I can't seem to understand how to pass a folder to load files from in the classpath. It works with the text file right in the same folder as the .class file or if I use files/test.txt instead of test.txt. What am I doing wrong?
Code:
import java.io.*;
public class T {
public static void main(String[] args) {
String line;
File f = new File("test.txt");
BufferedReader reader = null;
try {
reader = new BufferedReader(new FileReader(f));
while ((line = reader.readLine()) != null) {
System.out.println(line);
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (reader != null) {
reader.close();
}
} catch (IOException e) {
}
}
}
}
Folders and files:
stuff/T.java
stuff/T.class
Somewhere there is a files folder with the test.txt file which I want to give in the classpath.
I am running the test from the stuff folder in the command line in windows using the command java -cp .../files T.
String dirPath = "/Users/you/folder/";
String fileName = "test.txt";
File directory = new File(dirPath);
File file = new File(directory, fileName);
// Read file now
you can use .exists() on any file object to check if it exists or not.
Check if the File is a directory then loop through the contents of the directory if necessary.
public class T {
public static void main(String[] args) {
File f = new File("stuff");
if(f.isDirectory()){
for(File file:f.listFiles()){
printFileName(file);
}
}else{
printFileName(f);
}
}
private static void printFileName(File f) {
String line;
BufferedReader reader = null;
try {
reader = new BufferedReader(new FileReader(f));
while ((line = reader.readLine()) != null) {
System.out.println(line);
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (reader != null) {
reader.close();
}
} catch (IOException e) {
}
}
}
}
If you are unsure of which directory the code is looking for the Files output the current directory.
File file = new File(".");
System.out.println(file.getAbsolutePath());
Related
I have may wifi2.txt file in my assets file directory in Android Studio. However, I keep getting a NULLPointException when I try to access it. My code is below: (Thanks so much in advance)
//CSV FILE READING
File file = null;
try {
FileInputStream is = new FileInputStream(file);
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(getAssets().open("wifi2.txt")));
String line;
Log.e("Reader Stuff",reader.readLine());
while ((line = reader.readLine()) != null) {
Log.e("code",line);
String[] RowData = line.split(",");
LatLng centerXY = new LatLng(Double.valueOf(RowData[1]), Double.valueOf(RowData[2]));
if (RowData.length == 4) {
mMap.addMarker(new MarkerOptions().position(centerXY).title(String.valueOf(RowData[0]) + String.valueOf(RowData[3])).icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_GREEN)));
}
}
} catch (IOException ex) {
ex.printStackTrace();
} finally {
try {
is.close();
} catch (IOException e) {
e.printStackTrace();
}
}
} catch (FileNotFoundException e) {
e.printStackTrace();
}
//Done with CSV File Reading
In Kotlin, we can achieve this :-
val string = requireContext().assets.open("wifi2.txt").bufferedReader().use {
it.readText()
}
File file = null;
try {
FileInputStream is = new FileInputStream(file);
Actually you are not using FileInputStream anywhere. Just use this piece of code
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(getAssets().open("wifi2.txt")));
String line;
Log.e("Reader Stuff",reader.readLine());
while ((line = reader.readLine()) != null) {
Log.e("code",line);
String[] RowData = line.split(",");
LatLng centerXY = new LatLng(Double.valueOf(RowData[1]), Double.valueOf(RowData[2]));
if (RowData.length == 4) {
mMap.addMarker(new MarkerOptions().position(centerXY).title(String.valueOf(RowData[0]) + String.valueOf(RowData[3])).icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_GREEN)));
}
}
} catch (IOException ex) {
ex.printStackTrace();
}
Method to read a file FROM assets:
public static String readFile(AssetManager mgr, String path) {
String contents = "";
InputStream is = null;
BufferedReader reader = null;
try {
is = mgr.open(path);
reader = new BufferedReader(new InputStreamReader(is));
contents = reader.readLine();
String line = null;
while ((line = reader.readLine()) != null) {
contents += '\n' + line;
}
} catch (final Exception e) {
e.printStackTrace();
} finally {
if (is != null) {
try {
is.close();
} catch (IOException ignored) {
}
}
if (reader != null) {
try {
reader.close();
} catch (IOException ignored) {
}
}
}
return contents;
}
Usage: String yourData = LoadData("wifi2.txt");
Where wifi2.txt is assumed to reside in assets
public String LoadData(String inFile) {
String tContents = "";
try {
InputStream stream = getAssets().open(inFile);
int size = stream.available();
byte[] buffer = new byte[size];
stream.read(buffer);
stream.close();
tContents = new String(buffer);
} catch (IOException e) {
// Handle exceptions here
}
return tContents;
}
Reference
My solution using kotlin to load text from asset file
object AssetsLoader {
fun loadTextFromAsset(context: Context, file: String): String {
return context.assets.open(file).bufferedReader().use { reader ->
reader.readText()
}
}
}
use it like this:
val text = AssetsLoader.loadTextFromAsset(context, "test.json")
I need to open and read a downloaded file using selenium and I'm not quite sure how to do it. I see answers that suggests to download the file in a selected location. Does my code really need to start from downloading the file to selected location or can it start directly after downloading?
