一、添加pom依赖

添加 mybatis-plus依赖、删除mybatis依赖,我用的是ruoyi 3.8.5，主pom里面已经没有了mybatis的依赖，如果有的话注释一下

            <!--<dependency>
                <groupId>org.mybatis.spring.boot.starter</groupId>
                <artifactId>mybatis-spring-boot-starter</artifactId>
                <version>${mybatis.version}</version>
            </dependency>-->

这里添加mybatisplus依赖

        <pagehelper.boot.version>1.4.6</pagehelper.boot.version>
        <mybatis-plus.version>3.5.2</mybatis-plus.version>

<!--mybatis-plus-->
            <dependency>
                <groupId>com.baomidou</groupId>
                <artifactId>mybatis-plus-boot-starter</artifactId>
                <version>${mybatis-plus.version}</version>
            </dependency>
            <!-- pagehelper 分页插件 -->
            <dependency>
                <groupId>com.github.pagehelper</groupId>
                <artifactId>pagehelper-spring-boot-starter</artifactId>
                <version>${pagehelper.boot.version}</version>
                <exclusions>
                    <exclusion>
                        <groupId>org.mybatis</groupId>
                        <artifactId>mybatis</artifactId>
                    </exclusion>
                </exclusions>
            </dependency>

注意：一定要做mybatis依赖的移除，否则pagehelper还是依赖mybatis会与plus冲突，报错。

二、ruoyi-common下的pom.xml添加依赖

<!--mybatis-plus-->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
        </dependency>
        <!-- pagehelper 分页插件 -->
        <dependency>
            <groupId>com.github.pagehelper</groupId>
            <artifactId>pagehelper-spring-boot-starter</artifactId>
        </dependency>

解释一下为什么要在这里再次添加mybatis-plus依赖。根目录的依赖是放到了dependencyManagement标签里了，是声明，并没有真正引用，当子模块用到了相应的依赖时需要在自己的pom里再引用进来，此时不用写版本号，因为声明时已规定好了。现在common模块需要引用mymatis-plus，所以需要在这里添加进来。那为什么之前使用mybatis的时候这个pom里没有引用mybatis的依赖呢？是因为common模块还引用了分页插件，还记得上一步时我移除了分页插件中的mybatis依赖吗？因为分页插件本身依赖了mybatis，所以之前common可以不引用mybatis，但是现在mybatis已被移除，所以必须重新引入mybatis-plus，否则代码会报错。若依单模块版本就不会出现这个问题。

三、修改配置文件

ruoyi-admin下src\main\resources\application.yml,注释mybatis的配置，新增plus的配置，这段配置我是从若依官方拷贝过来的，如果跟你实际不一样就修改一下

## MyBatis配置
#mybatis:
#    # 搜索指定包别名
#    typeAliasesPackage: com.ruoyi.**.domain
#    # 配置mapper的扫描，找到所有的mapper.xml映射文件
#    mapperLocations: classpath*:mapper/**/*Mapper.xml
#    # 加载全局的配置文件
#    configLocation: classpath:mybatis/mybatis-config.xml
 
# MyBatis Plus配置
mybatis-plus:
  # 搜索指定包别名
  typeAliasesPackage: com.ruoyi.**.domain
  # 配置mapper的扫描，找到所有的mapper.xml映射文件
  mapperLocations: classpath*:mapper/**/*Mapper.xml
  # 加载全局的配置文件
  configLocation: classpath:mybatis/mybatis-config.xml

四、重写mybatis配置文件

在framework中，找到MybatisConfig文件，然后删除，在刚删除的文件夹下，新建一个MybatisPlus的java文件，复制已下内容到java文件中：

/**
 * Mybatis Plus 配置
 *
 * @author ruoyi
 */
@EnableTransactionManagement(proxyTargetClass = true)
@Configuration
public class MybatisPlusConfig
{
    @Bean
    public MybatisPlusInterceptor mybatisPlusInterceptor()
    {
        MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
        // 分页插件
        interceptor.addInnerInterceptor(paginationInnerInterceptor());
        // 乐观锁插件
        interceptor.addInnerInterceptor(optimisticLockerInnerInterceptor());
        // 阻断插件
        interceptor.addInnerInterceptor(blockAttackInnerInterceptor());
        return interceptor;
    }

