Stream API 入門 #jjug #javajo

Java女子部「Java本格入門！！！著者をお招きしちゃうよ(*´∀`*) 」
https://javajo.doorkeeper.jp/events/60742

JJUG ナイトセミナー 「Java エンジニアのためのJava(再)入門」
https://jjug.doorkeeper.jp/events/61857

Transcript

1. 4USFBN
   "1*
   ೖ໳ ʙ
   ͍·͞Βฉ͚ͳ͍4USFBNͷΩϗϯ "DSPRVFTU
   5FDIOPMPHZגࣜձࣾ
 ೔ຊ+BWBϢʔβʔάϧʔϓ
   ୩ຊ
   ৺
   
   !DFSP@U
   
2. ͳͥɺ4USFBN
   "1*Λ
 ֶͿ΂͖ͳͷ͔ʁ
3. ৽͍͔͠Βʁ
   ੑೳ͕͍͍͔Βʁ
   ؆ܿʹॻ͚Δ͔Βʁ
4. 4USFBN
   "1*ͷΑ͏ͳ
 ෺ࣄͷଊ͑ํ͕ࠓޙ਺೥ͷ
 ίʔσΟϯάʹඞཁͱ
 ͳͬͯ͘Δ͔Β
5. ৄ͍͠࿩͸ޙͰ΍Γ·͢
6. ·ͣ͸ʮ؆ܿʹॻ͚Δ͔Βʯ
 ͩͱଊ͑ͯ࢝Ί·͠ΐ͏
7. 5BCMF
   PG
   $POUFOUT w 4USFBN
   "1*ͱ͸ʁ
   w -BNCEBࣜͱ͸ʁ
   w 4USFBN
   "1*ͷॻ͖ํͱɺԡ͑͞ΔϙΠϯτ
   w ͳͥ4USFBN
   "1*͕ॏཁͳͷ͔
8. 4USFBN
   "1*ͱ͸ʁ
9. 4USFBN
   
   ྲྀΕ
11. ৄ͍͠࿩͸ޙͰ΍Γ·͢
12. େྔσʔλΛஞ࣍ॲཧ͢Δ
 ʮετϦʔϜॲཧʯΛ
 ؆ܿʹॻͨ͘Ίͷ"1*
13. ͚ͩͲɺ
 ίϨΫγϣϯͷૢ࡞Λ
 ؆ܿʹॻ͘͜ͱ΋Ͱ͖Δ
14. List<Student> students = new ArrayList<>(); students.add(new Student("Ken", 100)); students.add(new Student("Shin", 60)); students.add(new Student("Takuya", 80)); for (Student student : students) { if (student.getScore() >= 70) { System.out.println(student); } } ͜Ε͕
15. List<Student> students = new ArrayList<>(); students.add(new Student("Ken", 100)); students.add(new Student("Shin", 60)); students.add(new Student("Takuya", 80)); 
 students.stream() .filter(s -> s.getScore() >= 70) .forEach(System.out::println); ͜͏ͳΔ
16. ίϨΫγϣϯͷ
 ߜΓࠐΈɺม׵΍ɺ
 ͦΕͧΕͷཁૉ΁ͷॲཧɺ
 ूܭͳͲ͕Ͱ͖Δ
17. ͱ͸ݴ͑
18. Map<Dept, Long> groupByDeptAndFilter(List<Emp> list) { return list.stream() .collect(Collectors.groupingBy(emp -> emp.dept)) .entrySet() .stream() .collect(Collectors.toMap(entry -> entry.getKey(), entry -> entry.getValue() .stream() .filter(emp -> emp.sal > 1000) .count())); }
19. Կ͜ΕಡΊͳ͍
20. GPSจΛ࢖ͬͯ
 ॻ͖௚͢ͱ
21. Map<Dept, Long> groupByDeptClassic(List<Emp> list) { Map<Dept, Long> result = new HashMap<>(); for (Emp emp : list) { if (result.containsKey(emp.dept) == false) { result.put(emp.dept, 0L); } if (emp.sal > 1000) { Long count = result.get(emp.dept); count++; result.put(emp.dept, count); } } return result; }
22. ಡΈ΍͍͢ʂ
 ✌ Т✌
    ࡾ✌ Т ✌ࡾ
    ✌Т ✌
23. Έ͍ͨͳ͜ͱʹͳΔͷͰ
 ແཧͯ͠ෳࡶͳ΋ͷΛ
 4USFBN
    "1*Ͱ
 ॻ͘ඞཁ͸ͳ͍Ͱ͢
24. ৽͍͠΋ͷΛ࢖͏͜ͱ͕
 ৗʹΤϥ͍Θ͚͡Όͳ͍
25. ผʹੑೳ΋มΘΜͳ͍
26. ·ͣ͸جຊతͳॻ͖ํͱ
 ͦͷ֓೦Λֶͼ·͠ΐ͏
27. -BNCEBࣜͱ͸ʁ
28. ˓
    ϥϜμࣜ
 º
    ϥϯόμࣜ
29. List<Student> students = new ArrayList<>(); students.add(new Student("Ken", 100)); students.add(new Student("Shin", 60)); students.add(new Student("Takuya", 80)); 
 students.stream() .filter(s -> s.getScore() >= 70) .forEach(System.out::println); ͜ͷ෦෼
30. 4USFBN
    "1*Λ
 ؆ܿʹॻͨ͘Ίʹ
 ͔ܽͤͳ͍΋ͷ
31. -BNCEBࣜͱ͸
 ࣮૷͢΂͖ϝιου͕
 ͔ͭ͠ͳ͍ΠϯλϑΣʔεΛ
 ؆ܿʹදهͰ͖Δ΋ͷ
32. ͨͱ͑͹
    KBWBVUJM$PNQBSBUPS
 
