I want to write a matrix to a file in java by using jama library.However, only a empty file is produced. I am using the code below. What can be wrong?
PrintWriter writer = null;
try {
writer = new PrintWriter("deneme.txt", "UTF-8");
} catch (FileNotFoundException | UnsupportedEncodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
m3.print( writer,2,2);
writer could be null when it comes to this line of code. Move the m3.print(writer,2,2); inside of the try block.
PrintWriter writer = null;
try {
writer = new PrintWriter("deneme.txt", "UTF-8");
m3.print(writer, 2, 2);
} catch (FileNotFoundException | UnsupportedEncodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Related
I'm trying to modify a doc with Apache POI in Java.
At first the test.doc cannot be read with a exception raised up :
"org.apache.poi.poifs.filesystem.NotOLE2FileException: Invalid header signature; read 0x6576206C6D783F3C, expected 0xE11AB1A1E011CFD0 - Your file appears not to be a valid OLE2 document
"
So I saved the doc as "word 97 - 03" format,and then POI can read the doc properly.
But when I try to rewrite the content to a new file with nothing changed, the file output.doc cannot be opened by MS Office.
When I make a new doc myself with MS Office, the POI works well, everything goes right.
So the problem is "test.doc".
The test.doc is generated by some sort of a program which I can't access the code,so I don't know what goes wrong.
My question is :
1.As test.doc can be read by MS Office why can't POI without saving as a new format doc?
2.As the POI can read the doc, why it cannot write back to a new file(MS Office can't open)?
Here is my code:
FileInputStream fis = null;
try {
fis = new FileInputStream("test.doc");
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
POIFSFileSystem pfs = null;
try {
pfs = new POIFSFileSystem(fis);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
HWPFDocument hwdf = null;
try {
hwdf = new HWPFDocument(pfs);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
FileOutputStream fos = null;
try {
fos = new FileOutputStream(new File("output.doc"));
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
hwdf.write(fos);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally {
}
try {
fos.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
fis.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
pfs.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
The HEX stuff read as ASCII and read little-endian converts to <?xml ve, which indicates that test.doc is some other format than actually .doc/.docx.
Word will open other data-formats gracefully sometimes, upon saving it will be saved correctly in the Word-Format.
Therefore you will need to use a hex-editor to take a look at the contents of test.doc and if it is really in some broken format you need to find out where it is coming from and how the creation of that file can be fixed.
Hello I am having some issues with this simple task of conversion.
Here is my code bellow (rough but not so complex):
FileInputStream fis = new FileInputStream ("file");
BufferedReader reader = new BufferedReader(new InputStreamReader(fis,"CP1250"));
try {
StringBuilder sb = new StringBuilder();
String line = null;
try {
line = reader.readLine();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
while (line != null) {
sb.append(line);
if(line.contains(" "))
sb.append(System.lineSeparator());
try {
line = reader.readLine();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
String everything = sb.toString();
System.out.println(everything);
PrintWriter writer = null;
try {
writer = new PrintWriter("clean", "UTF-8");
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (UnsupportedEncodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
writer.println(everything);
writer.close();
}
finally {
try {
reader.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
But I get the same output as the input with the same encoding format.
Do you see anyway able to help?
The docs say that
1) public void println(String x)
Prints a String and then terminates the line. This method behaves as though it invokes print(String) and then println().
And 2)
public void print(String s)
Prints a string. If the argument is null then the string "null" is printed. Otherwise, the string's characters are converted into bytes according to the platform's default character encoding, and these bytes are written in exactly the manner of the write(int) method.
You probably will get your conversion done with
PrintWriter writer
= new PrintWriter(new OutputStreamWriter(new FileOutputStream("clean", true),
"UTF-8"));
I am trying to convert large 3gp file(>than 25mb) to byte array but it gives outofmemory exception.i am able to convert less than 25 mb 3gp file to bytearray.
File file1 = new File (Environment.getExternalStorageDirectory() + "1.3gp");
FileInputStream fis = null;
try {
fis = new FileInputStream(file1);
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
ByteArrayOutputStream bos = new ByteArrayOutputStream();
try {
while (fis.available() > 0) {
bos.write(fis.read());
}
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
byte[] bytes = bos.toByteArray();
File someFile = new File (Environment.getExternalStorageDirectory()+ "/output.txt");
FileOutputStream fos = null;
try {
fos = new FileOutputStream(someFile);
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
fos.write(bytes);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
fos.flush();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
fos.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
////
how to convert the large 3gp file into bytearray.
give a proper example or method.
Set the -Xmx option on the virtual machine being used to run the program to a larger value to give it more memory to work with.
You can do that as a command line option if running the program directly, or as a setting on the project in your IDE if running it from an IDE.
I am getting the occassional error message when I try to read a serialized object from a file. It works fine 9 times out of 10, but for some reason I get lots of these error message sin the catlog:
06-01 23:57:50.824: ERROR/MemoryFile(16077): MemoryFile.finalize() called while ashmem
still open
and
06-01 23:57:57.664: ERROR/MemoryFile(16077): java.io.IOException: munmap failed
The second message comes with no indication where the exception is caused. (Clearly when I'm loading the file, but I already have a try/catch around it.)
My loadfile method looks like this:
public TGame loadSavedGame(){
TGame g=null;
InputStream instream = null;
BufferedReader br=null;
InputStreamReader inputreader=null;
try {
File sdCard = Environment.getExternalStorageDirectory();
instream = new
FileInputStream(sdCard.getAbsolutePath()+"/egyptica/serializationtest");
// inputreader = new InputStreamReader(instream);
// br= new BufferedReader(inputreader);
} catch (FileNotFoundException e) {
e.printStackTrace();
return null;
}
try {
ObjectInputStream ois = new ObjectInputStream(instream);
try {
g= (TGame) ois.readObject();
try {
instream.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return g;
} catch (ClassNotFoundException ex) {
// TODO Auto-generated catch block
android.util.Log.e("DESERIALIZATION FAILED (CLASS NOT
FOUND):"+ex.getMessage(), "ex");
ex.printStackTrace();
return null;
}
} catch (StreamCorruptedException ex) {
android.util.Log.e("DESERIALIZATION FAILED (CORRUPT):"+ex.getMessage(),
"ex");
// TODO Auto-generated catch block
ex.printStackTrace();
return null;
} catch (IOException ex) {
android.util.Log.e("DESERIALIZATION FAILED (IO
EXCEPTION):"+ex.getMessage(), "ex");
// TODO Auto-generated catch block
ex.printStackTrace();
return null;
}
}
One possibility I have thought of is using a BufferedReader to rea the file. However I'm not sure how to go about doing this. Any help would be appreciated.
Try to put finally block after try and put there closing statements for your streams and also useful thing is to use:
FileInputStream.getFD().sync();
It makes sure that file really received your close/flush
I'm trying to save a url as a string so that I can use it in another part of my app but its not working properly. Here's what I have.
Saving
String FILENAME = "usertimetable";
String string = mWebView.getOriginalUrl();
FileOutputStream fos = null;
try {
fos = openFileOutput(FILENAME, Context.MODE_PRIVATE);
fos.write(string.getBytes());
fos.close();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Opening
FileInputStream fis = null;
try {
fis = openFileInput("usertimetable");
url = fis.toString();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Try using the read() method, rather than toString().
(http://developer.android.com/reference/java/io/FileInputStream.html for more info.)