我在资产文件夹里有几个文件。我需要把它们都复制到一个文件夹，比如/sdcard/folder。我想从一个线程中做这件事。我该怎么做?
当前回答
基于您的解决方案，我自己做了一些事情来允许子文件夹。有些人可能会觉得这很有用:
...
copyFileOrDir("myrootdir");
...
private void copyFileOrDir(String path) {
AssetManager assetManager = this.getAssets();
String assets[] = null;
try {
assets = assetManager.list(path);
if (assets.length == 0) {
copyFile(path);
} else {
String fullPath = "/data/data/" + this.getPackageName() + "/" + path;
File dir = new File(fullPath);
if (!dir.exists())
dir.mkdir();
for (int i = 0; i < assets.length; ++i) {
copyFileOrDir(path + "/" + assets[i]);
}
}
} catch (IOException ex) {
Log.e("tag", "I/O Exception", ex);
}
}
private void copyFile(String filename) {
AssetManager assetManager = this.getAssets();
InputStream in = null;
OutputStream out = null;
try {
in = assetManager.open(filename);
String newFileName = "/data/data/" + this.getPackageName() + "/" + filename;
out = new FileOutputStream(newFileName);
byte[] buffer = new byte[1024];
int read;
while ((read = in.read(buffer)) != -1) {
out.write(buffer, 0, read);
}
in.close();
in = null;
out.flush();
out.close();
out = null;
} catch (Exception e) {
Log.e("tag", e.getMessage());
}
}
其他回答
嗨，伙计们，我做了这样的事情。 用于n深度复制文件夹和文件复制。 它允许你复制所有的目录结构从Android资产管理器复制:)
private void manageAssetFolderToSDcard()
{
try
{
String arg_assetDir = getApplicationContext().getPackageName();
String arg_destinationDir = FRConstants.ANDROID_DATA + arg_assetDir;
File FolderInCache = new File(arg_destinationDir);
if (!FolderInCache.exists())
{
copyDirorfileFromAssetManager(arg_assetDir, arg_destinationDir);
}
} catch (IOException e1)
{
e1.printStackTrace();
}
}
public String copyDirorfileFromAssetManager(String arg_assetDir, String arg_destinationDir) throws IOException
{
File sd_path = Environment.getExternalStorageDirectory();
String dest_dir_path = sd_path + addLeadingSlash(arg_destinationDir);
File dest_dir = new File(dest_dir_path);
createDir(dest_dir);
AssetManager asset_manager = getApplicationContext().getAssets();
String[] files = asset_manager.list(arg_assetDir);
for (int i = 0; i < files.length; i++)
{
String abs_asset_file_path = addTrailingSlash(arg_assetDir) + files[i];
String sub_files[] = asset_manager.list(abs_asset_file_path);
if (sub_files.length == 0)
{
// It is a file
String dest_file_path = addTrailingSlash(dest_dir_path) + files[i];
copyAssetFile(abs_asset_file_path, dest_file_path);
} else
{
// It is a sub directory
copyDirorfileFromAssetManager(abs_asset_file_path, addTrailingSlash(arg_destinationDir) + files[i]);
}
}
return dest_dir_path;
}
public void copyAssetFile(String assetFilePath, String destinationFilePath) throws IOException
{
InputStream in = getApplicationContext().getAssets().open(assetFilePath);
OutputStream out = new FileOutputStream(destinationFilePath);
byte[] buf = new byte[1024];
int len;
while ((len = in.read(buf)) > 0)
out.write(buf, 0, len);
in.close();
out.close();
}
public String addTrailingSlash(String path)
{
if (path.charAt(path.length() - 1) != '/')
{
path += "/";
}
return path;
}
public String addLeadingSlash(String path)
{
if (path.charAt(0) != '/')
{
path = "/" + path;
}
return path;
}
public void createDir(File dir) throws IOException
{
if (dir.exists())
{
if (!dir.isDirectory())
{
throw new IOException("Can't create directory, a file is in the way");
}
} else
{
dir.mkdirs();
if (!dir.isDirectory())
{
throw new IOException("Unable to create directory");
}
}
}
最后创建一个Asynctask:
private class ManageAssetFolders extends AsyncTask<Void, Void, Void>
{
@Override
protected Void doInBackground(Void... arg0)
{
manageAssetFolderToSDcard();
return null;
}
}
从你的活动中:
new ManageAssetFolders().execute();
基于Yoram Cohen的回答，这里有一个支持非静态目标目录的版本。
