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Why can't I open this file in the assets folder? [duplicate]

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")

How can I save an ArrayList<MyObject> to a file?

How can I save an ArrayList to a file?
What am I doing wrong?
I have used this SO question to help me with Serializable objects.:
how to serialize ArrayList on android
and I used this SO question on how to write an array list:
Java - How Can I Write My ArrayList to a file, and Read (load) that file to the original ArrayList?
However when I attempt to write the to the file I get the error:
java.io.NotSerializableException: at
java.io.ObjectOutputStream.writeObject at
com.mycompany.MyClass.saveData
Here is MyClass that attempts to save the file
private ArrayList < MyCustomObject > arrayList;
private File dataFile;
private String FILE_NAME = "FILE_DATA.dat";
public void init(final Context context) {
this.appContext = context;
dataFile = new File(appContext.getFilesDir(), FILE_NAME);
if (dataFile.exists()) {
loadData();
} else {
try {
dataFile.createNewFile();
} catch (IOException e) {
e.printStackTrace();
}
arrayList = new ArrayList < MyCustomObject > ();
saveData();
}
}
private void saveData() {
FileOutputStream fos = null;
try {
fos = new FileOutputStream(dataFile);
} catch (FileNotFoundException e) {
e.printStackTrace();
} finally {
if (fos != null) {
ObjectOutputStream oos = null;
try {
oos = new ObjectOutputStream(fos);
if (oos != null) {
oos.writeObject(arrayList);
}
assert oos != null;
oos.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
private void loadData() {
FileInputStream fis = null;
try {
fis = new FileInputStream(dataFile);
} catch (FileNotFoundException e) {
e.printStackTrace();
} finally {
if (fis != null) {
ObjectInputStream ois = null;
try {
ois = new ObjectInputStream(fis);
if (ois != null) {
try {
arrayList = (ArrayList < MyCustomObject > ) ois.readObject();
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
} else {
}
assert ois != null;
ois.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
Here is MyCustomObject
public class MyCustomObject implements Serializable {
public String myname = "";
public String someOtherItem = "";
public int aNumber = 0;
public MyCustomObject getCustomObject() {
return this;
}
}

Replace this method
public MyCustomObject MyCustomObject() {
return this;
}
in your MyCustomObject class and your code should work fine. Use something like
public MyCustomObject getMyCustomObject() {
return this;
}
Because the way you name your method is conflicting wit the default constructor that java creates for MyCustomObject class when you do not provide a constructor yourself. I assume that you are using this method to be able to add an instance of MyCustomObject to your array list: you don't really need such a method but with the proper naming you can still use it.
You should also put sample datas in your ArrayList before saving it to the disk by calling the saveData() method.
Here is an illustration from your code that works. I am not sure what your Context object is exactly but your are using it to get access to the file path, so to get things going I just used a particular file path.
public class MyClass {
private ArrayList < MyCustomObject > arrayList;
private File dataFile;
private String FILE_NAME = "FILE_DATA.dat";
public void init(final Context context) {
dataFile = new File("C:\\lompo\\file1.txt");
if (dataFile.exists()) {
loadData();
} else {
try {
dataFile.createNewFile();
} catch (IOException e) {
e.printStackTrace();
}
arrayList = new ArrayList < MyCustomObject > ();
MyCustomObject obj1 = new MyCustomObject();
obj1.aNumber = 125;
obj1.myname = "HIS NAME";
arrayList.add(obj1);
saveData();
}
}
public static void main(String[] args) {
MyClass myClazz = new MyClass();
myClazz.init(null);
System.out.println("Arraylist has " + myClazz.arrayList.size() + " elements");
}
private void saveData() {
FileOutputStream fos = null;
try {
fos = new FileOutputStream(dataFile);
} catch (FileNotFoundException e) {
e.printStackTrace();
} finally {
if (fos != null) {
ObjectOutputStream oos = null;
try {
oos = new ObjectOutputStream(fos);
if (oos != null) {
oos.writeObject(arrayList);
}
assert oos != null;
oos.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
private void loadData() {
FileInputStream fis = null;
try {
fis = new FileInputStream(dataFile);
} catch (FileNotFoundException e) {
e.printStackTrace();
} finally {
if (fis != null) {
ObjectInputStream ois = null;
try {
ois = new ObjectInputStream(fis);
if (ois != null) {
try {
arrayList = (ArrayList < MyCustomObject > ) ois.readObject();
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
} else {
}
assert ois != null;
ois.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
}
As you can see in the code, the first run of the main method will save the file on disk with an arrayList populated by one object. The second run reads from the file and then I printed the number of elements and the infos that I have saved before: the picture illustrates the result