 ࣮૷͢Δ΂͖ϝιου͸
 DPNQBSF
33. void sort() { List<Student> studentList = new ArrayList<>(); studentList.add(new Student("Murata", 100)); studentList.add(new Student("Okada", 70)); studentList.add(new Student("Tanimoto", 80)); System.out.println(studentList); Collections.sort(studentList, new StudentComparator()); System.out.println(studentList); } class StudentComparator implements Comparator<Student> { @Override public int compare(Student student1, Student student2) { return Integer.compare(student1.getScore(), student2.getScore()); } } ͜ͷ෦෼
34. void sortAnonymous() { List<Student> studentList = new ArrayList<>(); studentList.add(new Student("Murata", 100)); studentList.add(new Student("Okada", 70)); studentList.add(new Student("Tanimoto", 80)); System.out.println(studentList); Collections.sort(studentList, new Comparator<Student>() { @Override public int compare(Student student1, Student student2) { return Integer.compare(student1.getScore(), student2.getScore()); } }); System.out.println(studentList); } ແ໊ΫϥεΛ࢖͏ͱ
35. void sortLambda() { List<Student> studentList = new ArrayList<>(); studentList.add(new Student("Murata", 100)); studentList.add(new Student("Okada", 70)); studentList.add(new Student("Tanimoto", 80)); System.out.println(studentList); Collections.sort(studentList, (student1, student2) -> Integer.compare(student1.getScore(), student2.getScore())); System.out.println(studentList); } -BNCEBΛ࢖͏ͱ
36. ࣮૷͢΂͖ϝιου͕
 ͔ͭ͠ͳ͍ΠϯλϑΣʔεΛ
 ʮؔ਺ܕΠϯλϑΣʔεʯ
 ͬͯݺͼ·͢
37. 4USFBN
    "1*ͷҾ਺͸
 جຊతʹ͢΂ͯ
 ؔ਺ܕΠϯλϑΣʔε
38. 4USFBN
    "1*Λ͢΂ͯ
 ແ໊ΫϥεͰ࡞Δͱ
 ಡΈͮΒͯ͘࢓ํͳ͍ͷͰ
 ؔ਺ͬΆ͘ॻ͚Δ
 -BNCEB͕ࣜಋೖ͞Εͨ
39. List<Student> students = new ArrayList<>(); students.add(new Student("Ken", 100)); students.add(new Student("Shin", 60)); students.add(new Student("Takuya", 80)); 
 students.stream() .filter(s -> s.getScore() >= 70) .forEach(System.out::println); ΋͜͠Ε͕
40. List<Student> students = new ArrayList<>(); students.add(new Student("Ken", 100)); students.add(new Student("Shin", 60)); students.add(new Student("Takuya", 80)); students.stream() .filter(new Predicate<Student>() { @Override public boolean test(Student student) { return student.getScore() >= 70; } }) .forEach(new Consumer<Student>() { @Override public void accept(Student student) { System.out.println(student); } }); ͜͏ͳΒ
41. ୭΋͓લΛѪ͞ͳ͍
42. -BNCEBࣜͷจ๏
43. -BNCEBࣜͷجຊจ๏
 
