什么是最简单的方法从android.net.Uri对象持有一个文件:类型转换为java.io.File对象在Android?
我尝试了下面的方法，但不管用:
File file = new File(Environment.getExternalStorageDirectory(), "read.me");
Uri uri = Uri.fromFile(file);
File auxFile = new File(uri.toString());
assertEquals(file.getAbsolutePath(), auxFile.getAbsolutePath());
当前回答
你可以使用这个函数从uri中获取文件在新的android和旧的
fun getFileFromUri(context: Context, uri: Uri?): File? {
uri ?: return null
uri.path ?: return null
var newUriString = uri.toString()
newUriString = newUriString.replace(
"content://com.android.providers.downloads.documents/",
"content://com.android.providers.media.documents/"
)
newUriString = newUriString.replace(
"/msf%3A", "/image%3A"
)
val newUri = Uri.parse(newUriString)
var realPath = String()
val databaseUri: Uri
val selection: String?
val selectionArgs: Array<String>?
if (newUri.path?.contains("/document/image:") == true) {
databaseUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI
selection = "_id=?"
selectionArgs = arrayOf(DocumentsContract.getDocumentId(newUri).split(":")[1])
} else {
databaseUri = newUri
selection = null
selectionArgs = null
}
try {
val column = "_data"
val projection = arrayOf(column)
val cursor = context.contentResolver.query(
databaseUri,
projection,
selection,
selectionArgs,
null
)
cursor?.let {
if (it.moveToFirst()) {
val columnIndex = cursor.getColumnIndexOrThrow(column)
realPath = cursor.getString(columnIndex)
}
cursor.close()
}
} catch (e: Exception) {
Log.i("GetFileUri Exception:", e.message ?: "")
}
val path = realPath.ifEmpty {
when {
newUri.path?.contains("/document/raw:") == true -> newUri.path?.replace(
"/document/raw:",
""
)
newUri.path?.contains("/document/primary:") == true -> newUri.path?.replace(
"/document/primary:",
"/storage/emulated/0/"
)
else -> return null
}
}
return if (path.isNullOrEmpty()) null else File(path)
}
其他回答
另一种方法是创建一个临时文件。做那件事:
fun createTmpFileFromUri(context: Context, uri: Uri, fileName: String): File? {
return try {
val stream = context.contentResolver.openInputStream(uri)
val file = File.createTempFile(fileName, "", context.cacheDir)
org.apache.commons.io.FileUtils.copyInputStreamToFile(stream,file)
file
} catch (e: Exception) {
e.printStackTrace()
null
}
}
我们使用Apache公共库FileUtils类。将它添加到您的项目:
implementation "commons-io:commons-io:2.7"
注意，MAKE SURE在使用后调用file.delete()。 查阅更多资料。
最好的解决方案
创建一个简单的FileUtil类，用于创建、复制和重命名文件
我使用了uri.toString()和uri.getPath()，但不适合我。 我终于找到了这个解。
import android.content.Context;
import android.database.Cursor;
import android.net.Uri;
import android.provider.OpenableColumns;
import android.util.Log;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
public class FileUtil {
private static final int EOF = -1;
private static final int DEFAULT_BUFFER_SIZE = 1024 * 4;
private FileUtil() {
}
public static File from(Context context, Uri uri) throws IOException {
InputStream inputStream = context.getContentResolver().openInputStream(uri);
String fileName = getFileName(context, uri);
String[] splitName = splitFileName(fileName);
File tempFile = File.createTempFile(splitName[0], splitName[1]);
tempFile = rename(tempFile, fileName);
tempFile.deleteOnExit();
FileOutputStream out = null;
try {
out = new FileOutputStream(tempFile);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
if (inputStream != null) {
copy(inputStream, out);
inputStream.close();
}
if (out != null) {
out.close();
}
return tempFile;
}
private static String[] splitFileName(String fileName) {
String name = fileName;
String extension = "";
int i = fileName.lastIndexOf(".");
if (i != -1) {
name = fileName.substring(0, i);
extension = fileName.substring(i);
}
return new String[]{name, extension};
}
private static String getFileName(Context context, Uri uri) {
String result = null;
if (uri.getScheme().equals("content")) {
