SharedPreferences 占用太多堆内存答案

【问题标题】：SharedPreferences taking too much heap memorySharedPreferences 占用太多堆内存
【发布时间】：2013-08-26 11:00:48
【问题描述】：

我正在使用 SharedPreferences 来存储我的游戏内容，例如您拥有的物品、您当前的金币、装备的物品等。

不使用 SharedPreferences 我会得到 25 到 27 MB 的堆，但是当我使用它时，我会得到 32 MB 的堆，它会增加 5MB。这是正常的还是我做错了什么？

package Util;
import android.app.Activity;

public class StorageInfo {
    public static StorageInfoHelper storage;
    public Activity _context;
    public StorageInfo (Activity context){
        _context = context;
        storage = new StorageInfoHelper(_context);
        storage.reset();
    }
}

package Util;

import android.app.Activity;
import android.content.SharedPreferences;


public class StorageInfoHelper {
    public static final String GoldKEY = "Gold";
    public static final String EquipedItensKEY = "EquipedItens";
    public static final String MyHeadItensKEY = "MyHeadItens";
    public static final String MyPowerUpItensKEY = "MyPowerUpItens";
    public static final String MyBodyItensKEY = "MyBodyItens";
    public static final String MyBoardItensKEY = "MyBoardItens";
    public static final String splitDefault = ",";
    public static final String goldDefault = "0";
    public static final String itenDefault = "0";
    public static final String equipItensDefault = "0,0,0,0";
    private static final int headCNT = 0;
    private static final int PowerUpCNT = 1;
    private static final int bodyCNT = 2;
    private static final int boardCNT = 3;
    private String myHead = new String();
    private String myPowerUp = new String();
    private String myBoard = new String();
    private String myBody = new String();
    private String myEquipedHead = new String();
    private String myEquipedPowerUp = new String();
    private String myEquipedBoard = new String();
    private String myEquipedBody = new String();
    private String myEquipedItens = new String();
    private SharedPreferences settings;
    private SharedPreferences.Editor editor;
    private Activity context;

    public StorageInfoHelper (Activity mycontext){
        context = mycontext;
    }

    private SharedPreferences getPreferences (){
        synchronized (StorageInfoHelper.class){
            if (settings != null){
                return settings;
            }else {
                settings = context.getPreferences(0);
                return settings; 
            }
        }
    }

    private SharedPreferences.Editor getEditor (){
        synchronized (StorageInfoHelper.class){
            if (editor != null){
                return editor;
            }else {
                editor = getPreferences().edit();
                return editor; 
            }
        }
    }

    protected String getStoredFiles(String key){
       // Restore preferences
       return settings.getString(key, new String());
    }

    protected void saveStoredFiles(String key, String value){
      // We need an Editor object to make preference changes.
      // All objects are from android.context.Context
      getEditor().putString(key, value);

      // Commit the edits!
      getEditor().commit();
    }

    public String getMyGold (){
        return getPreferences().getString(GoldKEY, goldDefault);
    }

    public String addGold (int value){
         getEditor().putString(GoldKEY, String.valueOf(Long.decode(getMyGold()) + value));
         getEditor().commit();
        return getMyGold();
    }

    public String getMyEquipedItens (){
        myEquipedItens = getPreferences().getString(EquipedItensKEY, equipItensDefault);
        return myEquipedItens;
    }

    public void setMyEquipedItens (String equipedItens){
        getEditor().putString(EquipedItensKEY, equipedItens);
        getEditor().commit();
        myEquipedItens = equipedItens;
    }

    public String getMyEquipedHead (){
        myEquipedItens = getMyEquipedItens();
        myEquipedHead = myEquipedItens.split(splitDefault)[headCNT];
        return myEquipedHead;
    }

    public void setMyEquipedHead (String head){
        myEquipedItens = getMyEquipedItens();
        myEquipedPowerUp = myEquipedItens.split(splitDefault)[PowerUpCNT];      
        myEquipedBody = myEquipedItens.split(splitDefault)[bodyCNT];
        myEquipedBoard = myEquipedItens.split(splitDefault)[boardCNT];
        myEquipedItens = head + splitDefault + myEquipedPowerUp + splitDefault + myEquipedBody + splitDefault + myEquipedBoard;
        setMyEquipedItens(myEquipedItens);
    }

    public String getMyEquipedPowerUp (){
        myEquipedItens = getMyEquipedItens();
        myEquipedPowerUp = myEquipedItens.split(splitDefault)[PowerUpCNT];
        return myEquipedPowerUp;
    }

    public void setMyEquipedPowerUp (String PowerUp){
        myEquipedItens = getMyEquipedItens();
        myEquipedHead = myEquipedItens.split(splitDefault)[headCNT];        
        myEquipedBody = myEquipedItens.split(splitDefault)[bodyCNT];
        myEquipedBoard = myEquipedItens.split(splitDefault)[boardCNT];
        myEquipedItens = myEquipedHead + splitDefault + PowerUp + splitDefault + myEquipedBody + splitDefault + myEquipedBoard;
        setMyEquipedItens(myEquipedItens);
    }

