W9_Live-Object-Oriented Programming and Design Principles

(1) Page 11

如何理解这两句话
image.png

(2) Page 31-36

两个 code 例子对比，没看懂如何体现了More Generic的思想
两个code例子转译在下面两个代码块了，缩进之类的重排之后应该没有破坏原意。。。应该没有。。。
(在PPT直接贴代码的英方是屑)

  1. public class Card {  // Class to represent playing cards.
  2.     private int suit;  // Number from 0 to 3 that codes for the suit --
  3.                        // spades, diamonds, clubs or hearts.
  4.     private int value; // Number from 1 to 13 that represents the value.
  5.     public boolean equals(Object obj) {
  6.         try {
  7.             Card other = (Card)obj;  // Type-cast obj to a Card.
  8.             if (suit == other.suit && value == other.value) {
  9.                 // The other card has the same suit and value as
  10.                 return true;
  11.             }
  12.             else return false;
  13.         }
  14.         catch (Exception e) {
  15.             // This will catch the NullPointerException that occurs if obj
  16.             // is null and the ClassCastException that occurs if obj is
  17.             // not of type Card.  In these cases, obj is not equal to
  18.             // this Card, so return false.
  19.             return false;
  20.         }
  21.     }
  22.     // other methods and constructors
  23. }
  1. /**
  2. * Represents a full name consisting of a first name and a last name.
  3. */
  4. public class FullName implements Comparable<FullName> {
  5.     private String firstName, lastName;  // Non-null first and last names.
  6.     public FullName(String first, String last) {  // Constructor.
  7.         if (first == null || last == null)
  8.             throw new IllegalArgumentException("Names must be non-null.");
  9.         firstName = first;
  10.         lastName = last;
  11.     }
  13.     public boolean equals(Object obj) {
  14.         try {
  15.             FullName other = (FullName)obj;  // Type-cast obj to type 
  16.             FullName
  17.             return firstName.equals(other.firstName) && lastName.equals(other.lastName);
  18.         }
  19.         catch (Exception e) {
  20.             return false;  // if obj is null or is not of type FullName
  21.         }
  22.     }
  24.     public int compareTo( FullName other ) {
  25.         if ( lastName.compareTo(other.lastName) < 0 ) {
  26.         // If lastName comes before the last name of
  27.         // the other object, then this FullName comes
  28.         // before the other FullName.  Return a negative
  29.         // value to indicate this.
  30.         return -1;
  31.         }
  32.         else if ( lastName.compareTo(other.lastName) > 0 ) {
  33.             // If lastName comes after the last name of
  34.             // the other object, then this FullName comes
  35.             // after the other FullName.  Return a positive
  36.             // value to indicate this.
  37.             return 1；
  38.         }
  39.         else {
  40.             // Last names are the same, so base the comparison on
  41.             // the first names, using compareTo from class String.
  42.             return firstName.compareTo(other.firstName);
  43.         }
  44.     }
  45.     // other methods and constructors
  46. }

W9_Rec-Design_Principles-1

(1) Page 63

这一页的内容没看懂
image.png

W10_Live_Designing_Programs_Networking_and_Defensive_Programming

(1) Page 7

这一页都不是特别懂，尤其是最后一个点
image.png

(2) Page 13

红框的这点没太懂
image.png

W11_Rec_Design_Patterns

(1) Page 37-41

工厂方法懂了，但没完全懂