三级联动下拉框

级联关系——商品管理，Redis

此次主要记录给商品管理新加的三级联动的下拉框，写微服务接口。也能实现APP的三级菜单。主要分两大块：查询数据库对Redis进行更新，根据列表级别和上级的code来查Redis

需再明确的知识点

PO 与 VO

Persistent object 持久对象，与数据库表相映射的Java对象。Value object，值对象。通常用于业务层之间的数据传递。

PO用在数据层，VO用在业务逻辑层和表示层。

GET 和 POST

GET - 基本的URL请求，一般用于执行查询操作。
- 缺：URL有长度限制，且明文暴露优：速度快

SpringMVC中的两种get方法：

    //(1)RequestParam  - 可省略注解，最常用的一般方法url: ？ &
    @RequestMapping(value = "/find/linkage", method = RequestMethod.GET)
    public ApiResponse<List<JcBcLinkageVo>> findLinkageMenu(@RequestParam(value="level",required=false,defaultValue="0")int level,@RequestParam("code")String code){}//required=false代表非必填参数
    //(2)PathVariable
    @RequestMapping(value = "/find/linkage/{level}/{code}", method = RequestMethod.GET)
public ApiResponse<List<JcBcLinkageVo>> findLinkageMenu(@PathVariable("level")int level,@PathVariable("code")String code){}

POST - 把数据放到body里面，一般配合from表单使用
- 慢的原因：
<1>（TCP三次握手）
post多（服务器返回100 - continue，客户端开始发送数据）
（服务器返回200 - ok）
<2> get会缓存数据
<3> post不能进行管道化传输

CollectionUtils集合操作类

CollectionUtils.isEmpty(null);  //true
 CollectionUtils.isEmpty(new ArrayList());   //ture
 CollectionUtils.isEmpty({a,b}); //false

 //CollectionUtils.isNotEmpty()相反

 /*
 *集合a: {1,2,3,3,4,5}
 *集合b: {3,4,4,5,6,7}
 */
 CollectionUtils.union(a, b)(并集);// {1,2,3,3,4,4,5,6,7}
 CollectionUtils.intersection(a, b)(交集);// {3,4,5}
 CollectionUtils.disjunction(a, b)(交集的补集);// {1,2,3,4,6,7}
 CollectionUtils.disjunction(b, a)(交集的补集);// {1,2,3,4,6,7}
 CollectionUtils.subtract(a, b)(A与B的差);// {1,2,3}
 CollectionUtils.subtract(b, a)(B与A的差);// {4,6,7}

MyBatis中的like语句

   <select id="findLinkageSon" resultMap="BaseResultMap" parameterType="java.lang.String">
          SELECT <include refid="Base_Column_List" />
          FROM jc_bc_linkage l WHERE l.`code` LIKE CONCAT(#{param},'%') AND l.`status`='1';
      </select>

String[] strs=str.split(",");

String.trim() 去首尾空格

清空弹框中的历史

级联下拉框

$("#id").val("<option value="">请选择</option>");

表格tbody

function removeTbody(){
    //全清空
    $("#tableid").html("");
    //清空选中
    var table = document.getElementById('tableid');
    var tbodies= table.getElementsByTagName("tbody");
    for(i=0;i<tbodies.length;i++){
        if(tbodies[i].id=='tid'){
            table.removeChild(tbodies[i]);
        }
    }
}

弹框调用

alertTip({
     type: 'confirm',
     msg: '修改加价率，加价率价和线上价会随着变化，确定要修改吗？',
     confirmCallBack: function(){
      changeRate(rate,totalId,sellingPrice,claimLocalPrice,serviceRate);
     }
   });

Redis更新

ConfigApi.java

/**
     * 商品分类三级列表缓存更新
     * @author QJJ
     * @return
     */
    @RequestMapping(value="cache/update/linkage",method = RequestMethod.GET)
    public ApiResponse<String> redisLinkageUpdate(){
        configService.updatelinkageRedis();
        return new ApiResponse<String>("更新linkage成功");
    }

