[移动开发]Android mmkv实现本地存储搜索历史记录

mmkv介绍：

https://github.com/Tencent/MMKV/wiki/android_tutorial_cn

1、build.gradle：

dependencies {
    api 'com.tencent:mmkv-static:1.2.10'
}

2、Application初始化：

//rootDir是本地存储文件夹
String rootDir = MMKV.initialize(this);
MMKV kv = MMKV.mmkvWithID("search_history_id", MMKV.MULTI_PROCESS_MODE);
App.kv = kv;


//App是一个公共类
public class App {
    public static MMKV kv;
}

3、 保存、获取历史记录Util类? 把之前用的sp注释掉了? 如果想用也可以参考

public class SearchHistoryUtil {
    //保存搜索历史记录
    public static void savaSearchWord(String keyword){
//        String searchHistoryData = TeSharedPreferences.getInstance().getString("search_history");
        String searchHistoryData = App.kv.decodeString("search_history");
        if(searchHistoryData != null){
            String[] tmpHistory = searchHistoryData.split(","); //逗号截取 保存在数组中
            List<String> historyList = new ArrayList<String>(Arrays.asList(tmpHistory)); //将该数组转换成ArrayList
            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 (keyword.equals(historyList.get(i))) {
                        historyList.remove(i);
                        break;
                    }
                }
                historyList.add(0, keyword); //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10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
//            TeSharedPreferences.getInstance().putString("search_history",sb.toString());
                App.kv.encode("search_history", sb.toString());
            } else {
                //之前未添加过
//            TeSharedPreferences.getInstance().putString("search_history",keyword);
                App.kv.encode("search_history", keyword);
            }
        }else{
            App.kv.encode("search_history", keyword);
        }

        Log.e("search_history", "搜索历史记录:" + App.kv.decodeString("search_history"));
    }

    //获取搜索记录
    public static List<String> getSearchHistory() {
//        String longHistory = TeSharedPreferences.getInstance().getString("search_history");
        String longHistory = App.kv.decodeString("search_history");
        if(longHistory != null){
            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;
        }
        return new ArrayList<>();
    }

4、sp代码

import android.content.Context;
import android.content.SharedPreferences;

import com.jumei.base.app.AppGlobalVar;

import java.util.HashMap;
import java.util.Map;

public class TeSharedPreferences {

    private static final String APP_COMMON = "app_common";
    public static final String APP_COOKIES = "app_cookies";
    public static final String APP_INIT = "app_init";

    private final SharedPreferences sharedPreferences;

    private static final HashMap<String, TeSharedPreferences> preferencesManagerHashMap = new HashMap<>();

    public static TeSharedPreferences getInstance() {
        return getInstance(APP_COMMON);
    }

    public static TeSharedPreferences getInstance(String fileName) {
        TeSharedPreferences instance = preferencesManagerHashMap.get(fileName);
        if (instance == null) {
            instance = new TeSharedPreferences(fileName);
            preferencesManagerHashMap.put(fileName, instance);
        }

        return instance;
    }

    private TeSharedPreferences(String fileName) {
        sharedPreferences = App.appContext.getSharedPreferences(fileName, Context.MODE_PRIVATE);
    }

    public void putString(String key, String value) {
        sharedPreferences.edit().putString(key, value).apply();
    }

    public void putBoolean(String key, boolean value) {
        sharedPreferences.edit().putBoolean(key, value).apply();
    }

    public void putInt(String key, int value) {
        sharedPreferences.edit().putInt(key, value).apply();
    }

    public void putFloat(String key, float value) {
        sharedPreferences.edit().putFloat(key, value).apply();
    }

    public String getString(String key) {
        return sharedPreferences.getString(key, "");
    }

    public String getString(String key, String defValue) {
        return sharedPreferences.getString(key, defValue);
    }

    public boolean getBoolean(String key, boolean defValue) {
        return sharedPreferences.getBoolean(key, defValue);
    }

    public int getInt(String key, int defValue) {
        return sharedPreferences.getInt(key, defValue);
    }

    public float getFloat(String key, float defValue) {
        return sharedPreferences.getFloat(key, defValue);
    }

    public Map<String, ?> getAll() {
        try {
            return sharedPreferences.getAll();
        } catch (Exception e) {
            return null;
        }
    }

    public void clear() {
        SharedPreferences.Editor editor = sharedPreferences.edit();
        editor.clear();
        editor.apply();
    }
}