Snippets
001 循环遍历将列表转为树结构
代码语言：javascript复制public List<UmsPermissionNode> treeList() {
List<UmsPermission> permissionList = list();
return permissionList.stream()
.filter(permission -> permission.getPid().equals(0L))
.map(permission -> covert(permission, permissionList))
.collect(Collectors.toList());
}
/**
* 将权限转换为带有子级的权限对象
* 当找不到子级权限的时候map操作不会再递归调用covert
*/
private UmsPermissionNode covert(UmsPermission permission, List<UmsPermission> permissionList) {
UmsPermissionNode node = new UmsPermissionNode();
BeanUtils.copyProperties(permission, node);
List<UmsPermissionNode> children = permissionList.stream()
.filter(subPermission -> subPermission.getPid().equals(permission.getId()))
.map(subPermission -> covert(subPermission, permissionList))
.collect(Collectors.toList());
node.setChildren(children);
return node;
}002 查询所有一级分类及子分类
属于上面的变种方式，重点关注 columnPrefix，他将 child_id 和 child_name 归纳到 children 字段里去。
<mapper namespace="com.macro.mall.dao.PmsProductCategoryDao">
<resultMap id="listWithChildrenMap" type="com.macro.mall.dto.PmsProductCategoryWithChildrenItem"
extends="com.macro.mall.mapper.PmsProductCategoryMapper.BaseResultMap">
<collection property="children" resultMap="com.macro.mall.mapper.PmsProductCategoryMapper.BaseResultMap"
columnPrefix="child_"></collection>
</resultMap>
<select id="listWithChildren" resultMap="listWithChildrenMap">
select
c1.id,
c1.name,
c2.id child_id,
c2.name child_name
from pms_product_category c1 left join pms_product_category c2 on c1.id = c2.parent_id
where c1.parent_id = 0
</select>
</mapper>003 自定义查询分页
代码语言：javascript复制@Override
@Transactional(propagation = Propagation.SUPPORTS)
public CommonListResult<UmsAdminVO> list(Integer pageNum, Integer pageSize) {
Page<UmsAdminVO> page = PageHelper.startPage(pageNum, pageSize).doSelectPage(() -> umsAdminDao.getAdminList());
ResultAttributes attributes = new ResultAttributes(page.getPageNum(), page.getPageSize(), page.getTotal());
return new CommonListResult<>(page.getResult(), attributes);
}
/** 未尝试 */
@Override
@Transactional(propagation = Propagation.SUPPORTS)
public List<OmsOrder> list(OmsOrderQueryParam queryParam, Integer pageSize, Integer pageNum) {
PageHelper.startPage(pageNum, pageSize);
return orderDao.getList(queryParam);
}<mapper namespace="com.nicestar.moemall.admin.dao.UmsAdminDao">
<resultMap id="AdminResultMap" type="com.nicestar.moemall.admin.model.vo.UmsAdminVO" extends="com.nicestar.moemall.mbg.mapper.UmsAdminMapper.BaseResultMap">
<collection property="roleIds" ofType="LONG">
<result column="role_id"/>
</collection>
</resultMap>
<select id="getAdminList" resultMap="AdminResultMap">
SELECT
a.*, ar.role_id role_id
FROM
ums_admin a
LEFT JOIN ums_admin_role_relation ar ON a.id = ar.admin_id
ORDER BY a.id ASC
</select>
</mapper>004 批量插入
代码语言：javascript复制<insert id="insertList">
INSERT INTO pms_product_ladder (product_id, count, discount, price) VALUES
<foreach collection="list" item="item" index="index" separator=",">
(#{item.productId,jdbcType=BIGINT},
#{item.count,jdbcType=INTEGER},
#{item.discount,jdbcType=DECIMAL},
#{item.price,jdbcType=DECIMAL})
</foreach>
</insert>005 添加登录日志
代码语言：javascript复制private void insertLoginLog(String username) {
UmsAdmin admin = getAdminByUsername(username);
UmsAdminLoginLog loginLog = new UmsAdminLoginLog();
loginLog.setAdminId(admin.getId());
loginLog.setCreateTime(new Date());
ServletRequestAttributes attributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
assert attributes != null;
HttpServletRequest request = attributes.getRequest();
loginLog.setIp(request.getRemoteAddr());
UserAgent ua = UserAgentUtil.parse(request.getHeader("user-agent"));
String userAgent = ua.getBrowser().toString() "/" ua.getVersion() ", " ua.getOs().toString();
loginLog.setUserAgent(userAgent);
