Android 数据持久化

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1.数据库SQLite
处理大量数据以及与数据有关的逻辑时使用
数据库数据文件data/data/packageName/datebases/test.db
platform tools目录 adb, sqlite3

给予权限才能看到.dbadb shell su -c "chmod 777 /data"su -c "chmod 777 /data/data"

查看数据文件用sqlite3
SELETE * FROM table;（分号）http://jingyan.baidu.com/article/c843ea0b9bbf1b77931e4ad4.html
2.轻量级处理SharedPreferences
适合app默认配置的保存（初始化时使用）
存

public static void put(Context context, String key, Object object) {    SharedPreferences sp = context.getSharedPreferences(FILE_NAME, Context.MODE_PRIVATE);    SharedPreferences.Editor editor = sp.edit();    if (object instanceof String) {        editor.putString(key, (String) object);    } else if (object instanceof Integer) {        editor.putInt(key, (Integer) object);    } else if (object instanceof Boolean) {        editor.putBoolean(key, (Boolean) object);    } else if (object instanceof Float) {        editor.putFloat(key, (Float) object);    } else if (object instanceof Long) {        editor.putLong(key, (Long) object);    } else {        editor.putString(key, object.toString());    }    SharedPreferencesCompat.apply(editor);}

取

public static Object get(Context context, String key, Object defaultObject) {    SharedPreferences sp = context.getSharedPreferences(FILE_NAME, Context.MODE_PRIVATE);    if (defaultObject instanceof String) {        return sp.getString(key, (String) defaultObject);    } else if (defaultObject instanceof Integer) {        return sp.getInt(key, (Integer) defaultObject);    } else if (defaultObject instanceof Boolean) {        return sp.getBoolean(key, (Boolean) defaultObject);    } else if (defaultObject instanceof Float) {        return sp.getFloat(key, (Float) defaultObject);    } else if (defaultObject instanceof Long) {        return sp.getLong(key, (Long) defaultObject);    }    return null;}

3.ContentProvider
跨应用共享数据和使用系统数据如联系人，图片，视频，音频

//query 获取联系人ContentResolver contentResolver = this.getContentResolver();Cursor cursor = contentResolver.query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI, null,null,null,null);if(cursor!=null) {    while (cursor.moveToNext()) {        int index = cursor.getColumnIndex(ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME);        String name = cursor.getString(index);        String phone = cursor.getString(cursor.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER));    }}

4.文件I/O
java.io.FileInputStream和java.io.FileOutputStream这两个类来实现对文件的读写(导出文件使用，不适合做数据交互)
5.网络请求服务器数据
少量涉及安全的数据需要实时获取并保存在服务器

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