Read and Write text file from my own class in Android Studio

I have been trying to create a class called TextFileReaderWriter I want to use the getters and setters to read and write to a text file in such a way that I can call the class and the method from anywhere in the program by simply using setfileContents(somestring) and somestring = getfileContents() something like this
example:
TextFileReaderWriter trw = new TextFileReaderWriter();
trw.setfileContents(somestring); //this would write 'somestring' to the text file.
String somestring = trw.getfileContents(); //this would return 'somestring' from the text file.
Here's what I have so far but it writes nothing to the file:
public class TextFileReaderWriter extends Activity{
String fileContents;
Context context;
String TAG = "MYTAG";
public TextFileReaderWriter(String fileContents, Context context) {
this.fileContents = fileContents;
this.context = context;
}
public String getFileContents() {
return fileContents;
}
public void setFileContents(String fileContents) {
this.fileContents = fileContents;
FileOutputStream fos = null;
try {
fos = context.openFileOutput("UserInputStore", Context.MODE_PRIVATE);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
OutputStreamWriter osw = new OutputStreamWriter(fos);
try {
osw.write(fileContents);
Log.d(TAG, fileContents);
} catch (IOException e) {
e.printStackTrace();
}
}
}

You don't need the OutputStreamWriter--FileOutputStreamwill do the trick just fine.
//what you had before
FileOutputStream fos = null;
try {
fos = context.openFileOutput(filename, Context.MODE_PRIVATE);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
//use just the file output stream to write the data
//data here is a String
if (fos != null) {
try {
fos.write(data.getBytes());
fos.close();
} catch (IOException e) {
e.printStackTrace();
}
}

Method to save data on disk :
protected static void saveDataOnDisk(String data) {
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
try {
ObjectOutput objectOutput = new ObjectOutputStream(byteArrayOutputStream);
objectOutput.writeObject(data);
byte[] buffer = byteArrayOutputStream.toByteArray();
File loginDataFile = (new File(filePath)); // file path where you want to write your data
loginDataFile.createNewFile();
FileOutputStream fileOutputStream = new FileOutputStream(loginDataFile);
fileOutputStream.write(buffer);
fileOutputStream.close();
objectOutput.flush();
objectOutput.close();
byteArrayOutputStream.flush();
byteArrayOutputStream.close();
Log.i(“SAVE”, ”———————-DONE SAVING”);
} catch(IOException ioe) {
Log.i(“SAVE”, “———serializeObject|”+ioe);
}
}
Method to fetch data from disk:
private static Object getDataFromDisk() {
try {
FileInputStream fileInputeStream = new FileInputStream(FilePath);
ObjectInputStream objectInputStream = new ObjectInputStream(fileInputeStream);
Object data = (Object) objectInputStream.readObject();
objectInputStream.close();
fileInputeStream.close();
return dataModel;
} catch (Exception error) {
Log.i(“FETCH”, ”—-getDataFromDisk———ERROR while reading|” + error);
}
return null;
}

while downloading the object from amazon s3 i cant able to download it to diffrent folder rather then the file uploaded path

while downloading the object from amazon s3 i cant able to download it to diffrent folder rather then the file uploaded path...why it is happening like this may be it is metaData problem....please post your valuable comments Thanks in advance..below am posting the code for upload and download
public void AmazonUpload(String fileObj) throws IOException {
try {
this.key = fileObj;
try {
if (this.key == null) {
} else {
if (readFile(this.key) != null) {
// this.key="1";
this.putObjResult = this.amzObj.putObject(new PutObjectRequest(this.bucketName, this.key, readFile(this.key)));
}
}
} catch (AmazonServiceException ae) {
System.out.println(ae.getMessage());
}
} catch (AmazonServiceException ex) {
Logger.getLogger(AthinioCloudMigration.class.getName()).log(Level.SEVERE, null, ex);
}
}
public void AmazonDownload(String dirName, String xmlFilename, String amazonid) throws ParserConfigurationException, SAXException, TransformerException, IOException {
String cloudid;
cloudid = amazonid;
this.comm = new CommonResources(xmlFilename);
this.RequestFiles=new ArrayList();
try {
this.RequestFiles = this.comm.getXML(cloudid);
if (this.RequestFiles != null) {
int len = this.RequestFiles.size();
System.out.println(len);
for (int index = 0; index < len; index++) {
this.CRobj = (CommonResources) this.RequestFiles.get(index);
if (cloudid.equals(this.CRobj.getCloudID())) {
this.newFile = new File(dirName + this.CRobj.getFileName().concat(".rec"));
System.out.println(newFile);
newFile.createNewFile();
this.metaData = this.amzObj.getObject(new GetObjectRequest(this.bucketName, (dirName + this.CRobj.getFileName())), this.newFile);
System.out.println(metaData);
java.io.File tmp = new java.io.File(dirName + this.CRobj.getFileName());
System.out.println(tmp);
tmp.delete();
76,23 87%

