NOTE: Thanks to user2602219 and Andrew Thompson I've solved my problem. I wish I could approve both answers right and vote up.
I've searched a lot. I've found something but they were not suitable for me.
All I want is write
Hello
World
as seen. But in my txt file it shows HelloWorld
try{
JTextArea area = new JTextArea();
String path = folder+"/"+name+".txt";
BufferedWriter output = new BufferedWriter(new FileWriter(path));
area.write(output);
output.close();
}
catch(IOException ex){}
The code above works fine. However, I've to do something before writing.
I've an encryption method (called enc). It takes a string and replaces letters wit another letters.
For example:
String text = "ABC";
String enc_text = enc(text);
//enc_text is now "ZXW";
But here is the thing. JTextArea.write looks for a "Writer" but I have to write a string because my encrypter returns a string.
Long story short. How to make
Hello
World
to this
Gteeu
Wuazx
Take the unencrypted string from the first text area.
Encrypt it.
Put the encrypted string in a second text area that is not immediately visible to the end user.
Use the JTextCompnent.write(..) method on the encrypted text area.
Try to use this:
String text = "Hello" + "\nWorld";
\n is a new line.
Did you try to read each line separately and then write it on the desired txt file? This way you could use "\n" to write on a new line. Another solution that came to my mind is using the following method:
String s = "";
s = s.format(something + "\n");
This way you would have lines in the string itself :)
static void writeStringToFile(File file, String data)
which allows you to write text to a file in one method call.
or use
FileUtils.writeStringToFile(new File("test.txt"), "Hello File");
Related
I've got a problem with input from user. I need to save input from user into binary file and when I read it and show it on the screen it isn't working properly. I dont want to put few hundreds of lines, so I will try to dexcribe it in more compact form. And encoding in NetBeans in properties of project is "UTF-8"
I got input from user, in NetBeans console or cmd console. Then I save it to object made up of strings, then add it to ArrayList<Ksiazka> where Ksiazka is my class (basically a book's properties). Then I save whole ArrayList object to file baza.bin. I do it by looping through whole list of objects of class Ksiazka, taking each String one by one and saving it into file baza.bin using method writeUTF(oneOfStrings). When I try to read file baza.bin I see question marks instead of special characters (ą, ć, ę, ł, ń, ó, ś, ź). I think there is a problem in difference in encoding of file and input data, but to be honest I don't have any idea ho to solve that.
Those are attributes of my class Ksiazka:
private String id;
private String tytul;
private String autor;
private String rok;
private String wydawnictwo;
private String gatunek;
private String opis;
private String ktoWypozyczyl;
private String kiedyWypozyczona;
private String kiedyDoOddania;
This is method for reading data from user:
static String podajDana(String[] tab, int coPokazac){
System.out.print(tab[coPokazac]);
boolean podawajDalej = true;
String linia = "";
Scanner klawiatura = new Scanner(System.in, "utf-8");
do{
try {
podawajDalej = false;
linia = klawiatura.nextLine();
}
catch(NoSuchElementException e){
System.err.println("Wystąpił błąd w czasie podawania wartości!"
+ " Spróbuj jeszcze raz!");
}
catch(IllegalStateException e){
System.err.println("Wewnętrzny błąd programu typu 2! Zgłoś to jak najszybciej"
+ " razem z tą wiadomością");
}
}while(podawajDalej);
return linia;
}
String[] tab is just array of strings I want to be able to show on the screen, each set (array) has its own function, int coPokazac is number of line from an array I want to show.
and this one saves all data from ArrayList<Ksiazka> to file baza.bin:
static void zapiszZmiany(ArrayList<Ksiazka> bazaKsiazek){
try{
RandomAccessFile plik = new RandomAccessFile("baza.bin","rw");
for(int i = 0; i < bazaKsiazek.size(); i++){
plik.writeUTF(bazaKsiazek.get(i).zwrocId());
plik.writeUTF(bazaKsiazek.get(i).zwrocTytul());
plik.writeUTF(bazaKsiazek.get(i).zwrocAutor());
plik.writeUTF(bazaKsiazek.get(i).zwrocRok());
plik.writeUTF(bazaKsiazek.get(i).zwrocWydawnictwo());
plik.writeUTF(bazaKsiazek.get(i).zwrocGatunek());
plik.writeUTF(bazaKsiazek.get(i).zwrocOpis());
plik.writeUTF(bazaKsiazek.get(i).zwrocKtoWypozyczyl());
plik.writeUTF(bazaKsiazek.get(i).zwrocKiedyWypozyczona());
plik.writeUTF(bazaKsiazek.get(i).zwrocKiedyDoOddania());
}
plik.close();
}
catch (FileNotFoundException ex){
System.err.println("Nie znaleziono pliku z bazą książek!");
}
catch (IOException ex){
System.err.println("Błąd zapisu bądź odczytu pliku!");
}
}
I think that there is a problem in one of those two methods (either I do something wrong while reading it or something wrong when it is saving data to file using writeUTF()) but even tho I tried few things to solve it, none of them worked.
