求出e=1+1/1!+1/2!+1/3!+……+1/n!+……的近似值的java applet程序

核心提示：//求出e=1+1/1!+1/2!+1/3!+……+1/n!+……的近似值,要求误差小于0.0001import java.applet.*;import java.awt.*;import java.awt.event.*;public class AT1_1

　　//求出e=1+1/1!+1/2!+1/3!+……+1/n!+……的近似值,要求误差小于0.0001import java.applet.*;import java.awt.*;import java.awt.event.*;public class AT1_1 extends Applet implements ActionListener{　TextField text1; Button Button1;　public void init() {　text1 = new TextField("0",10);　Button1 = new Button("清除");　add(text1);　add(Button1);　text1.addActionListener(this);　Button1.addActionListener(this); } public void start(){} public void stop(){} public void destory(){} public void paint(Graphics g) {　 g.drawString("在文本区输入数字n后回车",10,100);　g.drawString("文本区显示1+1/1!+1/2!+1/3!+……+1/n!+……的近似值",10,120); } public void actionPerformed(ActionEvent e) {　if(e.getSource()==text1)　{　 double sum=1,a=1;　 int i=1;　 int n=0;　 try　 {　 n = Integer.valueOf(text1.getText()).intValue();　 while(i<=n)　 {　　 a = a*(1.0/i);　　sum = sum + a;　　i=i+1;　 }　 sum=sum*10000;　 sum=Math.round(sum);　 sum=sum/10000;　 text1.setText(""+sum);　　 }　 catch(NumberFormatException Event)　 {　 text1.setText("请输入数字字符");　 }　}　else if(e.getSource()==Button1)　{　 text1.setText("0");　}　 }}