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[Recipe] Reading Input from Keyboard using DataInputStream Class (Java)
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Need to read data from Keyboard in a machine independent way.
DataInputStream is a FilterInputStream that read primitive data from an underlying input stream in a machine-independent way.
It provides convenience methods such as readInt(), readChar etc.
Below program will take the input from keyboard using DataInputStream with its inherited read method and print it to a file using FileOutputStream.
import java.io.*;
public class FileCopier {
public static void main(String[] args) throws IOException {
DataInputStream dis = new DataInputStream(System.in);
FileOutputStream fout = new FileOutputStream("myFile.txt");
System.out.println("Enter text (enter & to end):");
char ch;
while ((ch = (char) dis.read()) != '&')
fout.write(ch);
fout.close();
}
}
Important Notes
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Input will be read byte by byte and ends reading when a '&' is encountered.
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FileOutputStream constructor takes the name of the file as an argument.
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System.in is of type PrintStream and represents the standard input device which is keyboard by default.
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The readLine() method of the DataInputStream is deprecated as method does not properly convert bytes to characters. To use readLine() and other character convenience methods, a more popular approach is to use a BufferedReader with InputStreamReader.