KotlinでAPIを型安全にした話

Transcript

1. ,PUMJOͰ"1*Λܕ҆શʹͨ͠࿩ 
   3LU
   /PSJZVLJ
   *TIJEB 

2. ͍͋ͭ͝͞
   
   ࣗݾ঺հ
     ɾ໊લ
   /PSJZVLJ
   *TIJEB
    ɾαʔόαΠυʢ,PUMJO
   
   +BWB
   
   1)1
   
   1ZUIPO ɾΤϯδχΞ!3FUUZ ɾJ04
   4XJGU
   
   0CKFDUJWF$ ɾ"84΋ͦͦ͜͜৮Δ ɾ,PUMJOྺ
   ೥ϲ݄͘Β͍

   ɾ,PUMJO͔Θ͍͍ ɾ࠷ۙ,PUMJO͗ͯ͢͠+BWBΛ๨Ε͖ͯͨ ɾ,PUMJO/BUJWF
   ʹ΋ظ଴͍ͯ͠Δ IUUQTRJJUBDPNOPSJQJJUFNTFFDCEBDBGCE

3. ຊ೔ͷ͓࿩  ɾ,PUMJOΛಋೖͨ͠ܦҢ ɾ,PUMJOʹͯ͠Έͯײͨ͜͡ͱ

4. ࠃ಺/P
   ໊࣮άϧϝαʔϏε3FUUZͷӡӦ
   ೥ઃཱ
   XFCͱΞϓϦͰαʔϏεల։
   γϯάϧυϝΠϯ
   εϚϗϑΝʔετ
   ݄ؒར༻ऀ਺ສ 

5. 3FUUZ  ɾ8FC ɾΞϓϦ

6. ฐࣾʹ͓͚Δ,PUMJO  ɾΞϓϦ༻"1*ʹ,PUMJOΛ࢖͍ͬͯ·͢ ϒϥ΢β ΞϓϦ 8FCΞϓϦέʔγϣϯαʔό "1*αʔό %#

7. ,PUMJOΛಋೖͨ͠ܦҢ

8. 1)1Ͱ࡞ΒΕ͍ͯͨ"1*
     ɾ8FCΞϓϦέʔγϣϯʹ"1*Λੜ΍͍ͯͨ͠ ϒϥ΢β ΞϓϦ 8FCΞϓϦέʔγϣϯαʔό "1*αʔό %# ɾࣾ಺ʹ1)1Λॻ͚Δਓ͕ଟ͘։ൃεϐʔυ΋଎͍

9. 1)1Ͱ࡞ΒΕ͍ͯͨ"1*
     ɾ౰࣌ͷ"1*ͷಛ௃ ɾฦΓ஋͸΄΅+40/ܗ͕ࣜͩҧ͏͜ͱ΋͋Δ ɾ+40/ͷLFZʹೖΔ஋ͷܕ͕Ұҙʹఆ·Βͳ͍ ɾͲͷLFZʹͲΜͳ஋͕ೖͬͯ͘Δ͔ɺιʔείʔυΛݟͳ͍ͱ෼͔Βͳ͍ ɾ͍ͭͰ΋Ͳ͜Ͱ΋
   
   0, ΞϓϦ 8FCΞϓϦέʔγϣϯαʔό

   ˓˓ͷҰཡ͍ͩ͘͞ʂʢ͖ͬͱ"SSBZʣ GBMTF ɾฦΓ஋ͷόϦσʔγϣϯʢͦΕ͕ࣦഊ͔Ͳ͏͔΋ؚΊʣ͸ΫϥΠΞϯτଆͷ੹຿

10. 1)1͔Β+BWB΁  ɾ8FCΞϓϦέʔγϣϯͱ෼཭ͯ͠+BWB΁ ɾαʔόαΠυݴޠͱ࣮ͯ͠੷͕͋Γɺ'8΋๛෋ ɾΞϊςʔγϣϯͰ"1*ΛγϯϓϧʹఆٛͰ͖Δ+"934ͱ͍͏࢓༷͕͋Δ ΞϓϦ "1*αʔό ˓˓ͷҰཡ͍ͩ͘͞ʂʢ͖ͬͱ"SSBZʣ <\^
    \^>

