我想通过Dropbox API下载图片，所以我按照示例代码@ Android Dropbox API file download但我不明白如何将其集成到我当前的代码中。我尝试将api.getFileStream("dropbox", dbPath, null);更改为dropbox.getFileStream("dropbox", dbPath, null);，从而导致错误：
'getFileStream(java.lang.String, java.lang.String)' in 'com.dropbox.client2.DropboxAPI' cannot be applied to '(java.lang.String, java.lang.String, null)'
更新1：更改为`dropbox.getFileStream（FILE_DIR，null）
主要代码
public class Dropbox extends AppCompatActivity implements View.OnClickListener {
private DropboxAPI<AndroidAuthSession> dropbox;
private final static String FILE_DIR = "/DropboxSample/";
private final static String DROPBOX_NAME = "dropbox_prefs";
private final static String ACCESS_KEY = "Insert Key here";
private final static String ACCESS_SECRET = "Insert Key here";
private boolean isLoggedIn;
private Button logIn;
private Button uploadFile;
private Button downloadFile;
private Button listFiles;
private LinearLayout container;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_dropbox);
logIn = (Button) findViewById(R.id.dropbox_login);
logIn.setOnClickListener(this);
uploadFile = (Button) findViewById(R.id.upload_file);
uploadFile.setOnClickListener(this);
downloadFile = (Button) findViewById(download_file);
downloadFile.setOnClickListener(this);
listFiles = (Button) findViewById(R.id.list_files);
listFiles.setOnClickListener(this);
container = (LinearLayout) findViewById(R.id.container_files);
loggedIn(false);
AndroidAuthSession session;
AppKeyPair pair = new AppKeyPair(ACCESS_KEY, ACCESS_SECRET);
SharedPreferences prefs = getSharedPreferences(DROPBOX_NAME, 0);
String key = prefs.getString(ACCESS_KEY, null);
String secret = prefs.getString(ACCESS_SECRET, null);
if (key != null && secret != null) {
AccessTokenPair token = new AccessTokenPair(key, secret);
session = new AndroidAuthSession(pair ,token);
} else {
session = new AndroidAuthSession(pair );
}
dropbox = new DropboxAPI<>(session);
}
@Override
protected void onResume() {
super.onResume();
AndroidAuthSession session = dropbox.getSession();
if (session.authenticationSuccessful()) {
try {
session.finishAuthentication();
TokenPair tokens = session.getAccessTokenPair();
SharedPreferences prefs = getSharedPreferences(DROPBOX_NAME, 0);
SharedPreferences.Editor editor = prefs.edit();
editor.putString(ACCESS_KEY, tokens.key);
editor.putString(ACCESS_SECRET, tokens.secret);
editor.commit();
loggedIn(true);
} catch (IllegalStateException e) {
Toast.makeText(this, "Error during Dropbox authentication",
Toast.LENGTH_SHORT).show();
}
}
}
public void loggedIn(boolean isLogged) {
isLoggedIn = isLogged;
uploadFile.setEnabled(isLogged);
downloadFile.setEnabled(isLogged);
listFiles.setEnabled(isLogged);
logIn.setText(isLogged ? "Log out" : "Log in");
}
private final Handler handler = new Handler() {
public void handleMessage(Message msg) {
ArrayList<String> result = msg.getData().getStringArrayList("data");
for (String fileName : result) {
Log.i("ListFiles", fileName);
TextView tv = new TextView(Dropbox.this);
tv.setText(fileName);
container.addView(tv);
}
}
};
@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.dropbox_login:
if (isLoggedIn) {
dropbox.getSession().unlink();
loggedIn(false);
} else {
dropbox.getSession().startAuthentication(Dropbox.this);
}
break;
case R.id.list_files:
ListDropboxFiles list = new ListDropboxFiles(dropbox, FILE_DIR,
handler);
list.execute();
break;
case R.id.upload_file:
UploadFileToDropbox upload = new UploadFileToDropbox(dropbox, FILE_DIR);
upload.execute();
break;
case R.id.download_file:
try {
downloadDropboxFile(FILE_DIR,(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES+"CapturyGallery")));
} catch (IOException e) {
e.printStackTrace();
}
break;
default:
break;
}
}
public class UploadFileToDropbox extends AsyncTask<Void, Long, Boolean> {
private DropboxAPI<?> dropbox;
private String mPath;
private Context mContext;
private final ProgressDialog mDialog;
private DropboxAPI.UploadRequest mRequest;
private String mErrorMsg;
private File[] listFile;
private int mFilesUploaded;
private int mCurrentFileIndex;;
public UploadFileToDropbox(DropboxAPI<?> dropbox, String path) {
File file = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES), "/CapturyGallery");
listFile = file.listFiles();
mContext = Dropbox.this;
this.dropbox = dropbox;
this.mPath = path;
mFilesUploaded = 0 ;
mCurrentFileIndex = 0 ;
mDialog = new ProgressDialog(mContext);
mDialog.setMax(100);
mDialog.setMessage("Uploading file 1 /" +listFile.length);
mDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
mDialog.setProgress(0);
mDialog.setButton(ProgressDialog.BUTTON_POSITIVE, "Cancel", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
// This will cancel the putFile operation
try {
mRequest.abort();
} catch (Exception e) {
}
}
});
mDialog.show();
mDialog.setCanceledOnTouchOutside(false);
}
@Override
protected Boolean doInBackground(Void... params) {
try {
for (int y = 0; y < listFile.length; y++) {
mCurrentFileIndex = y;
File file = listFile[y];
// By creating a request, we get a handle to the putFile operation,
// so we can cancel it later if we want to
FileInputStream fis = new FileInputStream(file);
String path = mPath + file.getName();
mRequest = dropbox.putFileOverwriteRequest(path, fis, file.length(),
new ProgressListener() {
@Override
public long progressInterval() {
// Update the progress bar every half-second or so
return 5;
}
@Override
public void onProgress(long bytes, long total) {
if (isCancelled()) {
mRequest.abort();
} else {
publishProgress(bytes);
}
}
});
mRequest.upload();
if(!isCancelled()){
mFilesUploaded++;
}else{
return false;
}
}
return true;
}
catch (DropboxUnlinkedException e) {
// This session wasn't authenticated properly or user unlinked
mErrorMsg = "This app wasn't authenticated properly.";
} catch (DropboxFileSizeException e) {
// File size too big to upload via the API
mErrorMsg = "This file is too big to upload";
} catch (DropboxPartialFileException e) {
// We canceled the operation
mErrorMsg = "Upload canceled";
} catch (DropboxServerException e) {
// Server-side exception. These are examples of what could happen,
// but we don't do anything special with them here.