Since in Amazon S3 there is no folder structure you receive everything as a object.
For Example: In your bucket you store file in a folder like structure but when you request fro the objects from S3 you will receve your file like folder1/folder2/demo.txt.
So try this one, Get the InputStream for the S3 for your file like amazonS3.getObject(bucket, "folder1/folder2/demo.txt").getObjectContent();. After getting your InputStream pass your File Name, Download location and InputStream to the below method. If you use Java 7 use FileSystems.getDefault().getPath(fullPathWithFileName).getFileName().toString() to get file name from your object name.
public void saveFile(String uploadFileName, String path, InputStream inputStream) throws Exception {
DataOutputStream dos = null;
OutputStream out = null;
try {
File newDirectory = new File(path);
if (!newDirectory.exists()) {
newDirectory.mkdirs();
}
File uploadedFile = new File(path, uploadFileName);
out = new FileOutputStream(uploadedFile);
byte[] fileAsBytes = new byte[inputStream.available()];
inputStream.read(fileAsBytes);
dos = new DataOutputStream(out);
dos.write(fileAsBytes);
} catch (IOException io) {
io.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
if (out != null) {
out.close();
}
if (dos != null) {
dos.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
}

Webdynpro iText interactive PDF form

I'm working on a Java Webdynpro where I try to print out a Interactive PDF form.
I've been following the tutorial on: http://itextpdf.com/
Now when I print my new PDF 'temp.pdf', it shows the template with the correct text but the field are still empty.
Did I missed something in my code?
Code
public byte[] GetPDFFromFolder( java.lang.String folderPath )
{
//##begin GetPDFFromFolder()
byte[] byteLink = new byte[4096];
IResource folder = null;
Content content = null;
try {
IResourceContext rctx = ResourceFactory.getInstance().getServiceContext("cmadmin_service");
RID sisFolderRID = RID.getRID(folderPath);
folder = ResourceFactory.getInstance().getResource(sisFolderRID, rctx);
} catch (ResourceException e) {
e.printStackTrace();
}
StringBuilder bf = new StringBuilder();
try {
PdfWriter writer = null;
File file = new File("temp.pdf");
try {
FileOutputStream out = new FileOutputStream(file);
if (folder.isCollection()) {
ICollection folderColl = (ICollection) folder;
IResourceListIterator it = folderColl.getChildren().listIterator();
IResource res = it.next();
try {
try {
InputStream in = res.getContent().getInputStream();
PdfReader reader = new PdfReader(in);
try {
PdfStamper stamper = new PdfStamper(reader, out);
AcroFields form = stamper.getAcroFields();
if ("Document1.pdf".equals(res.getName())){
form.setField("TextField1Vertegenwoordigd", "Van Den Berghe Tim");
form.setField("TextField2Directeur", "341 - Carrefour Evere");
form.setField("TextField3Nr", "5588");
form.setField("TextField4RPR", "RPR waarde");
form.setField("TextField5BTW", "9999-999-999");
form.setField("TextField6Euro", "100");
form.setField("TextField7Periode", "8 maanden");
form.setField("TextField8Totaal", "133");
form.setField("TextField9Producten", "Cd - Eminem");
form.setField("TextField9Producten", "Bruin banket brood");
form.setField("TextField10Vanaf", "06/08/2013");
form.setField("TextField11Op", "06/09/2013");
form.setField("TextField12Te", "06/08/2013");
form.setField("TextField13Op", "06/09/2013");
}
else {// doesn't matter}
stamper.close();
reader.close();
out.close();
FileInputStream inn = new FileInputStream(file);
byteLink = IOUtils.toByteArray(inn);
} catch (DocumentException e) {
e.printStackTrace();
}
} catch (ContentException e) {
e.printStackTrace();
}
} catch (IOException e) {
e.printStackTrace();
}
}
} catch (FileNotFoundException e) {
e.printStackTrace();
}
} catch (ResourceException e) {
e.printStackTrace();
}
return byteLink;
//##end
}