Develop Reference

Trying to Continue the program when it returns file not found exception in java

I i am able to read the lines from csv and download the images from url when the url is not having the image it is showing file not found exception in middle of the program i want to continue the program with out terminating.
public static void main(String[] args) throws IOException {
InputStream inputStream = null;
OutputStream outputStream = null;
try {
BufferedReader br = new BufferedReader(new FileReader("D:\\imgdwnld\\file.csv"));
String line = br.readLine();
while ((line = br.readLine()) !=null){
URL url = new URL(line);
inputStream = url.openStream();
outputStream = new FileOutputStream("D:\\imgdwnld\\" +
line.substring(line.lastIndexOf("/")));
byte[] buffer = new byte[2048];
int length;
while ((length = inputStream.read(buffer)) != -1) {
outputStream.write(buffer, 0, length);
}
}
} catch (MalformedURLException e) {
System.out.println("MalformedURLException :- " + e.getMessage());
} catch (FileNotFoundException e) {
System.out.println("FileNotFoundException :- " + e.getMessage());
} catch (IOException e) {
System.out.println("IOException :- " + e.getMessage());
} finally {
try {
inputStream.close();
outputStream.close();
} catch (IOException e) {
System.out.println("Finally IOException :- " + e.getMessage());
}
}
}

This is the relevant outline of your code:
try {
...
while ((line = br.readLine()) !=null) {
... process each CSV line ...
}
} catch (IOException e) {
... handle it ...
}
At the place where you catch the exception you have already broken out of the main loop. Change the code to have this outline:
while ((line = br.readLine()) !=null) {
try {
... process one CSV line ...
} catch (IOException e) {
... handle it, the loop will proceed with the next line
}
}

You need to remove the "return" instruction from the corresponding catch (or maybe from the whole code). In your case, the instruction allows to "exit" the main method so the rest of instruction (those after the return statement) won't be executed.
Another tip is to separate this instructions in blocs. For example, if reading the CSV and the Img are not bound, you may need to encapsulate each treatment in an individual try-catch block. When parsing/reading the CSV file fails, your code may continue fetching the image.

read from csv, delete line based on first portion

In my app I am displaying the first portion of each line of the CSV in a JList, and when it is selected and a button is pressed (delete) I want it to remove that line from the file based on the first entry. I am trying the method where you have a temp file then write to it then rename it at the end but that isnt working out for some reason. Any ideas?
private void jButton4ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
// Delete service
String selected = (String) jList1.getSelectedValue();
File passwords = new File("/users/aak7133/desktop/passwords.txt");
File temp = new File("/users/aak7133/desktop/temp.txt");
try {
BufferedReader reader = new BufferedReader(new FileReader(passwords));
BufferedWriter writer = new BufferedWriter(new FileWriter(temp));
String line;
System.out.println(selected);
while ((line = reader.readLine()) != null) {
// trim newline when comparing with lineToRemove
//String trimmedLine = line.trim();
if (line.contains(selected)) {
continue;
}
writer.write(line);
}
boolean successful = temp.renameTo(passwords);
} catch (Exception e) {
}
updateList();
clearFields();
}

The problem is actually caused by the open reader and writer. This should work:
private void jButton4ActionPerformed(java.awt.event.ActionEvent evt) {
String selected = (String) jList1.getSelectedValue();
BufferedReader reader = null;
BufferedWriter writer = null;
try {
File passwords = new File("/users/aak7133/desktop/passwords.txt");
File temp = File.createTempFile("temp", ".txt", new File("/users/aak7133/desktop/"));
reader = new BufferedReader(new FileReader(passwords));
writer = new BufferedWriter(new FileWriter(temp));
String line;
System.out.println(selected);
while ((line = reader.readLine()) != null) {
// trim newline when comparing with lineToRemove
// String trimmedLine = line.trim();
if (line.contains(selected)) {
continue;
}
writer.write(line + "\n");
}
if (passwords.canWrite()) {
try {
reader.close();
reader = null;
} catch (IOException ignore) {}
try {
writer.close();
writer = null;
} catch (IOException ignore) {}
String path = passwords.getAbsolutePath();
passwords.delete();
boolean successful = temp.renameTo(new File(path));
System.out.println(successful);
}
} catch (Exception e) {
} finally {
if (reader != null) {
try {
reader.close();
} catch (IOException ignore) {}
}
if (writer != null) {
try {
writer.close();
} catch (IOException ignore) {}
}
}
updateList();
clearFields();
}

I figured out I needed to put passwords.delete() before temp.renameTo(passwords). This fixed the issue right away.

