Java/File Input Output/InputStreamReader

Create BufferedReader from InputStreamReader

 
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import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
public class Standard {
  public static void main(String args[]) throws IOException {
    BufferedReader cin = new BufferedReader(new InputStreamReader(System.in));
    String number;
    int total = 0;
    while ((number = cin.readLine()) != null) {
      try {
        total += Integer.parseInt(number);
      } catch (NumberFormatException e) {
        System.err.println("Invalid number in input");
        System.exit(1);
      }
    }
    System.out.println(total);
  }
}

Create BufferedReader from InputStreamReader and read line by line

 

import java.io.BufferedReader;
import java.io.InputStreamReader;
class ReadConsole {
  public static void main(String args[]) throws Exception {
    InputStreamReader isr = new InputStreamReader(System.in);
    BufferedReader br = new BufferedReader(isr);
    String s;
    while ((s = br.readLine()) != null) {
      System.out.println(s.length());
    }
    isr.close();
  }
}

Create BufferedReader from InputStreamReader and URL

 
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.URL;
public class Main {
  public static void main(String[] args) throws Exception {
    URL myURL = new URL("http://www.google.ru");
    BufferedReader so = new BufferedReader(new InputStreamReader(myURL.openStream()));
    while (true) {
      String output = so.readLine();
      if (output != null) {
        System.out.println(output);
      } else {
        break;
      }
    }
    so.close();
  }
}

Deal with Keyboard Input with BufferedReader

 
import java.io.BufferedReader;
import java.io.InputStreamReader;
public class Main {
  public static void main(String[] argv) throws Exception {
    System.out.print("Enter your name: ");
    InputStreamReader reader = new InputStreamReader(System.in);
    BufferedReader in = new BufferedReader(reader);
    String name = in.readLine();
    System.out.println("Hello, " + name + ". Enter three ints...");
    int[] values = new int[3];
    double sum = 0.0;
    for (int i = 0; i < values.length; i++) {
      System.out.print("Number " + (i + 1) + ": ");
      String temp = in.readLine();
      values[i] = Integer.parseInt(temp);
      sum += values[i];
    }
    System.out.println("The average equals " + sum / values.length);
  }
}

Reading ISO Latin-1 Encoded Data

 
import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.InputStreamReader;
public class Main {
  public static void main(String[] argv) throws Exception {
    BufferedReader in = new BufferedReader(new InputStreamReader(new FileInputStream("infilename"),
        "8859_1"));
    String str = in.readLine();
    System.out.println(str);
  }
}