After quick talk with lecturer I got information that I can use at most JDK 8.
You are using different techniques for reading and writing, and they are not compatible.
Despite the name, the writeUTF method of RandomAccessFile does not write a UTF-8 string. From the documentation:
Writes a string to the file using modified UTF-8 encoding in a machine-independent manner.
First, two bytes are written to the file, starting at the current file pointer, as if by the writeShort method giving the number of bytes to follow. This value is the number of bytes actually written out, not the length of the string. Following the length, each character of the string is output, in sequence, using the modified UTF-8 encoding for each character.
writeUTF will write a two-byte length, then write the string as UTF-8, except that '\u0000' characters are written as two UTF-8 bytes and supplementary characters are written as two UTF-8 encoded surrogates, rather than single UTF-8 codepoint sequences.
On the other hand, you are trying to read that data using new Scanner(System.in, "utf-8") and klawiatura.nextLine();. This approach is not compatible because:
The text was not written as a true UTF-8 sequence.
Before the text was written, two bytes indicating its numeric length were written. They are not readable text.
writeUTF does not write a newline. It does not write any terminating sequence at all, in fact.
The best solution is to remove all usage of RandomAccessFile and replace it with a Writer:
Writer plik = new FileWriter(new File("baza.bin"), StandardCharsets.UTF_8);
for (int i = 0; i < bazaKsiazek.size(); i++) {
plik.write(bazaKsiazek.get(i).zwrocId());
plik.write('\n');
plik.write(bazaKsiazek.get(i).zwrocTytul());
plik.write('\n');
// ...
I'm writing a Java program that saves data to UTF8 text files. However, I'd also like to provide the option to save to IBM437 for compatibility with an old program that uses the same sort of data files.
How can I check to see if the data the user is trying to save isn't representable in IBM437? At the moment the file saves without complaining but results in unusual characters being replaced with question marks.
I'd prefer it if I could show a warning to the user that the data they are saving isn't supported in IBM437. The user could then have the option of manually replacing characters with the nearest ASCII equivalent.
Current code for saving is:
String encoding = "UTF-8";
if (forceLegacySupport)
{
// Force character encoding to IBM437
encoding = "IBM437";
}
BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(saveFile.getAbsoluteFile()), encoding));
IOController.writeFileToDisk(bw);
bw.close();
As mentioned by JB Nizet in comments you can use charset encoder
and for creating text/String as UTF-8
just a suggestion from my end:
public static char[] cookie = "HEADER_COOKIE".toCharArray();
byte[] cookieInBytes = new byte[COOKIE_SIZE];
for(int i=0;i<cookie.length;i++)
{
if(i < cookie.length)
cookieInBytes[i] = (byte)cookie[i];
}
String headerStr = new String(cookieInBytes,StandardCharsets.UTF_8);
My program is reading from a .txt encoded with UTF-8. The reason why I'm using UTF-8 is to handle the characters åäö. The problem I come across is when the lines are read is that there seems to be some "rogue" characters sneaking in to the string which causes problems when I'm trying to store those lines into variables. Here's the code:
public void Läsochlista()
{
String Content = "";
String[] Argument = new String[50];
int index = 0;
Log.d("steg1", "steg1");
try{
InputStream inputstream = openFileInput("text.txt");
if(inputstream != null)
{
Log.d("steg2", "steg2");
//InputStreamReader inputstreamreader = new InputStreamReader(inputstream);
//BufferedReader bufferreader = new BufferedReader(inputstreamreader);
BufferedReader in = new BufferedReader(new InputStreamReader(inputstream, "UTF-8"));
String reciveString = "";
StringBuilder stringbuilder = new StringBuilder();
while ((reciveString = in.readLine()) != null)
{
Argument[index] = reciveString;
index++;
if(index == 6)
{
Log.d(Argument[0], String.valueOf((Argument[0].length())));
AllaPlatser.add(new Platser(Float.parseFloat(Argument[0]), Float.parseFloat(Argument[1]), Integer.parseInt(Argument[2]), Argument[3], Argument[4], Integer.parseInt(Argument[5])));
Log.d("En ny plats skapades", Argument[3]);
Arrays.fill(Argument, null);
index = 0;
}
}
inputstream.close();
Content = stringbuilder.toString();
}
}
catch (FileNotFoundException e){
Log.e("Filen", " Hittades inte");
} catch (IOException e){
Log.e("Filen", " Ej läsbar");
}
}
Now, I'm getting the error
Invalid float: "61.193521"
where the line only contains the chars "61.193521". When i print out the length of the string as read within the program, the output shows "10" which is one more character than the string is supposed to contain. The question; How do i get rid of those invisible "Rouge" chars? and why are they there in the first place?
