我正在从 ftp 服务器下载文件。下载代码工作正常，但是下载代码屏幕没有显示任何内容后，它变黑了。即使文件保存在指定目录中，下载功能也没有返回真实值。
public class FTPClass{
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_file_player);
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
Intent intent = getIntent();
dirname = intent.getStringExtra("currentDirName");
MyFTPClient mftp = new MyFTPClient();
createPath = mftp.getAppRootPath().concat("/"+ dirname);
mftp.setCurrentDir(createPath);
System.out.println(mftp.ftpChangeDirectory(createPath));
FTPFile[] farr = mftp.ftpListAllFiles();
System.out.println(farr.length);
for(int i = 0; i<farr.length;i++){
System.out.println("SRC: "+createPath+"/"+farr[i].getName());
String src = createPath+"/"+farr[i].getName();
System.out.println("DEST: "+"/data/data/com.example.ftpplayer" + "/app_"+dirname);
String dest ="/data/data/com.example.ftpplayer" + "/app_"+dirname+"/"+farr[i].getName();
System.out.println(mftp.downloadFile(src,dest));
}
}
}
public class CallingIntent extends Activity{
System.out.println("In item click ");
Intent intent = new Intent(getApplicationContext(), FTPClass.class);
String dir = ((TextView) view).getText().toString();
intent.putExtra("currentDirName", dir);
startActivity(intent);
}
public class MyFTPClient{
public boolean downloadFile(String srcPath , String destPath){
try {
FileOutputStream fos = new FileOutputStream(destPath);
System.out.println(mftp.retrieveFile(srcPath, fos)); // retrieve file doesn't return true
fos.flush();
fos.close();
return true;
} catch (FileNotFoundException e) {
e.printStackTrace();
}catch(IOException e){
e.printStackTrace();
}
return false;
}
}