标准IO输入输出流

Java提供了三个静态变量

• System.in: 为InputStream类型,标准输入流,默认为键盘输入值
• System.out:为PrintStream类型,标准输出流,默认为控制台输出
• System.err:为PrintStream类型,代表错误输出流,默认为控制台输出

以下代码实现将键盘输入,输出到控制台,以回车键结束:

package com.perficient.javabasic.test;

import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;

public class IOTesting {
	public static void main(String[] args) throws IOException {
		
		int c;
		InputStreamReader in = new InputStreamReader(System.in);
		OutputStreamWriter out = new OutputStreamWriter(System.out);
			
		System.out.println("Please Enter the strings ended by Enter key:");
		while ((c = in.read())!= '\n'){
				out.write(c);
			}
			
		out.close();
		in.close();
}
}