Develop Reference

FileNotFoundException but File present at right path

I'm new to programming, every time I try to read a file. I get FileNOtFoundException.
Where could I be going wrong?
import java.io.*;
import java.util.Scanner;
public class ReadFile
{
public ReadFile()
{
readFile();
}
public void readFile()
{
String filename = "trees.txt";
System.out.println(new File(".").getAbsolutePath()); //file is at this path.
String name = "";
try
{
FileReader inputFile = new FileReader(filename);
Scanner parser = new Scanner(inputFile);
while (parser.hasNextLine())
{
name = parser.nextLine();
System.out.println(name);
}
inputFile.close();
}
catch (FileNotFoundException exception)
{
System.out.println(filename + " not found");
}
}
}
Is there any other way I could read the file?

this code
FileReader inputFile = new FileReader(filename);
You must define full path to file with name filename if not it will open file not at current working directory
you should try
FileReader inputFile = new FileReader(new File(new File("."), filename));
// defind new File(".") it mean you will you open file in current working directory
you can read more at: Java, reading a file from current directory?

Try printing the path of the file you are actually trying to open so you can be sure that the file exists in the right location
String filename = "trees.txt";
File file = new File(filename);
System.out.println(file.getAbsolutePath());
Also, you are closing the FileReader inside the try, and not closing the Scanner, if some error ever occurs those resources will never be closed, you need to put those close statements in a finally block, or better use try with resources

Error reading a txt file

I am getting this error in my code when trying to read a file saved on the external storage of my phone :
java.io.FileNotFoundException: shopping.txt: open failed: ENOENT (No such file or directory)
I can manage to write data to this file with success, what I did a lot of times.
However, I cannot access for reading this same file, giving the entire path or through another method.
The code writing and saving successfully :
File path = new File(this.getFilesDir().getPath());
String value = "vegetables";
// File output = new File(path + File.separator + fileName);
File output = new File(getApplicationContext().getExternalFilesDir(null),"shopping.txt");
try {
FileOutputStream fileout = new FileOutputStream(output.getAbsolutePath());
OutputStreamWriter outputWriter=new OutputStreamWriter(fileout);
outputWriter.write(value);
outputWriter.close();
//display file saved message
// Toast.makeText(getBaseContext(), "File saved successfully!",
// Toast.LENGTH_LONG).show();
Toast.makeText(MainActivity.this,String.valueOf(output),Toast.LENGTH_LONG).show();
Log.d("MainActivity", "Chemin fichier = [" + output + "]");
}
catch (IOException e) {
Log.e("Exception", "File write failed: " + e.toString());
}
}
The writing piece of code crashing my app :
try
{
File gFile;
FileInputStream fis = new FileInputStream (new File("shopping.txt"));
//FileInputStream fis = openFileInput("/storage/emulated/0/Android/data/com.example.namour.shoppinglist/files/shopping.txt");
BufferedReader reader = new BufferedReader(new InputStreamReader(fis));
String line = null, input="";
while ((line = reader.readLine()) != null)
input += line;
Toast.makeText(MainActivity.this,line,Toast.LENGTH_LONG).show();
reader.close();
fis.close();
Toast.makeText(MainActivity.this,"Read successful",Toast.LENGTH_LONG).show();
//return input;
}
catch (IOException e)
{
Log.e("Exception", "File read failed: " + e.toString());
//toast("Error loading file: " + ex.getLocalizedMessage());
}
What am I doing wrong ?
For sure, not a problem of permissions, since I can write with success.
Many thanks for your help.

You missed to specifiy the correct path. You are looking for a file named shopping.txt in your current working directory (at runtime).
Create a new File object with the correct path and it will work:
File input = new File(getApplicationContext().getExternalFilesDir(null),"shopping.txt");. You could reuse your object from writing.

While opening the file, you are simply using new File("shopping.txt").
You need to specify the parent folder, like this:
new File(getExternalFilesDir(),"shopping.txt");

I recommend you make sure of org.apache.commons.io for IO, their FileUtils and FileNameUtils libs are great. ie: FileUtils.writeStringToFile(new File(path), data); Add this to gradle if you wish to use it: implementation 'org.apache.commons:commons-collections4:4.1'
In regards to your problem. When you write your file you are using:
getApplicationContext().getExternalFilesDir(null),"shopping.txt"
But when reading your file you are using:
FileInputStream fis = new FileInputStream (new File("shopping.txt"));
Notice that you didn't specify a path to shopping.txt simply the file name.
Why not do something like this instead:
//Get path to directory of your choice
public String GetStorageDirectoryPath()
{
String envPath = Environment.getExternalStorageDirectory().toString();
String path = FilenameUtils.concat(envPath, "WhateverDirYouWish");
return path;
}
//Concat filename with path
public String GetFilenameFullPath(String fileName){
return FilenameUtils.concat(GetStorageDirectoryPath(), fileName);
}
//Write
String fullFilePath = GetFilenameFullPath("shopping.txt");
FileUtils.writeStringToFile(new File(fullFilePath ), data);
//Read
File file = new File(fullFilePath);
StringBuilder text = new StringBuilder();
BufferedReader br = new BufferedReader(new FileReader(file));
String line;
while ((line = br.readLine()) != null){
text.append(line);
if(newLine)
text.append(System.getProperty("line.separator"));
}
br.close();