ConfigService.java

/**
     * 级联配置商品关系列表缓存信息更新
     * @author QJJ
     * @date 2018年10月9日 下午3:40:23
     */
    @SuppressWarnings("null")
    @Transactional(propagation=Propagation.NOT_SUPPORTED)
    public void updatelinkageRedis(){
        log.debug("更新级联缓存开始");
        //清除缓存
        configReidsUtil.removeLinkages();
        List<JcBcLinkage> linkageList = jcBcLinkageDao.findFirstGrand();//一级列表
        if(CollectionUtils.isEmpty(linkageList)){
            return;
        }
        configReidsUtil.saveLinkage(1,null,linkageList);
        List<JcBcLinkage> sonList = null;
        List<JcBcLinkage> childList = new ArrayList<>();
        List<JcBcLinkage> grandSonList = null;
        Map<String,List<JcBcLinkage>> childMap = new HashMap<>();
        Map<String,List<JcBcLinkage>> grandSonMap = new HashMap<>();
        for(JcBcLinkage linkage:linkageList) {
            sonList = jcBcLinkageDao.findLinkageSon(linkage.getCode());
            if(CollectionUtils.isEmpty(sonList)) {
                break;
            }
            for(JcBcLinkage son:sonList) {
                int level = son.getLevel();
                switch(level) {
                    case 1:
                        break;
                    case 2:
                        if(null == childMap.get(son.getParentCode())) {
                            childList = new ArrayList<>();
                            childList.add(son);
                            childMap.put(son.getParentCode(), childList);
                        }else {
                            childMap.get(son.getParentCode()).add(son);
                        }
                        break;
                    case 3:
                        if(null == grandSonMap.get(son.getParentCode())) {
                            grandSonList = new ArrayList<>();
                            grandSonList.add(son);
                            grandSonMap.put(son.getParentCode(), grandSonList);
                        }else {
                            grandSonMap.get(son.getParentCode()).add(son);
                        }
                        break;
                    default:
                        break;
                }
            }
        }
        if(!childMap.isEmpty()) {
            for(String code:childMap.keySet()) {
                configReidsUtil.saveLinkage(2, code, childMap.get(code));
            }
        }
        if(!grandSonMap.isEmpty()) {
            for(String code:grandSonMap.keySet()) {
                configReidsUtil.saveLinkage(3, code, grandSonMap.get(code));
            }
        }
        log.debug("一级二级增加个数：{}",linkageList.size());
        log.debug("二级三级增加个数：{}",grandSonMap.size());
        log.debug("更新缓存结束");
    }

ConfigReidsUtil.java

/**
      * 清除级联缓存
      */
     public void removeLinkages() {
         super.removePattern(LINKAGE1);
         super.removePattern(LINKAGE2);
     }
/**
      * 将对应linkagelist存入缓存
      * @author QJJ
      * @param level
      * @param code
      * @param linkageList
      */
     public void saveLinkage(int level,String code,List<JcBcLinkage> linkageList) {
         switch(level) {
            case 1:
                super.set(LINKAGE1, JacksonUtil.toJSon(linkageList));
                break;
            case 2:
                super.hmSet(LINKAGE2, code, JacksonUtil.toJSon(linkageList));
                break;
            case 3:
                super.hmSet(LINKAGE3, code, JacksonUtil.toJSon(linkageList));
                break;
            default:
                break;
         }
     }

Redis查找

ConfigApi.java

/**
     * 根据级别和内容查找列表
     * @author QJJ
     * @param level
     * @param code
     * @return ApiResponse<List<JcBcLinkageVo>>
     */
    @RequestMapping(value = "/find/linkage", method = RequestMethod.GET)
    public ApiResponse<List<JcBcLinkageVo>> findLinkageMenu(int level,String code){
        List<JcBcLinkageVo> linkageList = configService.findLinkages(level, code);
        return new ApiResponse<List<JcBcLinkageVo>>(linkageList);
    }

ConfigService.java

/**
     * 级联配置寻找对应list
     * @Title: List<JcBcLinkageVo> findLinkages
     * @author QJJ
     * @date 2018年9月20日 下午3:40:23
     */
    @Transactional(propagation=Propagation.NOT_SUPPORTED)
    public List<JcBcLinkageVo> findLinkages(int level,String code){
        log.debug("寻找级联关系开始");
        List<JcBcLinkageVo> linkagelist = configReidsUtil.findLinkageList(level,code);
        log.debug("寻找级联关系结束");
        return linkagelist;
    }