 Ҿ਺
    
    \
    ॲཧ
    ^
44. (Student student1, Student student2) -> { int score1 = student1.getScore(); int score2 = student2.getScore(); return Integer.compare(score1, score2); } (Student student) -> {
 System.out.println(student); } () -> {
 System.out.println("Hello!"); }
45. Ҿ਺ͷܕ͸লུͰ͖Δ
46. (Student student1, Student student2) -> { int score1 = student1.getScore(); int score2 = student2.getScore(); return Integer.compare(score1, score2); } (student1, student2) -> { int score1 = student1.getScore(); int score2 = student2.getScore(); return Integer.compare(score1, score2); }
47. ॲཧ͕ߦͳΒ
    SFUVSO
    ͱ
    \
    ^
    ͕
 লུͰ͖Δ
48. (student1, student2) -> { int score1 = student1.getScore(); int score2 = student2.getScore(); return Integer.compare(score1, score2); } 
 
 (student1, student2) -> { return Integer.compare(student1.getScore(), student2.getScore()); } (student1, student2) -> Integer.compare(student1.getScore(), student2.getScore())
49. Ҿ਺͕ͭͳΒ

    
    ΋লུͰ͖Δ
50. (Student student) -> {
 System.out.println(student); } 
 
 
 student -> System.out.println(student)
51. -BNCEBͷத਎͕
 ϝιουݺͼग़ͭ͠Ͱ
 Ҿ਺΋໌֬ͳΒ
 ϝιουࢀর͕࢖͑Δ
52. ϝιουࢀরͷจ๏
    Ϋϥε໊ϝιου໊
53. (Student student) -> {
 System.out.println(student); } 
 
 
 student -> System.out.println(student) System.out::println
54. (Student student) -> {
 return student.getScore(); } 
 
 
 student -> student.getScore(); Student::getScore
55. List<Student> students = new ArrayList<>(); students.add(new Student("Ken", 100)); students.add(new Student("Shin", 60)); students.add(new Student("Takuya", 80)); 
 students.stream() .filter(s -> s.getScore() >= 70) .forEach(System.out::println); ݁Ռɺ͜͏ͳΔ
56. ͜͜·Ͱ͸0,ʁ
57. 4USFBN
    "1*ͷॻ͖ํͱ
 ԡ͑͞ΔϙΠϯτ
58. ࡞Δ
    ૢ࡞͢Δ
    ·ͱΊΔ
59. Α͘࢖͏ύλʔϯ
 TUSFBN
    Ͱ࡞Γ
    NBQ
    ͰՃ޻͠
 pMUFS
    ͰߜΓࠐΈ
 DPMMFDU
    Ͱཉ͍͠ܗʹ͢Δ
60. ࡞Δ
61. 4USFBNΛฦ͢"1*Λ
 ݺͼग़͢͜ͱͰ
 4USFBNΛ࡞Δ
62. List<String> lines = Arrays.asList("Murata=100", "Okada=60", "Tanimoto=80"); List<Student> students = lines.stream() .map(s -> { String[] strings = s.split("="); return new Student(strings[0], Integer.valueOf(strings[1])); }) .filter(s -> s.getScore() >= 70) .collect(Collectors.toList()); $PMMFDUJPOTUSFBN
63. String[] lines = {"Murata=100", "Okada=60", "Tanimoto=80"}; List<Student> students = Arrays.stream(lines) .map(s -> { String[] strings = s.split("="); return new Student(strings[0], Integer.valueOf(strings[1])); }) .filter(s -> s.getScore() >= 70) .collect(Collectors.toList()); "SSBZTTUSFBN
64. .BQͳΒ
    FOUSZ4FU TUSFBN
    ϑΝΠϧΛߦͣͭಡΉͳΒ
    'JMFTMJOFT
    #VGGFSFE3FBEFSMJOFT
65. ૢ࡞͢Δ
 ʢதؒૢ࡞ʣ
66. ઈରʹ֮͑ͯཉ͍͠
    NBQͱpMUFS
67. ม׵΍ߜΓࠐΈͳͲͷ
 ૢ࡞Λߦ͏ͷ͕தؒૢ࡞
68. NBQ
    
