Archive for category Java IO
Using Scanner class to get input from user in java
Posted by Chirag Jain in Java, Java IO on December 24, 2009
java.util.Scanner class provides a way to get input from user:
Scanner scanner = new Scanner(System.in);
If input is String:
String string= scanner.nextLine();
//to read input as a whole line
or
String string= scanner.next();
// to read single word
To read integers:
int i= scanner.nextInt();
Here is an article helpful on Scanner.
Writing a file in java
Posted by Chirag Jain in Java, Java IO on December 17, 2009
Here is the code to write a string to a file in java:
import java.io.*;
class WriteFile {
public static void main(String args[]) {
try{
String s="data to write in file";
File f=new File("a.txt");
FileWriter fwr= new FileWriter(f);
Writer wr= new BufferedWriter(fwr);
wr.write(s);
wr.close();
}
catch(IOException ie) {
System.out.print(ie);
}
catch(Exception e) {
System.out.print(e);
}
}
}
First make a reference to file to which you want to write the data:
File f=new File("a.txt");
Here, in place of .txt, we can use any file extension as .srt,.xml,.doc etc
Then, create a file writer,
FileWriter fwr= new FileWriter(f);
Then, make a writer to write to the file:
Writer wr= new BufferedWriter(fwr);
then, call write function and pass the string:
wr.write(s);
Always remember to close the writer, otherwise it won’t write to the file:
wr.close();
We have to catch the exceptions thrown by the API methods also. To know more about exceptions, go to Java Exceptions