    /**
     * 分页插件，自动识别数据库类型 https://baomidou.com/guide/interceptor-pagination.html
     */
    public PaginationInnerInterceptor paginationInnerInterceptor()
    {
        PaginationInnerInterceptor paginationInnerInterceptor = new PaginationInnerInterceptor();
        // 设置数据库类型为mysql
        paginationInnerInterceptor.setDbType(DbType.MYSQL);
        // 设置最大单页限制数量，默认 500 条，-1 不受限制
        paginationInnerInterceptor.setMaxLimit(-1L);
        return paginationInnerInterceptor;
    }

    /**
     * 乐观锁插件 https://baomidou.com/guide/interceptor-optimistic-locker.html
     */
    public OptimisticLockerInnerInterceptor optimisticLockerInnerInterceptor()
    {
        return new OptimisticLockerInnerInterceptor();
    }

    /**
     * 如果是对全表的删除或更新操作，就会终止该操作 https://baomidou.com/guide/interceptor-block-attack.html
     */
    public BlockAttackInnerInterceptor blockAttackInnerInterceptor()
    {
        return new BlockAttackInnerInterceptor();
    }
}

五、把代码生成修改为mybatis-plus版本

ruoyi-generator下src\main\resources\vm\java 文件夹下面，直接文件内容替换：

1. domain.java.vm

package ${packageName}.domain;

#foreach ($import in $importList)
import ${import};
#end
import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import org.apache.commons.lang3.builder.ToStringBuilder;
import org.apache.commons.lang3.builder.ToStringStyle;
import com.rchuing.sis.common.annotation.Excel;
#if($table.crud || $table.sub)
import com.rchuing.sis.common.core.domain.BaseEntity;
#elseif($table.tree)
import com.fenghuang.common.core.domain.TreeEntity;
#end

/**
 * ${functionName}对象 ${tableName}
 *
 * @author ${author}
 * @date ${datetime}
 */
#if($table.crud || $table.sub)
    #set($Entity="BaseEntity")
#elseif($table.tree)
    #set($Entity="TreeEntity")
#end
@TableName(resultMap = "${packageName}.mapper.${ClassName}Mapper.${ClassName}Result")
public class ${ClassName} extends ${Entity}
        {
private static final long serialVersionUID = 1L;

#foreach ($column in $columns)
    #if(!$table.isSuperColumn($column.javaField))
    /** $column.columnComment */
        #if($column.list)
            #set($parentheseIndex=$column.columnComment.indexOf("（"))
            #if($parentheseIndex != -1)
                #set($comment=$column.columnComment.substring(0, $parentheseIndex))
            #else
                #set($comment=$column.columnComment)
            #end
            #if($parentheseIndex != -1)
            @Excel(name = "${comment}", readConverterExp = "$column.readConverterExp()")
            #elseif($column.javaType == 'Date')
            @JsonFormat(pattern = "yyyy-MM-dd")
            @Excel(name = "${comment}", width = 30, dateFormat = "yyyy-MM-dd")
            #else
            @Excel(name = "${comment}")
            #end
        #end
        #if($column.isPk == 1)
        @TableId(value = "$column.columnName",type = IdType.AUTO)
        #end
    private $column.javaType $column.javaField;

    #end
#end
#if($table.sub)
/** $table.subTable.functionName信息 */
private List<${subClassName}> ${subclassName}List;

#end
#foreach ($column in $columns)
    #if(!$table.isSuperColumn($column.javaField))
        #if($column.javaField.length() > 2 && $column.javaField.substring(1,2).matches("[A-Z]"))
            #set($AttrName=$column.javaField)
        #else
            #set($AttrName=$column.javaField.substring(0,1).toUpperCase() + ${column.javaField.substring(1)})
        #end
    public void set${AttrName}($column.javaType $column.javaField)
            {
            this.$column.javaField = $column.javaField;
            }

    public $column.javaType get${AttrName}()
            {
            return $column.javaField;
            }
    #end
#end

#if($table.sub)
public List<${subClassName}> get${subClassName}List()
        {
        return ${subclassName}List;
        }

public void set${subClassName}List(List<${subClassName}> ${subclassName}List)
        {
        this.${subclassName}List = ${subclassName}List;
        }