Always getting FileNotFoundException in java

I am using Scanner to read the File contents. For that I am using the following code.
public static void main (String[] args) throws IOException {
File file = new File("/File.txt");
Scanner sc = new Scanner(file);
while(sc.hasNextLine()) {
// Until the end
System.out.print(sc.nextLine());
}
sc.close();
}
But this code always throws FileNotFoundException. I have tried Googling this, but I can't find where to check the file. Secondly, I have created files with same name in almost every directory to check when would the Code catch the presence of file.
You can see in the Package I have created a file named File.txt so that code can find it whereever it looks for.
In the Java docs, I get to know that the File accepts a String parameter as
File file = new File("file_name");
But what sort or what would be the param here, isn't told. Can I get the help?

I think you want File file = new File("File.txt"); instead of File file = new File("/File.txt");, get rid of the slash. If what you want is a relative path, you want .\File.txt
As #deterministicFail says in the comments, it is not a good idea to hardcode path separators, instead use System.getProperty("path.separator"); This way your code should work in multiple plataforms, so your code would be:
To make it plataform independent (Asuming you are using a relative path):
File file = new File("." + System.getProperty("path.separator") + "File.txt");

Replace the line
File file = new File("/File.txt");
with
File file = new File(".\\File.txt");
or
File file = new File("File.txt");

File f=new File("testFile.txt");
For this kind of referral you need to put file in root of your eclipse project (In parallel of src). This problem is only when you are Using Eclipse IDE.
Best solution for this kind of problems is checking AbsolutePath of the file
System.out.println(f.getAbsolutePath());
It will give you path where your code is looking for file.

There are two possibilities if you are looking for the file in the working directory then either use "File.txt" or "./File.txt". In case of windows one more option would be to use ".\File.txt).
If that is not what you are looking for, you can check which path the file refers to using either of the two sysouts immediately after instantiating the file, which will give you the absolute path on your machine.
File f = new File("/File.txt");
System.out.println(f.getAbsolutePath());
System.out.println(f.getAbsoluteFile().getAbsolutePath());

I have never done it the way you did but this is how I read files.
This is the purpose of the class FileInpuStream. I use a buffer to get bytes.
If it is only a problem of path, why don't you simply use the complete path ? You can copy paste it from the file information.
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
public class Main {
public static void main(String[] args) {
FileInputStream fis = null;
try {
// object I use to read files
fis = new FileInputStream(new File("File.txt"));
byte[] buf = new byte[8];
int n = 0;
// while there is something in the file
while ((n = fis.read(buf)) >= 0) {
for (byte bit : buf) {
// do what you want
System.out.print("\t" + bit + "(" + (char) bit + ")");
System.out.println("");
}
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
try {
if (fis != null)
fis.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}

Try not to use the / in File.txt, and if you really have to, use the backslash instead \ since you're in Windows

