android系统DownloadManager下载工具类

package com.duke.mydownloadmanager; import android.content.Context; import android.content.pm.PackageManager; import android.os.Environment; import android.os.StatFs; import android.text.TextUtils; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.nio.charset.Charset; /** * @Author: duke * @DateTime: 2017-05-25 10:31 * @Description: 手机内部、外部存储空间操作 version 2.0 <br/> * <p> * 1、context.getPackageCodePath():/data/app/your_app.apk * 2、context.getPackageResourcePath():/data/app/your_app.apk * 3、context.getDatabasePath("dk"):/data/data/<package name>/databases/dk * 4、context.getDir("dk", Context.MODE_PRIVATE):/data/data/<package name>/app_dk * 5、context.getCacheDir():/data/data/<package name>/cache * 6、context.getFilesDir():/data/data/<package name>/files * 7、context.getExternalFilesDir("dk"):/storage/sdcard0/Android/data/<package name>/files/dk * 8、context.getExternalFilesDir(null):/storage/sdcard0/Android/data/<package name>/files * 9、context.getExternalFilesDir():/storage/sdcard0/Android/data/<package name>/files -->"清除数据",随app下载而删除 * 10、context.getExternalCacheDir():/storage/sdcard0/Android/data/<package name>/cache -->"清除缓存",随app下载而删除 * <p/> * 11、context.getLocalClassName():MainActivity * <p/> * 12、Environment.getRootDirectory():/system * 13、Environment.getDataDirectory():/data * 14、Environment.getDownloadCacheDirectory():/cache * 15、Environment.getExternalStorageDirectory():/storage/sdcard0 * 16、Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS):/storage/sdcard0/Download */ public class FileUtils { public static String getExtensionNameNoPoint(String path) { return getExtensionNameNoPoint(newFile(path)); } public static String getExtensionNameNoPoint(File file) { if (file == null) { return null; } String name = file.getName(); if ("".equals(name.trim())) { return null; } if (!name.contains(".")) { return null; } String[] arr = name.split("\\."); return arr[arr.length - 1]; } public static File newFile(String path) { if (path == null || "".equals(path.trim())) { return null; } return new File(path.trim()); } public static boolean createFolderAndFile(File file) { if (file == null) { return false; } if (file.exists()) { return true; } File parentFile = file.getParentFile(); if (parentFile == null) { return false; } if (!parentFile.exists()) { if (!parentFile.mkdirs()) { return false; } } try { if (file.createNewFile()) { return true; } } catch (IOException e) { e.printStackTrace(); return false; } return false; } public static void deleteFiles(String path) { deleteFiles(newFile(path)); } /** * 删除指定路径下的所有文件 * * @param deleteFile parent文件对象 * @return 是否全部删除成功 */ public static void deleteFiles(File deleteFile) { if (deleteFile == null || !deleteFile.exists()) { return; } if (deleteFile.isFile()) { try { deleteFile.delete(); } catch (Exception e) { e.printStackTrace(); } } else { File[] files = deleteFile.listFiles(); int size = files.length; for (int i = 0; i < size; i++) { deleteFiles(files[i]); } try { //delete this empty directory deleteFile.delete(); } catch (Exception e) { e.printStackTrace(); } } } public static long getFileSize(String path) { return getFileSize(newFile(path)); } public static long getFileSize(File file) { if (file == null || !file.exists()) { return -1; } //数组是引用传递 long[] arr = {0}; countFile(file, arr); return arr[0]; } private static void countFile(File file, long[] totalArr) { if (file == null || !file.exists()) { return; } if (file.isFile()) { totalArr[0] += file.length(); } else { File[] files = file.listFiles(); int size = files.length; for (int i = 0; i < size; i++) { countFile(files[i], totalArr); } } } public static boolean renameFile(String oldPath, String newPath) { return renameFile(newFile(oldPath), newFile(newPath)); } public static boolean renameFile(File oldFile, File newFile) { if (oldFile == null || !oldFile.exists()) { return false; } if (newFile == null) { return false; } if (!createFolderAndFile(newFile)) { return false; } return oldFile.renameTo(newFile); } public static boolean saveFile(String data, String filePath) { if (data == null || "".equals(data.trim())) { return false; } return saveFile(data.getBytes(), filePath); } public static boolean saveFile(byte[] data, String filePath) { if (data == null || data.length <= 0) { return false; } File file = newFile(filePath); if (!createFolderAndFile(file)) { return false; } if (!file.canWrite()) { return false; } FileOutputStream fos = null; try { fos = new FileOutputStream(file); fos.write(data); fos.flush(); return true; } catch (IOException e) { e.printStackTrace(); } finally { if (fos != null) { try { fos.close(); } catch (IOException e) { e.printStackTrace(); } finally { fos = null; } } } return false; } public static boolean copyOnlyFile(File oldFile, File newFile) { if (oldFile == null || !oldFile.exists()) { return false; } if (oldFile.isDirectory()) { return false; } if (newFile == null || newFile.isDirectory()) { return false; } if (!createFolderAndFile(newFile)) { return false; } FileInputStream inputStream = null; FileOutputStream outputStream = null; try { inputStream = new FileInputStream(oldFile); outputStream = new FileOutputStream(newFile); byte[] buffer = new byte[8192]; int len = 0; while ((len = inputStream.read(buffer)) != -1) { outputStream.write(buffer, 0, len); outputStream.flush(); } return true; } catch (Exception e) { e.printStackTrace(); } finally { if (outputStream != null) { try { outputStream.flush(); outputStream.close(); } catch (IOException e) { e.printStackTrace(); } fina