mybatis升级到mybatis-plus

升级plus

mybatis升级到mybatis-plus，两个共存
之前依赖只有mybatis,没有plus
做法：

排除mybatis部门依赖，添加新的plus

修改之后的依赖

            
                com.baomidou
                mybatis-plus-boot-starter
                ${mybatisplus.version}
            
   
   
            
                org.mybatis.spring.boot
                mybatis-spring-boot-starter
                ${mybatis-spring-boot.version}
                
                
                    
                        org.mybatis
                        mybatis
                    
                    
                        org.mybatis
                        mybatis-spring
                    
                
            

            
            
                com.github.pagehelper
                pagehelper-spring-boot-starter
                ${pagehelper.boot.version}
                
                
                    
                        org.mybatis.spring.boot
                        mybatis-spring-boot-starter
                    
                
            

重点：

更换

//        final SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
        //升级mybatis-plus之后需要替换为这个factory类
        MybatisSqlSessionFactoryBean sessionFactory=new MybatisSqlSessionFactoryBean();

完整配置代码

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

import com.baomidou.mybatisplus.annotation.DbType;
import com.baomidou.mybatisplus.extension.plugins.PaginationInterceptor;
import com.baomidou.mybatisplus.extension.spring.MybatisSqlSessionFactoryBean;
import com.dgp.common.utils.StringUtils;
import org.apache.ibatis.io.VFS;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
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;

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

    static final String DEFAULT_RESOURCE_PATTERN = "**/*.class";

    /**
     * 分页插件
     */
    @Bean
    public PaginationInterceptor paginationInterceptor() {
        return new PaginationInterceptor();
    }

//    /**
//     * 用于解决分页总数问题
//     */
//    @Bean
//    public MybatisPlusInterceptor mybatisPlusInterceptor() {
//        MybatisPlusInterceptor mybatisPlusInterceptor = new MybatisPlusInterceptor();
//        mybatisPlusInterceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.MYSQL));
//        return mybatisPlusInterceptor;
//    }

    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);

//        final SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
        //升级mybatis-plus之后需要替换为这个factory类
        MybatisSqlSessionFactoryBean sessionFactory=new MybatisSqlSessionFactoryBean();
        sessionFactory.setDataSource(dataSource);
        sessionFactory.setTypeAliasesPackage(typeAliasesPackage);
        sessionFactory.setMapperLocations(resolveMapperLocations(StringUtils.split(mapperLocations, ",")));
        sessionFactory.setConfigLocation(new DefaultResourceLoader().getResource(configLocation));

        //注意这里，需要引入拦截器才能使分页生效
        PaginationInterceptor paginationInterceptor = new PaginationInterceptor();
        sessionFactory.setPlugins(paginationInterceptor);
        return sessionFactory.getObject();
    }

}

分页插件问题

1.添加plus的插件

 /**
     * 分页插件
     */
    @Bean
    public PaginationInterceptor paginationInterceptor() {
        return new PaginationInterceptor();
    }

2. 注入

 @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);

//        final SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
        //升级mybatis-plus之后需要替换为这个factory类
        MybatisSqlSessionFactoryBean sessionFactory=new MybatisSqlSessionFactoryBean();
        sessionFactory.setDataSource(dataSource);
        sessionFactory.setTypeAliasesPackage(typeAliasesPackage);
        sessionFactory.setMapperLocations(resolveMapperLocations(StringUtils.split(mapperLocations, ",")));
        sessionFactory.setConfigLocation(new DefaultResourceLoader().getResource(configLocation));

        //注意这里，需要引入拦截器才能使分页生效
        PaginationInterceptor paginationInterceptor = new PaginationInterceptor();
        sessionFactory.setPlugins(paginationInterceptor);
        return sessionFactory.getObject();
    }

3.完整代码
就是上面升级plus 的代码.

参考文章：https://www.likecs.com/show-308411339.html