Saving to Android Internal Storage

At the moment i'm trying to save a response to the internal storage in the phone. Everything works fine up until i try and retrieve the data again. When i log out the retrieved data it only logs out one small section of the response and the rest isn't there. Ive tried deleting the file and calling it again just incase it was using an old one.
Saving Code
try {
String response = apiResponse.getRawResponse();
Log.e("Response", response);
FileOutputStream userInfo = openFileOutput("personal_profile", MODE_PRIVATE);
userInfo.write(response.getBytes());
userInfo.close();
} catch (Exception e) {
e.printStackTrace();
Retrieving Code
String response = "";
try {
FileInputStream fis = getActivity().openFileInput("personal_profile");
DataInputStream isr = new DataInputStream(fis);
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(isr));
StringBuilder sb = new StringBuilder();
String line;
while ((line = bufferedReader.readLine()) != null) {
sb.append(line);
}
line = response;
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
Log.e("Saved File", response);
Any kind of suggestions would be great!

REASON
The problem was that the line variable is assigned again in every iteration
Try this:
String response = "";
try {
FileInputStream fis = getActivity().openFileInput("personal_profile");
DataInputStream isr = new DataInputStream(fis);
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(isr));
StringBuilder sb = new StringBuilder();
String line;
while ((line = bufferedReader.readLine()) != null) {
sb.append(line);
}
line = response;
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
CHANGE LAST LINE
Log.e("Saved File", sb.toString());

Have you got this in your AndroidManifest.xml file?
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
Also, this link has everything you need to know about reading and writing files:
http://www.anddev.org/working_with_files-t115.html
Code::
String response = "";
try {
FileInputStream fis = getActivity().openFileInput("personal_profile");
DataInputStream isr = new DataInputStream(fis);
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(isr));
StringBuilder sb = new StringBuilder();
String line;
while ((line = bufferedReader.readLine()) != null) {
sb.append(line);
}
line = response;
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
Log.e("Saved File", sb.toString());

How do you read a .txt file in Android?

I am newbie in android development. Today for i was trying to display all my practiced programs of java in my application. I want the application to read the data written in .txt file.
In which folder should I store all my programs? They are more than 100.
I want to display the content of program 2 when I clicked the 2 on the list view or any other
Can we store the text files in database? If so how can I access them ? How can I read them?
Any basic ideas how can I solve this?

You can kept text file in raw / assets folder.
To read them just use this code.
From Assets:
BufferedReader reader = new BufferedReader(
new InputStreamReader(getAssets().open("YourTextFile.txt")));
From Raw:
InputStream inputStream = context.getResources().openRawResource(R.id.yourresoureid);
InputStreamReader inputreader = new InputStreamReader(inputStream)
as you are a java programmer no need to tell how to read data from InputStream, if your really want then tell me I will post the rest of the code.
Saving that huge amount of data in data base is not a good idea.
Example to read data from InputStream
BufferedInputStream bis=new BufferedInputStream(inputstream);
ByteArrayBuffer baf=new ByteArrayBuffer(1000);
while((k=bis.read())!=-1)
{
baf.append((byte)k);
}
String results=new String(baf.toByteArray());

Start with something easy and work up to the database option.
Yes, the answer would be quite long, and I think a tutorial on SQLite would be a place to start on this.
2,1. Try putting your text files in the assets folder and reading them like this. This code reads a file, and dumps it line by line into the log.
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_read);
AssetManager assetManager = getAssets();
try {
BufferedReader br = new BufferedReader(new InputStreamReader(
assetManager.open("hi.txt")));
// InputStream inputStream = assetManager.open("hi.txt");
// BufferedReader br = new BufferedReader(
// new InputStreamReader(inputStream));
String lineIn;
while ((lineIn = br.readLine()) != null) {
Log.d("ReadTheDamnFile", lineIn);
}
assetManager.close();
} catch (IOException e) {
}
}

try this its work fine :)
try
{
if(poslist==0)
{
in = this.getAssets().open("file1.txt");
iv.setBackgroundResource(R.drawable.fileimage1);
}
}
catch (IOException e)
{
e.printStackTrace();
}
try {
reader = new BufferedReader(new InputStreamReader(in,"UTF-8"));
} catch (UnsupportedEncodingException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
String line="";
String s ="";
try
{
line = reader.readLine();
}
catch (IOException e)
{
e.printStackTrace();
}
while (line != null)
{
s = s + line;
s =s+"\n";
try
{
line = reader.readLine();
}
catch (IOException e)
{
e.printStackTrace();
}
}
tv.setText(""+s);
}
public void onClick(View v){
try {
line = reader.readLine();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
if (line != null){
tv.setText(line);
} else {
//you may want to close the file now since there's nothing more to be done here.
}

How can I read a text file in Android?

