BaseAppCaching类封装了SharedPreferences的操作。这是一个基础类库，可以用于多个项目。里面将类对象转换为Json，用的是Gson的库。所以，提供了GsonUtil。但同时，为了解藕，也提供了ParseUtil类和IParseUtil协议。其中，ApplicationUtils.getApplication()，返回的是全局的application，这里替换成你自己的就行。
这是BaseAppCaching的代码：
/** * @Author Lyf * @CreateTime 2018/3/1 * @Description An BaseAppCaching class is caching data of app in SharePreference. * data will be encrypted with Base64 when it cached in SP * and decrypted with Base64 when it got from SP. **/
public class BaseAppCaching {
private static BaseAppCaching mBaseAppCaching;
protected static BaseAppCaching getAppCaching() {
if (mBaseAppCaching == null) {
synchronized (BaseAppCaching.class) {
if (mBaseAppCaching == null) {
mBaseAppCaching = new BaseAppCaching();
}
}
}
return mBaseAppCaching;
}
/** * Uses a default key "BaseAppCaching" to save a class object in SP. */
public <T> void saveAppCaching(T appCaching) {
try {
getSharedPreferences().edit().putString(this.getClass().getSimpleName(),
encryptCaching(ParseUtil.toJson(appCaching))).apply();
} catch (IOException e) {
e.printStackTrace();
}
}
public <T> void saveAppCaching(String key, T appCaching) {
try {
getSharedPreferences().edit().putString(key,
encryptCaching(ParseUtil.toJson(appCaching))).apply();
} catch (IOException e) {
e.printStackTrace();
}
}
/** * Uses a default key "BaseAppCaching" to get a object of T from SP. */
@Nullable
public <T> T getAppCaching(Class<T> tClass) {
String json = getSharedPreferences().getString(this.getClass().getSimpleName(), null);
if (json == null) {
return null;
}
return ParseUtil.parseJson(decryptCaching(json), tClass);
}
@Nullable
public <T> T getAppCaching(String key, Class<T> tClass) {
String json = getSharedPreferences().getString(key, null);
if (json == null) {
return null;
}
return ParseUtil.parseJson(decryptCaching(json), tClass);
}
/** * encrypt json. You can rewrite this method in subclass. */
protected String encryptCaching(String json) throws IOException {
return new String(Base64.encode(json.getBytes(), Base64.DEFAULT));
}
/** * decrypt json. You can rewrite this method in subclass. */
protected String decryptCaching(String json) {
return new String(Base64.decode(json, Base64.DEFAULT));
}
private SharedPreferences getSharedPreferences() {
if (ApplicationUtils.getApplication() == null) {
throw new RuntimeException("You have to initialize the mContext before invoked this method!");
}
return ApplicationUtils.getApplication().getSharedPreferences(ApplicationUtils.getApplication().getPackageName(), Context.MODE_PRIVATE);
}
}这是ParseUtil的代码：
public class ParseUtil {
private static IParseUtil INSTANCE;
private static IParseUtil getParseUtil() {
if (INSTANCE == null) {
synchronized (ParseUtil.class) {
if (INSTANCE == null) {
// Instead of your parsing util if you need.
INSTANCE = new GsonUtil();
}
}
}
return INSTANCE;
}
public static <T> T parseJson(String json, Class<T> tClass) {
return getParseUtil().parseJson(json, tClass);
}
public static String toJson(Object object) {
return getParseUtil().toJson(object);
}
public static <T> T parseInterfaceGenericJson(String json, Class tClass){
return getParseUtil().parseInterfaceGenericJson(json,tClass);
}
}这是GsonUtil的代码：
public class GsonUtil implements IParseUtil {
private static Gson gson = new Gson();
/** * Converts a json string into a T bean. */
public static <T> T convertJson2Bean(String json, Class<T> tClass) {
return gson.fromJson(json, tClass);
}
/** * Converts an object into a string. */
public static String convertObject2Json(Object object) {
return gson.toJson(object);
}
@Override
public <T> T parseJson(String json, Class<T> tClass) {
return GsonUtil.convertJson2Bean(json, tClass);
}
@Override
public <T> T parseInterfaceGenericJson(String json, Class tClass) {
return gson.fromJson(json, (((ParameterizedType)
(tClass.getClass().getGenericInterfaces())[0])
.getActualTypeArguments()[0]));
}
@Override
public String toJson(Object object) {
return GsonUtil.convertObject2Json(object);
}
}这是接口IParseUtil的代码：
public interface IParseUtil {
/** * Converts a json string into a T bean. */
<T> T parseJson(String json, Class<T> tClass);
/** * Converts a json string into a T bean. T should be a Interface generic type. */
<T> T parseInterfaceGenericJson(String json, Class tClass);
/** * Converts an object into a string. */
String toJson(Object object);
}
这是实际使用示例：
/** * @Author Lyf * @CreateTime 2018/3/1 * @Description An AppCaching class is caching data of app in SharePreference. **/
public class AppCaching extends BaseAppCaching {
public static void saveUserInfo(IUserInfo userInfo) {
getAppCaching().saveAppCaching(userInfo);
}
public static void saveSystemConfig(ISystemConfig systemConfig) {
getAppCaching().saveAppCaching(systemConfig);
}
public static IUserInfo getUserInfo() {
return getAppCaching().getAppCaching(IUserInfo.class);
}
public static ISystemConfig getSystemConfig() {
return getAppCaching().getAppCaching(ISystemConfig.class);
}
public static <T> void saveData(String key, T tData) {
getAppCaching().saveAppCaching(key, tData);
}
public static <T> T getData(String key, Class<T> tClass) {
return getAppCaching().getAppCaching(key, tClass);
}
@Override
protected String encryptCaching(String json) throws IOException {
return super.encryptCaching(json);
}
@Override
protected String decryptCaching(String json) {
return super.decryptCaching(json);
}
}附上可以跑的项目(0 warnings, 0 errors):
代码位于cache包下：
https://github.com/SuperBeagleDog/OkMVP
