fileoutputstream

how can I delete line from txt?

由 倾然丶 夕夏残阳落幕 提交于 2019-12-09 22:58:54
问题 I mean , I want to delete line from my text on android. How can I delete? I do not want to read one txt and create another with removing line. I want to delete line from my existing txt. thanks. 回答1: This is a pretty tricky problem, despite it looking a trivial one. In case of variable lines length, maybe your only option is reading the file line by line to indentify offset and length of the target line. Then copying the following portion of the file starting at offset , eventually truncating

How to overwrite/reuse the existing output path for Hadoop jobs again and agian

由 為{幸葍}努か 提交于 2019-12-09 07:46:34
问题 I want to overwrite/reuse the existing output directory when I run my Hadoop job daily. Actually the output directory will store summarized output of each day's job run results. If I specify the same output directory it gives the error "output directory already exists". How to bypass this validation? 回答1: What about deleting the directory before you run the job? You can do this via shell: hadoop fs -rmr /path/to/your/output/ or via the Java API: // configuration should contain reference to

Unable to copy SQLite database from assests folder to device memory

由 回眸只為那壹抹淺笑 提交于 2019-12-08 11:12:43
问题 I'm Unable to copy SQLite database from assests folder to device memory(trying on emulator). I have a database in my project's assests folder which has a table containing 1000s of pre-existing rows . I intend to copy the existing file from the assets folder into the database folder of emulator. Piece of ACTIVITY @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); //All views(list,textboxes) are declared. try { dbM =

Read-Only error when saving image from URL in Android

由 假装没事ソ 提交于 2019-12-08 09:37:31
问题 I am trying to save an image from a web URL in an android application however when I run it, the log cat throws an exception saying its "read only". I don't know whats going on. Here is my downloader class: public class ImageDownload { public static void downloader(String imageURL, String fileName) { try { URL url = new URL("http://www.exampleurl.com/" + imageURL); File file = new File(fileName); URLConnection con = url.openConnection(); InputStream is = con.getInputStream();

Reading data from multiple zip files and combining them to one

由 天大地大妈咪最大 提交于 2019-12-07 16:29:33
问题 I want to read data from lets say 4 zip files called zip1, zip2, zip3, zip4. All of these zip files are split from this 1 big zip file called "BigZip". I want to combine the zip files into one and then compare the bytes if the 1 bigzip file matches the size of bytes with the combined zip file of (zip1+zip2+zip3+zip4). I am getting a very small file size when I combine the size of 4 zip files. What am I doing wrong? Here is my code for the same: targetFilePath1, targetFilePath2,

why sometime it throws FileNotFoundException

由 烈酒焚心 提交于 2019-12-06 17:11:59
问题 The code works for most of the time, but some time it throws exception. Couldn't figure out what could cause it. What is does is to create a file at /storage/emulated/0/Download/theFileName.jpg and write data to it (from sourceFile which does exist), but got "file not exist" exception for the newly created file. (it does have uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE", and uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE " in manifest). File

Reading data from multiple zip files and combining them to one

由 蹲街弑〆低调 提交于 2019-12-05 23:19:33
I want to read data from lets say 4 zip files called zip1, zip2, zip3, zip4. All of these zip files are split from this 1 big zip file called "BigZip". I want to combine the zip files into one and then compare the bytes if the 1 bigzip file matches the size of bytes with the combined zip file of (zip1+zip2+zip3+zip4). I am getting a very small file size when I combine the size of 4 zip files. What am I doing wrong? Here is my code for the same: targetFilePath1, targetFilePath2, targetFilePath3, targetFilePath4 belongs to path of 4 zip files. sourceFilePath is the path to BigZip file class Test

Write and read binary files in Android

由 久未见 提交于 2019-12-05 12:31:59
I created a custom object of type Task and I want to save it in a binary file in internal storage. Here is the class I created: public class Task { private String title; private int year; private int month; private int day; private int hour; private int minute; public Task(String inputTitle, int inputYear, int inputMonth, int inputDay, int inputHour, int inputMinute) { this.title = inputTitle; this.year = inputYear; this.month = inputMonth; this.day = inputDay; this.hour = inputHour; this.minute = inputMinute; } public String getTitle() { return this.title; } public int getYear() { return this

File operations in android Q beta

由 时光毁灭记忆、已成空白 提交于 2019-12-04 15:10:41
1)Target set to Android Q with ""android.permission.WRITE_EXTERNAL_STORAGE"" 2) use getExternalStorageDirectory or getExternalStoragePublicDirectory and FileOutputStream(file) saving file throws java.io.FileNotFoundException: /storage/emulated/0/myfolder/mytext.txt: open failed: ENOENT (No such file or directory) 3) use getExternalFilesDir api and saving is success but wont show up even after MediaScannerConnection.scanFile. /storage/emulated/0/Android/data/my.com.ui/files/Download/myfolder/mytext.txt What is best way to copy file from internal memory to SDCARD in android Q and refresh. In

How to write a file using Intent.ACTION_CREATE_DOCUMENT

由 眉间皱痕 提交于 2019-12-04 06:23:43
问题 In simple words, I want to convert a viewgroup to a jpg image file. As Environment.getExternalStorageDirectory is deprecated, I use this intent Intent.ACTION_CREATE_DOCUMENT private void createFile(String mimeType, String fileName) { Intent intent = new Intent(Intent.ACTION_CREATE_DOCUMENT); intent.addCategory(Intent.CATEGORY_OPENABLE); intent.setType(mimeType); intent.putExtra(Intent.EXTRA_TITLE, fileName); startActivityForResult(intent, WRITE_REQUEST_CODE); } In the onActivityResult(); I
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