安卓应用清除缓存一般清理目录和代码（带弹框

一个应用安装完成，会有缓存，缓存一般分为内部存储的和外置的，内存中路径为/data/data/pacgage_name/文件，先来看看一般缓存会存在哪些文件中：

(1)缓存文件夹：

/data/data/com.xx/cache

(2)sharePreferance文件夹：

/data/data/com.xx/shared_prefs

(3)DB数据库文件夹：

/data/data/com.xx/databases

(4)files文件夹:（指向同一文件夹）

context.getFilesDir()

/data/data/com.xx/files

(5)外置缓存文件夹:context.getExternalCacheDir()

(6)lib文件夹，一般可以不清理该文件夹：

"/data/data/com.gtafe.zhpj/lib"

一般一个应用的缓存都存在这些文件夹中，接下直接上代码吧，把计算缓存和清除缓存都用一个类封装（带弹框）：

/**
 * Created by lan.zheng on 2016/9/1.
 */
public class CacheUtil {
    private static final String CACHE_DATA_DB = "/data/data/com.gtafe.zhpj/databases";
    private static final String CACHE_DATA_SF = "/data/data/com.gtafe.zhpj/shared_prefs";
    private static final String CACHE_DATA_CACHE = "/data/data/com.gtafe.zhpj/cache";
    private static File lFileDB;
    private static File lFileSF;
    private static File lFileC;
    /**
     * 获取所有缓存
     * @param context
     * @return
     * @throws Exception
     */
    public static String getTotalCacheSize(Context context) throws Exception {
        lFileDB = new File(CACHE_DATA_DB);
        lFileSF = new File(CACHE_DATA_SF);
        lFileC = new File(CACHE_DATA_CACHE);
        //内存缓存DB和SF,cache,files文件
        long cacheSizeDB = getFolderSize(lFileDB);
        long cacheSizeSF = getFolderSize(lFileSF);
        long cacheSizeC = getFolderSize(lFileC);
        long cacheSize = cacheSizeDB + cacheSizeSF + cacheSizeC + getFolderSize(context.getFilesDir());  //context.getFilesDir()或者像上面一样直接用路径
        //fresco产生的cache，如果需要就加入下面这行代码
        //long cacheSizeFresco = Fresco.getImagePipelineFactory().getMainDiskStorageCache().getSize();
        cacheSize = cacheSize +  cacheSizeFresco;
        if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
            cacheSize = cacheSize +  getFolderSize(context.getExternalCacheDir());
        }
        return getFormatSize(cacheSize);
    }

    /**
     * 清除所有缓存
     * @param context
     * @return
     */
    static boolean isClearSuccess = true;
    public static void clearAllCache(Context context,ShowClearResultListener showClearResultListener) {
        mListener = showClearResultListener;  //监听初始化
        showWaitingDialog(context);  //弹框等待
        //清理Fresco的缓存
        ImagePipeline imagePipeline = Fresco.getImagePipeline();
        imagePipeline.clearCaches();
        //清理内存和文件缓存
        isClearSuccess = deleteDir(lFileDB);
        isClearSuccess = deleteDir(lFileSF);
        isClearSuccess = deleteDir(lFileC);
        isClearSuccess = deleteDir(context.getFilesDir());
        if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
            isClearSuccess = deleteDir(context.getExternalCacheDir());
        }

        //TODO 别的缓存
       /* if(context.getCacheDir() != null){
            deleteDir(context.getCacheDir());
        }*/
    }

    private static boolean deleteDir(File dir) {
        if (dir != null && dir.isDirectory()) {
            String[] children = dir.list();
            for (int i = 0; i < children.length; i++) {
                boolean success = deleteDir(new File(dir, children[i]));
                if (!success) {
                    return false;
                }
            }
        }
        return dir.delete();
    }

    // 获取文件
    //Context.getExternalFilesDir() --> SDCard/Android/data/你的应用的包名/files/ 目录，一般放一些长时间保存的数据
    //Context.getExternalCacheDir() --> SDCard/Android/data/你的应用包名/cache/目录，一般存放临时缓存数据
    public static long getFolderSize(File file) throws Exception {
        long size = 0;
        try {
            File[] fileList = file.listFiles();
            for (int i = 0; i < fileList.length; i++) {
                Log.d("test11","file"+i+" = "+fileList[i].toString());
                // 如果下面还有文件
                if (fileList[i].isDirectory()) {
                    size = size + getFolderSize(fileList[i]);
                } else {
                    size = size + fileList[i].length();
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return size;
    }

