常用的工具类

BaseApp

public class BaseApp extends Application {
    private static BaseApp sBaseApp;
    //默认不是夜间模式
    public static int mMode = AppCompatDelegate.MODE_NIGHT_NO;

    @Override
    public void onCreate() {
        super.onCreate();
        sBaseApp = this;
    }

    public static BaseApp getInstance(){
        return sBaseApp;
    }

}

ToastUtil（Toast 工具类）

public class ToastUtil {
    public static void showShort(String msg){
        //避免内存泄漏的一个方法,用到上下文的地方,能用application的就application
        Toast.makeText(BaseApp.getInstance(),msg,Toast.LENGTH_SHORT).show();
    }
    public static void showLong(String msg){
        //避免内存泄漏的一个方法,用到上下文的地方,能用application的就application
        Toast.makeText(BaseApp.getInstance(),msg,Toast.LENGTH_LONG).show();
    }
}

MyAppGlideModule（自动缓存图片的工具类，不需要调用，放到项目里就可以）

import android.content.Context;

import com.bumptech.glide.Glide;
import com.bumptech.glide.GlideBuilder;
import com.bumptech.glide.Registry;
import com.bumptech.glide.annotation.GlideModule;
import com.bumptech.glide.load.engine.cache.ExternalPreferredCacheDiskCacheFactory;
import com.bumptech.glide.module.AppGlideModule;

@GlideModule
public class MyAppGlideModule extends AppGlideModule {

    // "me" 是应用在内存卡里创建的文件名，自己随便起
    @Override
    public void applyOptions(Context context, GlideBuilder builder) {
        builder.setDiskCache(new ExternalPreferredCacheDiskCacheFactory(
                context,"me",1024*1024*500));
    }

    @Override
    public void registerComponents(Context context, Glide glide, Registry registry) {

    }
}

HttpUtils、RxUtils、Constants（Retrofit+Rxjava网络请求数据时使用）

1.HttpUtils

import java.io.File;
import java.io.IOException;
import java.util.concurrent.TimeUnit;
import okhttp3.Cache;
import okhttp3.CacheControl;
import okhttp3.Interceptor;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;
import retrofit2.Retrofit;
import retrofit2.adapter.rxjava2.RxJava2CallAdapterFactory;
import retrofit2.converter.gson.GsonConverterFactory;

public class HttpUtils {

    private final Retrofit.Builder mRetrofitBuilder;

    private HttpUtils(){
        OkHttpClient mOkHttpClient = getOkHttpClient();
        mRetrofitBuilder = getRetrofit(mOkHttpClient);
    }

    private static volatile HttpUtils instance;
    public static HttpUtils getInstance(){
        if(instance == null){
            synchronized (HttpUtils.class){
                if(instance == null){
                    instance = new HttpUtils();
                }
            }
        }
        return instance;
    }

    //获取数据加载的Retrofit
    private Retrofit.Builder getRetrofit(OkHttpClient okHttpClient){
        return new Retrofit.Builder()
                .client(okHttpClient)
                .addConverterFactory(GsonConverterFactory.create())
                .addCallAdapterFactory(RxJava2CallAdapterFactory.create());
    }

    /**
     * 固定模板
     * 创建带缓存的OkhttpClient
     * @return
     */
    private OkHttpClient getOkHttpClient() {
        //设置本地缓存文件
        File cacheFile = new File(Constants.PATH_CACHE);
        //设置缓存文件大小
        Cache cache = new Cache(cacheFile, 1024 * 1024 * 50);
        return new OkHttpClient.Builder().
                cache(cache)
                .addInterceptor(new MyCacheinterceptor())
                .addNetworkInterceptor(new MyCacheinterceptor())
                //设置缓存时间
                .writeTimeout(60, TimeUnit.SECONDS)
                .readTimeout(60, TimeUnit.SECONDS)
                .connectTimeout(10, TimeUnit.SECONDS)
                //设置错误重连
                .retryOnConnectionFailure(true).build();
    }

