Application 初始化context
public class MyApplication extends Application { public static Context mContext; @Override public void onCreate() { super.onCreate(); initContext(this); } private void initContext(Context context) { mContext = context; } }
Sp封装类
public class SpUtils {
public static SharedPreferences sp;
private Context mContext;
private static SharedPreferences getSp() {
if (sp == null) {
sp = MyApplication.mContext.getSharedPreferences("config", Context.MODE_PRIVATE);
}
return sp;
}
public static void clear() {
SharedPreferences preferences = getSp();
SharedPreferences.Editor editor = preferences.edit();
editor.clear();
editor.commit();
}
public static void remove(String key) {
SharedPreferences preferences = getSp();
//删除指定数据
SharedPreferences.Editor editor = preferences.edit();
editor.remove(key);
editor.commit();
}
public static void putBitmap(String key, Bitmap bitmap) {
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.PNG, 80, byteArrayOutputStream);
byte[] byteArray = byteArrayOutputStream.toByteArray();
String imageString = new String(Base64.encodeToString(byteArray, Base64.DEFAULT));
putString(key, imageString);
}
public static Bitmap getBitMap(String key) {
String imageString = getString(key);
byte[] byteArray = Base64.decode(imageString, Base64.DEFAULT);
ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(byteArray);
//第三步:利用ByteArrayInputStream生成Bitmap
Bitmap bitmap = BitmapFactory.decodeStream(byteArrayInputStream);
return bitmap;
}
/**
* 存入字符串
*
* @param key 字符串的键
* @param value 字符串的值
*/
public static void putString(String key, String value) {
SharedPreferences preferences = getSp();
//存入数据
SharedPreferences.Editor editor = preferences.edit();
editor.putString(key, value);
editor.commit();
}
/**
* 获取字符串
*
* @param key 字符串的键
* @return 得到的字符串
*/
public static String getString(String key) {
SharedPreferences preferences = getSp();
return preferences.getString(key, "");
}
/**
* 获取字符串
*
* @param key 字符串的键
* @param value 字符串的默认值
* @return 得到的字符串
*/
public static String getString(String key, String value) {
SharedPreferences preferences = getSp();
return preferences.getString(key, value);
}
/**
* 保存布尔值
*
* @param key 键
* @param value 值
*/
public static void putBoolean(String key, boolean value) {
SharedPreferences sp = getSp();
SharedPreferences.Editor editor = sp.edit();
editor.putBoolean(key, value);
editor.commit();
}
/**
* 获取布尔值
*
* @param key 键
* @param defValue 默认值
* @return 返回保存的值
*/
public static boolean getBoolean(String key, boolean defValue) {
SharedPreferences sp = getSp();
return sp.getBoolean(key, defValue);
}
/**
* 保存long值
*
* @param key 键
* @param value 值
*/
public static void putLong(String key, long value) {
SharedPreferences sp = getSp();
SharedPreferences.Editor editor = sp.edit();
editor.putLong(key, value);
editor.commit();
}
/**
* 获取long值
*
* @param key 键
* @param defValue 默认值
* @return 保存的值
*/
public static long getLong(String key, long defValue) {
SharedPreferences sp = getSp();
return sp.getLong(key, defValue);
}
/**
* 保存int值
*
* @param key 键
* @param value 值
*/
public static void putInt(String key, int value) {
SharedPreferences sp = getSp();
SharedPreferences.Editor editor = sp.edit();
editor.putInt(key, value);
editor.commit();
}
/**
* 获取long值
*
* @param key 键
* @param defValue 默认值
* @return 保存的值
*/
public static int getInt(String key, int defValue) {
SharedPreferences sp = getSp();
return sp.getInt(key, defValue);
}
/**
* 保存对象
*
* @param key 键
* @param obj 要保存的对象(Serializable的子类)
* @param <T> 泛型定义
*/
public static <T extends Serializable> void putObject(String key, T obj) {
try {
put(key, obj);
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* 获取对象
*
* @param key 键
* @param <T> 指定泛型
* @return 泛型对象
*/
public static <T extends Serializable> T getObject(String key) {
try {
return (T) get(key);
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
/**
* 存储List集合
*
* @param key 存储的键
* @param list 存储的集合
*/
public static void putList(String key, List<? extends Serializable> list) {
try {
put(key, list);
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* 获取List集合
*
* @param key 键
* @param <E> 指定泛型
* @return List集合
*/
public static <E extends Serializable> List<E> getList(String key) {
try {
return (List<E>) get(key);
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
/**
* 存储Map集合
*
* @param key 键
* @param map 存储的集合
* @param <K> 指定Map的键
* @param <V> 指定Map的值
*/
public static <K extends Serializable, V extends Serializable> void putMap(
String key, Map<K, V> map) {
try {
put(key, map);
} catch (Exception e) {
e.printStackTrace();
}
}
public static <K extends Serializable, V extends Serializable> Map<K, V> getMap(Context context,
String key) {
try {
return (Map<K, V>) get(key);
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
/**
* 存储对象
*/
private static void put(String key, Object obj)
throws IOException {
if (obj == null) {//判断对象是否为空
return;
}
ByteArrayOutputStream baos = new ByteArrayOutputStream();
ObjectOutputStream oos = null;
oos = new ObjectOutputStream(baos);
oos.writeObject(obj);
// 将对象放到OutputStream中
// 将对象转换成byte数组,并将其进行base64编码
String objectStr = new String(Base64.encode(baos.toByteArray(), Base64.DEFAULT));
baos.close();
oos.close();
putString(key, objectStr);
}
/**
* 获取对象
*/
private static Object get(String key)
throws IOException, ClassNotFoundException {
String wordBase64 = getString(key);
// 将base64格式字符串还原成byte数组
if (TextUtils.isEmpty(wordBase64)) { //不可少,否则在下面会报java.io.StreamCorruptedException
return null;
}
byte[] objBytes = Base64.decode(wordBase64.getBytes(), Base64.DEFAULT);
ByteArrayInputStream bais = new ByteArrayInputStream(objBytes);
ObjectInputStream ois = new ObjectInputStream(bais);
// 将byte数组转换成product对象
Object obj = ois.readObject();
bais.close();
ois.close();
return obj;
}
}