spring boot之mybatis分页多种方法

太过爱你忘了你带给我的痛 2022-06-09 00:44 167阅读 0赞

我们讲一下mybatis集成的四种方式（可以先翻看一下上篇博客），顺带把分页pageHelper讲了  
分页插件先加上

<dependency>  
          <groupId>com.github.pagehelper</groupId>  
          <artifactId>pagehelper</artifactId>  
          <version>4.1.1</version>  
        </dependency>

**方法一**  
在启动java类中添加注入bean：sqlSessionFactory和dataSource

@ComponentScan
    @MapperScan("org.test1.mapper")
    @SpringBootApplication
    public class Application { 
    
        @Bean
        @ConfigurationProperties(prefix="spring.datasource")
        public DataSource dataSource(){
            return new org.apache.tomcat.jdbc.pool.DataSource();
        }
    
        @Bean(name="sqlSessionFactory")
        public SqlSessionFactory sqlSessionFactoryBean() throws Exception{
            SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
            sqlSessionFactoryBean.setDataSource(dataSource());
    
            //分页插件
            PageHelper pageHelper = new PageHelper();
            Properties properties = new Properties();
            //properties.setProperty("dialet", "Oracle");
            properties.setProperty("resonable", "false");
            properties.setProperty("pageSizeZero", "true");
            pageHelper.setProperties(properties);
            sqlSessionFactoryBean.setPlugins(new Interceptor[]{pageHelper});
    
    
            PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
            sqlSessionFactoryBean.setMapperLocations(resolver.getResources("classpath:/mybatis/*.xml"));
            return sqlSessionFactoryBean.getObject();
        }
        @Bean
        public PlatformTransactionManager transactionManager(){
            return new DataSourceTransactionManager(dataSource());
        }
        public static void main(String args[]){
    
            SpringApplication.run(Application.class);
        }
    }

调用：  
`PageHelper.startPage(1,1)`;  
param：第几页，页面几条数据

这是对于我们上篇博客集成mybatis的方法，直接添加个拦截就可以了；  
具体的可以看上篇博客

方法二

我们再试另一种方法：  
加两个config文件  
通过添加@Configuration来解决的注入dataSource和sqlSessionFactory的

@Configuration
    @EnableTransactionManagement
    public class MyBatisConfig implements TransactionManagementConfigurer { 
    
        @Autowired
        DataSource dataSource;
    
        @Bean(name = "sqlSessionFactory")
        public SqlSessionFactory sqlSessionFactoryBean() {
            SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
            bean.setDataSource(dataSource);
            bean.setTypeAliasesPackage("org.test1.mapper");
    
            //分页插件
            PageHelper pageHelper = new PageHelper();
            Properties properties = new Properties();
            properties.setProperty("reasonable", "true");
            properties.setProperty("supportMethodsArguments", "true");
            properties.setProperty("returnPageInfo", "check");
            properties.setProperty("params", "count=countSql");
            pageHelper.setProperties(properties);
    
            //添加插件
            bean.setPlugins(new Interceptor[]{pageHelper});
    
            //添加XML目录
            ResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
            try {
                bean.setMapperLocations(resolver.getResources("classpath:/mybatis/*.xml"));
                return bean.getObject();
            } catch (Exception e) {
                e.printStackTrace();
                throw new RuntimeException(e);
            }
        }
    
        @Bean
        public SqlSessionTemplate sqlSessionTemplate(SqlSessionFactory sqlSessionFactory) {
            return new SqlSessionTemplate(sqlSessionFactory);
        }
    
        @Bean
        public PlatformTransactionManager annotationDrivenTransactionManager() {
            return new DataSourceTransactionManager(dataSource);
        }
    }

@Configuration
    //TODO 注意，由于MapperScannerConfigurer执行的比较早，所以必须有下面的注解
    @AutoConfigureAfter(MyBatisConfig.class)
    public class MyBatisMapperScannerConfig{ 
    
      @Bean
      public MapperScannerConfigurer mapperScannerConfigurer() {
          MapperScannerConfigurer mapperScannerConfigurer = new MapperScannerConfigurer();
          mapperScannerConfigurer.setSqlSessionFactoryBeanName("sqlSessionFactory");
          mapperScannerConfigurer.setBasePackage("org.test1.mapper");
          return mapperScannerConfigurer;
      }
    
    }

其它没有区别；

方法三

第三种超级简单的办法：  
**但注意添加mapper扫描**  
就是把我们configuration这步给省去了；用的人家启动时默认的sqlSessionFactory；  
直接在application.properties中添加：`mybatis.mapperLocations: classpath:/mybatis/*.xml；`  
启动即可；  
需要配置的话可以添加mybatis的其他参数

# MyBatis mybatis: 
    typeAliasesPackage: com.tony.entity 
    mapperLocations: classpath:/com/tony/mapper/*.xml configLocation: classpath:/mybatis-config.xml

mybatis-config.xml

<?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="logImpl" value="LOG4J"/>
        </settings>
        <typeAliases>
            <typeAlias type="org.test.mapper.testMapper" alias="Student" />
        </typeAliases>
        <plugins>
            
            <plugin interceptor="com.github.pagehelper.PageHelper">
                <property name="dialect" value="mysql"/>
                <property name="offsetAsPageNum" value="false"/>
                <property name="rowBoundsWithCount" value="false"/>
                <property name="pageSizeZero" value="true"/>
                <property name="reasonable" value="false"/>
                <property name="supportMethodsArguments" value="false"/>
                <property name="returnPageInfo" value="none"/>
            </plugin>
        </plugins>
        <mappers>
            <mapper resource="/mybatis/user.xml"/>
        </mappers>
    
    </configuration>

参考：[http://www.jianshu.com/p/5ef281100bb6/][http_www.jianshu.com_p_5ef281100bb6]  
[http://blog.csdn.net/qincidong/article/details/76120968][http_blog.csdn.net_qincidong_article_details_76120968]

方法四  
上文提到过的，什么也不用做，直接在mapper接口中写方法就Ok了；这种功能集成太少,没有插件；

@Select("select id from table1") 
        public int getMsg3();

前三种方法其实最终目的都一样  
方法一和方法二其实差不多，都是通过手动注解的方式将mybatis和分页加载;  
而方法三则是系统自动加载，个人推荐方法三；

[http_www.jianshu.com_p_5ef281100bb6]: http://www.jianshu.com/p/5ef281100bb6/
[http_blog.csdn.net_qincidong_article_details_76120968]: http://blog.csdn.net/qincidong/article/details/76120968