 ཁૉΛผͷཁૉʹม׵͢Δ
    pMUFS
    
    ৚݅Λࢦఆͯ͠ߜΓࠐΉ
69. List<String> lines = Arrays.asList("Murata=100", "Okada=60", "Tanimoto=80"); List<Student> students = lines.stream() .map(s -> { String[] strings = s.split("="); return new Student(strings[0], Integer.valueOf(strings[1])); }) .filter(s -> s.getScore() >= 70) .collect(Collectors.toList()); } NBQͱpMUFS
70. List<String> lines = Arrays.asList("Murata=100", "Okada=60", "Tanimoto=80"); List<Student> students = lines.stream() .map(s -> { String[] strings = s.split("="); return new Student(strings[0], Integer.valueOf(strings[1])); })
 // この時点でStudentのstreamになる .filter(s -> s.getScore() >= 70) // この時点でMurataとTanimotoが残ったstreamになる .collect(Collectors.toList()); } NBQͱpMUFS
71. MJNJUͰ݅਺ΛߜΔ
    EJTUJODUͰϢχʔΫʹߜΔ
 TPSUFEͰฒ΂ม͑Δ
 ͳͲͳͲ
72. Α͋͘Δޡղࠞཚ
73. NBQͳͲͷม׵ॲཧͰ͸
 ཁૉͷ਺͸มΘΒͳ͍
74. ཁૉΛ͍͔ͭ͘·ͱΊͯ
 ॲཧ͢Δ
 Έ͍ͨͳ͜ͱ͸Ͱ͖ͳ͍
 ʢྫɿෳ਺ߦͷϩάϑΝΠϧॲཧʣ
75. ͋͘·Ͱɺ݅݅ɺ
 Կ͔͢Δ͍ͬͯ͏΋ͷ
76. pMUFSͰ෼ذ͢Δ͜ͱ͸
 Ͱ͖ͳ͍
77. ͜ͷ৚݅ͷ4USFBNɺ
 ͦͷ৚݅ͷ4USFBNɺ
 ͋ͷ৚݅ͷ4USFBNɺ
 ͲΕʹ΋֘౰͠ͳ͍4USFBN
 Έ͍ͨͳ͜ͱ͸Ͱ͖ͳ͍
78. ͋͘·Ͱ΋
 4USFBN͸ຊ
79. qBU.BQΛ࢖͑͹
    ͭͷཁૉ͔Β
 ෳ਺ͷཁૉΛ
 ࡞Δ͜ͱ͸Ͱ͖Δ
80.   
     
       
    ͔Β
            
    ͸࡞ΕΔ
81. Ͱ΋આ໌͸ׂѪ͢ΔΑʂ
82. ·ͱΊΔ
 ʢऴ୺ૢ࡞ʣ
83. 4USFBNΛ
 -JTUʹͨ͠Γ.BQʹͨ͠Γ
    ߹ܭ஋΍ฏۉ஋Λܭࢉͨ͠Γ
84. ࠷ޙʹ݁Ռͱͯ͠
 औΓग़͢΋ͷ͕
 ऴ୺ૢ࡞
85. Ұ൪࢖͏ͷ͕
 DPMMFDUͱ$PMMFDUPSTͷ
 ૊Έ߹Θͤ
86. List<String> lines = Arrays.asList("Murata=100", "Okada=60", "Tanimoto=80"); List<Student> students = lines.stream() .map(s -> { String[] strings = s.split("="); return new Student(strings[0], Integer.valueOf(strings[1])); }) .filter(s -> s.getScore() >= 70) .collect(Collectors.toList()); } DPMMFDU
87. $PMMFDUPSTUP4FU
 $PMMFDUPSTUP.BQ
    Ͱ4FU΍.BQʹม׵
88. String[] lines = {"Murata=100", "Okada=60", "Tanimoto=80"}; Map<String, Student> students = Arrays.stream(lines) .map(s -> { String[] strings = s.split("="); return new Student(strings[0], Integer.valueOf(strings[1])); }) .collect(Collectors.toMap(s -> s.getName(), s -> s)); return students; $PMMFDUPSTUP.BQ
89. $PMMFDUPSTKPJOJOHͰ
 શ෦ͭͳ͛ͨจࣈྻʹม׵
90. $PMMFDUPSTHSPVQJOH#Z Ͱ
 -JTUͷ.BQΛ࡞Δ
91. DPMMFDUҎ֎ͷऴ୺ૢ࡞
92. GPS&BDI
    