使用copyFileOrDir(getDataDir()， "")来写入应用程序内部存储文件夹/data/data/pkg_name/
Supports subfolders. Supports custom and non-static target directory Avoids copying "images" etc fake asset folders like private void copyFileOrDir(String TARGET_BASE_PATH, String path) { AssetManager assetManager = this.getAssets(); String assets[] = null; try { Log.i("tag", "copyFileOrDir() "+path); assets = assetManager.list(path); if (assets.length == 0) { copyFile(TARGET_BASE_PATH, path); } else { String fullPath = TARGET_BASE_PATH + "/" + path; Log.i("tag", "path="+fullPath); File dir = new File(fullPath); if (!dir.exists() && !path.startsWith("images") && !path.startsWith("sounds") && !path.startsWith("webkit")) if (!dir.mkdirs()) Log.i("tag", "could not create dir "+fullPath); for (int i = 0; i < assets.length; ++i) { String p; if (path.equals("")) p = ""; else p = path + "/"; if (!path.startsWith("images") && !path.startsWith("sounds") && !path.startsWith("webkit")) copyFileOrDir(TARGET_BASE_PATH, p + assets[i]); } } } catch (IOException ex) { Log.e("tag", "I/O Exception", ex); } } private void copyFile(String TARGET_BASE_PATH, String filename) { AssetManager assetManager = this.getAssets(); InputStream in = null; OutputStream out = null; String newFileName = null; try { Log.i("tag", "copyFile() "+filename); in = assetManager.open(filename); if (filename.endsWith(".jpg")) // extension was added to avoid compression on APK file newFileName = TARGET_BASE_PATH + "/" + filename.substring(0, filename.length()-4); else newFileName = TARGET_BASE_PATH + "/" + filename; out = new FileOutputStream(newFileName); byte[] buffer = new byte[1024]; int read; while ((read = in.read(buffer)) != -1) { out.write(buffer, 0, read); } in.close(); in = null; out.flush(); out.close(); out = null; } catch (Exception e) { Log.e("tag", "Exception in copyFile() of "+newFileName); Log.e("tag", "Exception in copyFile() "+e.toString()); } }
复制所有文件和目录从资产到您的文件夹!
为了更好地复制，使用apache Commons IO
public void doCopyAssets() throws IOException {
File externalFilesDir = context.getExternalFilesDir(null);
doCopy("", externalFilesDir.getPath());
}
//这是复制的主要方法
private void doCopy(String dirName, String outPath) throws IOException {
String[] srcFiles = assets.list(dirName);//for directory
for (String srcFileName : srcFiles) {
String outFileName = outPath + File.separator + srcFileName;
String inFileName = dirName + File.separator + srcFileName;
if (dirName.equals("")) {// for first time
inFileName = srcFileName;
}
try {
InputStream inputStream = assets.open(inFileName);
copyAndClose(inputStream, new FileOutputStream(outFileName));
} catch (IOException e) {//if directory fails exception
new File(outFileName).mkdir();
doCopy(inFileName, outFileName);
}
}
}
public static void closeQuietly(AutoCloseable autoCloseable) {
try {
if(autoCloseable != null) {
autoCloseable.close();
}
} catch(IOException ioe) {
//skip
}
}
public static void copyAndClose(InputStream input, OutputStream output) throws IOException {
copy(input, output);
closeQuietly(input);
closeQuietly(output);
}
public static void copy(InputStream input, OutputStream output) throws IOException {
byte[] buffer = new byte[1024];
int n = 0;
while(-1 != (n = input.read(buffer))) {
output.write(buffer, 0, n);
}
}
这就是我的个性化文本提取类，希望对大家有用。
package lorenzo.morelli.platedetector;
import android.content.Context;
import android.content.res.AssetManager;
import android.graphics.Bitmap;
import com.googlecode.tesseract.android.TessBaseAPI;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
public class TextExtractor {
private final Context context;
private final String dirName;
private final String language;