loginLogMapper.insert(loginLog);
}006 Mybatis 排序和模糊查询
代码语言：javascript复制@Override
@Transactional(propagation = Propagation.SUPPORTS)
public CommonListResult<PmsBrand> list(Integer pageNum, Integer pageSize, String name) {
PageHelper.startPage(pageNum, pageSize);
Example example = new Example(PmsBrand.class);
example.orderBy("sort").desc();
Example.Criteria criteria = example.createCriteria();
if (!StringUtils.isEmpty(name)) {
criteria.andLike("name", "%" name "%");
}
List<PmsBrand> pmsBrandList = pmsBrandMapper.selectByExample(example);
PageInfo<PmsBrand> info = new PageInfo<>(pmsBrandList);
ResultAttributes attributes = new ResultAttributes(info.getPageNum(), info.getPageSize(), info.getTotal());
return new CommonListResult<>(pmsBrandList, attributes);
}007 Mybatis 批量更新
代码语言：javascript复制private void updateRole(Long adminId, List<Long> roleIds) {
// 先删除原有关系
Example example = new Example(UmsAdminRoleRelation.class);
Example.Criteria criteria = example.createCriteria();
criteria.andEqualTo("adminId", adminId);
umsAdminRoleRelationMapper.deleteByExample(example);
// 批量插入新关系
List<UmsAdminRoleRelation> relationList = roleIds.stream()
.map(roleId -> {
UmsAdminRoleRelation relation = new UmsAdminRoleRelation();
relation.setAdminId(adminId);
relation.setRoleId(roleId);
return relation;
}).collect(Collectors.toList());
umsAdminRoleRelationMapper.insertList(relationList);
}008 自定义验证注解
主要实现：
FlagValidatorFlagValidatorClass
@Documented
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.FIELD, ElementType.PARAMETER})
@Constraint(validatedBy = FlagValidatorClass.class)
public @interface FlagValidator {
String[] value() default {};
String message() default "flag is not found";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
}public class FlagValidatorClass implements ConstraintValidator<FlagValidator, Integer> {
private String[] values;
@Override
public void initialize(FlagValidator flagValidator) {
this.values = flagValidator.value();
}
@Override
public boolean isValid(Integer value, ConstraintValidatorContext constraintValidatorContext) {
boolean isValid = false;
if (value == null) {
// 当状态为空时使用默认值
return true;
}
for (String val : values) {
if (val.equals(String.valueOf(value))) {
isValid = true;
break;
}
}
return isValid;
}
}使用：
代码语言：javascript复制@ApiModelProperty(value = "是否进行显示", required = true)
@FlagValidator(value = {"0","1"}, message = "显示状态不正确")
private Integer showStatus;009 简单的文件上传
代码语言：javascript复制@RestController
@RequestMapping("/tool")
public class ToolController {
private static final String uploadUrl = "https://sm.ms/api/v2/upload";
@ApiOperation(value = "文件上传")
@PostMapping("/upload")
public CommonResult<String> upload(@RequestParam("file") MultipartFile file) throws IOException {
String path = System.getProperty("java.io.tmpdir") "/" IdUtil.simpleUUID() file.getOriginalFilename();
File convFile = new File(path);
file.transferTo(convFile);
HashMap<String, Object> paramMap = new HashMap<>();
paramMap.put("smfile", convFile);
String result = HttpUtil.post(uploadUrl, paramMap);
JSONObject jsonObject = JSONUtil.parseObj(result);
if (!jsonObject.getStr("code").equals("success")) {
return CommonResult.failed("上传失败");
}
JSONObject data = jsonObject.getJSONObject("data");
log.info("jsonObject: {}", jsonObject);
String imgUrl = data.getStr("url");
return CommonResult.ok(imgUrl);
}
}010 批量建立和插入关系
代码语言：javascript复制/**
* 建立和插入关系
*
* @param dao 可以操作的 DAO
* @param dataList 要插入的数据
* @param productId 建立关系的 id
*/
private void relateAndInsertList(Object dao, List dataList, Long productId) {
try {
if (CollectionUtils.isEmpty(dataList)) return;
for (Object item : dataList) {
Method setId = item.getClass().getMethod("setId", Long.class);
setId.invoke(item, (Long) null);
