Java by API/java.io/FileWriter

FileWriter: close()

 
 
import java.io.File;
import java.io.FileWriter;
public class Main {
  public static void main(String[] args) throws Exception{
    File file = new File("user.txt");
    FileWriter writer = new FileWriter(file, true);
    writer.write("username=java;password=secret" + System.getProperty("line.separator"));
    writer.flush();
    writer.close();
  }
}

FileWriter: flush()

 
 
import java.io.File;
import java.io.FileWriter;
public class Main {
  public static void main(String[] args) throws Exception{
    File file = new File("user.txt");
    FileWriter writer = new FileWriter(file, true);
    writer.write("username=java;password=secret" + System.getProperty("line.separator"));
    writer.flush();
    writer.close();
  }
}

FileWriter: write(int i)

  
/*
 * Output:
 *  
 */
import java.io.FileReader;
import java.io.FileWriter;
//copy file
public class MainClass {
  public static void main(String args[]) {
    try {
      FileReader fr = new FileReader(args[0]);
      FileWriter fw = new FileWriter(args[1]);
      int i;
      while ((i = fr.read()) != -1) {
        fw.write(i);
      }
      fw.close();
      fr.close();
    } catch (Exception e) {
      System.out.println("Exception: " + e);
    }
  }
}

new FileWriter(File file)

 
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
public class Main {
  public static void main(String[] args) throws IOException {
    File inputFile = new File("farrago.txt");
    File outputFile = new File("outagain.txt");
    FileReader in = new FileReader(inputFile);
    FileWriter out = new FileWriter(outputFile);
    int c;
    while ((c = in.read()) != -1)
      out.write(c);
    in.close();
    out.close();
  }
}

new FileWriter("LPT1:")

  
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
public class MainClass {
  public static void main(String[] args) {
    try {
      FileWriter fw = new FileWriter("LPT1:");
      PrintWriter pw = new PrintWriter(fw);
      String s = "www.jexp.ru";
      int i, len = s.length();
      for (i = 0; len > 80; i += 80) {
        pw.print(s.substring(i, i + 80));
        pw.print("\r\n");
        len -= 80;
      }
      if (len > 0) {
        pw.print(s.substring(i));
        pw.print("\r\n");
      }
      pw.close();
    } catch (IOException e) {
      System.out.println(e);
    }
  }
}

new FileWriter(String fileName, boolean append)

  
import java.io.BufferedWriter;
import java.io.FileWriter;
public class Main {
  public static void main(String[] argv) throws Exception {
    BufferedWriter out = new BufferedWriter(new FileWriter("filename", true));
    out.write("aString");
    out.close();
  }
}

new FileWriter(String string)

  
/*
 * Output:
 *  
 */
import java.io.FileReader;
import java.io.FileWriter;
//copy file
public class MainClass {
  public static void main(String args[]) {
    try {
      FileReader fr = new FileReader(args[0]);
      FileWriter fw = new FileWriter(args[1]);
      int i;
      while ((i = fr.read()) != -1) {
        fw.write(i);
      }
      fw.close();
      fr.close();
    } catch (Exception e) {
      System.out.println("Exception: " + e);
    }
  }
}