public TextExtractor(final Context context, final String dirName, final String language) {
this.context = context;
this.dirName = dirName;
this.language = language;
}
public String extractText(final Bitmap bitmap) {
final TessBaseAPI tessBaseApi = new TessBaseAPI();
final String datapath = this.context.getFilesDir()+ "/tesseract/";
checkFile(new File(datapath + this.dirName + "/"), datapath, this.dirName, this.language);
tessBaseApi.init(datapath, this.language);
tessBaseApi.setImage(bitmap);
final String extractedText = tessBaseApi.getUTF8Text();
tessBaseApi.end();
return extractedText;
}
private void checkFile(final File dir, final String datapath, final String dirName, final String language) {
//directory does not exist, but we can successfully create it
if (!dir.exists()&& dir.mkdirs()) {
copyFiles(datapath, dirName, language);
} //The directory exists, but there is no data file in it
if(dir.exists()) {
final String datafilepath = datapath + "/" + dirName + "/" + language + ".traineddata";
final File datafile = new File(datafilepath);
if (!datafile.exists()) {
copyFiles(datapath, dirName, language);
}
}
}
private void copyFiles(final String datapath, final String dirName, final String language) {
try {
//location we want the file to be at
final String filepath = datapath + "/" + dirName + "/" + language + ".traineddata";
//get access to AssetManager
final AssetManager assetManager = this.context.getAssets();
//open byte streams for reading/writing
final InputStream instream = assetManager.open(dirName + "/" + language + ".traineddata");
final OutputStream outstream = new FileOutputStream(filepath);
//copy the file to the location specified by filepath
byte[] buffer = new byte[1024];
int read;
while ((read = instream.read(buffer)) != -1) {
outstream.write(buffer, 0, read);
}
outstream.flush();
outstream.close();
instream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
要使用它，你需要训练过的数据文件。你可以从这个链接下载trainddata文件。
一旦你下载了你想要的traineddata文件，你需要在你的Android项目中创建一个名为assets的Android资源目录。在新创建的资产文件夹中，你需要创建一个名为“tessdata”的常规目录，在那里你可以放置你的训练数据文件。 最后你必须初始化MainActivity中的“TextExtractor”类。
final TextExtractor textExtractor = new TextExtractor(this, "tessdata", "eng");
第一个参数是上下文，第二个参数是刚刚创建的目录名，最后一个参数是刚刚下载的训练数据的语言。
要提取文本，你必须调用"extractText"方法:
final String text = textExtractor.extractText(imageWithText);
注意，extractText需要一个位图图像才能工作!! 你可以用这一行从你的可绘制文件中创建一个BitMap图像:
final BitMap image = BitmapFactory.decodeResource(getResources(), R.drawable.test_image);
如果你需要更多的支持，我建议你遵循这个有用的指南:https://github.com/SamVanRoy/Android_OCR_App
基于您的解决方案，我自己做了一些事情来允许子文件夹。有些人可能会觉得这很有用:
...
copyFileOrDir("myrootdir");
...
private void copyFileOrDir(String path) {
AssetManager assetManager = this.getAssets();
String assets[] = null;
try {
assets = assetManager.list(path);
if (assets.length == 0) {
copyFile(path);
} else {
String fullPath = "/data/data/" + this.getPackageName() + "/" + path;
File dir = new File(fullPath);
if (!dir.exists())
dir.mkdir();
for (int i = 0; i < assets.length; ++i) {
copyFileOrDir(path + "/" + assets[i]);
}
}
} catch (IOException ex) {
Log.e("tag", "I/O Exception", ex);
}
}
private void copyFile(String filename) {
AssetManager assetManager = this.getAssets();
InputStream in = null;
OutputStream out = null;
try {
in = assetManager.open(filename);
String newFileName = "/data/data/" + this.getPackageName() + "/" + filename;
out = new FileOutputStream(newFileName);
byte[] buffer = new byte[1024];
int read;
while ((read = in.read(buffer)) != -1) {
out.write(buffer, 0, read);
}
in.close();
in = null;
out.flush();
out.close();
out = null;
} catch (Exception e) {
Log.e("tag", e.getMessage());
}
}
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