[Android][工具类]FileUtils

import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.net.Uri;import android.os.Environment;import android.util.Log;import java.io.File;import java.io.FileInputStream;import java.io.FileOutputStream;import java.io.IOException;import java.math.BigDecimal;import java.nio.channels.FileChannel;import java.text.SimpleDateFormat;import java.util.Date;import java.util.Locale;/** * 文件相关工具类 * 如：递归获取文件大小,格式化单位,删除文件或文件夹,压缩文件, * 创建一个JPEG格式的图片文件,拷贝文件 * */public class FileUtils {    /**     * 递归获取文件大小     *     * @param file 文件夹     * @return 文件大小     */    public static long getFolderSize(File file) {        long size = 0;        try {            File[] fileList = file.listFiles();            for (int i = 0; i < fileList.length; i++) {                // 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) {            return 0;        }        return size;    }    /**     * 格式化单位     *     * @param size 文件大小     * @return 如10MB、10KB、10GB     */    public static String getFormatSize(double size) {        double kiloByte = size / 1024;        if (kiloByte < 1) {            if (size == 0) {                return "0MB";            }            return size + "Byte";        }        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";    }    /**     * 删除文件或文件夹     *     * @param file 文件或文件夹     */    public static void deleteFiles(File file) {        if (file == null) return;        if (file.isFile() || file.list().length == 0) {            file.delete();        } else {            File[] files = file.listFiles();            for (File f : files) {                deleteFiles(f);//递归删除每一个文件                f.delete();//删除该文件夹            }        }    }    /**     * 压缩文件     *     * @param path 文件路径     * @return 压缩后的文件     */    public static File scal(String path) {        File outputFile = new File(path);        long fileSize = outputFile.length();        final long fileMaxSize = 200 * 300;        BitmapFactory.Options options = new BitmapFactory.Options();        options.inJustDecodeBounds = true;        BitmapFactory.decodeFile(path, options);        double scale = Math.sqrt((float) fileSize / fileMaxSize);        Log.d("scale", scale + "");        options.outHeight = 420;        options.outWidth = 600;        options.inSampleSize = (int) (scale + 0.5);        options.inJustDecodeBounds = false;        Bitmap bitmap = BitmapFactory.decodeFile(path, options);        outputFile = new File(createImageFile().getPath());        FileOutputStream fos;        try {            fos = new FileOutputStream(outputFile);            bitmap.compress(Bitmap.CompressFormat.JPEG, 50, fos);            fos.close();        } catch (IOException e) {            e.printStackTrace();        }        if (!bitmap.isRecycled()) {            bitmap.recycle();        } else {            File tempFile = outputFile;            outputFile = new File(createImageFile().getPath());            copyFileUsingFileChannels(tempFile, outputFile);        }        return outputFile;    }    /**     * 创建一个JPEG格式的图片文件     *     * @return 文件File     */    public static File createImageFile() {        String timeStamp = new SimpleDateFormat("yyyy-MM-dd HH-mm-SS", Locale.CHINA).format(new Date());        String imageFileName = "JPEG_ " + timeStamp + "_";        File storageDir = Environment.getExternalStoragePublicDirectory(                Environment.DIRECTORY_PICTURES);        File image = null;        try {            image = File.createTempFile(                    imageFileName,  /* prefix */                    ".jpg",         /* suffix */                    storageDir      /* directory */            );        } catch (IOException e) {            e.printStackTrace();        }        return image;    }    /**     * 创建一个JPEG格式的图片文件     *     * @return 文件Uri     */    public static Uri createImageFileUri() {        return Uri.fromFile(createImageFile());    }    /**     * 拷贝文件     *     * @param source 初始文件     * @param dest   目标文件     */    public static void copyFileUsingFileChannels(File source, File dest) {        FileChannel inputChannel = null;        FileChannel outputChannel = null;        try {            inputChannel = new FileInputStream(source).getChannel();            outputChannel = new FileOutputStream(dest).getChannel();            outputChannel.transferFrom(inputChannel, 0, inputChannel.size());        } catch (IOException e) {            e.printStackTrace();        } finally {            try {                assert inputChannel != null;                inputChannel.close();                assert outputChannel != null;                outputChannel.close();            } catch (IOException e) {                e.printStackTrace();            }        }    }}
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