SPUtil-工具类 是专门对 Android共享首选项 SharedPreferences 的数据保存/数据获取,提供了公共的方法行为;
package common.library.utils; import android.content.Context; import android.content.SharedPreferences; import java.lang.reflect.InvocationTargetException; import java.lang.reflect.Method; import java.math.BigDecimal; import java.util.Map; /** * @Author Liudeli * @Describe: */ public class SPUtil { /** * 保存在手机里面的文件名 */ // public static final String FILE_NAME = "share_data"; /** * 保存数据的方法,我们需要拿到保存数据的具体类型,然后根据类型调用不同的保存方法 */ /*public static void put(Context context, String key, Object object) { put(context, FILE_NAME, key, object); }*/ public static void put(Context context, String spFileName, String key, Object object) { SharedPreferences sp = context.getSharedPreferences(spFileName, 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); } public static void putString(Context context, String spFileName, String key, String stringData) { SharedPreferences sp = context.getSharedPreferences(spFileName, Context.MODE_PRIVATE); SharedPreferences.Editor editor = sp.edit(); editor.putString(key, stringData); editor.commit(); // SharedPreferencesCompat.apply(editor); } /** * 得到保存数据的方法,我们根据默认值得到保存的数据的具体类型,然后调用相对于的方法获取值 */ /*public static Object get(Context context, String key, Object defaultObject) { return get(context, FILE_NAME, key, defaultObject); }*/ public static Object get(Context context, String spName, String key, Object defaultObject) { SharedPreferences sp = context.getSharedPreferences(spName, 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; } public static String getString(Context context, String spName, String key, String stringDataDefault) { SharedPreferences sp = context.getSharedPreferences(spName, Context.MODE_PRIVATE); return sp.getString(key, stringDataDefault); } /** * 移除某个key值已经对应的值 */ /*public static void remove(Context context, String key) { remove(context, FILE_NAME, key); }*/ public static void remove(Context context, String spFileName, String key) { SharedPreferences sp = context.getSharedPreferences(spFileName, Context.MODE_PRIVATE); SharedPreferences.Editor editor = sp.edit(); editor.remove(key); SharedPreferencesCompat.apply(editor); } /** * 清除所有数据 */ /*public static void clear(Context context) { clear(context, FILE_NAME); }*/ public static void clear(Context context, String spFileName) { SharedPreferences sp = context.getSharedPreferences(spFileName, Context.MODE_PRIVATE); SharedPreferences.Editor editor = sp.edit(); editor.clear(); SharedPreferencesCompat.apply(editor); } /** * 查询某个key是否已经存在 */ /*public static boolean contains(Context context, String key) { return contains(context, FILE_NAME, key); }*/ public static boolean contains(Context context, String spFileName, String key) { SharedPreferences sp = context.getSharedPreferences(spFileName, Context.MODE_PRIVATE); return sp.contains(key); } /** * 返回所有的键值对 */ /*public static Map<String, ?> getAll(Context context) { return getAll(context, FILE_NAME); }*/ public static Map<String, ?> getAll(Context context, String spName) { SharedPreferences sp = context.getSharedPreferences(spName, Context.MODE_PRIVATE); return sp.getAll(); } /** * 创建一个解决SharedPreferencesCompat.apply方法的一个兼容类 */ private static class SharedPreferencesCompat { private static final Method sApplyMethod = findApplyMethod(); /** * 反射查找apply的方法 */ @SuppressWarnings({"unchecked", "rawtypes"}) private static Method findApplyMethod() { try { Class clz = SharedPreferences.Editor.class; return clz.getMethod("apply"); } catch (NoSuchMethodException e) { } return null; } /** * 如果找到则使用apply执行,否则使用commit */ public static void apply(SharedPreferences.Editor editor) { try { if (sApplyMethod != null) { sApplyMethod.invoke(editor); return; } } catch (IllegalArgumentException e) { } catch (IllegalAccessException e) { } catch (InvocationTargetException e) { } editor.commit(); } } public static void main(String args[]) { // BigDecimal bigDecimal = 11111111112.46; BigDecimal b1 = new BigDecimal(Double.toString(11111111112.46)); System.out.println(new BigDecimal(11111111112.46)); System.out.println(new BigDecimal("11111111112.46")); System.out.println(b1.toString()); } }