首页 > 技术文章 > SharedPreference 封装成工具类

endian11 2018-07-18 14:21 原文

package com.example.admin.mybledemo.utils;

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

import java.lang.reflect.Method;
import java.util.Map;

/**
 * Created by LiuLei on 2016/7/15.
 *
 */
public class SPUtils {

    /**
     * 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
     *
     * @param context
     * @param key
     * @param object
     */
    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 == null ? null : String.valueOf(object));
        }
        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
     *
     * @param context
     * @param key
     * @param defaultObject
     * @return
     */
    public static <T> T get(Context context, String key, T defaultObject) {
	    SharedPreferences sp = context.getSharedPreferences(FILE_NAME, Context.MODE_PRIVATE);
	    if (defaultObject instanceof String) {
		    return (T) sp.getString(key, (String) defaultObject);
	    } else if (defaultObject instanceof Integer) {
		    return (T) Integer.valueOf(sp.getInt(key, (Integer) defaultObject));
	    } else if (defaultObject instanceof Boolean) {
		    return (T) Boolean.valueOf(sp.getBoolean(key, (Boolean) defaultObject));
	    } else if (defaultObject instanceof Float) {
		    return (T) Float.valueOf(sp.getFloat(key, (Float) defaultObject));
	    } else if (defaultObject instanceof Long) {
		    return (T) Long.valueOf(sp.getLong(key, (Long) defaultObject));
	    } else {
		    return (T) sp.getString(key, (String) defaultObject);
	    }
    }

    /**
     * 移除某个key值已经对应的值
     *
     * @param context
     * @param key
     */
    public static void remove(Context context, String key) {
        SharedPreferences sp = context.getSharedPreferences(FILE_NAME, Context.MODE_PRIVATE);
        SharedPreferences.Editor editor = sp.edit();
        editor.remove(key);
        SharedPreferencesCompat.apply(editor);
    }

    /**
     * 清除所有数据
     *
     * @param context
     */
    public static void clear(Context context) {
        SharedPreferences sp = context.getSharedPreferences(FILE_NAME, Context.MODE_PRIVATE);
        SharedPreferences.Editor editor = sp.edit();
        editor.clear();
        SharedPreferencesCompat.apply(editor);
    }

    /**
     * 查询某个key是否已经存在
     *
     * @param context
     * @param key
     * @return
     */
    public static boolean contains(Context context, String key) {
        SharedPreferences sp = context.getSharedPreferences(FILE_NAME, Context.MODE_PRIVATE);
        return sp.contains(key);
    }

    /**
     * 返回所有的键值对
     *
     * @param context
     * @return
     */
    public static Map<String, ?> getAll(Context context) {
        SharedPreferences sp = context.getSharedPreferences(FILE_NAME, Context.MODE_PRIVATE);
        return sp.getAll();
    }

    /**
     * 创建一个解决SharedPreferencesCompat.apply方法的一个兼容类
     *
     * @author zhy
     */
    private static class SharedPreferencesCompat {
        private static final Method sApplyMethod = findApplyMethod();

        /**
         * 反射查找apply的方法
         *
         * @return
         */
        @SuppressWarnings({"unchecked", "rawtypes"})
        private static Method findApplyMethod() {
            try {
                Class clz = SharedPreferences.Editor.class;
                return clz.getMethod("apply");
            } catch (NoSuchMethodException e) {
                e.printStackTrace();
            }
            return null;
        }

        /**
         * 如果找到则使用apply执行,否则使用commit
         *
         * @param editor
         */
        public static void apply(SharedPreferences.Editor editor) {
            try {
                if (sApplyMethod != null) {
                    sApplyMethod.invoke(editor);
                    return;
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
            editor.commit();
        }
    }

}

  

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