After opening the file I must also read it. Can anyone give me an idea on how to do this? Thank you!
You can read file using following code :
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
public class ReadFileExample1 {
private static final String FILENAME = "E:\\test\\filename.txt";
public static void main(String[] args) {
BufferedReader br = null;
FileReader fr = null;
try {
fr = new FileReader(FILENAME);
br = new BufferedReader(fr);
String sCurrentLine;
br = new BufferedReader(new FileReader(FILENAME));
while ((sCurrentLine = br.readLine()) != null) {
System.out.println(sCurrentLine);
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (br != null)
br.close();
if (fr != null)
fr.close();
} catch (IOException ex) {
ex.printStackTrace();
}
}
}
}
Hope it will help you.
You can use this line of code to handel download a file from chrome and forefox browser.
public static File waitForDownloadToComplete(File downloadPath, String fileName) throws Exception {
boolean isFileFound = false;
int waitCounter = 0;
while (!isFileFound) {
logger.info("Waiting For Download To Complete....");
for (File tempFile : downloadPath.listFiles()) {
if (tempFile.getName().contains(fileName)) {
String tempEx = FilenameUtils.getExtension(tempFile.getName());
// crdownload - For Chrome, part - For Firefox
if (tempEx.equalsIgnoreCase("crdownload") || tempEx.equalsIgnoreCase("part")) {
Thread.sleep(1000);
} else {
isFileFound = true;
logger.info("Download To Completed....");
return tempFile;
}
}
}
Thread.sleep(1000);
waitCounter++;
if (waitCounter > 25) {
isFileFound = true;
}
}
throw new Exception("File Not Downloaded");
}
}
Am using nio2 to read the external file in my desktop using eclipse. I am getting the exception for the following code.
"java.nio.file.NoSuchFileException: C:\Users\User\Desktop\JEE\FirstFolder\first.txt"
Kindly advise how to resolve it? Tried using command prompt also. Getting the same exception.
public class ReadingExternalFile {
public static void main(String[] args) {
Path p1= Paths.get("C:\\Users\\User\\Desktop\\FirstFolder\\first.txt");
System.out.println(p1.toString());
System.out.println(p1.getRoot());
try(InputStream in = Files.newInputStream(p1);
BufferedReader reader = new BufferedReader(new InputStreamReader(in)))
{
System.out.println("Inside try");
String line=null;
while((line=reader.readLine())!=null){
if (!line.equals("")) {
System.out.println(line);
}
//System.out.println(line);
}
} catch (IOException e) {
System.out.println( e);
}
}
}
I dont understand why you are using a Path object, you can simply make the file using the File object and just using the string as the path, and then wraping it in a file reader object then wrapping that in a buffered reader, the end should look something like this:
public static void main(String[] args) {
try {
File file = new File("C:\\Users\\User\\Desktop\\FirstFolder\\first.txt");
FileReader fr = new FileReader(file);
BufferedReader bfr = new BufferedReader(fr);
System.out.println(bfr.readLine());
bfr.close();
} catch (IOException e){
e.printStackTrace();
}
}
don't forget to close your streams after reading and writing, also use readable names (don't do what I've done, use meaningful names!)
Try below code hope this will help you.
Path p1= Paths.get("C:\\Users\\user\\Desktop\\FirstFolder\\first.txt");
try(
BufferedReader reader = Files.newBufferedReader(p1, Charset.defaultCharset()))
{
System.out.println("Inside try");
String line=null;
while((line=reader.readLine())!=null){
if (!line.equals("")) {
System.out.println(line);
}
//System.out.println(line);
}
} catch (IOException e) {
System.out.println( e);
}
Try this.