Corrupted docx generated using zipping

Let me just start out by saying I created an account on here because I've been beating my head against a wall in order to try and figure this out, so here it goes.
Also, I have already seen this question here. Neither one of those answers have helped and I have tried both of them.
I need to create a word document with a simple table and data inside. I decided to create a sample document in which to get the xml that I need to create the document. I moved all the folders from the unzipped docx file into my assets folder. Once I realized I couldn't write to the assets folder, I wrote a method to copy all the files and folders over to an external storage location of the device and then write the document I created to the same location. From there Im trying to zip the files back up to a .docx file. This is where things arent working.
The actual docx file is created and I can move it to my computer through the DDMS but when I go to view it Word says its corrupt. Heres whats weird though, if I unzip it and then rezip it on my computer without making any changes what so ever it works perfectly. I have used a program (for mac) called DiffMerge to compare the sample unzipped docx file to the unzipped docx that I have created and it says they are exactly the same. So, I think it has something to do with the zipping process in Android.
I have also tried unzipping the sample docx file on my computer, moving all the files and folders over to my assets folder including the document.xml file and just try to zip it up without adding my own document.xml file and using the sample one and that doesnt work either. Another thing I tried was to place the actual docx file in my assets folder, unzipping it onto my external storage and then rezipping it without doing anything. This also fails.
I'm basically at a loss. Please somebody help me figure this out.
Here is some of my code:
moveDocxFoldersFromAssetsToExternalStorage() is called first.
After that is called all the files have been moved over.
Then, I create the document.xml file and place it in the word directory where it belongs
Everything is where it should be and I now try to create the zip file.
.
private boolean moveDocxFoldersFromAssetsToExternalStorage(){
File rootDir = new File(this.externalPath);
rootDir.mkdir();
copy("");
// This is to get around a glitch in Android which doesnt list files or folders
// with an underscore at the beginning of the name in the assets folder.
// This renames them once they are saved to the device.
// We need it to show up in the list in order to move them.
File relsDir = new File(this.externalPath + "/word/rels");
File renameDir = new File(this.externalPath + "/word/_rels");
relsDir.renameTo(renameDir);
relsDir = new File(this.externalPath + "/rels");
renameDir = new File(this.externalPath + "/_rels");
relsDir.renameTo(renameDir);
// This is to get around a glitch in Android which doesnt list hidden files.
// We need it to show up in the list in order to move it.
relsDir = new File(this.externalPath + "/_rels/rels.rename");
renameDir = new File(this.externalPath + "/_rels/.rels");
relsDir.renameTo(renameDir);
return true;
}
private void copy(String outFileRelativePath){
String files[] = null;
try {
files = this.mAssetManager.list(ASSETS_RELATIVE_PATH + outFileRelativePath);
} catch (IOException e) {
e.printStackTrace();
}
String assetFilePath = null;
for(String fileName : files){
if(!fileName.contains(".")){
String outFile = outFileRelativePath + java.io.File.separator + fileName;
copy(outFile);
} else {
File createFile = new File(this.externalPath + java.io.File.separator + outFileRelativePath);
createFile.mkdir();
File file = new File(createFile, fileName);
assetFilePath =
ASSETS_RELATIVE_PATH + outFileRelativePath + java.io.File.separator + fileName;
InputStream in = null;
OutputStream out = null;
try {
in = this.mAssetManager.open(assetFilePath);
out = new FileOutputStream(file);
copyFile(in, out);
in.close();
out.flush();
out.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
private void copyFile(InputStream in, OutputStream out) throws IOException {
byte[] buffer = new byte[1024];
int read;
while((read = in.read(buffer)) != -1){
out.write(buffer, 0, read);
}
}
private void zipFolder(String srcFolder, String destZipFile) throws Exception{
FileOutputStream fileWriter = new FileOutputStream(destZipFile);
ZipOutputStream zip = new ZipOutputStream(fileWriter);
zip.setMethod(Deflater.DEFLATED);
zip.setLevel(ZipOutputStream.STORED);
addFolderToZip(this.externalPath, "", zip);
zip.finish();
zip.close();
}
private void addFolderToZip(String externalPath, String folder, ZipOutputStream zip){
File file = new File(externalPath);
String files[] = file.list();
for(String fileName : files){
try {
File currentFile = new File(externalPath, fileName);
if(currentFile.isDirectory()){
String outFile = externalPath + java.io.File.separator + fileName;
addFolderToZip(outFile, folder + java.io.File.separator + fileName, zip);
} else {
byte[] buffer = new byte[8000];
int len;
FileInputStream in = new FileInputStream(currentFile);
zip.putNextEntry(new ZipEntry(folder + java.io.File.separator + fileName));
while((len = in.read(buffer)) > 0){
zip.write(buffer, 0, len);
}
zip.closeEntry();
in.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
EDIT
Here is the code I wrote in order to get it working correctly based on what #edi9999 said below. I created a separate class that Im going to expand and add to and probably clean up a bit but this is working code. It adds all the files in a directory to the zip file and recursively calls itself to add all the subfiles and folders.
private class Zip {
private ZipOutputStream mZipOutputStream;
private String pathToZipDestination;
private String pathToFilesToZip;
public Zip(String pathToZipDestination, String pathToFilesToZip) {
this.pathToZipDestination = pathToZipDestination;
this.pathToFilesToZip = pathToFilesToZip;
}
public void zipFiles() throws Exception{
FileOutputStream fileWriter = new FileOutputStream(pathToZipDestination);
this.mZipOutputStream = new ZipOutputStream(fileWriter);
this.mZipOutputStream.setMethod(Deflater.DEFLATED);
this.mZipOutputStream.setLevel(8);
AddFilesToZip("");
this.mZipOutputStream.finish();
this.mZipOutputStream.close();
}
private void AddFilesToZip(String folder){
File mFile = new File(pathToFilesToZip + java.io.File.separator + folder);
String mFiles[] = mFile.list();
for(String fileName : mFiles){
File currentFile;
if(folder != "")
currentFile = new File(pathToFilesToZip, folder + java.io.File.separator + fileName);
else
currentFile = new File(pathToFilesToZip, fileName);
if(currentFile.isDirectory()){
if(folder != "")
AddFilesToZip(folder + java.io.File.separator + currentFile.getName());
else
AddFilesToZip(currentFile.getName());
} else {
try{
byte[] buffer = new byte[8000];
int len;
FileInputStream in = new FileInputStream(currentFile);
if(folder != ""){
mZipOutputStream.putNextEntry(new ZipEntry(folder + java.io.File.separator + fileName));
} else {
mZipOutputStream.putNextEntry(new ZipEntry(fileName));
}
while((len = in.read(buffer)) > 0){
mZipOutputStream.write(buffer, 0, len);
}
mZipOutputStream.closeEntry();
in.close();
} catch (IOException e){
e.printStackTrace();
}
}
}
}
}