ConfigReidsUtil.java

/**
      * 寻找linkageList
      * @author QJJ
      * @param key
      * @return
      */
     @SuppressWarnings({ "null", "unchecked" })
    public List<JcBcLinkageVo> findLinkageList(int level,String key){
         List<JcBcLinkageVo> childlist = null;
         Object obj = null;
         switch(level){
             case 1:
                 obj= super.get(LINKAGE1);
                 if(obj != null) {
                     childlist = JacksonUtil.readValue((String)obj, new TypeReference<List<JcBcLinkageVo>>() {});
                 }
                 break;
            case 2:
                obj = redis.hmGet(LINKAGE2,key);
                if(obj != null) {
                    childlist = JacksonUtil.readValue((String)obj, new TypeReference<List<JcBcLinkageVo>>() {});
                }
                break;
            case 3:
                obj= redis.hmGet(LINKAGE3,key);
                if(obj != null) {
                    childlist = JacksonUtil.readValue((String)obj, new TypeReference<List<JcBcLinkageVo>>() {});
                }
                break;
            default:
                break;
         }
         return childlist;
     }

JcBcLinkageDao.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<!-- ============================================================== -->
<!-- ================可直接使用Base配置文件中定义的节点！================ -->
<!-- ============================================================== -->
<mapper namespace="com.jiaanpei.common.config.dao.JcBcLinkageDao">
  <!-- 请在下方添加自定义配置-->
    <select id="findFirstGrand" resultMap="BaseResultMap">
        SELECT <include refid="Base_Column_List" />
        FROM jc_bc_linkage l WHERE l.`level`='1' AND l.`status`='1';
    </select>
    <select id="findLinkageSon" resultMap="BaseResultMap" parameterType="java.lang.String">
        SELECT <include refid="Base_Column_List" />
        FROM jc_bc_linkage l WHERE l.`code` LIKE CONCAT(#{param},'%') AND l.`status`='1';
    </select>
</mapper>

JcBcLinkageDao.java

package com.jiaanpei.common.config.dao;

import java.util.List;

import org.apache.ibatis.annotations.Mapper;

import com.jiaanpei.common.config.po.JcBcLinkage;
import com.jiaanpei.common.config.vo.JcBcLinkageVo;

import ins.framework.mybatis.MybatisBaseDao;

/**
 *
 * 表jc_bc_linkage对应的基于MyBatis实现的Dao接口<br/>
 * 在其中添加自定义方法
 *
 */
@Mapper
public interface JcBcLinkageDao extends MybatisBaseDao<JcBcLinkage, String> {
    /**
     * 取出一级列表
     * @param id
     * @param limit
     * @return
     */
    public List<JcBcLinkage> findFirstGrand();
    /**
     * 按一级code找出对应的一级二级三级列表
     * @param code
     * @return
     */
    public List<JcBcLinkage> findLinkageSon(String code);
}

组装三级业务对象

    
    /**
     * 组装三级对象
     * @Title: List<JcBcLinkageVo> findLinkages
     * @author QJJ
     * @date 2018年10月9日 下午3:40:23
     */
    @Transactional(propagation=Propagation.NOT_SUPPORTED)
    public List<JcBcLinkageVo> findLinkages(String findType){
        log.debug("寻找级联关系开始");
        Map<String,List<JcBcLinkageVo>> map1 = configReidsUtil.findLinkageMap();
        List<JcBcLinkageVo> linkagelist = null;//一级
        List<JcBcLinkageVo> childrenlist = null;//二级
        List<JcBcLinkageVo> grandsons = null;//三级
        for(String key:map1.keySet()) {//一级key
            childrenlist = map1.get(key);
            for(JcBcLinkageVo children:childrenlist) {//循环二级对象去找三级
                grandsons = configReidsUtil.findLinkageMap(children.getCode()+"-"+children.getName());
                children.setChildList(grandsons);
            }
            if("2".equals(findType)) {
                return childrenlist;
            }
            JcBcLinkageVo linkage = new JcBcLinkageVo();
            String[] linkageKeys = key.split("-");
            linkage.setCode(linkageKeys[0]);
            linkage.setName(linkageKeys[1]);
            linkage.setChildList(childrenlist);
            linkagelist.add(linkage);
        }
        log.debug("寻找级联关系结束");
        return null;
    }