Slide 1
Files And Streamsa. Using the Files Classb. Random Access
Filesc. Streamd. Byte and character Streame. Buffered ReaderFiles
and StreamUse theFileclass for typical operations such as copying,
moving, renaming, creating, opening, deleting, and appending to
files. You can also use theFileclass to get and set file attributes
orDate Time information related to the creation, access, and
writing of a file.Using The FILE Classrandom access files as their
name implies, once they are opened, they can be read from or
written to in a random manner just by using a record number or you
can add to the end since you will know how many records are in the
file.Random Access FilesStreamis the abstract base class of all
streams. A stream is an abstraction of a sequence of bytes, such as
a file, an input/output device, an inter-process communication
pipe, or a TCP/IP socket. TheStreamclass and its derived classes
provide a generic view of these different types of input and
output, isolating the programmer from the specific details of the
operating system and the underlying devices.STREAMSthree
fundamental operations
1.You can read from streams. Reading is the transfer of data
from a stream into a data structure, such as an array of
bytes.2.You can write to streams. Writing is the transfer of data
from a data structure into a stream.3.Streams can support seeking.
Seeking is the querying and modifying of the current position
within a stream. Seek
Character streamsare intended exclusively for character
data.Byte streamsare intended for general purpose input and output.
Of course, fundamentally all data consist of patterns of bits
grouped into 8-bit bytes. So, logically all streams could be called
"byte streams". However streams that are intended for bytes that
represent characters are called "character streams" and all others
are called "byte streams".Byte and Character StreamsBuffered
Streamcan be composed around certain types of streams. It provides
implementations for reading and writing bytes to an underlying data
source or repository. Use Binary Reader andBinary Writer for
reading and writing other data types.Buffered
Streamscatch(FileNotFoundException ex){
System.out.println(ex.getMessage() + " in the specified
directory."); System.exit(0); } catch(IOException e){
System.out.println(e.getMessage()); } } public static void
main(String[] args){ copyfile("c:\\out.txt","d:\\kulafu.edi");
} }import java.io.*;
public class CopyFile{ private static void copyfile(String
srFile, String dtFile){ try{ File f1 = new File(srFile); File f2 =
new File(dtFile); InputStream in = new FileInputStream(f1); //For
Append the file.// OutputStream out = new
FileOutputStream(f2,true);
//For Overwrite the file. OutputStream out = new
FileOutputStream(f2);
byte[] buf = new byte[1024]; int len; while ((len =
in.read(buf)) > 0){ out.write(buf, 0, len); } in.close();
out.close(); System.out.println("File copied."); }import
java.io.*;class FileWrite { public static void main(String args[])
{ try{ // Create file FileWriter fstream = new
FileWriter("out.txt"); BufferedWriter out = new
BufferedWriter(fstream); out.write("pink"); //Close the output
stream out.close(); }catch (Exception e){//Catch exception if any
System.err.println("Error: " + e.getMessage()); } }}import
java.io.*;
public class ReadAccessFile{ public static void main(String[]
args) throws IOException{ BufferedReader in = new
BufferedReader(new InputStreamReader(System.in));
System.out.print("Enter File name : "); String str = in.readLine();
File file = new File(str); if(!file.exists()) {
System.out.println("File does not exist."); System.exit(0); }try {
// Send data to the client. Console.Write("Sending data ... "); int
bytesSent = serverSocket.Send( dataToSend, 0, dataToSend.Length,
SocketFlags.None); Console.WriteLine("{0} bytes sent.\n",
bytesSent.ToString());
// Set the timeout for receiving data to 2 seconds.
serverSocket.SetSocketOption(SocketOptionLevel.Socket,
SocketOptionName.ReceiveTimeout, 2000);
// Receive data from the client. Console.Write("Receiving data
... "); try { do { bytesReceived =
serverSocket.Receive(receivedData, 0, receivedData.Length,
SocketFlags.None); totalReceived += bytesReceived; }
while(bytesReceived != 0); } catch(SocketException e) {
if(e.ErrorCode == WSAETIMEDOUT) { // Data was not received within
the given time. // Assume that the transmission has ended. } else {
Console.WriteLine("{0}: {1}\n", e.GetType().Name, e.Message); } }
finally { Console.WriteLine("{0} bytes received.\n",
totalReceived.ToString()); } } finally {
serverSocket.Shutdown(SocketShutdown.Both);
Console.WriteLine("Connection shut down."); serverSocket.Close(); }
}}
public class Server { static void Main() { // This is a Windows
Sockets 2 error code. const int WSAETIMEDOUT = 10060;
Socket serverSocket; int bytesReceived, totalReceived = 0;
byte[] receivedData = new byte[2000000];
// Create random data to send to the client. byte[] dataToSend =
new byte[2000000]; new Random().NextBytes(dataToSend);
IPAddress ipAddress =
Dns.Resolve(Dns.GetHostName()).AddressList[0];
IPEndPoint ipEndpoint = new IPEndPoint(ipAddress, 1800);
// Create a socket and listen for incoming connections.
using(Socket listenSocket = new Socket( AddressFamily.InterNetwork,
SocketType.Stream, ProtocolType.Tcp)) {
listenSocket.Bind(ipEndpoint); listenSocket.Listen(1);
// Accept a connection and create a socket to handle it.
serverSocket = listenSocket.Accept(); Console.WriteLine("Server is
connected.\n"); }
import java.io.FileReader;import java.io.FileWriter;import
java.io.IOException;
public class CopyCharacters { public static void main(String[]
args) throws IOException {
FileReader inputStream = null; FileWriter outputStream =
null;
try { inputStream = new FileReader("xanadu.txt"); outputStream =
new FileWriter("characteroutput.txt");
int c; while ((c = inputStream.read()) != -1) {
outputStream.write(c); } } finally { if (inputStream != null) {
inputStream.close(); } if (outputStream != null) {
outputStream.close(); } } }}
