1. public abstract class Computer {
    2.     public abstract String getRAM();
    4.     public abstract String getHDD();
    6.     public abstract String getCPU();
    8.     @Override
    9.     public String toString() {
    10.         return "RAM= " + this.getRAM() + ", HDD=" + this.getHDD() + ", CPU=" + this.getCPU();
    11.     }
    12. }
    1. public class PC extends Computer{
    2.     private String ram;
    3.     private String hdd;
    4.     private String cpu;
    6.     public PC() {
    7.     }
    8.     public PC(String ram, String hdd, String cpu) {
    9.         this.ram = ram;
    10.         this.hdd = hdd;
    11.         this.cpu = cpu;
    12.     }
    14.     @Override
    15.     public String getRAM() {
    16.         return this.ram;
    17.     }
    19.     @Override
    20.     public String getHDD() {
    21.         return this.hdd;
    22.     }
    24.     @Override
    25.     public String getCPU() {
    26.         return this.cpu;
    27.     }
    28. }
    1. public class Server extends Computer {
    2.     private String ram;
    3.     private String hdd;
    4.     private String cpu;
    6.     public Server() {
    7.     }
    8.     public Server(String ram, String hdd, String cpu) {
    9.         this.ram = ram;
    10.         this.hdd = hdd;
    11.         this.cpu = cpu;
    12.     }
    14.     @Override
    15.     public String getRAM() {
    16.         return this.ram;
    17.     }
    19.     @Override
    20.     public String getHDD() {
    21.         return this.hdd;
    22.     }
    24.     @Override
    25.     public String getCPU() {
    26.         return this.cpu;
    27.     }
    28. }
    1. public class ComputerFactory {
    2.     /*使用 字符串 + 分支选择，来创建指定的子对象*/
    3.     public static Computer getComputer(String type, String ram, String hdd, String cpu) {
    4.         if ("PC".equalsIgnoreCase(type)) {
    5.             return new PC(ram, hdd, cpu);
    6.         } else if ("Server".equalsIgnoreCase(type)) {
    7.             return new Server(ram, hdd, cpu);
    8.         }
    9.         return null;
    10.     }
    12.     /*使用反射调用无参构造函数创建对象*/
    13.     public static Computer getComputer(Class<? extends Computer> classType) {
    14.         System.out.println("classType.getName() = " + classType.getName());
    15.         Computer obj = null;
    16.         try {
    17.             obj = (Computer) Class.forName(classType.getName()).getDeclaredConstructor().newInstance();
    18.         } catch (InstantiationException | NoSuchMethodException | InvocationTargetException | ClassNotFoundException | IllegalAccessException e) {
    19.             e.printStackTrace();
    20.         }
    21.         return obj;
    22.     }
    24.     /*使用反射条用有参构造函数创建对象*/
    25.     public static Computer getComputer(Class<? extends Computer> classType, String ram, String hdd, String cpu) {
    26.         System.out.println("classType.getName() = " + classType.getName());
    27.         Computer obj = null;
    28.         try {
    29.             Constructor<?> constructor = Class.forName(classType.getName()).getConstructor(String.class, String.class, String.class);
    30.             obj = (Computer) constructor.newInstance(ram, hdd, cpu);
    31.         } catch (InstantiationException | NoSuchMethodException | InvocationTargetException | ClassNotFoundException | IllegalAccessException e) {
    32.             e.printStackTrace();
    33.         }
    34.         return obj;
    35.     }
    36. }
    1. public class Client {
    3.     /*public static void main(String[] args) {
    4.         Computer pc = ComputerFactory.getComputer("pc", "2 GB", "500 GB", "2.4 GHz");
    5.         Computer server = ComputerFactory.getComputer("server", "16 GB", "1 TB", "2.9 GHz");
    6.         System.out.println("Factory PC Config::" + pc);
    7.         System.out.println("Factory Server Config::" + server);
    8.     }*/
    10.     /*public static void main(String[] args) {
    11.         Computer computer = ComputerFactory.getComputer(PC.class);
    12.         System.out.println("computer = " + computer);
    13.     }*/
    15.     public static void main(String[] args) {
    16.         Computer pc = ComputerFactory.getComputer(PC.class, "2 GB", "500 GB", "2.4 GHz");
    17.         Computer server = ComputerFactory.getComputer(Server.class, "16 GB", "1 TB", "2.9 GHz");
    18.         System.out.println("Factory PC Config::" + pc);
    19.         System.out.println("Factory Server Config::" + server);
    20.     }
    21. }