if (e.error == DropboxServerException._401_UNAUTHORIZED) {
// Unauthorized, so we should unlink them. You may want to
// automatically log the user out in this case.
} else if (e.error == DropboxServerException._403_FORBIDDEN) {
// Not allowed to access this
} else if (e.error == DropboxServerException._404_NOT_FOUND) {
// path not found (or if it was the thumbnail, can't be
// thumbnailed)
} else if (e.error == DropboxServerException._507_INSUFFICIENT_STORAGE) {
// user is over quota
} else {
// Something else
}
// This gets the Dropbox error, translated into the user's language
mErrorMsg = e.body.userError;
if (mErrorMsg == null) {
mErrorMsg = e.body.error;
}
} catch (DropboxIOException e) {
// Happens all the time, probably want to retry automatically.
mErrorMsg = "Network error. Try again.";
} catch (DropboxParseException e) {
// Probably due to Dropbox server restarting, should retry
mErrorMsg = "Dropbox error. Try again.";
} catch (DropboxException e) {
// Unknown error
mErrorMsg = "Unknown error. Try again.";
} catch (FileNotFoundException e) {
}
return false;
}
@Override
protected void onProgressUpdate(Long... progress) {
long totalBytes = 0;
long bytesUploaded = 0;
for (int i = 0; i < listFile.length; i++) {
Long bytes = listFile[i].length();
totalBytes += bytes;
if (i < mCurrentFileIndex) {
bytesUploaded += bytes;
}
bytesUploaded += progress[0];
int percent = 100;
int percent1 = (int) (percent * (bytesUploaded/totalBytes));
mDialog.setMessage("Uploading file " + (mCurrentFileIndex + 1) + " / " + listFile.length);
mDialog.setProgress(percent1);
}
}
@Override
protected void onPostExecute(Boolean result) {
mDialog.dismiss();
if (result) {
showToast("Successfully uploaded");
} else {
showToast(mErrorMsg);
}
}
private void showToast(String msg) {
Toast error = Toast.makeText(Dropbox.this, msg, Toast.LENGTH_LONG);
error.show();
}
}
public class ListDropboxFiles extends AsyncTask<Void, Void, ArrayList<String>> {
private DropboxAPI<?> dropbox;
private String path;
private Handler handler;
public ListDropboxFiles(DropboxAPI<?> dropbox, String path, Handler handler) {
this.dropbox = dropbox;
this.path = path;
this.handler = handler;
}
@Override
protected ArrayList<String> doInBackground(Void... params) {
ArrayList<String> files = new ArrayList<String>();
try {
DropboxAPI.Entry directory = dropbox.metadata(path, 1000, null, true, null);
for (DropboxAPI.Entry entry : directory.contents) {
files.add(entry.fileName());
}
} catch (DropboxException e) {
e.printStackTrace();
}
return files;
}
@Override
protected void onPostExecute(ArrayList<String> result) {
Message msgObj = handler.obtainMessage();
Bundle b = new Bundle();
b.putStringArrayList("data", result);
msgObj.setData(b);
handler.sendMessage(msgObj);
}
}
从示例代码中添加
private boolean downloadDropboxFile(String dbPath, File localFile) throws IOException {
BufferedInputStream br = null;
BufferedOutputStream bw = null;
try {
if (!localFile.exists()) {
localFile.createNewFile(); //otherwise dropbox client will fail silently
}
FileDownload fd = dropbox.getFileStream("dropbox", dbPath, null);
br = new BufferedInputStream(fd.is);
bw = new BufferedOutputStream(new FileOutputStream(localFile));
byte[] buffer = new byte[4096];
int read;
while (true) {
read = br.read(buffer);
if (read <= 0) {
break;
}
bw.write(buffer, 0, read);
}
} finally {
//in finally block:
if (bw != null) {
bw.close();
}
if (br != null) {
br.close();
}
}
return true;
}
}
>
答案 0 :(得分：0)
错误消息表明方法定义是：
getFileStream(java.lang.String, java.lang.String)
这也是the documentation for the getFileStream method in the Dropbox Android Core SDK所显示的内容。
但是，您尝试使用三个参数：
(java.lang.String, java.lang.String, null)
因此，要正确调用该方法，您应该删除最后一个参数（null）。