java learning part2

input and output

文本界面的输入输出
1. 使用Scanner类
java.util.Scanner
nextInt();
nextDouble();
next();
Scanner scanner = new Scanner(System.in);
int a = scanner.nextInt();
System.out.printf("%d\n", a);

2. use java.io
System.in.read()
System.out.print()

输入一行
BufferedReader in = new BufferedReader(new InputStreamReader( System.in ));
s = in.readLine();
ss = in.readLine();
n = Integer.parseInt( ss );
d = Double.parseDouble( ss );

图形界面的输入输出
文本框 TextField 输入
标签 Label 输出
按钮Button 执行命令
首先需要创建一个Frame