根据首字母排序

最近在套前台页面，前端小姐姐的页面是这样的：

界面1

需求很简单，就是根据title的首字母来排序，然后在根据首字母来分组展示。
当我看了我们的数据库里面的数据时，发现我们没有将title的首字母存进去，这就需要我们在代码中进行转换（将汉字转换为汉语拼音，在将汉语拼音转换为大写，截取出第一个字母来进行分组），这样说起来还是有点复杂昂，接下来就实现（我使用的是JFinal框架）：

1、从数据库中查询出数据

public List<Record> queryOrgListPage(String orgTypeId, String title) {
        List<Object> params = new ArrayList<Object>();        String sql = "select * from station_config where status=1 and org_id=? ";
        params.add(orgTypeId);        if (title != null || "".equals(title) || "null".equals(title)) {
            sql += (" and title like concat('%',?,'%') ");
            params.add(title);
        }        try {            return Db.find(sql, params.toArray());
        } catch (Exception e) {            // TODO Auto-generated catch block
            e.printStackTrace();            return null;
        }
    }

就是简单的将数据从数据库中查询出来供我们去处理

2、将title字段转换为汉语拼音，并且转换为大写，截取第一个字母，最后将这个字母存放到一个新增的字段中

// 将首字母先暂时存到一个闲置的字段中
        for (int i = 0; i < orgLists.size(); i++) {
            Record record = orgLists.get(i);            try {                // 将title字段转换为汉语拼音，转换为大写，然后在截取第一个字母
                record.set("initial", ConvertPinyin.getPinyin(record.get("title")).toUpperCase().substring(0, 1));
            } catch (Exception e) {                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }

这里我们需要借助一个jar包，即pinyin4j-2.5.0.jar，没有的小伙伴可以去我这里下载：https://download.csdn.net/download/qq_32376365/10622225。

3、根据汉语拼音来排序

// list排序
        Collections.sort(list, new Comparator<Record>() {            public int compare(Record arg0, Record arg1) {
                String o1 = arg0.get("title");
                String o2 = arg1.get("title");                for (int i = 0; i < o1.length() && i < o2.length(); i++) {                    int codePoint1 = o1.charAt(i);                    int codePoint2 = o2.charAt(i);                    if (Character.isSupplementaryCodePoint(codePoint1)
                            || Character.isSupplementaryCodePoint(codePoint2)) {
                        i++;
                    }                    if (codePoint1 != codePoint2) {                        if (Character.isSupplementaryCodePoint(codePoint1)
                                || Character.isSupplementaryCodePoint(codePoint2)) {                            return codePoint1 - codePoint2;
                        }

                        String pinyin1 = PinyinHelper.toHanyuPinyinStringArray((char) codePoint1) == null ? null
                                : PinyinHelper.toHanyuPinyinStringArray((char) codePoint1)[0];
                        String pinyin2 = PinyinHelper.toHanyuPinyinStringArray((char) codePoint2) == null ? null
                                : PinyinHelper.toHanyuPinyinStringArray((char) codePoint2)[0];                        if (pinyin1 != null && pinyin2 != null) { // 两个字符都是汉字
                            if (!pinyin1.equals(pinyin2)) {                                return pinyin1.compareTo(pinyin2);
                            }
                        } else {                            return codePoint1 - codePoint2;
                        }
                    }
                }                return o1.length() - o2.length();
            }
        });

这段我也是在网上拔的，具体那个忘了，感谢老铁的代码

缓解一下

这样我们就已经在后台处理好我们需要的数据了，但是现在的数据时每条数据都有一个initial字段，里面存放的是title的首字母，并没有进行分组，那么我们就要到页面上去分组展示了

4、去页面上进行分组展示

    //获取组织机构列表
        function getNewsList(newsTypeId,searchValue){
            $.ajax({                url:"xxx",                type:"post",                data:xxx,                dataType:"json",                success:function(data){                    if(data.code==200){                        var orgList=data.data;
                        $("input[name='searchvalue']").val(data.msg);                        var contentDiv=$("#organise_box");
                        contentDiv.empty();                        if(orgList.length<=0){
                            contentDiv.hide();                            return;
                        }else{
                            contentDiv.show();
                        }                        var initialTemp="A";//存放临时的大写首字母
                        var tag=1;//判断是否是第一次进入，用来控制首字母的显示
                        var flag = 12;                        for(var i=0;i<orgList.length;i++){                            //取出首字母
                            var initial=orgList[i].initial;                            //首字母
                            var divInitital;                            //内容div
                            var divItem;                            //组织机构名称
                            var itemName;                            //判断首字母是否发生了变化,发生变化则替换initialTemp的值
                            if(initial==initialTemp){//第一次相等则进入，进行首字母索引和itemDiv的创建（创建一次）
                                if(tag==1){
                                    divInitital=$('<div class="organise-list-type">'+initial+'</div>');
                                    divItem=$('<div class="organise-list-detail"></div>');
                                    itemName=$('<a href="'+orgList[i].url+'" target="_blank"><span>'+orgList[i].title+'</span></a>');
                                    divItem.append(itemName);
                                    tag=2;
                                }else{
                                    itemName=$('<a href="'+orgList[i].url+'" target="_blank"><span>'+orgList[i].title+'</span></a>');
                                    divItem.append(itemName);
                                }
                            }else{
                                initialTemp=initial;
                                tag=1;
                                i--;//减一，回到上一次循环
                                if(divItem!=null){//组装div
                                    var organiseList=$('<div class="organise-list" ></div>');
                                    organiseList.append(divInitital);
                                    organiseList.append(divItem);
                                    contentDiv.append(organiseList);
                                }
                                divItem=null;
                                flag=0;
                            }                            if(orgList.length-1==i){//组装div
                                var organiseList=$('<div class="organise-list" ></div>');
                                organiseList.append(divInitital);
                                organiseList.append(divItem);
                                contentDiv.append(organiseList);
                                
                            }
                            
                        }                        if(searchValue){//组装div
                            var organiseList=$('<div class="organise-list" ></div>');
                            organiseList.append(divInitital);
                            organiseList.append(divItem);
                            contentDiv.append(organiseList);
                            
                        }
                    }else{                        //无数据
                    }
                
                }
            });
        }

作者：根艮哏艮根
链接：https://www.jianshu.com/p/7cc2bc5b1efe