I think I've got what's wrong.
When I opened your corrupted File, and opened it on winrar, I saw antislashes at the beginning of the folders, which is unusual:
When I rezip the file after unzipping it, the antislashes are not there anymore and the file opens in Word so I think it should be the issue.
I think the code is wrong here:
String outFile = externalPath + java.io.File.separator + fileName;
should be
if (externalPath=="")
String outFile = externalPath + fileName;
else
String outFile = externalPath + java.io.File.separator + fileName;

File handling in java

I have the below code.
The below source code is from the file x.java. The hi.html is present in the same directory as x.java.
I get a file not found exception even though the file is present. Am I missing something ?
public void sendStaticResource() throws IOException{
byte[] bytes = new byte[1024];
FileInputStream fis = null;
try{
File file = new File("hi.html");
boolean p = file.exists();
int i = fis.available();
fis = new FileInputStream(file);
int ch = fis.read(bytes, 0, 1024);
while(ch!=-1){
output.write(bytes, 0, ch);
ch = fis.read(bytes, 0, 1024);
}
}catch(Exception e){
String errorMessage = "file not found";
output.write(errorMessage.getBytes());
}finally {
if(fis != null){
fis.close();
}
}
}

The directory of the .java file is not necessarily the direction your code runs in! You can check the current working dir of your program by in example:
System.out.println( System.getProperty( "user.dir" ) );
You could use the System.getProperty( "user.dir" ) string to make your relative filename an absolute one! Just prefix it to your filename :)

Take a look at your "user.dir" property.
String curDir = System.getProperty("user.dir");
That's where the program will root its search for files that don't have a complete path.

Catch the FileNotFoundException before catching Exception so as to be sure that is the real Exception type.
Since you don't give an absolute location for a file it searches from your working directory. You can store the absolute path in a property file and use that instead or use System.getProperty("user.dir") to return the directory that you are running the Java app from.
Code to get Key-Value from Property files
private void getPropertyFileValues() {
String currentPath = System.getProperty("user.dir") + System.getProperty("file.separator") + "Loader.properties";
FileInputStream fis = null;
try {
fis = new FileInputStream(currentPath);
} catch (FileNotFoundException ex) {
ex.printStackTrace();
}
Properties props = new Properties();
try {
props.load(fis);
} catch (IOException ex) {
ex.printStackTrace();
}
String filePath= props.getProperty("FILE_PATH");
try {
fis.close();
} catch (IOException ex) {
ex.printStackTrace();
}
}

I guess you get a NullPointerException:
FileInputStream fis = null;
then the call:
int i = fis.available();
will result in an NullPointerException as the first non-null assignment to fis is later:
fis = new FileInputStream(file);

File Handling in Java:
Use File class for Representing and manipulating file or folder/directory.
you can use constructor :
ex. File file = new File("path/file_name.txt");
or
File file = new File("Path","file_name");
File representation example:
import java.io.File;
import java.util.Date;
import java.io.*;
import java.util.*;
public class FileRepresentation {
public static void main(String[] args) {
File f =new File("path/file_name.txt");
if(f.exists()){
System.out.println("Name " + f.getName());
System.out.println("Absolute path: " +f.getAbsolutePath());
System.out.println("Is writable " +f.canWrite());
System.out.println("Is readable " + f.canRead());
System.out.println("Is File " + f.isFile());
System.out.println("Is Directory " + f.isDirectory());
System.out.println("Last Modified at " + new Date(f.lastModified()));
System.out.println("Length " + f.length() +"bytes long.");
}//if
}//main
}//class

Write data character by character, into Text file by Java:
use FileWriter Class-
import java.io.FileWriter;
import java.io.PrintWriter;
import java.io.Writer;
public class WriteFile {
public static void main(String[] args) throws Exception{
//File writer takes chars and convert into bytes and write to a file
FileWriter writer = new FileWriter("path/file_name.txt");
//if file not exits then created it, else override data
writer.write('A');
writer.write('E');
writer.write('I');
writer.write('O');
writer.write('U');
writer.close();
System.out.println("Successfully Written");
}
}