file I/O question

[slurper]

try {

FileInputStream fis = new FileInputStream("README.TXT");
int n;
while ((n = fis.available()) > 0) {
byte[] b = new byte[n];
int result = fis.read(b);
if (result == -1) break;
String s = new String(b);
System.out.print(s); }
// End while
}
// End try catch (IOException e) {System.err.println(e);}
System.out.println();

i wonder if this code snippet is correct. I think it is possible that not
all content of README.TXT will be printed.
the loop will run as long as there are bytes available without blocking the
program. but will there be bytes available after opening the file? the
program needs to block immediately waiting for I/O, or do i see this wrong?

tx

[Jan Thomä]

Hi,

the code is somewhat inefficient, since you create a ton of arrays and
string objects. It would be better just to create a maybe 64k array, read
it in and thats it. Oh and use a streamreader for the conversion of bytes
to chars. something lieke

int n =0;
char[] chars = new char[64000];

FileInputStream fis = new FileInputStream("README.TXT");
InputStreamReader reader = new InputStreamReader( fis );
StringBuffer buf = new StringBuffer();
while( (n = reader.read( chars, 0, chars.length )) != -1 ) {
buf.append( chars, 0, n ); // put into buffer
}
reader.close();
System.out.println( buf.toString() );

That way you just have one char array and reuse it. Also you dont produce a
ton of temporary string objects.

Best regards,
Jan

slurper wrote:

try {

FileInputStream fis = new FileInputStream("README.TXT");
int n;
while ((n = fis.available()) > 0) {
byte[] b = new byte[n];
int result = fis.read(b);
if (result == -1) break;
String s = new String(b);
System.out.print(s); }
// End while
}
// End try catch (IOException e) {System.err.println(e);}
System.out.println();

i wonder if this code snippet is correct. I think it is possible that not
all content of README.TXT will be printed.
the loop will run as long as there are bytes available without blocking
the program. but will there be bytes available after opening the file? the
program needs to block immediately waiting for I/O, or do i see this
wrong?

tx

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