MybatisPlus关联查询的完美实现方案

Set<Long> systemProjectFileSecurityIdSet = records.stream().map(SystemProjectFileSecurityGroupSetting::getSystemProjectFileSecurityId).collect(Collectors.toSet());
Map<Long, SystemProjectFileSecurity> systemProjectFileSecurityMap = new HashMap<>();
if (!systemProjectFileSecurityIdSet.isEmpty()) {
            systemProjectFileSecurityMap.putAll(systemProjectFileSecurityService.listByIds(systemProjectFileSecurityIdSet)
                    .stream()
                    .collect(Collectors.toMap(SystemProjectFileSecurity::getSystemProjectFileSecurityId, systemProjectFileSecurity -> systemProjectFileSecurity)));
}

Map<Long, SystemProjectFileSecurity> systemProjectFileSecurityMap = 
    linkTableUtils.linkSystemProjectFileSecurity(records, SystemProjectFileSecurityGroupSetting::getSystemProjectFileSecurityId);

import com.baomidou.mybatisplus.extension.service.IService;
import org.springframework.stereotype.Component;
 
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.function.Function;
import java.util.stream.Collectors;
 
/**
 * 链接其他表的工具类
 *
 * @author zengqinghua
 */
@Component
public class LinkTableUtils {
 
    /**
     * 链接 XXX表
     */
    public <T> Map<Long, SystemProjectFileSecurity> linkSystemProjectFileSecurity(List<T> records, Function<T, Long> getKey) {
        return this.linkTable(
                TableEnum.SystemProjectFileSecurity,
                records, getKey,
                SystemProjectFileSecurity::getSystemProjectFileSecurityId
        );
    }
 
    /**
     * 链接 表（通用方法）
     *
     * @param tableEnum 表名枚举
     * @param records   数据源列表
     * @param getKey    查询的Id
     * @param getRKey   map的key
     * @param <T>       数据源
     * @param <R>       结果
     * @return
     */
    public <T, R> Map<Long, R> linkTable(
            TableEnum tableEnum,
            List<T> records, Function<T, Long> getKey,
            Function<R, Long> getRKey
    ) {
        if (records.isEmpty()) {
            return new HashMap<>();
        }
 
        IService<R> iService = (IService) ApplicationContextUtil.getBean(tableEnum.tClass);
 
        // 得到对应的id
        Set<Long> idSet = records.stream().map(getKey).collect(Collectors.toSet());
        Map<Long, R> map = new HashMap<>();
        if (!idSet.isEmpty()) {
            map.putAll(iService.listByIds(idSet)
                    .stream()
                    .collect(Collectors.toMap(getRKey, data -> data)));
        }
        return map;
    }
 
    public enum TableEnum {
        SystemProjectFileSecurity("xxxx", ISystemProjectFileSecurityService.class);
 
        private final String tableRemark;
        private final Class tClass;
 
        TableEnum(String tableRemark, Class tClass) {
            this.tableRemark = tableRemark;
            this.tClass = tClass;
        }
    }
}