20070329 Object Oriented Programing Tips
0 likes410 views
The document discusses several design patterns including strategy, template method, factory method, command, state, null object, and dependency injection. It provides examples of how each pattern can be implemented in code by defining interfaces and classes that implement the pattern. The examples demonstrate how different design patterns address common programming problems by organizing code in a reusable and flexible manner.
More Related Content
What's hot (20)
Viewers also liked (13)
Similar to 20070329 Object Oriented Programing Tips (20)
More from Shingo Furuyama (12)
Recently uploaded (20)
20070329 Object Oriented Programing Tips
- 2. M
- 3. public class Shape{ protected int h,w; public void setWidth(int w){ this.w = w; } public void setHeight(int h){ this.h = h; → } } public class Rectangele extends Shape{ } public class Square extends Rectangle{ protected int h,w; public void setWidth(int w){ this.w = w; → this.h = h; } public void setHeight(int h){ this.w = w; this.h = h; } }
- 4. LSP public class Shape{ protected int h,w; ArrayList<Rectangele> list public void setWidth(int w){ = new ArrayList<Rectangele>(); this.w = w; } public void setHeight(int h){ for(Rectangler r : list){ } this.h = h; r.setWidth(20); } r.setHeight(10); } public class Rectangele extends Shape{ } public class Square extends Rectangle{ protected int h,w; public void setWidth(int w){ this.w = w; this.h = h; } List Square public void setHeight(int h){ this.w = w; this.h = h; } }
- 5. public class User{ public void dosth(Shape s){ public Interface Shape{ s.dosth(); public void dosth(); } } } public class Rectangle implements Shape{ public class Square implements Shape{ public void dosth(){ public void dosth(){ System.out.println(“do something”); System.out.println(“do something”); } } } } Light Weight POJP Plain Old Java Object
- 6. Gof 23 new →
- 7. Temprate Method Strategy Factory Method Command State Null Object
- 8. Template Method public abstract class DBInterface{ public class OracleInterface extends DBInterface{ public Date getData(){ protected void init(){ init(); // Data data = getData(); exit(); return data; } } protected Data getData(){ protected abstract void init(); // protected abstract Data getData(); } protected abstract void exit(); protected void exit(){ } // } extends }ublic class FireBirdInterface extends DBInterface{ p //// } Data DBInterface = =public
- 9. Strategy public Interface DBInterface{ public class OracleInterface implements DBInterface{ public void init(); public void init(){ public Data getData(); // public void exit(); } } public Data getData(){ // } implements public void exit(){ // } } public class FireBirdInterface implements DBInterface{ //// } Template DBInterface
- 10. Template Method Strategy public class TemlePrinter { Template Method main(){ DBInterface di = new OracleInterface(); print(di.getData()); uses } getData() } public class StratPrinter { main(){ Strategy DBInterface di = new OracleInterface(); di.init() print(di.getData()); uses init() getData() di.exit(); } exit() } Template Method Strategy = Template Method Strategy Strategy init DB Template Method
- 11. Factory Method public Interface Bond{ public Interface BondFactory{ creates public int getMaturity(); public Bond getBondInstance(); public BigDecimal getFairValue(); } } implements implements public class TreasuryFactory implements BondFactory{ public class Treasury implements Bond{ public Bond getBondInstance(){ //// return new Treasury(); } } } public class ConvertibleFactory implements BondFactory{ public class Convertible implements Bond{ public Bond getBondInstance(){ //// return new Convertible(); } } } Bond Strategy Template Factory Factory
- 12. Command public class User{ public void dosth(Tranzaction t,String id){ t.do(id); public Interface Tranzaction{ } public void do(String id); } } public class addCommand implements Tranzaction{ public void do(String id){ // } } public class removeCommand implements Tranzaction{ public void do(String id){ // } }
- 13. State public class User{ State s = n; public void dosth(){ public Interface State{ s.do(); public int do(); } } } public class GoodState implements State{ public void do(){ System.ouit.println(“Good State”); } } public class BadState implements State{ public void do(){ System.ouit.println(“Good State”); } }
- 14. Null Object Null public class User{ public void dosth(Tranzaction t,String id){ public Interface Tranzaction{ t.do(id); public void do(String id); } } } public class NullCommand implements Tranzaction{ public void do(String id){ // } }
- 15. DI Dipendency Injection public class User{ public void dosth(Tranzaction t,String id){ t.do(id); public Interface Tranzaction{ } public void do(String id); } } DI Tranzaction public class removeCommand implements Tranzaction{ public void do(String id){ // } }
- 16. DI new – – DI – Spring – Seaser2 – EJB 3.0