Java IO流 改變標準輸入輸出設備

改變標準輸入輸出設備

通過System類中的setIn和setOut方法

package test;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintStream;

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

		System.setIn(new FileInputStream("PersonDemo.java"));

		System.setOut(new PrintStream("zzz.txt"));

		// 鍵盤的最常見寫法。
		BufferedReader bufr = new BufferedReader(new InputStreamReader(
				System.in));

		BufferedWriter bufw = new BufferedWriter(new OutputStreamWriter(
				System.out));

		String line = null;

		while ((line = bufr.readLine()) != null) {
			if ("over".equals(line))
				break;
			bufw.write(line.toUpperCase());
			bufw.newLine();
			bufw.flush();
		}

		bufr.close();

	}
}