carshop.java

java 完全探索的随书源码

/*
 * CarShop
 */
import java.lang.reflect.*;

public class CarShop {
  Car carList[];

  public CarShop( String[] carTypes ) {
    // create and start a car of each specified type
    carList = new Car[carTypes.length];
    for ( int i=0; i<carTypes.length; i++ ) {
      carList[i] = createCar(carTypes[i], new TireSpecification());
      startCar( carList[i] );
    }
  }


  public Car createCar(String carName, TireSpecification tires) {
    Car newCar = null;
    try {
      Object constructorParam[] = new TireSpecification[1];
      constructorParam[0]= tires;

      // get the class name for the car that you want
      Class carClass = Class.forName(carName);

      // create an array of Classes, and use this to
      // array to find the constructor that you want
      Class parameters[] = new Class[1];
      parameters[0]= TireSpecification.class;
      Constructor  con = carClass.getDeclaredConstructor(parameters);

      // create a car instance for the carList
      newCar = (Car)con.newInstance(constructorParam);
    }
    catch (Exception e) {
      System.out.println("Error creating " + carName);
    }
    return newCar;
  }

  public void startCar(Car theCar) {
    try {
      // Define a zero-length Class array to represent
      // the empty parameter list of the start method
      Class parameters[] = new Class[0];
      Class carType = theCar.getClass();
      Method meth = carType.getDeclaredMethod("start", parameters);

      // invoke the method on the specified car
      meth.invoke(theCar,parameters);
    }
    catch (Exception e) {
      System.out.println("Error starting car: " + e);
    }
  }

  // supply names of car types as command line arguments
  public static void main( String args[] ) {
    // create a car shop that contains the specified car types
    CarShop shop = new CarShop( args );
    for ( int i=0; i<shop.carList.length; i++ ) {
      System.out.println( shop.carList[i] );
    }
  }
}