mybatis升级mybatis-plus

1.引入pom

 <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>${mybatis-plus.version}</version>
        </dependency>
 <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-core</artifactId>
            <version>3.5.2</version>
            <scope>compile</scope>
        </dependency>
<dependency>
                <groupId>com.baomidou</groupId>
                <artifactId>mybatis-plus-generator</artifactId>
                <version>${mybatis-plus-generator.version}</version>
            </dependency>

　　2. 配置mybatis-plus

package com.ktg.framework.config;

import com.baomidou.mybatisplus.annotation.DbType;
import com.baomidou.mybatisplus.extension.plugins.MybatisPlusInterceptor;
import com.baomidou.mybatisplus.extension.plugins.inner.BlockAttackInnerInterceptor;
import com.baomidou.mybatisplus.extension.plugins.inner.OptimisticLockerInnerInterceptor;
import com.baomidou.mybatisplus.extension.plugins.inner.PaginationInnerInterceptor;
import com.baomidou.mybatisplus.extension.spring.MybatisSqlSessionFactoryBean;
import com.ktg.common.utils.StringUtils;
import org.apache.ibatis.io.VFS;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.boot.autoconfigure.SpringBootVFS;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.env.Environment;
import org.springframework.core.io.DefaultResourceLoader;
import org.springframework.core.io.Resource;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.core.io.support.ResourcePatternResolver;
import org.springframework.core.type.classreading.CachingMetadataReaderFactory;
import org.springframework.core.type.classreading.MetadataReader;
import org.springframework.core.type.classreading.MetadataReaderFactory;
import org.springframework.util.ClassUtils;

import javax.sql.DataSource;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;

/**
 * Mybatis支持*匹配扫描包
 * 
 */
@Configuration
public class MyBatisConfig
{
    @Autowired
    private Environment env;

    static final String DEFAULT_RESOURCE_PATTERN = "**/*.class";
    @Bean
    public MybatisPlusInterceptor mybatisPlusInterceptor() {
        MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
        interceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.MYSQL));
        interceptor.addInnerInterceptor(new BlockAttackInnerInterceptor());
        // 分页插件
        //interceptor.addInnerInterceptor(paginationInnerInterceptor());
        // 乐观锁插件
        interceptor.addInnerInterceptor(optimisticLockerInnerInterceptor());
        return interceptor;
    }

//    @Bean
//    public ConfigurationCustomizer myBatisConfigurationCustomizer() {
//        return configuration -> {
//            configuration.getTypeAliasRegistry().registerAliases("com.ktg.flink.entity");
//            configuration.getTypeAliasRegistry().registerAliases("com.ktg.metadata.entity");
//            configuration.getTypeAliasRegistry().registerAliases("com.ktg.rtc.entity");
//            configuration.getTypeAliasRegistry().registerAliases("com.ktg.spark.entity");
//            configuration.getTypeAliasRegistry().registerAliases("com.ktg.system.entity");
//        };
//    }
    /**
     * 分页插件，自动识别数据库类型
     */
    public PaginationInnerInterceptor paginationInnerInterceptor() {
        PaginationInnerInterceptor paginationInnerInterceptor = new PaginationInnerInterceptor();
        // 设置最大单页限制数量，默认 500 条，-1 不受限制
        paginationInnerInterceptor.setMaxLimit(-1L);
        // 分页合理化
        paginationInnerInterceptor.setOverflow(true);
        return paginationInnerInterceptor;
    }