    public String getMyEquipedBoard (){
        myEquipedItens = getMyEquipedItens();
        myEquipedBoard = myEquipedItens.split(splitDefault)[boardCNT];
        return myEquipedBoard;
    }

    public void setMyEquipedBoard (String board){
        myEquipedItens = getMyEquipedItens();
        myEquipedHead = myEquipedItens.split(splitDefault)[headCNT];
        myEquipedPowerUp = myEquipedItens.split(splitDefault)[PowerUpCNT];      
        myEquipedBody = myEquipedItens.split(splitDefault)[bodyCNT];
        myEquipedItens = myEquipedHead + splitDefault + myEquipedPowerUp + splitDefault + myEquipedBody + splitDefault + board;
        setMyEquipedItens(myEquipedItens);
    }

    public String getMyEquipedBody () {
        myEquipedItens = getMyEquipedItens();
        myEquipedBody = myEquipedItens.split(splitDefault)[bodyCNT];
        return myEquipedBody;
    }

    public void setMyEquipedBody (String body){
        myEquipedItens = getMyEquipedItens();
        myEquipedHead = myEquipedItens.split(splitDefault)[headCNT];
        myEquipedPowerUp = myEquipedItens.split(splitDefault)[PowerUpCNT];      
        myEquipedBoard = myEquipedItens.split(splitDefault)[boardCNT];
        myEquipedItens = myEquipedHead + splitDefault + myEquipedPowerUp + splitDefault + body + splitDefault + myEquipedBoard;
        setMyEquipedItens(myEquipedItens);
    }

    public String getMyHeads (){
        myHead = getPreferences().getString(MyHeadItensKEY, itenDefault);
        return  myHead;
    }

    public void addInMyHeads (String head) {
        myHead = getPreferences().getString(MyHeadItensKEY, itenDefault);
        myHead = myHead + splitDefault + head;
        getEditor().putString(MyHeadItensKEY, myHead);
        getEditor().commit();
    }

    public String getMyPowerUps (){
        myPowerUp = getPreferences().getString(MyPowerUpItensKEY, itenDefault);
        return myPowerUp;
    }

    public void addInMyPowerUps (String PowerUp) {
        myPowerUp = getPreferences().getString(MyPowerUpItensKEY, itenDefault);
        myPowerUp = myPowerUp + splitDefault + PowerUp;
        getEditor().putString(MyPowerUpItensKEY, myPowerUp);
        getEditor().commit();
    }

    public String getMyBoards (){
        myBoard = getPreferences().getString(MyBoardItensKEY, itenDefault);
        return myBoard;
    }

    public void addInMyBoard (String board) {
        myBoard = getPreferences().getString(MyBoardItensKEY, itenDefault);
        myBoard = myBoard + splitDefault + board;
        getEditor().putString(MyBoardItensKEY, myBoard);
        getEditor().commit();
    }

    public String getMyBodys (){
        myBody = getPreferences().getString(MyBodyItensKEY, itenDefault);
        return myBody;
    }

    public void addInMybodys (String body) {
        myBody = getPreferences().getString(MyBodyItensKEY, itenDefault);
        myBody = myBody + splitDefault + body;
        getEditor().putString(MyBodyItensKEY, myBody);
        getEditor().commit();
    }

    public void reset() {
         getEditor().clear();
         editor.commit();

    }

}

我只在应用启动时启动一次 StorageInfo：

 public class Splash extends Activity {
ImageView imgDuck;
 public void onCreate(Bundle savedInstanceState) {   
     super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
        WindowManager.LayoutParams.FLAG_FULLSCREEN);
        getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
        setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);

        setContentView(R.layout.splash);

        FadeInDuck();
        new StorageInfo(this);

 }
}

而我是这样使用的：

Util.MyTextView imgView = (Util.MyTextView) findViewById(R.id.txtCoins);       
        imgView.setText(StorageInfo.storage.getMyGold());

我从不同的上下文（net.ui 和 net.game）调用它。有问题吗？

【问题讨论】：

你只是存储了几个Stringsand ome Ints, this file should not be that big (5 MB). On the other hand, could you confirm that the SharedPreferences`文件有那么大（我的意思是在存储上查找）？如果它变得那么大，那么您可能不需要使用 SQLite 来存储这些结果、黄金等。
我怎样才能得到这个文件？
您可以在应用程序组件中的任何位置找到该文件，或者如果它不是私有的 - > /data/data/Util/shared_prefs/preference_filename.xml 或 /data/data/Util/shared_prefs/Util_preferences.xml。

标签： java android memory heap-memory

【解决方案1】：

如果您在共享首选项中存储许多不同的值，我相信这是众所周知的事情。

将数据存储在 SQLite 数据库中可能会更好。

【讨论】：

好吧，它的值并不多.. 基本上： YourCurrentMoney = String YourCurrentHead = String with commas (max 7 itens) YourCurrentBody = String with commas (max 7 itens) YourCurrentBoard = String with commas (max 7 itens )

【解决方案2】：

根据this 的回答，SharedPreference 在加载后存储在内存中，在上下文中（一旦特定的上下文被销毁，将被删除）

【讨论】：