Cursor cursor = context.getContentResolver().query(uri, null, null, null, null);
try {
if (cursor != null && cursor.moveToFirst()) {
result = cursor.getString(cursor.getColumnIndex(OpenableColumns.DISPLAY_NAME));
}
} catch (Exception e) {
e.printStackTrace();
} finally {
if (cursor != null) {
cursor.close();
}
}
}
if (result == null) {
result = uri.getPath();
int cut = result.lastIndexOf(File.separator);
if (cut != -1) {
result = result.substring(cut + 1);
}
}
return result;
}
private static File rename(File file, String newName) {
File newFile = new File(file.getParent(), newName);
if (!newFile.equals(file)) {
if (newFile.exists() && newFile.delete()) {
Log.d("FileUtil", "Delete old " + newName + " file");
}
if (file.renameTo(newFile)) {
Log.d("FileUtil", "Rename file to " + newName);
}
}
return newFile;
}
private static long copy(InputStream input, OutputStream output) throws IOException {
long count = 0;
int n;
byte[] buffer = new byte[DEFAULT_BUFFER_SIZE];
while (EOF != (n = input.read(buffer))) {
output.write(buffer, 0, n);
count += n;
}
return count;
}
}
在代码中使用FileUtil类
try {
File file = FileUtil.from(MainActivity.this,fileUri);
Log.d("file", "File...:::: uti - "+file .getPath()+" file -" + file + " : " + file .exists());
} catch (IOException e) {
e.printStackTrace();
}
对于那些在这里寻找图像解决方案的人，特别是在这里。
private Bitmap getBitmapFromUri(Uri contentUri) {
String path = null;
String[] projection = { MediaStore.Images.Media.DATA };
Cursor cursor = getContentResolver().query(contentUri, projection, null, null, null);
if (cursor.moveToFirst()) {
int columnIndex = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
path = cursor.getString(columnIndex);
}
cursor.close();
Bitmap bitmap = BitmapFactory.decodeFile(path);
return bitmap;
}
你可以使用这个函数从uri中获取文件在新的android和旧的
fun getFileFromUri(context: Context, uri: Uri?): File? {
uri ?: return null
uri.path ?: return null
var newUriString = uri.toString()
newUriString = newUriString.replace(
"content://com.android.providers.downloads.documents/",
"content://com.android.providers.media.documents/"
)
newUriString = newUriString.replace(
"/msf%3A", "/image%3A"
)
val newUri = Uri.parse(newUriString)
var realPath = String()
val databaseUri: Uri
val selection: String?
val selectionArgs: Array<String>?
if (newUri.path?.contains("/document/image:") == true) {
databaseUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI
selection = "_id=?"
selectionArgs = arrayOf(DocumentsContract.getDocumentId(newUri).split(":")[1])
} else {
databaseUri = newUri
selection = null
selectionArgs = null
}
try {
val column = "_data"
val projection = arrayOf(column)
val cursor = context.contentResolver.query(
databaseUri,
projection,
selection,
selectionArgs,
null
)
cursor?.let {
if (it.moveToFirst()) {
val columnIndex = cursor.getColumnIndexOrThrow(column)
realPath = cursor.getString(columnIndex)
}
cursor.close()
}
} catch (e: Exception) {
Log.i("GetFileUri Exception:", e.message ?: "")
}
val path = realPath.ifEmpty {
when {
newUri.path?.contains("/document/raw:") == true -> newUri.path?.replace(
"/document/raw:",
""
)
newUri.path?.contains("/document/primary:") == true -> newUri.path?.replace(
"/document/primary:",
"/storage/emulated/0/"
)
else -> return null
}
}
return if (path.isNullOrEmpty()) null else File(path)
}
public String getRealPathFromURI（Uri uri） {
String result;
Cursor cursor = getContentResolver().query(uri, null, null, null, null);
if (cursor == null) {
result = uri.getPath();
cursor.close();
return result;
}
cursor.moveToFirst();
int idx = cursor.getColumnIndex(MediaStore.Images.ImageColumns.DATA);
result = cursor.getString(idx);
cursor.close();
return result;
}
然后使用从URI中获取文件:
File finalFile = newFile(getRealPathFromURI(uri));
——希望能帮到你----
