星期四八点多左眼上跳:Java编程题！！！

JDK编译运行通过
import java.io.*;
public class multiply
{public static void main (String args[])
{try
{
BufferedReader read=new BufferedReader(new InputStreamReader(System.in));
System.out.println("请输入第一个数：");
double a=Double.parseDouble(read.readLine());
System.out.println("请输入第二个数：");
double b=Double.parseDouble(read.readLine());
System.out.println(a+"*"+b+"="+a*b);
}
catch(IOException e)
{}
}

import java.io.*;

public class Calculator {
public static void main (String[] args){
Multiply m = new Multiply();
m.start();
}
}

class Keyboard {
private static BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
public static String readInput() {
try {
return in.readLine();
}
catch (IOException e) {
System.out.println("An error has occurred in the Keyboard.readInput() method");
System.out.println(e.toString());
System.exit(-1);
}
return null;
}
}

class Multiply {
public void start() {
System.out.println("请输入第一个数字: ");
int firstNum = readInt();
System.out.println("请输入第二个数字: ");
int secondNum = readInt();
int result = firstNum * secondNum;
System.out.println(firstNum + " * " + secondNum + " = " + result);
//System.out.println("Your number was:" + inputNumber);
}
private int readInt() {
int output = Integer.parseInt(Keyboard.readInput());
return output;
}
}

注：主程序是 Calculator
Keyboard 是读取用户输入的 class
Multiply 是算法的 class

希望有所帮助，谢谢

public class Count
{
public static void main(String args[]){

int data1,data2;
data1=dat2=0;
System.out.println("Input the two data");
try{
BufferedReader in=new BufferedReader (new InputStreamReader(System.in));
data1=Integer.parsInt(in.read());
data2=Integer.parsInt(in.read());
System.out.println(data1+"*"+data2+"="+data1*data2);

}catch(Exception exc){
exc.printStackTrace();
}

}
}

以上做法不对，如果输入小数就会出现问题！

import java.io.*;
import java.math.BigDecimal;

class a_1
{
public static void main(String args[]) throws IOException
{
BufferedReader readin=new BufferedReader(new InputStreamReader(System.in));
System.out.println("Enter one number:");
//BufferedReader readin=new BufferedReader(new InputStreamReader(System.in));
String aa=readin.readLine();

System.out.println("Enter two number:");
String bb=readin.readLine();
//System.out.println(aa);

//BigDecimal a=new BigDecimal(aa);
//BigDecimal b=new BigDecimal(bb);
//BigDecimal bigRes=a.divide(b,20,a.ROUND_HALF_EVEN);

BigDecimal a=new BigDecimal(aa);
BigDecimal b=new BigDecimal(bb);

BigDecimal bigRes=a.multiply(b);

System.out.println(bigRes.toString());
}
}