#end
@Override
public String toString() {
        return new ToStringBuilder(this,ToStringStyle.MULTI_LINE_STYLE)
    #foreach ($column in $columns)
        #if($column.javaField.length() > 2 && $column.javaField.substring(1,2).matches("[A-Z]"))
            #set($AttrName=$column.javaField)
        #else
            #set($AttrName=$column.javaField.substring(0,1).toUpperCase() + ${column.javaField.substring(1)})
        #end
            .append("${column.javaField}", get${AttrName}())
    #end
    #if($table.sub)
            .append("${subclassName}List", get${subClassName}List())
    #end
        .toString();
        }
        }

2. mapper.java.vm

package ${packageName}.mapper;

import java.util.List;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import ${packageName}.domain.${ClassName};
#if($table.sub)
import ${packageName}.domain.${subClassName};
#end

/**
 * ${functionName}Mapper接口
 *
 * @author ${author}
 * @date ${datetime}
 */
public interface ${ClassName}Mapper extends BaseMapper<${ClassName}> {
    /**
     * 查询${functionName}
     *
     * @param ${pkColumn.javaField} ${functionName}主键
     * @return ${functionName}
     */
    public ${ClassName} select${ClassName}By${pkColumn.capJavaField}(${pkColumn.javaType} ${pkColumn.javaField});

    /**
     * 查询${functionName}列表
     *
     * @param ${className} ${functionName}
     * @return ${functionName}集合
     */
    public List<${ClassName}> select${ClassName}List(${ClassName} ${className});

    /**
     * 新增${functionName}
     *
     * @param ${className} ${functionName}
     * @return 结果
     */
    public int insert${ClassName}(${ClassName} ${className});

    /**
     * 修改${functionName}
     *
     * @param ${className} ${functionName}
     * @return 结果
     */
    public int update${ClassName}(${ClassName} ${className});

    /**
     * 删除${functionName}
     *
     * @param ${pkColumn.javaField} ${functionName}主键
     * @return 结果
     */
    public int delete${ClassName}By${pkColumn.capJavaField}(${pkColumn.javaType} ${pkColumn.javaField});

    /**
     * 批量删除${functionName}
     *
     * @param ${pkColumn.javaField}s 需要删除的数据主键集合
     * @return 结果
     */
    public int delete${ClassName}By${pkColumn.capJavaField}s(${pkColumn.javaType}[] ${pkColumn.javaField}s);
#if($table.sub)

    /**
     * 批量删除${subTable.functionName}
     *
     * @param ${pkColumn.javaField}s 需要删除的数据主键集合
     * @return 结果
     */
    public int delete${subClassName}By${subTableFkClassName}s(${pkColumn.javaType}[] ${pkColumn.javaField}s);

    /**
     * 批量新增${subTable.functionName}
     *
     * @param ${subclassName}List ${subTable.functionName}列表
     * @return 结果
     */
    public int batch${subClassName}(List<${subClassName}> ${subclassName}List);


    /**
     * 通过${functionName}主键删除${subTable.functionName}信息
     *
     * @param ${pkColumn.javaField} ${functionName}ID
     * @return 结果
     */
    public int delete${subClassName}By${subTableFkClassName}(${pkColumn.javaType} ${pkColumn.javaField});
#end
}

3. service.java.vm

package ${packageName}.service;

import java.util.List;
import ${packageName}.domain.${ClassName};
import com.baomidou.mybatisplus.extension.service.IService;

/**
 * ${functionName}Service接口
 *
 * @author ${author}
 * @date ${datetime}
 */
public interface I${ClassName}Service extends IService<${ClassName}> {
    /**
     * 查询${functionName}
     *
     * @param ${pkColumn.javaField} ${functionName}主键
     * @return ${functionName}
     */
    public ${ClassName} select${ClassName}By${pkColumn.capJavaField}(${pkColumn.javaType} ${pkColumn.javaField});

    /**
     * 查询${functionName}列表
     *
     * @param ${className} ${functionName}
     * @return ${functionName}集合
     */
    public List<${ClassName}> select${ClassName}List(${ClassName} ${className});

    /**
     * 新增${functionName}
     *
     * @param ${className} ${functionName}
     * @return 结果
     */
    public int insert${ClassName}(${ClassName} ${className});