    /**
     * 固定模板
     */
    private class MyCacheinterceptor implements Interceptor {
        @Override
        public Response intercept(Chain chain) throws IOException {
            Request request = chain.request();
            //这里就是说判读我们的网络条件，要是有网络的话我么就直接获取网络上
            // 面的数据，要是没有网络的话我么就去缓存里面取数据
            if (!SystemUtil.isNetworkConnected()) {
                request = request
                        .newBuilder()
                        .cacheControl(CacheControl.FORCE_CACHE)
                        .build();
            }
            Response originalResponse = chain.proceed(request);
            if (SystemUtil.isNetworkConnected()) {
                int maxAge = 0;
                // 有网络时, 不缓存, 最大保存时长为0
                return originalResponse.newBuilder()
                        .removeHeader("Pragma")
                        .header("Cache-Control", "public ,max-age=" + maxAge)
                        .build();
            } else {
                //s秒
                int maxStale = 60 * 60 * 24;
                return originalResponse.newBuilder()
                        .removeHeader("Pragma")
                        //这里的设置的是我们的没有网络的缓存时间，
                        // 想设置多少就是多少。
                        .header("Cache-Control", "public, only-if-cached," +
                                " max-stale=" + maxStale)
                        .build();
            }

        }
    }

    //创建Retrofit请求数据接口
    public synchronized  T getApiserver(String baseUrl,Class tClass){
        return mRetrofitBuilder.baseUrl(baseUrl).build().create(tClass);
    }

  /*  //创建Retrofit请求数据接口
    public synchronized  T getApiserver(String baseUrl,Class tClass){
        return mRetrofit.create(tClass);
    }*/
}

2.RxUtils

import io.reactivex.Flowable;
import io.reactivex.FlowableTransformer;
import io.reactivex.Observable;
import io.reactivex.ObservableSource;
import io.reactivex.ObservableTransformer;
import io.reactivex.android.schedulers.AndroidSchedulers;
import io.reactivex.schedulers.Schedulers;

public class RxUtils {

    /**
     * 同一线程处理
     * @param 
     * @return
     */
    public static  FlowableTransformer rxSchedulerHelper(){
        //compose简化线程
        return new FlowableTransformer() {
            @Override
            public Flowable apply(Flowable upstream) {
                return upstream.subscribeOn(Schedulers.io())
                        .observeOn(AndroidSchedulers.mainThread());
            }
        };
    }

    public static ObservableTransformer rxObservableSchedulerHelper(){
        //compose 简化线程
        return new ObservableTransformer() {
            @Override
            public ObservableSource apply(Observable upstream) {
                return upstream.subscribeOn(Schedulers.io())
                        .observeOn(AndroidSchedulers.mainThread());
            }
        };
    }

}

3.Constants

public interface Constants {
    boolean isDebug = true;


    String PATH_SDCARD = Environment.getExternalStorageDirectory().getAbsolutePath() +
            File.separator + "codeest" + File.separator + "GeekNews";

    String FILE_PROVIDER_AUTHORITY="com.baidu.geek.fileprovider";

    //网络缓存的地址
    String PATH_DATA = BaseApp.getInstance().getCacheDir().getAbsolutePath() +
            File.separator + "data";

    String PATH_CACHE = PATH_DATA + "/NetCache";
    String DATA = "data";
    //夜间模式
    String MODE = "mode";
    String NIGHT_CURRENT_FRAG_POS = "fragment_pos";
    String DATE="date";
}

用法

// DailyNewsBean 数据的bean类
// CallBack MVP中的callback接口
public void getData(final CallBack callBack) {
        HttpService httpService = HttpUtils.getInstance().getApiserver(HttpService.dailyNewsUrl, HttpService.class);
        httpService.getDailyNewsData().compose(RxUtils.rxObservableSchedulerHelper())
                .subscribe(new Observer() {
                    @Override
                    public void onSubscribe(Disposable d) {

                    }

                    @Override
                    public void onNext(DailyNewsBean dailyNewsBean) {
                        callBack.onSuccess(dailyNewsBean);
                    }

                    @Override
                    public void onError(Throwable e) {
                        callBack.onFail(e.getMessage());
                    }

                    @Override
                    public void onComplete() {

                    }
});

接口

public interface HttpService {
    String dailyNewsUrl="http://news-at.zhihu.com/api/4/";
    @GET("news/latest")
    Observable getDailyNewsData();
}

SpUtil（记住密码等可以使用）

//Sharepreference
public class SpUtil {
    /**
     * 保存在手机里面的文件名
     */
    private static final String FILE_NAME = "share_date";
    
    
    /**
     * 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 key
     * @param object 
     */
    public static void setParam( String key, Object object){
        