 ೚ҙͷॲཧΛ͢Δ
 ʢ໭Γ஋ͳ͠ʣ
93. NBY
    NJO
    
 ࠷େͷ݅ɺ࠷খͷ݅ΛऔΔ
    pOE'JSTU
    
 ࠷ॳͷ݅ΛऔΔ
94. ਺஋ͷ4USFBNͳΒ
 BWFSBHFͱ͔΋औΕΔ
95. ཁ͢Δʹ
 4USFBNΛ
 ԿΒ͔ͷܗͰ
 ू໿ͯ͠औΓग़͢΋ͷ
96. ऴ୺ૢ࡞͸
 Ұճ͔͠Ͱ͖ͳ͍
97. UP-JTUͱGPS&BDIͷ
 ྆ํΛ͢Δ͜ͱ͸Ͱ͖ͳ͍
98. ͱ͍͏ลΓΛ౿·͑ͯ
 GSPN
    PME
    +BWB
 UP
    NPEFSO
    +BWB
99. List<Transaction> list = new ArrayList<>(); try (BufferedReader reader = Files.newBufferedReader(Paths.get(fileName))) { String line; while ((line = reader.readLine()) != null) { String[] s = line.split(","); Transaction tx = new Transaction(); tx.date = LocalDate.parse(s[0]); tx.accountId = s[1]; tx.amount = Integer.valueOf(s[2]); tx.name = s[3]; tx.note = s[4]; list.add(tx); } } catch (IOException e) { throw new RuntimeException("failed to parse date or read file", e); } return list; GSPN
    
100. try (Stream<String> stream = Files.lines(Paths.get(fileName))) { return stream .map(line -> { String[] s = line.split(","); Transaction tx = new Transaction(); tx.date = LocalDate.parse(s[0]); tx.accountId = s[1]; tx.amount = Integer.valueOf(s[2]); tx.name = s[3]; tx.note = s[4]; return tx; }) .collect(Collectors.toList()); } catch (IOException e) { throw new UncheckedIOException("failed to read file", e); } UP
     4USFBN
101. try (Stream<String> stream = Files.lines(Paths.get(fileName))) { return stream .map(line -> { String[] s = line.split(","); Transaction tx = new Transaction(); tx.date = LocalDate.parse(s[0]); tx.accountId = s[1]; tx.amount = Integer.valueOf(s[2]); tx.name = s[3]; tx.note = s[4]; return tx; }) .collect(Collectors.toList()); } catch (IOException e) { throw new UncheckedIOException("failed to read file", e); } UP
     4USFBN ϑΝΠϧΛಡΈࠐΜͰ
 Streamͱͯ͠ฦ͢ϝιου
 ʢߦ͝ͱʹॲཧʣ ߦͷStringΛ
 Transactionʹม׵ Listʹͯ͠ฦ͢
102. // 取引履歴の取得 List<Transaction> list = read(fileName); // 全件表示 for (Transaction tx : list) { System.out.println(tx); } // 残高の計算 int sum = 0; for (Transaction tx : list) { sum += tx.amount; } System.out.println(sum); // 6月分のみ表示 for (Transaction tx : list) { if (tx.date.getMonth() == Month.JUNE) { System.out.println(tx); } } GSPN
     
