import java.io.*;

public class Test {

    public static void main(String args[]) {

        try {

            String s="ABCDE";

            byte b[]=s.getBytes();

            FileOutputStream file=new FileOutputStream("test.txt",true);

            file.write(b);

            file.close();

        }

        catch(IOException e) {

            System.out.println(e.toString());

        }

    }

}

File f = new File(填代码处);

file =new FileReader(f);

in=new BufferedReader(file);

class A {

    public void show() {

        System.out.println("数字");

    }

}

class B extends A {

    @Override

    public void show() {

        System.out.println("技术");

    }

}

class C extends A {

    @Override

    public void show() {

        System.out.println("产业");

    }

}

class D extends A {

    @Override

    public void show() {

        System.out.println("学院");

    }

}

public class Test {

    public static void main(String[] args) {

               A a = new B();

                 a.show();

}

}

public class Demo {

public static void main(String[] args) {

char ch = 'c';

switch (ch) {

case 'a':

System.out.print("a");

break;

case 'b':

System.out.print("ab");

case 'c':

System.out.print("c");

default:

System.out.print("d");

}

}

}

public class Test {

public static void main(String[] args) {

int i = 0, sum = 0;

while (i <= 10) {

sum += i;

i++;

if (i % 2 == 0)

continue;

}

System.out.println(sum);

}

}