    ɾฦΓ஋ͷܕΛ10+0 ී௨ͷ+BWBΦϒδΣΫτ Ͱࣄલʹఆٛ ˠ
    ܕ҆શͳ"1*ͰΞϓϦΤϯδχΞʹฏ࿨ͳੈքΛ ɾࣦഊͨ͠Β
    YY
    
    YY
    Λฦ͢

11. ɾ+BWBͩͬͨͷͰ݁ߏϞμϯͳॻ͖ํ͕Ͱ͖͍ͯͨ +BWB͔Β,PUMJO΁ͷҠߦ
      ɾ࣮͸Ҡߦ͢Δͭ΋Γ͸ͳ͔ͬͨ ɾ1)1ͷࠒͱൺ΂ͯ"1*͕֨ஈʹྑ͘ͳͬͯɺຬ଍͍ͯͨ͠

12. +BWB͔Β,PUMJO΁ͷҠߦ
      ɾҠߦͨ͠ཧ༝ ɾ͋Δ೔ಥવ͜Μͳ΋ͷ͕ ˠ
    ͓΋ΉΖʹ,PUMJO͕ಋೖ͞Εͨ

13. "1*ͷݱࡏ  ΏΔ΍͔ʹ,PUMJOԽΛਐߦத

14. ,PUMJOʹͯ͠Έͯײͨ͜͡ͱ

15.  ɾ͢ΜͳΓಋೖͰ͖Δ ɾطʹ+BWBͷϓϩμΫτ͕͋Δ৔߹ɺͦ͜ʹ,PUMJOΛೖΕΔͷ͸ͱͯ΋؆୯ ɾ+BWBͩͱಈ͍ͨͷʹॻ͖׵͑ͨΒಈ͔ͳ͘ͳͬͨɺͱ͍͏͜ͱ͸·ͣͳ͍ ,PUMJOʹͯ͠Έͯ ɾ͋Δ6UJMJUZ͚ͩॻ͖׵͑ͱ͍͏͜ͱ΋؆୯ ɾ,PUMJO͔Θ͍͍ ɾ/6--ڐ༰ܕ
    
    ܕਪ࿦
    
    ϥϜμ
    ͳͲϞμϯͳݴޠͷػೳΛҰ௨Γඋ͑Δ ɾ+BWB͔ΒͪΌΜͱίʔϧͰ͖ΔͷͰ+BWB͔͠ॻ͔ͳ͍ਓ͕͍ͯ΋҆৺ ɾൺֱతετϨεগͳ͘ॻ͚Δݴޠͷͭ

    ɾ࢖͑͹࢖͏΄ͲΑΓྑ͍ॻ͖ํ͕ݟ͔ͭͬͯ͘Δ

16. Ҡߦͯ͠ؾ͍ͮͨ,PUMJOͷϝϦοτ
      ɾ/VMMBCJMJUZΛίϯύΠϥϨϕϧͰఆٛͰ͖Δ ɾͦ΋ͦ΋1)1͔ΒҠߦͨ͠໨త͸ɺฦΓ஋ͷܕΛݫີʹఆٛ͢Δ͜ͱ ɾ+BWB࣌୅ʹ͸!/VMMBCMFΞϊςʔγϣϯͰදݱ͍͕ͯͨ͠ɺίϯύΠϥ
 ɹνΣοΫ͕ͳ͍ͨΊ࣮ଶͱҟͳ͍ͬͯͨ ɾΫϥΠΞϯτଆ͕0QUJPOBMͷػߏΛ࣋ͭݴޠͰॻ͔ΕΔ͜ͱ͕૿͖͍͑ͯͯΔ ˠ
    /6--ڐ༰͔Ͳ͏͔Λهड़͢Δ͜ͱ͸ɺܕΛهड़͢Δ
 ɹ
    ͜ͱͱಉ͘͡Β͍ॏཁ