    /**
     * 修改${functionName}
     *
     * @param ${className} ${functionName}
     * @return 结果
     */
    public int update${ClassName}(${ClassName} ${className});

    /**
     * 批量删除${functionName}
     *
     * @param ${pkColumn.javaField}s 需要删除的${functionName}主键集合
     * @return 结果
     */
    public int delete${ClassName}By${pkColumn.capJavaField}s(${pkColumn.javaType}[] ${pkColumn.javaField}s);

    /**
     * 删除${functionName}信息
     *
     * @param ${pkColumn.javaField} ${functionName}主键
     * @return 结果
     */
    public int delete${ClassName}By${pkColumn.capJavaField}(${pkColumn.javaType} ${pkColumn.javaField});
}

4. serviceimpl.java.vm

package ${packageName}.service.impl;

import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import java.util.List;
#foreach ($column in $columns)
#if($column.javaField == 'createTime' || $column.javaField == 'updateTime')
import com.rchuing.common.utils.DateUtils;
#break
#end
#end
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
#if($table.sub)
import java.util.ArrayList;
import com.rchuing.common.utils.StringUtils;
import org.springframework.transaction.annotation.Transactional;
import ${packageName}.domain.${subClassName};
#end
import ${packageName}.mapper.${ClassName}Mapper;
import ${packageName}.domain.${ClassName};
import ${packageName}.service.I${ClassName}Service;

/**
 * ${functionName}Service业务层处理
 *
 * @author ${author}
 * @date ${datetime}
 */
@Service
public class ${ClassName}ServiceImpl extends ServiceImpl<${ClassName}Mapper, ${ClassName}> implements I${ClassName}Service {
    @Autowired
    private ${ClassName}Mapper ${className}Mapper;

    /**
     * 查询${functionName}
     *
     * @param ${pkColumn.javaField} ${functionName}主键
     * @return ${functionName}
     */
    @Override
    public ${ClassName} select${ClassName}By${pkColumn.capJavaField}(${pkColumn.javaType} ${pkColumn.javaField}) {
        return ${className}Mapper.select${ClassName}By${pkColumn.capJavaField}(${pkColumn.javaField});
    }

    /**
     * 查询${functionName}列表
     *
     * @param ${className} ${functionName}
     * @return ${functionName}
     */
    @Override
    public List<${ClassName}> select${ClassName}List(${ClassName} ${className}) {
        return ${className}Mapper.select${ClassName}List(${className});
    }

    /**
     * 新增${functionName}
     *
     * @param ${className} ${functionName}
     * @return 结果
     */
#if($table.sub)
    @Transactional
#end
    @Override
    public int insert${ClassName}(${ClassName} ${className}) {
#foreach ($column in $columns)
#if($column.javaField == 'createTime')
        ${className}.setCreateTime(DateUtils.getNowDate());
#end
#end
#if($table.sub)
        int rows = ${className}Mapper.insert${ClassName}(${className});
        insert${subClassName}(${className});
        return rows;
#else
        return ${className}Mapper.insert${ClassName}(${className});
#end
    }

    /**
     * 修改${functionName}
     *
     * @param ${className} ${functionName}
     * @return 结果
     */
#if($table.sub)
    @Transactional
#end
    @Override
    public int update${ClassName}(${ClassName} ${className}) {
#foreach ($column in $columns)
#if($column.javaField == 'updateTime')
        ${className}.setUpdateTime(DateUtils.getNowDate());
#end
#end
#if($table.sub)
        ${className}Mapper.delete${subClassName}By${subTableFkClassName}(${className}.get${pkColumn.capJavaField}());
        insert${subClassName}(${className});
#end
        return ${className}Mapper.update${ClassName}(${className});
    }

    /**
     * 批量删除${functionName}
     *
     * @param ${pkColumn.javaField}s 需要删除的${functionName}主键
     * @return 结果
     */
#if($table.sub)
    @Transactional
#end
    @Override
    public int delete${ClassName}By${pkColumn.capJavaField}s(${pkColumn.javaType}[] ${pkColumn.javaField}s) {
#if($table.sub)
        ${className}Mapper.delete${subClassName}By${subTableFkClassName}s(${pkColumn.javaField}s);
#end
        return ${className}Mapper.delete${ClassName}By${pkColumn.capJavaField}s(${pkColumn.javaField}s);
    }