103. // 取引履歴の取得 read(fileName).stream() .forEach(System.out::println); // 残高の計算 int sum = read(fileName).stream() .mapToInt(tx -> tx.amount) .sum(); System.out.println(sum); // 6月分のみ表示 read(fileName).stream() .filter(tx -> tx.date.getMonth() == Month.JUNE) .forEach(System.out::println); UP4USFBN
104. // 取引履歴の取得 read(fileName).stream() .forEach(System.out::println); // 残高の計算 int sum = read(fileName).stream() .mapToInt(tx -> tx.amount) .sum(); System.out.println(sum); // 6月分のみ表示 read(fileName).stream() .filter(tx -> tx.date.getMonth() == Month.JUNE) .forEach(System.out::println); UP4USFBN ͢΂ͯͷཁૉʹ͍ͭͯ
 ॱ൪ʹॲཧ औҾֹΛint஋ͱͯ͠औΓग़ͯ͠
 intͷstreamʢIntStreamʣʹ͔ͯ͠Β
 ߹ܭ஋Λऔಘ 6݄ͷΈΛऔΓग़ͯ͠
 શ݅දࣔ
105. ΋͏গ͠ࠐΈೖͬͨ಺༰͸
 ϥΠϒίʔσΟϯάͰ
106. ͳͥ4USFBN
     "1*͕
 ॏཁͳͷ͔ʁ
107. $PMMFDUJPOΛ؆ܿʹ
 ѻ͑ΔΑ͏ʹͳΔมΘΓʹ
 ݁ߏɺ֮͑Δ͜ͱ͕ଟ͍
108. େͯ͠༥௨΋ར͔ͳ͍
109. ͡Ό͊ͳΜͰ4USFBNΛ
 ࢖͏ͷ͔ʁ
110. 4USFBN
     "1*ͷ
 େ͖ͳ໨త͸
 4USFBNΛѻ͏͜ͱ
112. $PMMFDUJPO͸
 طʹ಺༰͕ܾ·͍ͬͯΔ
 σʔλ
     ʢ$PME
     4USFBNʣ
113. ຊདྷͷ4USFBN͸
 ઈ͑ͣͯ͠
 ͔͠΋΋ͱͷਫʹ͋Βͣ
114. 8FCͷϦΫΤετ΍
 ΩϡʔΠϯάॲཧͳͲ
     ಺༰΍্ݶ͕
 ܾ·ͬͯͳ͍΋ͷ
 ʢ)PU
     4USFBNʣ
115. +BWB
     ͷ4USFBN
     "1*͸
 جຊతʹ$PME
     4USFBNΛ
 ѻ͏ͨΊͷ΋ͷ
116. ओઓ৔͸)PU
     4USFBN
117. )PU
     4USFBNʹ
 ඞཁͳ΋ͷ
118. 
     ΢Οϯυ΢ؔ਺
119. ྫɿ
     ਺ສͷηϯαʔ͔Β
 ૹ৴͞Εͨ৘ใΛ
 ड৴͠ͳ͕Β
 ूܭॲཧΛ͢Δ
120. ड৴ॲཧͱฒߦͯ͠ɺ
 ਺݅ͣͭ·ͱΊͯूܭ͢Δɺ
 ਺ඵͣͭूܭ͢Δɺ
 ໰୊͕͋Ε͹Ξϥʔτ
121. ͦΜͳ͜ͱ͕Ͱ͖Δ
 ΢Οϯυ΢ؔ਺͕ඞཁ
122. +BWB
     Ͱଟগ͸ೖΔ͕
 ࠓͷͱ͜Ζ͸
 3Y+BWB΍3FBDUPSΛ࢖͏
123. void monitorGauge(Flux<Double> input) { input.bufferTimeout(100, Duration.ofSeconds(10)) .subscribe(list -> { DoubleSummaryStatistics stats = list.stream() .mapToDouble(Double::doubleValue) .summaryStatistics(); if (stats.getMax() > maxThreshold) { alert(Level.WARNING); } if (stats.getAverage() > averageThreshold) { alert(Level.SEVERE); } }); } 3FBDUPSͷ"1*
124. void monitorGauge(Flux<Double> input) { input.bufferTimeout(100, Duration.ofSeconds(10)) .subscribe(list -> { DoubleSummaryStatistics stats = list.stream() .mapToDouble(Double::doubleValue) .summaryStatistics(); if (stats.getMax() > maxThreshold) { alert(Level.WARNING); } if (stats.getAverage() > averageThreshold) { alert(Level.SEVERE); } }); } 3FBDUPSͷ"1* 100݅΋͘͠͸10ඵؒͷσʔλΛ
 ·ͱΊͯॲཧ͢Δ ʢूܭͯ͠ᮢ஋Λ௒͑ͨΒΞϥʔτʣ
125. 
     ϊϯϒϩοΩϯά"1*
126. ྫɿ
 σʔλετΞ͔Β
 ສ݅ͷϨίʔυΛ
 औಘͨ͋͠ͱ
 ͦͷৄࡉσʔλΛ݅ͣͭ
 ສճऔಘ͢Δ
127. ֓ཁσʔλΛऔಘ͔ͯ͠Β
 ৄࡉσʔλΛऔಘ͢Δ
128. ͜Ε·Ͱ͸ಉظॲཧͰ
 σʔλϕʔεʹΞΫηε͢Δ
 Α͏ͳγεςϜΛͣͬͱ
 ࡞͖ͬͯ·ͨ͠
129. 42-Λສճ
 ൃߦ͢Δඞཁ͕͋Ε͹
 ॱ൪ʹສճൃߦͯ͠
 ੑೳ໰୊͕ى͖͍ͯ·ͨ͠
130. WebΞϓϦ DB 1ສճͷSQLͰ
 ੑೳ໰୊͕ൃੜ
131. WebΞϓϦ DB ͪΐͬͱ޻෉ͯ͠
 গ͠ॏ͍ͨΫΤϦͰΧόʔ
132. ϚΠΫϩαʔϏε ϚΠΫϩαʔϏε 1ສճͷαʔϏεݺͼग़͠
133. ϚΠΫϩαʔϏε ϚΠΫϩαʔϏε ͜ͷ1ສճͷαʔϏεݺͼग़͠Λ
 ʮͰ͖Δ͚ͩಉ࣌ʹʯ
 ࣮ߦ͍ͨ͠
134. ϊϯϒϩοΩϯάͳ
 ඇಉظ"1*ͱͯ͠
 ΍͸Γ
 3Y+BWBɺ3FBDUPSΛ࢖͏
135. Mono<Map<Student, List<Score>>> map =
 studentService.fetchStudents("1年3組") .flatMap(student -> scoreService.fetchScore(2017, student.id)
 .collectList() .map(scores -> Tuples.of(student, scores))) .collectMap(Tuple2::getT1, Tuple2::getT2); // 出力 System.out.println(map.block());
 