17. Ҡߦͯ͠ؾ͍ͮͨ,PUMJOͷϝϦοτ
      ɾσʔλϗϧμΫϥεͷఆٛ ɾฦΓ஋ͷܕΛ10+0 ී௨ͷ+BWBΦϒδΣΫτ Ͱࣄલʹఆٛ͢Δඞཁ͕͋Δ ɾ+BWBͩͱఆٛ͢Δͷ͕ͪΐͬͱΊΜͲ͍͘͞ public class

    GetRestaurantResponse { private long restaurantId; private String restaurantName; public long getRestaurantId() { return this.restaurantId; } public String getRestaurantName() { return this.restaurantName; } }

18. Ҡߦͯ͠ؾ͍ͮͨ,PUMJOͷϝϦοτ
      ɾσʔλϗϧμΫϥεͷఆٛ ɾ,PUMJOͷ৔߹ɺEBUB
    DMBTTΛ࢖͑͹γϯϓϧʹهड़Ͱ͖Δ data class GetRestaurantResponse( val restaurantId:

    Long, val restaurantName: String )

19. Ҡߦͯ͠ؾ͍ͮͨ,PUMJOͷϝϦοτ
      ɾ$MBTT
    %FMFHBUJPO ɾجຊతͳܕΛ૊Έ߹ΘͤͯฦΓ஋Λ࡞Γ͍ͨέʔε͸ׂͱΑ͋͘Δ ɾ+BWBͩͱఆٛ͢Δͷ͕͍ͩͿΊΜͲ͍͘͞ public class GetReviewResponse implements

    IReview, IRestaurant, IUser { private IReview review; private IRestaurant restaurant; private IUser user; public long getReviewId() { return this.review.getReviewId(); } public String getUserName() { return this.user.getUserName(); } public String getRestaurantName() { return this.restaurant.getRestaurantName(); } ... }

20. Ҡߦͯ͠ؾ͍ͮͨ,PUMJOͷϝϦοτ
      ɾ$MBTT
    %FMFHBUJPO ɾΠϯλϑΣʔεͷ࣮૷ΛଞͷΫϥεʹҠৡͰ͖Δ ɾQSPQFSUZΛࡉ͔͘JOUFSGBDFԽ͓͚ͯ͠͹ɺฦΓ஋ΫϥεΛࡉ͔͘ఆٛՄೳʹ data class GetReviewResponse( private

    val review: IReview, private val restaurant: IRestaurant, private val user: IUser ) : IReview by review, IRestaurant by restaurant, IUser by user { // ෳ਺ͷinterfaceͰఆ͕͔ٛͿͬͯΔͱ͖͚ͩ໌ࣔతʹࢦఆ override val userId: Int = this.user.userId }

21. ·ͱΊ  ɾ,PUMJO
    
    
    ͸͢ΜͳΓಋೖͰ͖Δʂ
    ɾฐࣾͰ΋ɺ͋Δ೔͓΋ΉΖʹ,PUMJO͕௥Ճ͞Ε͔ͯͦ͜ΒঃʑʹҠߦ͍ͯ͠·͢ ɾ,PUMJOͷ͍͍ͱ͜Ζ
 ɾطʹ+BWBͷϓϩμΫτ͕͋Δ৔߹ɺͦ͜ʹ,PUMJOΛೖΕΔͷ͸ͱͯ΋؆୯ ɾ/VMMڐ༰ܕͰ֎෦ΠϯλϑΣʔεΛΑΓݫີʹఆٛͰ͖Δ ɾEBUB
    DMBTTΛ࢖ͬͯσʔλϗϧμΛγϯϓϧʹఆٛͰ͖Δ ɾ$MBTT
    %FMFHBUJPO ɾଞʹ΋͍Ζ͍Ζ