从零自学Java-10.充分利用现有对象

package com.jsample; import java.util.*; public class StringLister {
String[] names = { "Spanky", "Buckwheat", "Daria",
"Stymie", "Marianne", "Scotty", "Tommy", "Chubby" }; public StringLister(String[] moreNames){
Vector<String> list = new Vector<String>();
for (int i = 0; i < moreNames.length; i++){
list.add(moreNames[i]);
}
Collections.sort(list);
for (String name : list){
System.out.println(name);
}
} public static void main(String[] args){
StringLister lister = new StringLister(args);
}
}

package com.jsample; import java.awt.*; public class PointTester {
public static void main(String[] args){
Point objcet1 = new Point(11,22);
Point3D object2 = new Point3D(7,6,64);
Point4D object3 = new Point4D(12,56,73,90); System.out.println("The 2D point is located at (" + objcet1.x
+ ", " + objcet1.y + ")");
System.out.println("\tIt's being moved to (4,13)");
objcet1.move(4,13);
System.out.println("The 2D point is now at (" + objcet1.x
+ ", " + objcet1.y + ")");
System.out.println("\tIt's being moved -10 units on the x "
+ "and y axes");
objcet1.translate(-10,-10);
System.out.println("The 2D point ends up at (" + objcet1.x
+ ", " + objcet1.y + ")\n"); System.out.println("The 3D point is located at (" + object2.x
+ ", " + object2.y + ", " + object2.z + ")");
System.out.println("\tIt's being moved to (10, 22, 71)");
object2.move(10,22,71);
System.out.println("The 3D point is now at (" + object2.x
+ ", " + object2.y + ", " + object2.z +")");
System.out.println("\tIt's being moved -20 units on the x,y "
+ "and z axes");
object2.move(-20,-20,-20);
System.out.println("The 3D point ends up at (" + object2.x
+ ", " + object2.y + ", " + object2.z + ")\n"); System.out.println("The 4D point is located at (" + object3.x
+ ", " + object3.y + ", " + object3.z + ", " + object3.t + ")");
System.out.println("\tIt's being moved to (9, 1, 7, 4)");
object3.move(9,1,7,4);
System.out.println("The 4D point is now at (" + object3.x
+ ", " + object3.y + ", " + object3.z + ", " + object3.t + ")");
System.out.println("\tIt's being moved 20 units on the x,y "
+ "and z axes");
object3.move(20,20,20,20);
System.out.println("The 4D point ends up at (" + object3.x
+ ", " + object3.y + ", " + object3.z + ", " + object3.t + ")");
}
}

package com.jsample; import java.awt.*; public class Point3D extends Point{
public int z; public Point3D(int x, int y, int z){
super(x,y);
this.z=z;
} public void move(int x, int y, int z){
this.z += z;
super.translate(x,y);
}
}

package com.jsample; public class Point4D extends Point3D{
public int t; public Point4D(int x, int y, int z, int t){
super(x,y,z);
if (t < 0)
return;
this.t = t;
} public void move(int x, int y, int z, int t){
this.z += z;
this.t += t;
super.translate(x,y);
}
}