    /**
     * 格式化单位
     *
     * @param size
     * @return
     */
    public static String getFormatSize(double size) {
        double kiloByte = size / 1024;
        if (kiloByte < 1) {
//            return size + "Byte";
            return "0.0M";
        }

        double megaByte = kiloByte / 1024;
        if (megaByte < 1) {
            BigDecimal result1 = new BigDecimal(Double.toString(kiloByte));
            return result1.setScale(2, BigDecimal.ROUND_HALF_UP)
                    .toPlainString() + "KB";
        }

        double gigaByte = megaByte / 1024;
        if (gigaByte < 1) {
            BigDecimal result2 = new BigDecimal(Double.toString(megaByte));
            return result2.setScale(2, BigDecimal.ROUND_HALF_UP)
                    .toPlainString() + "MB";
        }

        double teraBytes = gigaByte / 1024;
        if (teraBytes < 1) {
            BigDecimal result3 = new BigDecimal(Double.toString(gigaByte));
            return result3.setScale(2, BigDecimal.ROUND_HALF_UP)
                    .toPlainString() + "GB";
        }
        BigDecimal result4 = new BigDecimal(teraBytes);
        return result4.setScale(2, BigDecimal.ROUND_HALF_UP).toPlainString()
                + "TB";
    }


    /**
     * 弹框确认方法
     */
    public static void showWaitingDialog(Context context){
        //弹框
        popupConfirmDialog(context , "清除中...", R.mipmap.ic_clear_cache);
    }


    private static Dialog modifyDialog;
    static ShowClearResultListener mListener;
    private static void popupConfirmDialog(Context context, String content, int resId) {
        //弹框内容
        if (modifyDialog == null) {
            View contentView = LayoutInflater.from(context).inflate(R.layout.dialog_waiting_for_opr, null);
            TextView modifyContent = (TextView) contentView.findViewById(R.id.dialog_content_text);
            modifyContent.setText(content);
            ImageView modifyImage = (ImageView)contentView.findViewById(R.id.dialog_content_image);
            modifyImage.setImageDrawable(context.getResources().getDrawable(resId));
            modifyDialog = new Dialog(context, R.style.clearCacheDialogTheme);  //使用自定义的样式
            modifyDialog.setCanceledOnTouchOutside(false);  //外围点击不消失
            modifyDialog.setContentView(contentView);
        }
        modifyDialog.show();
        sleepToWaitClear();
    }

    static Handler mHandler = new Handler();
    private static void sleepToWaitClear(){
        mHandler.postDelayed(mRunnableDialogDismiss,1000);  //延迟启动
    }

    private static Runnable mRunnableDialogDismiss = new Runnable() {
        @Override
        public void run() {
            if(modifyDialog != null ){
                modifyDialog.dismiss();
                modifyDialog = null;
                mListener.Clear(isClearSuccess);
            }
        }
    };

    /**
     * 1秒后回调清除结果
     */
    public interface ShowClearResultListener{
        void Clear(boolean isClear);
    }

}

弹框的样式调用：

    <style name="clearCacheDialogTheme" parent="android:Theme.Dialog">
        <item name="android:windowFrame">@nullitem>
        <item name="android:windowIsFloating">trueitem>
        <item name="android:windowIsTranslucent">trueitem>
        <item name="android:windowNoTitle">trueitem>
        <item name="android:backgroundDimEnabled">trueitem>
        <item name="android:backgroundDimAmount">0.3item>
        <item name="android:windowBackground">@color/transparentitem>
        <item name="android:radius">8dpitem>
    style>

封装的弹框代码（圆角代码省略@drawable/dialog_content_radius）：

xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:layout_width="wrap_content"
              android:layout_height="wrap_content"
              android:background="@drawable/dialog_content_radius"
              android:paddingTop="@dimen/hdp_20.0"
              android:paddingBottom="@dimen/hdp_20.0"
              android:paddingLeft="@dimen/wdp_20.0"
              android:paddingRight="@dimen/wdp_20.0"
              android:orientation="vertical"
              android:gravity="center"
              android:layout_gravity="center">

        <ImageView
            android:paddingBottom="@dimen/hdp_20.0"
            android:paddingLeft="@dimen/wdp_80.0"
            android:paddingRight="@dimen/wdp_80.0"
            android:id="@+id/dialog_content_image"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@mipmap/ic_clear_cache"/>

        <TextView
            android:id="@+id/dialog_content_text"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:ellipsize="end"
            android:maxLines="5"
            android:text="含笑半步癫"
            android:textSize="@dimen/sp_16.0"
            android:textColor="@color/text_666666"
            android:gravity="center"/>
LinearLayout>

最后就是在主函数中使用了：

（1）获取缓存大小：

String cacheSize=CacheUtil.getTotalCacheSize(this);
            cache_size.setText(cacheSize);

（2）清除缓存：

CacheUtil.clearAllCache(UserCenterActivity.this, new CacheUtil.ShowClearResultListener() {
                    @Override
                    public void Clear(boolean isClear) {
                        if(isClear){
                           cache_size.setText("0.0M");
                        }
                    }
                });

以上就是清除缓存的方法，最后发现一个问题，在安卓4.4一下的系统中清除缓存后和管理器看到的结果是一样的，但是 4.4以上的系统在管理器显示还是有些缓存没被清除，这个问题有人知道为什么吗？