本地sp保存搜索记录，并且去重的，读取，删除记录的工具类

最新推荐文章于 2022-06-26 19:53:52 发布

原创最新推荐文章于 2022-06-26 19:53:52 发布 · 723 阅读

0 ·

CC 4.0 BY-SA版权

移动开发专栏收录该内容

34 篇文章

订阅专栏

本文介绍了一个用于管理搜索历史记录的Java类，包括保存、获取和删除历史记录的功能。该类利用SharedPreferences来持久化存储数据，并通过一系列方法实现对历史记录的操作。

public class HistoryData {

    private final static String PREFERENCE_NAME = "superservice_ly";
    private final static String SEARCH_HISTORY="linya_history";
    // 保存搜索记录
    public static void saveSearchHistory(String inputText) {
        SharedPreferences sp = StudentFoodDiscountApplication.studentFoodDiscountApplication.getSharedPreferences(PREFERENCE_NAME, Context.MODE_PRIVATE);
        if (TextUtils.isEmpty(inputText)) {
            return;
        }
        String longHistory = sp.getString(SEARCH_HISTORY, "");  //获取之前保存的历史记录
        String[] tmpHistory = longHistory.split(","); //逗号截取 保存在数组中
        List<String> historyList = new ArrayList<String>(Arrays.asList(tmpHistory)); //将改数组转换成ArrayList
        SharedPreferences.Editor editor = sp.edit();
        if (historyList.size() > 0) {
            //1.移除之前重复添加的元素
            for (int i = 0; i < historyList.size(); i++) {
                if (inputText.equals(historyList.get(i))) {
                    historyList.remove(i);
                    break;
                }
            }
            historyList.add(0, inputText); //将新输入的文字添加集合的第0位也就是最前面(2.倒序)
            if (historyList.size() > 10) {
                historyList.remove(historyList.size() - 1); //3.最多保存8条搜索记录 删除最早搜索的那一项
            }
            //逗号拼接
            StringBuilder sb = new StringBuilder();
            for (int i = 0; i < historyList.size(); i++) {
                sb.append(historyList.get(i) + ",");
            }
            //保存到sp
            editor.putString(SEARCH_HISTORY, sb.toString());
            editor.commit();
        } else {
            //之前未添加过
            editor.putString(SEARCH_HISTORY, inputText + ",");
            editor.commit();
        }
    }
    //获取搜索记录
    public static List<String> getSearchHistory() {
        SharedPreferences sp = StudentFoodDiscountApplication.studentFoodDiscountApplication.getSharedPreferences(PREFERENCE_NAME, Context.MODE_PRIVATE);
        String longHistory = sp.getString(SEARCH_HISTORY, "");
        String[] tmpHistory = longHistory.split(","); //split后长度为1有一个空串对象
        List<String> historyList = new ArrayList<String>(Arrays.asList(tmpHistory));
        if (historyList.size() == 1 && historyList.get(0).equals("")) { //如果没有搜索记录，split之后第0位是个空串的情况下
            historyList.clear();  //清空集合，这个很关键
        }
        return historyList;
    }

    //删除本地的记录

    public static void deleteSearchHistory(){
        SharedPreferences sp = StudentFoodDiscountApplication.studentFoodDiscountApplication.getSharedPreferences(PREFERENCE_NAME, Context.MODE_PRIVATE);
        sp.edit().clear().commit();
    }

}