MybatisPlus拓展功能(内附全功能代码)

package com.itheima.mp.service.impl; import cn.hutool.core.bean.BeanUtil; import cn.hutool.core.collection.CollUtil; import cn.hutool.core.util.StrUtil; import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper; import com.baomidou.mybatisplus.core.conditions.update.UpdateWrapper; import com.baomidou.mybatisplus.core.metadata.OrderItem; import com.baomidou.mybatisplus.extension.conditions.query.LambdaQueryChainWrapper; import com.baomidou.mybatisplus.extension.plugins.pagination.Page; import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl; import com.baomidou.mybatisplus.extension.toolkit.Db; import com.itheima.mp.domain.dto.PageDTO; import com.itheima.mp.domain.po.Address; import com.itheima.mp.domain.po.User; import com.itheima.mp.domain.query.UserQuery; import com.itheima.mp.domain.vo.AddressVO; import com.itheima.mp.domain.vo.UserVO; import com.itheima.mp.enums.UserStatus; import com.itheima.mp.mapper.UserMapper; import com.itheima.mp.service.IUserService; import com.sun.org.apache.bcel.internal.generic.NEW; import lombok.AllArgsConstructor; import org.omg.CORBA.PRIVATE_MEMBER; import org.springframework.aop.framework.autoproxy.BeanNameAutoProxyCreator; import org.springframework.stereotype.Service; import org.springframework.util.StringUtils; import java.util.ArrayList; import java.util.Collections; import java.util.List; import java.util.Map; import java.util.stream.Collectors; @Service @AllArgsConstructor public class UserServiceImpl extends ServiceImpl<UserMapper, User> implements IUserService { private final UserMapper userMapper; @Override public void deductMoneyById(Long id, Integer money) { // 查询用用户余额是否支持扣减 // 已经注入mapper了 // User user1 = baseMapper.selectById(id); User user = this.getById(id); if (user == null || user.getStatus() == UserStatus.FROZEN) { throw new RuntimeException("用户状态异常"); } // 校验用户余额是否支持扣减 if (user.getBalance() - money < 0) { throw new RuntimeException("用户余额不足"); } UpdateWrapper<User> wrapper = new UpdateWrapper<>(); wrapper.eq("id",id); // 完成扣减 baseMapper.deductMoneyById(wrapper,money); } @Override public List<User> queryUsers(UserQuery query) { List<User> list = lambdaQuery() .like(query.getName() != null, User::getUsername, query.getName()) .eq(query.getStatus() != null, User::getStatus, query.getStatus()) .gt(query.getMinBalance() != null, User::getBalance, query.getMinBalance()) .lt(query.getMaxBalance() != null, User::getBalance, query.getMaxBalance()) .list(); // 执行查询并返回结果 return list; } @Override public UserVO queryUserAndAddressById(long id) { // 1.查询用户 User user = getById(id); if (user == null || user.getStatus() == UserStatus.FROZEN) { throw new RuntimeException("用户状态异常"); } // 2.查询地址 // 避免循环依赖 List<Address> list = Db.lambdaQuery(Address.class).eq(Address::getUserId, id).list(); UserVO userVO = new UserVO(); BeanUtil.copyProperties(user, userVO); if (CollUtil.isNotEmpty(list)) { userVO.setAddresses(BeanUtil.copyToList(list, AddressVO.class)); } // 2.查询地址 return userVO; } // @Override // public List<UserVO> queryUsersAndAddress(List<Long> ids) { // List<User> users = listByIds(ids); // if(CollUtil.isEmpty(users)){ // return Collections.emptyList(); // } // Map<Long, List<Address>> collect = Db.lambdaQuery(Address.class).in(Address::getUserId, ids).list().stream() // .collect(Collectors.groupingBy(Address::getUserId)); // List<UserVO> userVOS = new ArrayList<>(); // for (int i = 0; i < users.size(); i++) { // UserVO userVO = new UserVO(); // BeanUtil.copyProperties(users.get(i),userVO); // userVO.setAddresses(BeanUtil.copyToList(collect.get(users.get(i).getId()),AddressVO.class)); // userVOS.add(userVO); // } // return userVOS; // } @Override public List<UserVO> queryUsersAndAddress(List<Long> ids) { List<User> users = listByIds(ids); if (CollUtil.isEmpty(users)) { return Collections.emptyList(); } // 查询所有相关的地址列表，并按 userId 分组 Map<Long, List<Address>> addressMap = Db.lambdaQuery(Address.class) .in(Address::getUserId, ids) .list().stream() .collect(Collectors.groupingBy(Address::getUserId)); // 使用 Stream API 转换 User 列表到 UserVO 列表，并关联地址信息 return users.stream().map(user -> { UserVO userVO = new UserVO(); BeanUtil.copyProperties(user, userVO); // 复制 User 属性到 UserVO // 使用 getOrDefault 避免 NullPointerException，并转换地址列表到 AddressVO 列表 List<AddressVO> addresses = addressMap.getOrDefault(user.getId(), Collections.emptyList()).stream() .map(address -> { AddressVO addressVO = new AddressVO(); BeanUtil.copyProperties(address, addressVO); // 复制 Address 属性到 AddressVO return addressVO; }).collect(Collectors.toList()); userVO.setAddresses(addresses); // 封装地址信息到 UserVO return userVO; }).collect(Collectors.toList()); } @Override public PageDTO<UserVO> queryUsersPage(UserQuery query) { Page<User> page = new Page<>(); // 创建分页对象 if (query.getPageNo()!=null|| query.getPageSize()!=null){ page.setPages(query.getPageNo()); page.setSize(query.getPageSize()); } // 添加排序，根据 query.getIsAsc() 的值确定升序或降序 if (query.getIsAsc()) { page.addOrder(OrderItem.asc("balance")); // 升序 } else { page.addOrder(OrderItem.desc("balance")); // 降序 } // 创建查询条件 LambdaQueryWrapper<User> queryWrapper = new LambdaQueryWrapper<>(); if (StrUtil.isNotEmpty(query.getName())) { queryWrapper.like(User::getUsername, query.getName()); } queryWrapper.eq(User::getStatus, UserStatus.NORMAL); Page<User> page1= userMapper.selectPage(page, queryWrapper); PageDTO<UserVO> pageDTO = new PageDTO<>(); pageDTO.setList(BeanUtil.copyToList(page1.getRecords(), UserVO.class)); // 总条数 pageDTO.setTotal(page1.getTotal()); // 总页数 pageDTO.setPages(page1.getPages()); // 执行分页查询并返回结果 return pageDTO; } }