java:system根据输入的内容，然后输出

//限制读取的字符长度
		InputStream ips = System.in;
		byte b[] = new byte[20];
		System.out.println("请输入:");
		int len = ips.read(b);
		System.out.println( new String(b, 0, len)  );
		
		
		//不限制读取的输入的字符长度
		InputStream ipt = System.in;
		System.out.println("请输入:");
		int temp = 0;
		StringBuffer buff = new StringBuffer();
		while( (temp = ipt.read()) !=-1 )
		{
			
			char c = (char)temp;
			//判断是否打回车键
			if(c == ‘\n‘)
			{
				break;
			}
			buff.append(c);
		}
		System.out.println("输入的字符是：" + buff );