I want to read the text from a text file. In the code below, an exception occurs (that means it goes to the catch block). I put the text file in the application folder. Where should I put this text file (mani.txt) in order to read it correctly?
try
{
InputStream instream = openFileInput("E:\\test\\src\\com\\test\\mani.txt");
if (instream != null)
{
InputStreamReader inputreader = new InputStreamReader(instream);
BufferedReader buffreader = new BufferedReader(inputreader);
String line,line1 = "";
try
{
while ((line = buffreader.readLine()) != null)
line1+=line;
}catch (Exception e)
{
e.printStackTrace();
}
}
}
catch (Exception e)
{
String error="";
error=e.getMessage();
}

Try this :
I assume your text file is on sd card
//Find the directory for the SD Card using the API
//*Don't* hardcode "/sdcard"
File sdcard = Environment.getExternalStorageDirectory();
//Get the text file
File file = new File(sdcard,"file.txt");
//Read text from file
StringBuilder text = new StringBuilder();
try {
BufferedReader br = new BufferedReader(new FileReader(file));
String line;
while ((line = br.readLine()) != null) {
text.append(line);
text.append('\n');
}
br.close();
}
catch (IOException e) {
//You'll need to add proper error handling here
}
//Find the view by its id
TextView tv = (TextView)findViewById(R.id.text_view);
//Set the text
tv.setText(text.toString());
following links can also help you :
How can I read a text file from the SD card in Android?
How to read text file in Android?
Android read text raw resource file

If you want to read file from sd card. Then following code might be helpful for you.
StringBuilder text = new StringBuilder();
try {
File sdcard = Environment.getExternalStorageDirectory();
File file = new File(sdcard,"testFile.txt");
BufferedReader br = new BufferedReader(new FileReader(file));
String line;
while ((line = br.readLine()) != null) {
text.append(line);
Log.i("Test", "text : "+text+" : end");
text.append('\n');
} }
catch (IOException e) {
e.printStackTrace();
}
finally{
br.close();
}
TextView tv = (TextView)findViewById(R.id.amount);
tv.setText(text.toString()); ////Set the text to text view.
}
}
If you wan to read file from asset folder then
AssetManager am = context.getAssets();
InputStream is = am.open("test.txt");
Or If you wan to read this file from res/raw foldery, where the file will be indexed and is accessible by an id in the R file:
InputStream is = getResources().openRawResource(R.raw.test);
Good example of reading text file from res/raw folder

Put your text file in Asset Folder...& read file form that folder...
see below reference links...
http://www.technotalkative.com/android-read-file-from-assets/
http://sree.cc/google/reading-text-file-from-assets-folder-in-android
Reading a simple text file
hope it will help...

Try this code
public static String pathRoot = "/sdcard/system/temp/";
public static String readFromFile(Context contect, String nameFile) {
String aBuffer = "";
try {
File myFile = new File(pathRoot + nameFile);
FileInputStream fIn = new FileInputStream(myFile);
BufferedReader myReader = new BufferedReader(new InputStreamReader(fIn));
String aDataRow = "";
while ((aDataRow = myReader.readLine()) != null) {
aBuffer += aDataRow;
}
myReader.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return aBuffer;
}

First you store your text file in to raw folder.
private void loadWords() throws IOException {
Log.d(TAG, "Loading words...");
final Resources resources = mHelperContext.getResources();
InputStream inputStream = resources.openRawResource(R.raw.definitions);
BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
try {
String line;
while ((line = reader.readLine()) != null) {
String[] strings = TextUtils.split(line, "-");
if (strings.length < 2)
continue;
long id = addWord(strings[0].trim(), strings[1].trim());
if (id < 0) {
Log.e(TAG, "unable to add word: " + strings[0].trim());
}
}
} finally {
reader.close();
}
Log.d(TAG, "DONE loading words.");
}

Shortest form for small text files (in Kotlin):
val reader = FileReader(path)
val txt = reader.readText()
reader.close()

Try this
try {
reader = new BufferedReader(new InputStreamReader(in,"UTF-8"));
} catch (UnsupportedEncodingException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
String line="";
String s ="";
try
{
line = reader.readLine();
}
catch (IOException e)
{
e.printStackTrace();
}
while (line != null)
{
s = s + line;
s =s+"\n";
try
{
line = reader.readLine();
}
catch (IOException e)
{
e.printStackTrace();
}
}
tv.setText(""+s);
}