OO Design之SOLID原则

• Single Responsibility Principle（单一功能）
  • A class should have only one reason to change.
• Open Close Principle（开闭原则）
  • Software entities like classes, modules and functions should be open for extension but closed for modifications.
• Liskov's Substitution Principle（里氏替换）
  • Derived types must be completely substitutable for their base types.
• Interface Segregation Principle（接口隔离）
  • Clients should not be forced to depend upon interfaces that they don't use.
• Dependency Inversion Principle（依赖反转）
  • High-level modules should not depend on low-level modules. Both should depend on abstractions.
  • Abstractions should not depend on details. Details should depend on abstractions.

http://www.oodesign.com/design-principles.html