    /**
     * 删除${functionName}信息
     *
     * @param ${pkColumn.javaField} ${functionName}主键
     * @return 结果
     */
#if($table.sub)
    @Transactional
#end
    @Override
    public int delete${ClassName}By${pkColumn.capJavaField}(${pkColumn.javaType} ${pkColumn.javaField}) {
#if($table.sub)
        ${className}Mapper.delete${subClassName}By${subTableFkClassName}(${pkColumn.javaField});
#end
        return ${className}Mapper.delete${ClassName}By${pkColumn.capJavaField}(${pkColumn.javaField});
    }
#if($table.sub)

    /**
     * 新增${subTable.functionName}信息
     *
     * @param ${className} ${functionName}对象
     */
    public void insert${subClassName}(${ClassName} ${className}) {
        List<${subClassName}> ${subclassName}List = ${className}.get${subClassName}List();
        ${pkColumn.javaType} ${pkColumn.javaField} = ${className}.get${pkColumn.capJavaField}();
        if (StringUtils.isNotNull(${subclassName}List))
        {
            List<${subClassName}> list = new ArrayList<${subClassName}>();
            for (${subClassName} ${subclassName} : ${subclassName}List)
            {
                ${subclassName}.set${subTableFkClassName}(${pkColumn.javaField});
                list.add(${subclassName});
            }
            if (list.size() > 0)
            {
                ${className}Mapper.batch${subClassName}(list);
            }
        }
    }
#end
}

5. sub-domain.java.vm

package ${packageName}.domain;

#foreach ($import in $subImportList)
import ${import};
#end
import org.apache.commons.lang3.builder.ToStringBuilder;
import org.apache.commons.lang3.builder.ToStringStyle;
import com.rchuing.common.annotation.Excel;
import com.rchuing.common.core.domain.BaseEntity;

/**
 * ${subTable.functionName}对象 ${subTableName}
 *
 * @author ${author}
 * @date ${datetime}
 */
public class ${subClassName} extends BaseEntity {
    private static final long serialVersionUID = 1L;

#foreach ($column in $subTable.columns)
#if(!$table.isSuperColumn($column.javaField))
    /** $column.columnComment */
#if($column.list)
#set($parentheseIndex=$column.columnComment.indexOf("（"))
#if($parentheseIndex != -1)
#set($comment=$column.columnComment.substring(0, $parentheseIndex))
#else
#set($comment=$column.columnComment)
#end
#if($parentheseIndex != -1)
    @Excel(name = "${comment}", readConverterExp = "$column.readConverterExp()")
#elseif($column.javaType == 'Date')
    @JsonFormat(pattern = "yyyy-MM-dd")
    @Excel(name = "${comment}", width = 30, dateFormat = "yyyy-MM-dd")
#else
    @Excel(name = "${comment}")
#end
#end
    private $column.javaType $column.javaField;

#end
#end
#foreach ($column in $subTable.columns)
#if(!$table.isSuperColumn($column.javaField))
#if($column.javaField.length() > 2 && $column.javaField.substring(1,2).matches("[A-Z]"))
#set($AttrName=$column.javaField)
#else
#set($AttrName=$column.javaField.substring(0,1).toUpperCase() + ${column.javaField.substring(1)})
#end
    public void set${AttrName}($column.javaType $column.javaField) {
        this.$column.javaField = $column.javaField;
    }

    public $column.javaType get${AttrName}() {
        return $column.javaField;
    }
#end
#end

    @Override
    public String toString() {
        return new ToStringBuilder(this,ToStringStyle.MULTI_LINE_STYLE)
#foreach ($column in $subTable.columns)
#if($column.javaField.length() > 2 && $column.javaField.substring(1,2).matches("[A-Z]"))
#set($AttrName=$column.javaField)
#else
#set($AttrName=$column.javaField.substring(0,1).toUpperCase() + ${column.javaField.substring(1)})
#end
            .append("${column.javaField}", get${AttrName}())
#end
            .toString();
    }
}

六、测试

系统工具 -> 代码生成 -> 预览

image.png

七、注意

1.这里可能有些包的路径不对，把爆红的包删除，重新导入就可！

2.因为实际项目路径不同，这里****可能****需要手动修改！

image.png

3.在BaseEntity类中

image.png