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
public class BufferedReaderExample {
public static void main(String[] args) {
BufferedReader br = null;
try {
String sCurrentLine;
br = new BufferedReader(new FileReader("C:\\Users\\User\\Desktop\\FirstFolder\\first.txt"));
while ((sCurrentLine = br.readLine()) != null) {
System.out.println(sCurrentLine);
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (br != null)br.close();
} catch (IOException ex) {
ex.printStackTrace();
}
}
}
}
public static void main(String[] args) {
try {
File file = new File("C:\\Users\\User\\Desktop\\FirstFolder\\first.txt");
FileReader freader = new FileReader(file);
BufferedReader bufreader = new BufferedReader(freader);
System.out.println(bufreader.readLine());
bufreader.close();
} catch (IOException e){
e.printStackTrace();
}
}
I used following method to write data to a file in one android application
private void writeFileToInternalStorage() {
String eol = System.getProperty("line.separator");
BufferedWriter writer = null;
try{
writer = new BufferedWriter(new OutputStreamWriter(openFileOutput("myFile.txt", MODE_WORLD_WRITEABLE|MODE_WORLD_READABLE)));
writer.write("Hello world!");
}
catch (Exception e)
{
e.printStackTrace();
}
finally
{
if (writer != null)
{
try
{
writer.close();
}
catch (IOException e)
{
e.printStackTrace();
}
}
}
}
Then I tried to read that file from another android application using this method
private void readFileFromInternalStorage(){
String eol = System.getProperty("line.separator");
BufferedReader input = null;
try
{
input = new BufferedReader(new InputStreamReader(openFileInput("myFile1.txt")));
String line;
StringBuffer buffer = new StringBuffer();
while ((line = input.readLine()) != null)
{
buffer.append(line + eol);
}
TextView tv = (TextView) findViewById(R.id.textView);
tv.setText(buffer.toString().trim());
}
catch (Exception e)
{
e.printStackTrace();
}
finally
{
if (input != null)
{
try
{
input.close();
}
catch (IOException e)
{
e.printStackTrace();
}
}
}
}
Second method can't read the file. I added read write permissions also, but it shows only blank screen. What can be the error and how can I correct that ??. I'm new to Android programming and need your help.
Thanks!
The problem is
openFileOutput("myFile.txt", MODE_WORLD_WRITEABLE|MODE_WORLD_READABLE))
The documentation says:
This file is written to a path relative to your app within the
So the case is you are writing file in path relative to application 1 and trying to read it from
path relative to application 2.
You should be able to call Environment.getExternalStorageDirectory() to get the root path to the SD card and use that to create a FileOutputStream. From there, just use the standard java.io routines.
Look below snippet to write file to SD card.
private void writeToSDCard() {
try
{
File file = new File(Environment.getExternalStorageDirectory(),
"filename");
BufferedWriter writer = new BufferedWriter(new FileWriter(file));
writer.write("Hello World");
writer.close();
} catch (IOException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
}
Look below snippet to read file saved on SD card.
private void readFileFromSDCard() {
File directory = Environment.getExternalStorageDirectory();
// Assumes that a file article.rss is available on the SD card
File file = new File(directory + "/article.rss");
if (!file.exists()) {
throw new RuntimeException("File not found");
}
Log.e("Testing", "Starting to read");
BufferedReader reader = null;
try {
reader = new BufferedReader(new FileReader(file));
StringBuilder builder = new StringBuilder();
String line;
while ((line = reader.readLine()) != null) {
builder.append(line);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
if (reader != null) {
try {
reader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
Your best bet is to place it into the scdcard into something like /sdcard/Android/data/package/shared/
I have a list of files in the directory C:\Users\Mahady\Desktop\Java 31122011\src\register\
they are like this....
100100545.txt
100545454.txt etc etc
in each file, file data are like this line by line:
Bob
1234
4834
London
9852
1
My question is, how do i read each files one by one in the directory and for each files read all lines except line 3. i would then like to merge this data in word and create letters. thanks
Detailed Answer....
import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
public class FileRead {
public static void main(String[] args) {
FileReader fileReader = null;
BufferedReader bufferedReader = null;
try {
File folder = new File("C:/Users/Mahady/Desktop/Java 31122011/src/register/");
if (folder.isDirectory()) {
for (File file : folder.listFiles()) {
fileReader = new FileReader(file);
bufferedReader = new BufferedReader(fileReader);
String line = null;
int lineCount = 0;
while (null != (line = bufferedReader.readLine())) {
lineCount++;
if (3 != lineCount) {
System.out.println(line);
}
}
}
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
if (null != bufferedReader)
try {
bufferedReader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
Hope this would help you.
Try this:
File dir = new File("C:\\Users\\Mahady\\Desktop\\Java 31122011\\src\\register\\");
for (string fn : dir.list()) {
FileInputStream fstream = new FileInputStream(fn);
DataInputStream in = new DataInputStream(fstream);
BufferedReader br = new BufferedReader(new InputStreamReader(in));
String strLine;
while ((strLine = br.readLine()) != null) {
System.out.println (strLine);
}
in.close();
}
Obviously, you will need to add exception handling code around this skeletal implementation.