    /**
     * 乐观锁插件
     */
    public OptimisticLockerInnerInterceptor optimisticLockerInnerInterceptor() {
        return new OptimisticLockerInnerInterceptor();
    }
    public static String setTypeAliasesPackage(String typeAliasesPackage)
    {
        ResourcePatternResolver resolver = (ResourcePatternResolver) new PathMatchingResourcePatternResolver();
        MetadataReaderFactory metadataReaderFactory = new CachingMetadataReaderFactory(resolver);
        List<String> allResult = new ArrayList<String>();
        try
        {
            for (String aliasesPackage : typeAliasesPackage.split(","))
            {
                List<String> result = new ArrayList<String>();
                aliasesPackage = ResourcePatternResolver.CLASSPATH_ALL_URL_PREFIX
                        + ClassUtils.convertClassNameToResourcePath(aliasesPackage.trim()) + "/" + DEFAULT_RESOURCE_PATTERN;
                Resource[] resources = resolver.getResources(aliasesPackage);
                if (resources != null && resources.length > 0)
                {
                    MetadataReader metadataReader = null;
                    for (Resource resource : resources)
                    {
                        if (resource.isReadable())
                        {
                            metadataReader = metadataReaderFactory.getMetadataReader(resource);
                            try
                            {
                                result.add(Class.forName(metadataReader.getClassMetadata().getClassName()).getPackage().getName());
                            }
                            catch (ClassNotFoundException e)
                            {
                                e.printStackTrace();
                            }
                        }
                    }
                }
                if (result.size() > 0)
                {
                    HashSet<String> hashResult = new HashSet<String>(result);
                    allResult.addAll(hashResult);
                }
            }
            if (allResult.size() > 0)
            {
                typeAliasesPackage = String.join(",", (String[]) allResult.toArray(new String[0]));
            }
            else
            {
                throw new RuntimeException("mybatis typeAliasesPackage 路径扫描错误,参数typeAliasesPackage:" + typeAliasesPackage + "未找到任何包");
            }
        }
        catch (IOException e)
        {
            e.printStackTrace();
        }
        return typeAliasesPackage;
    }

    public Resource[] resolveMapperLocations(String[] mapperLocations)
    {
        ResourcePatternResolver resourceResolver = new PathMatchingResourcePatternResolver();
        List<Resource> resources = new ArrayList<Resource>();
        if (mapperLocations != null)
        {
            for (String mapperLocation : mapperLocations)
            {
                try
                {
                    Resource[] mappers = resourceResolver.getResources(mapperLocation);
                    resources.addAll(Arrays.asList(mappers));
                }
                catch (IOException e)
                {
                    // ignore
                }
            }
        }
        return resources.toArray(new Resource[resources.size()]);
    }

    @Bean
    public SqlSessionFactory sqlSessionFactory(DataSource dataSource) throws Exception
    {
        String typeAliasesPackage = env.getProperty("mybatis.typeAliasesPackage");
        String mapperLocations = env.getProperty("mybatis.mapperLocations");
        String configLocation = env.getProperty("mybatis.configLocation");
        typeAliasesPackage = setTypeAliasesPackage(typeAliasesPackage);
        VFS.addImplClass(SpringBootVFS.class);
//想使用mybatsiplus的分页插件，需要在此处配置分页插件。我遇到的问题就是因为没有在此处配置分页，导致返回的total始终为0

MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
// 分页插件
interceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.MYSQL));
// 防止全表更新与删除
interceptor.addInnerInterceptor(new BlockAttackInnerInterceptor());
// 乐观锁插件
interceptor.addInnerInterceptor(optimisticLockerInnerInterceptor());

        //final SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
        MybatisSqlSessionFactoryBean sessionFactory = new MybatisSqlSessionFactoryBean();
        sessionFactory.setDataSource(dataSource);
        sessionFactory.setTypeAliasesPackage(typeAliasesPackage);
        sessionFactory.setMapperLocations(resolveMapperLocations(StringUtils.split(mapperLocations, ",")));
        sessionFactory.setConfigLocation(new DefaultResourceLoader().getResource(configLocation));

        sessionFactory.setPlugins(interceptor);

        return sessionFactory.getObject();
    }
}

　　3. 注解配置

package com.ktg.framework.config;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.autoconfigure.jackson.Jackson2ObjectMapperBuilderCustomizer;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.EnableAspectJAutoProxy;

import java.util.TimeZone;

/**
 * 程序注解配置
 *
 */
@Configuration
// 表示通过aop框架暴露该代理对象,AopContext能够访问
@EnableAspectJAutoProxy(exposeProxy = true)
// 指定要扫描的Mapper类的包的路径
@MapperScan(basePackages = {"com.ktg.**.mapper"})
public class ApplicationConfig
{
    /**
     * 时区配置
     */
    @Bean
    public Jackson2ObjectMapperBuilderCustomizer jacksonObjectMapperCustomization()
    {
        return jacksonObjectMapperBuilder -> jacksonObjectMapperBuilder.timeZone(TimeZone.getDefault());
    }
}

4. yml配置

mybatis:
  typeAliasesPackage: com.ktg.**.domain
  mapperLocations: classpath*:mapper/**/*Mapper.xml
  configLocation: classpath:mybatis/mybatis-config.xml