        String type = object.getClass().getSimpleName();
        SharedPreferences sp = BaseApp.getInstance().getSharedPreferences(FILE_NAME, Context.MODE_PRIVATE);
        SharedPreferences.Editor editor = sp.edit();
        
        if("String".equals(type)){
            editor.putString(key, (String)object);
        }
        else if("Integer".equals(type)){
            editor.putInt(key, (Integer)object);
        }
        else if("Boolean".equals(type)){
            editor.putBoolean(key, (Boolean)object);
        }
        else if("Float".equals(type)){
            editor.putFloat(key, (Float)object);
        }
        else if("Long".equals(type)){
            editor.putLong(key, (Long)object);
        }
        
        editor.commit();
    }
    
    
    /**
     * 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 key
     * @param defaultObject
     * @return
     */
    public static Object getParam(String key, Object defaultObject){
        String type = defaultObject.getClass().getSimpleName();
        SharedPreferences sp = BaseApp.getInstance().getSharedPreferences(FILE_NAME, Context.MODE_PRIVATE);
        
        if("String".equals(type)){
            return sp.getString(key, (String)defaultObject);
        }
        else if("Integer".equals(type)){
            return sp.getInt(key, (Integer)defaultObject);
        }
        else if("Boolean".equals(type)){
            return sp.getBoolean(key, (Boolean)defaultObject);
        }
        else if("Float".equals(type)){
            return sp.getFloat(key, (Float)defaultObject);
        }
        else if("Long".equals(type)){
            return sp.getLong(key, (Long)defaultObject);
        }
        
        return null;
    }
}

用法

// Constants.NIGHT_CURRENT_FRAG_POS 存储或获取数据的标记
// 保存 
// 0 要保存的数据
SpUtil.setParam(Constants.NIGHT_CURRENT_FRAG_POS, 0);
// 获取
// 0 获取数据的默认值，可以随便输入，类型和要获取到的数据的类型一样就可以
int type = (int) SpUtil.getParam(Constants.NIGHT_CURRENT_FRAG_POS, 0);

SystemUtil

里面有方法可以实现根据手机的分辨率从 dp 的单位 转成为 px(像素)，从 px(像素) 的单位 转成为 dp

public class SystemUtil {

    /**
     * 检查WIFI是否连接
     */
    public static boolean isWifiConnected() {
        ConnectivityManager connectivityManager = (ConnectivityManager) BaseApp.getInstance().getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo wifiInfo = connectivityManager
                .getNetworkInfo(ConnectivityManager.TYPE_WIFI);
        return wifiInfo != null;
    }
    /**
     * 检查手机网络(4G/3G/2G)是否连接
     */
    public static boolean isMobileNetworkConnected() {
        ConnectivityManager connectivityManager = (ConnectivityManager) BaseApp.getInstance().getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo mobileNetworkInfo = connectivityManager
                .getNetworkInfo(ConnectivityManager.TYPE_MOBILE);
        return mobileNetworkInfo != null;
    }
    /**
     * 检查是否有可用网络
     */
    public static boolean isNetworkConnected() {
        ConnectivityManager connectivityManager = (ConnectivityManager) BaseApp.getInstance().getSystemService(Context.CONNECTIVITY_SERVICE);
        return connectivityManager.getActiveNetworkInfo() != null;
    }

    /**
     * 保存文字到剪贴板
     * @param context
     * @param text
     */
    public static void copyToClipBoard(Context context, String text) {
        ClipData clipData = ClipData.newPlainText("url", text);
        ClipboardManager manager = (ClipboardManager) context.getSystemService(Context.CLIPBOARD_SERVICE);
        manager.setPrimaryClip(clipData);
        Toast.makeText(context,"已复制到剪贴板",Toast.LENGTH_SHORT).show();
    }