When you save a file as "UTF-8", your editor may be writing a byte-order mark (BOM) at the beginning of the file.
See if there's an option in your editor to save UTF-8 without the BOM.
Apparently the BOM is just a pain in the butt: What's different between UTF-8 and UTF-8 without BOM?
I know you want to be able to have extended characters in your data; however, you may want to pick a different encoding like Latin-1 (ISO 8859-1).
Or you can just read & discard the first three bytes from the input stream before you wrap it with the reader.
Unfortunately you have not provided the sample text file so testing with your code exactly is not possible and here is the theoretical answer based on guess, what could have been the reasons:
Looks like it is BOM related issue and you may have to treat this. Some related detail is given here: http://www.rgagnon.com/javadetails/java-handle-utf8-file-with-bom.html
And some information here: What is XML BOM and how do I detect it?
Basically there are various situation:
In one of the situation we face issues when we don't read and write using correct encoding.
In another situation we use an editor or reader which doesn't support UTF-8
Third is when we are using correct encoding for reading and writing, we are not facing issue in a text editor but facing issue in some other application or program. I think your issues is related to third case.
In third situation we may have to remove the BOM using a program or deal with it according to our context.
Here is some solution I guess you may find interesting:
UTF-8 file reading: the first character issue
You can use code given in this threads answer or use apache commons to deal with it:
Byte order mark screws up file reading in Java
I have a .csv file that contains:
scenario, custom, master_data
1, ${CUSTOM}, A_1
I have a string:
a, b, c
and I want to replace 'custom' with 'a, b, c'. How can I do that and save to the existing .csv file?
Probably the easiest way is to read in one file and output to another file as you go, modifying it on a per-line basis
You could try something with tokenizers, this may not be completely correct for your output/input, but you can adapt it to your CSV file formatting
BufferedReader reader = new BufferedReader(new FileReader("input.csv"));
BufferedWriter writer = new BufferedWriter(new FileWriter("output.csv"));
String custom = "custom";
String replace = "a, b, c";
for(String line = reader.readLine(); line != null; line = reader.readLine())
{
String output = "";
StringTokenizer tokenizer = new StringTokenizer(line, ",");
for(String token = tokenizer.nextToken(); tokenizer.hasMoreTokens(); token = tokenizer.nextToken())
if(token.equals(custom)
output = "," + replace;
else
output = "," + token;
}
readInventory.close();
If this is for a one off thing, it also has the benefit of not having to research regular expressions (which are quite powerful and useful, good to know, but maybe for a later date?)
Have a look at Can you recommend a Java library for reading (and possibly writing) CSV files?
And once the values have been read, search for strings / value that start with ${ and end with }. Use Java Regular Expressions like \$\{(\w)\}. Then use some map for looking up the found key, and the related value. Java Properties would be a good candidate.
Then write a new csv file.
Since your replacement string is quite unique you can do it quickly without complicated parsing by just reading your file into a buffer, and then converting that buffer into a string. Replace all occurrences of the text you wish to replace with your target text. Then convert the string to a buffer and write that back to the file...
Pattern.quote is required because your string is a regular expression. If you don't quote it you may run into unexpected results.
Also it's generally not smart to overwrite your source file. Best is to create a new file then delete the old and rename the new to the old. Any error halfway will then not delete all your data.
final Path yourPath = Paths.get("Your path");
byte[] buff = Files.readAllBytes(yourPath);
String s = new String(buff, Charset.defaultCharset());
s = s.replaceAll(Pattern.quote("${CUSTOM}"), "a, b, c");
Files.write(yourPath, s.getBytes());
Please have a look at the following code:
ArrayList<String> text = data.getStringArrayListExtra(RecognizerIntent.EXTRA_RESULTS);
int cursorPosition = edtTEXT.getSelectionStart();
String currentString = edtTEXT.getText().toString().trim();
voiceEdt.append(text.get(0), cursorPosition, cursorPosition+1)
Toast.makeText(VoiceNotes.this, "Status: "+writeInMiddle, Toast.LENGTH_LONG).show();
My attempt is to append the text to the place where the cursor is located. Most probbly it will be at the middle of a sentence. For an example, take the text "Welcome to abc". If the text is at the beginning of the text abc then the new text should get appened at the beginning of the abc.
My above code doesn't work, it appends nothing. Anyway, the edtTEXT is an EditText.
What is wrong here?
use insert() method instead of append(). see example,
String s = "This a String";
StringBuffer buffer = new StringBuffer(s);
buffer.insert(5, "is ");
System.out.println(buffer.toString());
// will give "This is a String"