用 Groovy 减少代码冗余

    
import java.math.BigDecimal;

public class Bike {
   private String manufacturer;
   private String model;
   private int frame;
   private String serialNo;
   private double weight;
   private String status;
   private BigDecimal cost;

   public Bike(String manufacturer,String model,int frame,
     String serialNo,double weight,String status) {
      this.manufacturer = manufacturer;
      this.model = model;
      this.frame = frame;
      this.serialNo = serialNo;
      this.weight = weight;
      this.status = status;
   }

   public String toString() {
      return "com.springbook.Bike : " +
            "manufacturer -- " + manufacturer +
            "/n: model -- " + model +
            "/n: frame -- " + frame +
            "/n: serialNo -- " + serialNo +
            "/n: weight -- " + weight +
            "/n: status -- " + status +
            "./n"; }

   public String getManufacturer() { return manufacturer; }

   public void setManufacturer(String manufacturer) {
      this.manufacturer = manufacturer;
   }

   public String getModel() { return model; }

   public void setModel(String model) { this.model = model; }

   public int getFrame() { return frame; }

   public void setFrame(int frame) { this.frame = frame; }

   public String getSerialNo() { return serialNo; }

   public void setSerialNo(String serialNo) { this.serialNo = serialNo; }

   public double getWeight() { return weight; }

   public void setWeight(double weight) { this.weight = weight; }

   public String getStatus() { return status; }

   public void setStatus(String status) { this.status = status; }

   public BigDecimal getCost() { return cost; }

   public void setCost(BigDecimal cost) {
     this.cost = cost.setScale(3,BigDecimal.ROUND_HALF_UP);
   }

}  

  
class Bike {

  String manufacturer
  String model
  Integer frame
  String serialNo
  Double weight
  String status
  BigDecimal cost

  public void setCost(BigDecimal newCost) {
    cost = newCost.setScale(3,BigDecimal.ROUND_HALF_UP)
  }


  public String toString() {
    return """Bike:
         manufacturer --  ${manufacturer} 
         model -- ${model}
         frame -- ${frame} 
         serialNo -- ${serialNo}  
      """
  }
}

  
class BikeTest extends GroovyTestCase {
  void testBike() {
    // Groovy way to initialize a new object
    def b = new Bike(manufacturer:"Shimano",model:"Roadmaster")

    // explicitly call the default accessors
    assert b.getManufacturer() == "Shimano"
    assert b.getModel() == "Roadmaster"

    // Groovier way to invoke accessors
    assert b.model == "Roadmaster"
    assert b.manufacturer == "Shimano"
  }
}

  
import java.util.List;

public interface RentABike {
   List getBikes();
   Bike getBike(String serialNo);
   void setStoreName(String name);
   String getStoreName();
}

    
import java.util.List;
import java.util.ArrayList;
import java.util.Iterator;

public class ArrayListRentABike implements RentABike {
   private String storeName;
   final List bikes = new ArrayList();

   public void setStoreName(String name) {
      this.storeName = name;
   }

   public String getStoreName() {
      return storeName;
   }

   public ArrayListRentABike(String storeName) {
      this.storeName = storeName;
      bikes.add(new Bike("Shimano","Roadmaster",20,"11111",15,"Fair"));
      bikes.add(new Bike("CannonDale","F2000 XTR",18,"22222",12,"Excellent"));
      bikes.add(new Bike("Trek","6000",19,"33333",12.4,"Fair"));
   }

   public String toString() { return "com.springbook.RentABike: " + storeName; }

   public List getBikes() { return bikes; }

   public Bike getBike(String serialNo) {
      Iterator iter = bikes.iterator();
      while(iter.hasNext()) {
         Bike bike = (Bike)iter.next();
         if(serialNo.equals(bike.getSerialNo())) return bike;

      }
      return null;
   }
}

  
public class ArrayListRentABike {
  String storeName
  List bikes = []
  public ArrayListRentABike(){		
    // add new instances of Bike using Groovy's initializer Syntax
    bikes << new Bike(manufacturer:"Shimano",model:"Roadmaster",
      frame: 20,serialNo:"11111",weight:15,status:"Fair")
    bikes << new Bike(manufacturer:"CannonDale",model:"F2000",
      frame: 18,serialNo:"22222",weight:12,status:"Excellent")
    bikes << new Bike(manufacturer:"Trek",model:"6000",
      frame: 19,serialNo:"33333",weight:12.4,status:"Fair")
  }

  // Groovy returns the last value if no return statement is specified
  public String toString() { "Store Name:=" + storeName }

  // Find a bike by the serial number
  def getBike(serialNo) { bikes.find{it.serialNo == serialNo} }

}

  
public class CommandLineView {
   private RentABike rentaBike;

   public CommandLineView() {}

   public void setRentaBike(RentABike rentaBike) {
      this.rentaBike = rentaBike;
   }

   public RentABike getRentaBike() { return this.rentaBike; }

   public void printAllBikes() {
      System.out.println(rentaBike.toString());
      Iterator iter = rentaBike.getBikes().iterator();
      while(iter.hasNext()) {
         Bike bike = (Bike)iter.next();
         System.out.println(bike.toString());
      }
   }
}

  
public class CommandLineView {
  def rentaBike  // no interface or concrete type required,duck typing in action

  def printAllBikes() {
    println rentaBike
    rentaBike.bikes.each{ println it}  // no iterators or casting
  }
}

        
<beans>
    <bean id="rentaBike" class="ArrayListRentABike">
        <property name="storeName"><value>"Bruce's Bikes (spring bean)"</value></property>
    </bean>
    <bean id="commandLineView" class="CommandLineView">
        <property name="rentaBike"><ref bean="rentaBike"/></property>
    </bean>
</beans>

  
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class RentABikeAssembler {
   public static final void main(String[] args) {
      // Create a Spring application context object
      ClassPathXmlApplicationContext ctx = 
        new ClassPathXmlApplicationContext("RentABike-context.xml");

      // retrieve an object from Spring and cast to a specific type
      CommandLineView clv = (CommandLineView)ctx.getBean("commandLineView");

      clv.printAllBikes();
   }
}

  
import org.springframework.context.support.ClassPathXmlApplicationContext

class RentABikeAssembler {
  public static final void main(String[] args) {
    // Create a Spring application context object
    def ctx = new ClassPathXmlApplicationContext("RentABike-context.xml")

    //Ask Spring for an instance of CommandLineView,with a 
    //Bike store implementation set by Spring
    def clv = ctx.getBean("commandLineView")

    //duck typing again
    clv.printAllBikes()
  }
}