Java 7 for Absolute Beginners

(nextflipdebug5) #1

CHAPTER 8 ■ WRITING AND READING FILES


public static void main(String[] args) {
// Specify the file
String fileName = "C:" + File.separator + "test"
+ File.separator + "Hamlet.txt";
File hamletFile = new File(fileName);
// Set up a byte array to hold the file's content
byte[] content = new byte[0];
try {
// Create an input stream for the file
FileInputStream hamletInputStream = new FileInputStream(hamletFile);
// Figure out how much content the file has
int bytesAvailable = hamletInputStream.available();
// Set the content array to the length of the content
content = new byte[bytesAvailable];
// Load the file's content into our byte array
hamletInputStream.read(content);
// Close the stream
hamletInputStream.close();
} catch (FileNotFoundException fnfe) {
System.out.println("Couldn't find a file called " + fileName);
} catch (IOException ioe) {
System.out.println("Couldn't read from a file called " + fileName);
}
// Reverse the contents of our array, just so we'll
// know we did something to the file's content
reverseByteArray(content);
try {
// Create a stream for our output
FileOutputStream hamletOutputStream
= new FileOutputStream(hamletFile);
// Write our output to our stream
// (and thus to our file)
hamletOutputStream.write(content);
// Close the output stream
hamletOutputStream.close();
} catch (FileNotFoundException fnfe) {
System.out.println("Couldn't find a file called " + fileName);
} catch (IOException ioe) {
System.out.println("Couldn't write to a file called " + fileName);
}
}

private static void reverseByteArray(byte[] inBytes) {
int inLength = inBytes.length;
for (int i = 0; i < inLength >> 1; i++) {
byte temp = inBytes[i];
inBytes[i] = inBytes[inLength - i - 1];
inBytes[inLength - i - 1] = temp;
}
}
}
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