计算和清除webview缓存

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致谢：感谢各位大神以及梁神

public class CleanCacheUtil {    private Context mContext;    private static CleanCacheUtil cleanCacheUtil;    private CleanCacheUtil(Context mContext) {        this.mContext = mContext;    }    public static CleanCacheUtil getInstance(Context mContext) {        if (cleanCacheUtil == null) {            cleanCacheUtil = new CleanCacheUtil(mContext);        }        return cleanCacheUtil;    }    public String countSize() {        // 计算缓存大小        long fileSize = 0;        String cacheSize = "0KB";        File cacheDir = mContext.getCacheDir();// /data/data/package_name/cache        fileSize += getDirSize(cacheDir);        File externalCacheDir = getExternalCacheDir(mContext);//"<sdcard>/Android/data/<package_name>/cache/"        fileSize += getDirSize(externalCacheDir);        fileSize -= 1024 * 10;//因为总是清不干净，所以减去一点        if (fileSize > 0)            cacheSize = formatFileSize(fileSize);        return cacheSize;    }    /**     * 获取目录文件大小     *     * @param dir     * @return     */    public static long getDirSize(File dir) {        if (dir == null) {            return 0;        }        if (!dir.isDirectory()) {            return 0;        }        long dirSize = 0;        File[] files = dir.listFiles();        for (File file : files) {            if (file.isFile()) {                dirSize += file.length();            } else if (file.isDirectory()) {                dirSize += file.length();                dirSize += getDirSize(file); // 递归调用继续统计            }        }        return dirSize;    }    /**     * 判断当前版本是否兼容目标版本的方法     *     * @param VersionCode     * @return     */    public static boolean isMethodsCompat(int VersionCode) {        int currentVersion = android.os.Build.VERSION.SDK_INT;        return currentVersion >= VersionCode;    }    public static File getExternalCacheDir(Context context) {        // return context.getExternalCacheDir(); API level 8        // e.g. "<sdcard>/Android/data/<package_name>/cache/"        return context.getExternalCacheDir();    }    /**     * 转换文件大小     *     * @param fileS     * @return B/KB/MB/GB     */    public static String formatFileSize(long fileS) {        java.text.DecimalFormat df = new java.text.DecimalFormat("#.00");        String fileSizeString = "";        if (fileS < 1024) {            fileSizeString = df.format((double) fileS) + "B";        } else if (fileS < 1048576) {            fileSizeString = df.format((double) fileS / 1024) + "KB";        } else if (fileS < 1073741824) {            fileSizeString = df.format((double) fileS / 1048576) + "MB";        } else {            fileSizeString = df.format((double) fileS / 1073741824) + "G";        }        return fileSizeString;    }    //在项目中经常会使用到WebView 控件,当加载html 页面时,会在/data/data/package_name目录下生成database与cache 两个文件夹。请求的url 记录是保存在WebViewCache.db,而url 的内容是保存在WebViewCache 文件夹下    /**     * 清除app缓存     */    public void clearAppCache() {        //先删除WebViewCache目录下的文件        mContext.deleteDatabase("webview.db");        mContext.deleteDatabase("webview.db-shm");        mContext.deleteDatabase("webview.db-wal");        mContext.deleteDatabase("webviewCache.db");        mContext.deleteDatabase("webviewCache.db-shm");        mContext.deleteDatabase("webviewCache.db-wal");        //清除数据缓存//        clearCacheFolder(mContext.getFilesDir(), System.currentTimeMillis());        clearCacheFolder(mContext.getCacheDir(), System.currentTimeMillis());        String cacheDirPath = mContext.getFilesDir().getAbsolutePath()                + "/webcache";        clearCacheFolder(new File(cacheDirPath), System.currentTimeMillis());        //2.2版本才有将应用缓存转移到sd卡的功能        clearCacheFolder(getExternalCacheDir(mContext), System.currentTimeMillis());//        AdsUtil.clearinfo(mContext);    }    /**     * 清除缓存目录     *     * @param dir     目录     * @param curTime 当前系统时间     * @return     */    private int clearCacheFolder(File dir, long curTime) {        int deletedFiles = 0;        if (dir != null && dir.isDirectory()) {            try {                for (File child : dir.listFiles()) {                    if (child.isDirectory()) {                        deletedFiles += clearCacheFolder(child, curTime);                    }                    if (child.lastModified() < curTime) {                        if (child.delete()) {                            deletedFiles++;                        }                    }                }            } catch (Exception e) {                e.printStackTrace();            }        }        return deletedFiles;    }}

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