개발자 용이~

package ch04;

import java.io.*;

public class FileView2 {

  public static void main(String[] args) {

    if (args.length != 1) {

      System.out.println("사용법 : java FileView2 파일명");

      System.exit(0);

    }

    FileInputStream fis = null;

    try {

      fis = new FileInputStream(args[0]);

      int readcount = 0;

      byte[] buffer = new byte[512];

      while ( (readcount = fis.read(buffer)) != -1 ) {

        System.out.write(buffer, 0, readcount);

      }

    } catch (Exception e) {

      e.printStackTrace();

    } finally {

      try {

        fis.close();

      } catch (IOException e) {

        e.printStackTrace();

      }

    }

  }

}

int i = 0;

while ((i = fis.read()) != -1) {

  System.out.write(i);

}

package ch04;

import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.io.IOException;

public class FileStreamCopy {

  public static void main(String[] args) {

    if (args.length != 2) {

      System.out.println("사용법 : java FileStreamCopy 파일1 파일2");

      System.exit(0);

    }

    FileInputStream fis = null;

    FileOutputStream fos = null;

    try {

      fis = new FileInputStream(args[0]);

      fos = new FileOutputStream(args[1]);

      byte[] buffer = new byte[512];

      int readCount = 0;

      while ( (readCount = fis.read(buffer)) != -1 ) {

        fos.write(buffer, 0, readCount);

      }

      System.out.println("복시가 완료되었습니다.");

    } catch (Exception e) {

      e.printStackTrace();

    } finally {

      try {

        fis.close();

      } catch (IOException e) {

        e.printStackTrace();

      }

      try {

        fos.close();

      } catch (IOException e) {

        e.printStackTrace();

      }

    }

  }

}

package ch03;

public class InheritanceTest {

  public static void main(String[] args) {

    FirstChild fc = new FirstChild();

    System.out.println(fc.read());

    SecondChild sc = new SecondChild();

    System.out.println(sc.read());

    ThirdChild tc1 = new ThirdChild(fc);

    System.out.println(tc1.read());

    ThirdChild tc2 = new ThirdChild(sc);

    System.out.println(tc2.read());

  }

}

class Parent {

  public String read() {

    return "Parent 입니다.";

  }

}

class FirstChild extends Parent {

  @Override

  public String read() {

    return super.read() + ": FirstChild";

  }

}

class SecondChild extends Parent {

  @Override

  public String read() {

    return super.read() + ": SecondChild";

  }

}

class ThirdChild extends Parent {

  Parent p;

  public ThirdChild(Parent p) {

    this.p = p;

  }

  @Override

  public String read() {

    return p.read() + ": ThirdChild";

  }

}

package ch03;

class Parent2 {

  int i = 7;

  public int get() {

    return i;

  }

}

class Child2 extends Parent2 {

  int i = 5;

  @Override

  public int get() {

    return i;

  }

}

public class ChildTest {

  public static void print(Parent2 p) {

    System.out.println(p.i);

    System.out.println(p.get());

  }

  public static void main(String[] args) {

    Parent2 p = new Parent2();

    System.out.println("----- 1 -----");

    System.out.println(p.i);

    System.out.println(p.get());

    Child2 c = new Child2();

    System.out.println("----- 2 -----");

    System.out.println(c.i);

    System.out.println(c.get());

    Parent2 p2 = new Child2();

    System.out.println("----- 3 -----");

    System.out.println(p2.i);

    System.out.println(p2.get());

    System.out.println("----- 4 -----");

    print(c);

    print(p2);

  }

}

import java.io.*;

public class BufferdReaderTest {

  public static void main(String[] args) {

    InputStreamReader isr = new InputStreamReader(System.in);

    BufferedReader br = new BufferedReader(isr);

    String line;

    try {

      line = br.readLine();

      System.out.println("키보드로 부터 입력받은 문자열 : " + line);

    } catch (IOException e) {

      e.printStackTrace();

    }

  }

}

InputStreamReader isr = new InputStreamReader(System.in);

BufferedReader br = new BufferedReader(isr);

// 은행 계좌

class BankAccount {

  private int balance = 100; // 잔고 100달러

  // 잔고 확인

  public int getBalance() {

    return balance;

  }

  // 인출

  public void withdraw(int amount) {

    balance = balance - amount;

  }

}

public class RyanAdnMonicaJob implements Runnable {

  private BankAccount account = new BankAccount();

  public static void main(String[] args) {

    RyanAdnMonicaJob theJob = new RyanAdnMonicaJob(); // Runnable갹체의 인스턴스 만들기

    // 똑같은 통장(똑같은 인스턴스)을 사용하는 두개의 쓰레드를 만듭니다.)

    Thread one = new Thread(theJob);

    Thread two = new Thread(theJob);

    one.setName("Ryan");

    two.setName("Monica");

    one.start();

    two.start();

  }

  public void run() {

    for (int x = 0; x < 10; x++) {

      makeWithdrawal(10);

      if (account.getBalance() < 0)

        System.out.println("Overdrawn!!");

    }

  }

  private void makeWithdrawal(int amount) {

    if (account.getBalance() >= amount) {

      System.out.println(Thread.currentThread().getName()

          + " is about to withdraw");

      try {

        System.out.println(Thread.currentThread().getName()

            + " is going to sleep!!");

        Thread.sleep(1000);

      } catch (InterruptedException ex) {

        ex.printStackTrace();

      }

      System.out.println(Thread.currentThread().getName() + " work up.");

      account.withdraw(amount);

      System.out.println(Thread.currentThread().getName()

          + " completes the withdrawal");

      System.out.println("잔고가 " + account.getBalance() + "달러 남았습니다.");

    } else {

      System.out.println("*Sorry, not enough for "

          + Thread.currentThread().getName());

    }

  }

}