Question

求高手用JAVA编写一个通用程序，计算交通工具运行1000KM所需要时间.

已知每种交通工具速度都是3个整数ABC的表达式，
其中Car007速度公式为A*B/C，Plane为A+B+C，
编写ComputeTime.java;Plane.java;Car007.java和接口Common.java
要求增加第三种交通工具时不必改动现有程序，只需编写新的交通工具程序

Answer 1

package test;
public interface Common {
public double computeSpeed(double a, double b, double c);
}
public class Car007 implements Common{
@Override
public double computeSpeed(double a, double b, double c) {
// TODO Auto-generated method stub
if(c == 0.0) {
throw new ArithmeticException("除数为0");
}
if( a * b < 0.0) {
try {
throw new Exception("速度不能为负数");
} catch (Exception e) {
// TODO Auto-generated catch block
System.out.println("a = " + a + "; b = " + b);
}
}
return a * b / c;
}
}
public class Plane implements Common{

@Override
public double computeSpeed(double a, double b, double c) {
// TODO Auto-generated method stub
if( a + b + c < 0.0) {
try {
throw new Exception("速度不能为负数");
} catch (Exception e) {
// TODO Auto-generated catch block
System.out.println("a = " + a + "; b = " + b + ";c = " + c);
}
}
return a + b + c;
}
}
public class ComputeTime {
/*
*调用时， s = 1000
*/
public double getTime(double s, double a, double b, double c) {
double time = Integer.MAX_VALUE;//表示车速为0，不可能到达
double speed = new Car007().computeSpeed(a, b, c);
if(!(speed == 0.0)) {
time = s / speed;
}
return time;
}
}
public class Test {

/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
System.out.println(new ComputeTime().getTime(1000, 10, 20, 30));
}

}
//计算结果：150.0

Answer 2

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