【Spring Boot】配置mybatis plus 分页插件 total 为0 解决方案分享

网上爬坑一上午 很多没说明到位 分享下自己解决过程.

有可能出错地点:

1.spring boot 使用 @Configuration 注解 java类 配置方式 没设置上插件 interceptor
2.没设置数据库方言 DialectType
3.引入了多个分页插件
4.代码里面重复实例化了多个page

@Configuration
@MapperScan("com.**.mapper")
@EnableTransactionManagement
public class MybatisDataSourceConfig {
    private static final Logger log = LoggerFactory.getLogger(MybatisDataSourceConfig.class);

    private static final String MAPPER_LOCATION = "classpath*:mybatis/**/*.xml";

    @Value("${mybatis-plus.global-config.dbColumnUnderline}")
    private Boolean dbColumnUnderline;
    @Autowired
    @Qualifier("mybatisDataSource")
    private DataSource mybatisDataSource;

    @Bean(name = "mybatisTransactionManager")
    public DataSourceTransactionManager masterTransactionManager() {
        return new DataSourceTransactionManager(mybatisDataSource);
    }


    @Bean(name = "mybatisSessionFactory")
    public SqlSessionFactory mybatisSessionFactory() throws Exception {
        //解决查询返回结果含null没有对应字段值问题     
        MybatisConfiguration configuration = new MybatisConfiguration();
        configuration.setCallSettersOnNulls(true);
        //配置slq打印日志
        configuration.setLogImpl(org.apache.ibatis.logging.stdout.StdOutImpl.class);
        //峰驼转换
        configuration.setMapUnderscoreToCamelCase(dbColumnUnderline);
        //注意把SqlSessionFactory 换成mybitaisPlus的 否则使用自带方法会报错
        MybatisSqlSessionFactoryBean sessionFactory = new MybatisSqlSessionFactoryBean();
        sessionFactory.setDataSource(mybatisDataSource);
        //mybatis对应spring boot环境的配置
        sessionFactory.setVfs(SpringBootVFS.class);
        //xml扫描路径
        sessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver().getResources(MybatisDataSourceConfig.MAPPER_LOCATION));
        //配置实体包路径
        sessionFactory.setTypeAliasesPackage("com.**.entity");
        //配置自定义类型转换 类包路径
        sessionFactory.setTypeHandlersPackage("com.**.convert");
        //添加分页插件 注意要添加到插件很多没说明这一步
        Interceptor[] interceptor = {paginationInterceptor()};
        sessionFactory.setPlugins(interceptor);
        sessionFactory.setConfiguration(configuration);
        return sessionFactory.getObject();
    }

    @Bean
    public SqlSessionTemplate sqlSessionTemplate() throws Exception {
        return new SqlSessionTemplate(mybatisSessionFactory());
    }


    /**
     * 分页插件
     */
    @Bean
    public PaginationInterceptor paginationInterceptor() {
        PaginationInterceptor paginationInterceptor = new PaginationInterceptor();
        paginationInterceptor.setDialectType("mysql");
        // paginationInterceptor.setLimit(你的最大单页限制数量，默认 500 条，小于 0 如 -1 不受限制);
        return paginationInterceptor;
    }

成功调用后sql 语句会添加 分页部分

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