；

public class SysuserServiceImpl{ 
    	@Transactional
    	public Sysuser update(Sysuser user){ 
    		//一个开启了事务的service方法
    	}
    }

### 3、pageHelper分页支持 ###

在`pom.xml`中添加分页启动器；

<dependency>
                <groupId>com.github.pagehelper</groupId>
                <artifactId>pagehelper-spring-boot-starter</artifactId>
                <version>1.2.5</version>
            </dependency>

在`application.yml`中设置分页合理化；

pagehelper:
      reasonable: true

> 分页合理化就是你无法翻到第-1页，也不会超出总页数；

### 4、逆向工程 ###

在`pom.xml`中添加逆向工程插件；

<plugin>
                    <groupId>org.mybatis.generator</groupId>
                    <artifactId>mybatis-generator-maven-plugin</artifactId>
                    <version>1.3.2</version>
                    <dependencies>
                        <dependency>
                            <groupId>mysql</groupId>
                            <artifactId>mysql-connector-java</artifactId>
                            <version>5.1.26</version>
                        </dependency>
                    </dependencies>
    
                    <configuration>
                        <configurationFile>${basedir}/src/main/resources/mybatis/generatorConfig.xml</configurationFile>
                        <overwrite>true</overwrite>
                    </configuration>
                </plugin>

添加`generatorConfig.xml`配置文件；  
change只有，在右侧就可以看到新增的插件；  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NhbHRzb3Vs_size_16_color_FFFFFF_t_70]

### 其他： ###

`generatorConfig.xml`配置文件

<?xml version="1.0" encoding="UTF-8"?>
    <!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="DB2Tables" targetRuntime="MyBatis3">
    		<commentGenerator>
    			<property name="suppressDate" value="true"/>
    			<property name="suppressAllComments" value="true"/>
    		</commentGenerator>
    		<jdbcConnection driverClass="com.mysql.jdbc.Driver" connectionURL="jdbc:mysql://127.0.0.1:3306/how2java" userId="root" password="root">
    		</jdbcConnection>
    		<javaTypeResolver>
    			<property name="forceBigDecimals" value="false"/>
    		</javaTypeResolver>
    		
    		<javaModelGenerator targetPackage="com.example.test.entity" targetProject="src/main/java">
    			<property name="enableSubPackages" value="true"/>
    			
           	 	<property name="trimStrings" value="true"/>
    		</javaModelGenerator>
    		
    		<sqlMapGenerator targetPackage="com.example.test.mapper" targetProject="src/main/java">
    			<property name="enableSubPackages" value="true"/>
    		</sqlMapGenerator>
    		
    		<javaClientGenerator type="XMLMAPPER" targetPackage="com.example.test.dao" targetProject="src/main/java">
    			<property name="enableSubPackages" value="true"/>
    		</javaClientGenerator>
    
    		<table tableName="sysuser" domainObjectName="Sysuser" enableCountByExample="false" enableUpdateByExample="false" enableDeleteByExample="false" enableSelectByExample="false" selectByExampleQueryId="false"></table>
    	</context>
    </generatorConfiguration>

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NhbHRzb3Vs_size_16_color_FFFFFF_t_70]: /images/20211126/40e4b4f58733478ea28f48620434d599.png