Selles näites õpime faili sisendvoona laadima, kasutades Java klassi FileInputStream.
Selle näite mõistmiseks peaksid teil olema teadmised järgmistest Java programmeerimise teemadest:
- Java failiklass
- Java InputStream klass
- Java FileInputStream klass
Näide 1: Java-programm tekstifaili laadimiseks InputStreamina
import java.io.InputStream; import java.io.FileInputStream; public class Main ( public static void main(String args()) ( try ( // file input.txt is loaded as input stream // input.txt file contains: // This is a content of the file input.txt InputStream input = new FileInputStream("input.txt"); System.out.println("Data in the file: "); // Reads the first byte int i = input.read(); while(i != -1) ( System.out.print((char)i); // Reads next byte from the file i = input.read(); ) input.close(); ) catch(Exception e) ( e.getStackTrace(); ) ) )
Väljund
Andmed failis: see on faili input.txt sisu.
Ülaltoodud näites on meil fail nimega input.txt . Faili sisu on
This is a content of the file input.txt.
Siin kasutasime FileInputStream
klassi input.txt faili laadimiseks sisendvoona. Seejärel kasutasime read()
meetodit failist kõigi andmete lugemiseks.
Näide 2: Java-fail InputStreamina Java-faili laadimiseks
Mõelgem, et meil on Java-fail nimega Test.java ,
class Test ( public static void main(String() args) ( System.out.println("This is Java File"); ) )
Selle Java-faili saame ka sisendvoona laadida.
import java.io.InputStream; import java.io.FileInputStream; public class Main ( public static void main(String args()) ( try ( // file Test.java is loaded as input stream InputStream input = new FileInputStream("Time.java"); System.out.println("Data in the file: "); // Reads the first byte int i = input.read(); while(i != -1) ( System.out.print((char)i); // Reads next byte from the file i = input.read(); ) input.close(); ) catch(Exception e) ( e.getStackTrace(); ) ) )
Väljund
Andmed failis: klassi test (avalik staatiline void main (String () args) (System.out.println ("See on Java-fail");))
Ülaltoodud näites oleme FileInputStream
klassi kasutanud Java-faili sisendvoona laadimiseks.