Method setProductId = item.getClass().getMethod("setProductId", Long.class);
setProductId.invoke(item, productId);
}
Method insertList = dao.getClass().getMethod("insertList", List.class);
insertList.invoke(dao, dataList);
} catch (Exception e) {
throw new RuntimeException(e.getMessage());
}
}011 批量更新状态
代码语言：javascript复制@Override
public int updateDeleteStatus(List<Long> ids, Integer deleteStatus) {
PmsProduct record = new PmsProduct();
record.setDeleteStatus(deleteStatus);
PmsProductExample example = new PmsProductExample();
example.createCriteria().andIdIn(ids);
return productMapper.updateByExampleSelective(record, example);
}012 条件查询
如果提供关键字，则根据关键字和删除状态搜索，否则只按删除状态搜索。
代码语言：javascript复制@Override
public List<PmsProduct> list(String keyword) {
PmsProductExample productExample = new PmsProductExample();
PmsProductExample.Criteria criteria = productExample.createCriteria();
criteria.andDeleteStatusEqualTo(0);
if(!StringUtils.isEmpty(keyword)){
criteria.andNameLike("%" keyword "%");
productExample.or().andDeleteStatusEqualTo(0).andProductSnLike("%" keyword "%");
}
return productMapper.selectByExample(productExample);
}需求 1：where 查询，需要支持（a or b or c）and d，也就是 a、b、c 三个条件是或的关系，然后再与 d 相与。
代码语言：javascript复制Example e = new Example(User.class);
Example.Criteria c = e.createCriteria();
//关键字查询部分
String keyword = pageReq.getKeyword();
if (StringUtils.isNotEmpty(keyword)) {
c.orEqualTo("userName", keyword).orEqualTo("policeNo", keyword).orEqualTo("realName", keyword);
}
//部门查询部门
Example.Criteria criteria = e.createCriteria();
criteria.andEqualTo("departmentId", departmentId);
e.and(criteria);需求 2：(a=? And b=?) or (a=? And c=?)
写法 1：
代码语言：javascript复制DemoExample example=new DemoExample();
DemoExample.Criteria criteria1=example.createCriteria();
criteria1.andAEqualTo(?).andBEqualTo(?);
DemoExample.Criteria criteria2=example.createCriteria();
criteria2.andAEqualTo(?).andCEqualTo(?);
example.or(criteria2);写法 2：
代码语言：javascript复制DemoExample example=new DemoExample();
example.or().andAEqualTo(?).andBEqualTo(?);
example.or().andAEqualTo(?).andCEqualTo(?);013 模糊查询
代码语言：javascript复制 <select id="getList" resultMap="com.nicestar.moemall.mbg.mapper.OmsOrderMapper.BaseResultMap">
SELECT *
FROM oms_order
WHERE delete_status = 0
<if test="queryParam.orderSn!=null and queryParam.orderSn!=''">
AND order_sn = #{queryParam.orderSn}
</if>
<if test="queryParam.status!=null">
AND `status` = #{queryParam.status}
</if>
<if test="queryParam.sourceType!=null">
AND source_type = #{queryParam.sourceType}
</if>
<if test="queryParam.orderType!=null">
AND order_type = #{queryParam.orderType}
</if>
<if test="queryParam.createTime!=null and queryParam.createTime!=''">
AND create_time LIKE concat(#{queryParam.createTime},"%")
</if>
<if test="queryParam.receiverKeyword!=null and queryParam.receiverKeyword!=''">
AND (
receiver_name LIKE concat("%",#{queryParam.receiverKeyword},"%")
OR receiver_phone LIKE concat("%",#{queryParam.receiverKeyword},"%")
)
</if>
</select>014 批量更新
代码语言：javascript复制<update id="delivery">
UPDATE oms_order
SET
delivery_sn = CASE id
<foreach collection="list" item="item">
WHEN #{item.orderId} THEN #{item.deliverySn}
</foreach>
END,
delivery_company = CASE id
<foreach collection="list" item="item">
WHEN #{item.orderId} THEN #{item.deliveryCompany}
</foreach>
END,
delivery_time = CASE id
<foreach collection="list" item="item">
WHEN #{item.orderId} THEN now()
</foreach>
END,
`status` = CASE id
<foreach collection="list" item="item">
WHEN #{item.orderId} THEN 2
</foreach>
END
WHERE
id IN
<foreach collection="list" item="item" separator="," open="(" close=")">
#{item.orderId}
</foreach>
AND `status` = 1
</update>概念
SKU、SPU
SKU（Stock Keeping Unit）是指库存量单位，SPU（Standard Product Unit）是指标准产品单位。举个例子：iphone xs 是一个 SPU，而 iphone xs 公开版 64G 银色是一个 SKU。
