erro java.lang.error System.in e System.out

bom dia, ta acontecendo um error estranho no meu codigo.

package br.com.alura.java.io.teste;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;

public class teste {
    public static void main(String[] args) throws IOException {

        System.out.println();
        InputStream fis = new System.in; //<---aqui
        InputStreamReader isr = new InputStreamReader(fis);
        BufferedReader br = new BufferedReader(isr);    

        OutputStream fos = new System.out; //<----aqui tbm;
        OutputStreamWriter osw = new OutputStreamWriter(fos);
        BufferedWriter bw = new BufferedWriter(osw);    

        String linha = br.readLine();

        while (linha != null && !linha.isEmpty()) {
            bw.write(linha);
            bw.newLine();
            bw.flush();
            linha = br.readLine();
        }
        br.close();
        bw.close();
    }

}

o seguinte erro aparece:

Exception in thread "main" java.lang.Error: Unresolved compilation problems: 
    System.in cannot be resolved to a type
    System.out cannot be resolved to a type

    at br.com.alura.java.io.teste.teste.main(teste.java:15)