Writing to File

[Manoj Zachariah]

how do i write the contents of an OutputStreamWriter object into a file???

[karl koch]

check out the java.io package:
there you can find the java.io.FileWriter and java.io.FileOutputstream.
dont forget to close the stream or writer.

karl

[Manoj Zachariah]

can somebody finsih the code for me!!!
it creates a file called temp.txt but doesnt write into it.

 import java.io.*;
class fileAccess  
{
public static void main(String[] args)
{
fileAccess fa = new fileAccess();
fa.fileReader();
}
void fileReader() 
{
try
{
FileReader fr = new FileReader("rule1.xml");
BufferedReader br = new BufferedReader(fr);
FileWriter fw = new FileWriter("temp.txt");
BufferedWriter bw = new BufferedWriter(fw);

String record = null;
int reccount=0;
while((record = br.readLine()) != null)
{
reccount++;
System.out.println("Record : " + reccount + " " + record);
fw.write(record);
}
}
catch (IOException e)
{
System.out.println("file exception");
e.printStackTrace();
}
}
}
 

[Chandra Bairi]

just add the statement bw.flush(). You should be able to see the o/p in the file.
hope that helps.
Shekar.

[Chandra Bairi]

beg u pardon fw.flush()
Shekar.

[Manoj Zachariah]

can you tell me what flush does?

[Chandra Bairi]

when you are using a buffered writer what happens is the data that you are reading from the file gets buffered. The data will be written to the file in two ways. One is by explicitly using the flush which is like pushing the data to the file after getting buffered. the other way is when the buffer gets full it automatically gets flushed. but it is always better to flush the data.
in one line you collect the data and push the data with flush.
hope this helps.
shekar.

[Dirk Schreckmann]

Moving this to the I/O and Streams forum...

[Jim Yingst]

You should get in the habit of calling close() on a Reader/Writer/InputStream/OutputStream when you're done with it. Preferably in a finally{} clause to ensure it happens even if an exception is thrown. This will also call flush() as part of the close() operation, so you don't really need to call flush() separately.

[Jim Yingst]

Incidentally, readLine() will return a String that does not include any line terminators (\n or \r). So when you write the record to a new file, you probably want to add new line terminators too. This is typically achieved by using a PrintWriter, which has a println() method which uses your platform's default line terminator.