    /**
     * 保存图片到本地
     * @param context
     * @param url
     * @param bitmap
     */
    public static Uri saveBitmapToFile(Context context, String url, Bitmap bitmap,
                                       View container, boolean isShare){
        String fileName = url.substring(url.lastIndexOf("/"),url.lastIndexOf(".")) + ".png";
        File fileDir = new File(Constants.PATH_SDCARD);
        if (!fileDir.exists()){
            fileDir.mkdirs();
        }
        File imageFile = new File(fileDir,fileName);
        Uri uri = Uri.fromFile(imageFile);
        if (isShare && imageFile.exists()) {
            if (Build.VERSION.SDK_INT >= 24) {
                uri = FileProvider.getUriForFile(context.getApplicationContext(),
                        Constants.FILE_PROVIDER_AUTHORITY, imageFile);
            }
            return uri;
        }
        try {
            FileOutputStream fos = new FileOutputStream(imageFile);
            boolean isCompress = bitmap.compress(Bitmap.CompressFormat.PNG, 90, fos);
            if (isCompress) {
                ToastUtil.showShort("保存妹纸成功n(*≧▽≦*)n");
            } else {
                ToastUtil.showShort("保存妹纸失败ヽ(≧Д≦)ノ");
            }
            fos.flush();
            fos.close();
        } catch (IOException e) {
            e.printStackTrace();
            ToastUtil.showShort("保存妹纸失败ヽ(≧Д≦)ノ");
        }
        try {
            MediaStore.Images.Media.insertImage(context.getContentResolver(), imageFile.getAbsolutePath(), fileName, null);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
        context.sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE,uri));
        if (Build.VERSION.SDK_INT >= 24) {
            uri = FileProvider.getUriForFile(context.getApplicationContext(),
                    Constants.FILE_PROVIDER_AUTHORITY, imageFile);
        }
        return uri;
    }

    /**
     * 根据手机的分辨率从 dp 的单位 转成为 px(像素)
     */
    public static int dp2px(Context context, float dpValue) {
        final float scale = context.getResources().getDisplayMetrics().density;
        return (int) (dpValue * scale + 0.5f);
    }

    public static int dp2px(float dpValue) {
        final float scale = BaseApp.getInstance().getResources().getDisplayMetrics().density;
        return (int) (dpValue * scale + 0.5f);
    }

    /**
     * 根据手机的分辨率从 px(像素) 的单位 转成为 dp
     */
    public static int px2dp(Context context, float pxValue) {
        final float scale = context.getResources().getDisplayMetrics().density;
        return (int) (pxValue / scale + 0.5f);
    }

    public static int px2dp(float pxValue) {
        final float scale = BaseApp.getInstance().getResources().getDisplayMetrics().density;
        return (int) (pxValue / scale + 0.5f);
    }

    /**
     * 获取进程号对应的进程名
     *
     * @param pid 进程号
     * @return 进程名
     */
    public static String getProcessName(int pid) {
        BufferedReader reader = null;
        try {
            reader = new BufferedReader(new FileReader("/proc/" + pid + "/cmdline"));
            String processName = reader.readLine();
            if (!TextUtils.isEmpty(processName)) {
                processName = processName.trim();
            }
            return processName;
        } catch (Throwable throwable) {
            throwable.printStackTrace();
        } finally {
            try {
                if (reader != null) {
                    reader.close();
                }
            } catch (IOException exception) {
                exception.printStackTrace();
            }
        }
        return null;
    }
}

UIModeUtil（应用切换日夜间模式时使用）

里面使用到的BaseApp和Constants上面有

/**
 * 使用这个类需要把style设置成日夜间的样式:Theme.AppCompat.DayNight.NoActionBar
 */
public class UIModeUtil {

    /**
     * 夜间模式切换
     */
    public static void changeModeUI(AppCompatActivity activity){
        int currentNightMode = activity.getResources().getConfiguration().uiMode & Configuration.UI_MODE_NIGHT_MASK;

        if(currentNightMode == Configuration.UI_MODE_NIGHT_NO){
            //日间模式,切成夜间模式
            activity.getDelegate().setLocalNightMode(AppCompatDelegate.MODE_NIGHT_YES);
            SpUtil.setParam(Constants.MODE,AppCompatDelegate.MODE_NIGHT_YES);
            BaseApp.mMode = AppCompatDelegate.MODE_NIGHT_YES;
        }else{
            activity.getDelegate().setLocalNightMode(AppCompatDelegate.MODE_NIGHT_NO);
            SpUtil.setParam(Constants.MODE,AppCompatDelegate.MODE_NIGHT_NO);
            BaseApp.mMode = AppCompatDelegate.MODE_NIGHT_NO;
        }
    }

    /**
     * 设置当前的模式
     * @param activity
     */
    public static void setActModeFromSp(AppCompatActivity activity){
        int mode = (int) SpUtil.getParam(Constants.MODE, AppCompatDelegate.MODE_NIGHT_NO);
        activity.getDelegate().setLocalNightMode(mode);
    }

    /**
     * 设置当前的模式
     * @param activity
     */
    public static void setActModeUseMode(AppCompatActivity activity,int mode){
        activity.getDelegate().setLocalNightMode(mode);
    }

    public static void setAppMode(int mode){
        AppCompatDelegate.setDefaultNightMode(mode);
    }
}