 
 // 呼び出すAPI Flux<Student> fetchStudents(String className); Flux<Score> fetchScore(int year, int id) 3FBDUPSͷ"1*
136. Mono<Map<Student, List<Score>>> map =
 studentService.fetchStudents("1年3組") .flatMap(student -> scoreService.fetchScore(2017, student.id)
 .collectList() .map(scores -> Tuples.of(student, scores))) .collectMap(Tuple2::getT1, Tuple2::getT2); // 出力 System.out.println(map.block());
 
 
 // 呼び出すAPI Flux<Student> fetchStudents(String className); Flux<Score> fetchScore(int year, int id) 3FBDUPSͷ"1* ʢৄࡉ͸ׂѪ͢Δ͚Ͳʣ
 APIݺͼग़͠ΛϊϯϒϩοΩϯά͔ͭ
 ඇಉظʹݺͼग़͢͜ͱͰ
 ॲཧશମͷ࣌ؒΛ୹ॖ
 ͔͠΋ར༻εϨου਺͕গͳ͍
137. ͜͏͍͏΋ͷ͸ɺ͢΂ͯ
 4USFBN
     "1*ͷΑ͏ͳ
 ܗͰهड़͞ΕΔ͜ͱʹͳΔ
138. ॲཧͷฒྻ౓Λ͋͛ͯ
 େྔσʔλ΍
 େྔϦΫΤετΛ
 ࡹ͘Α͏ͳ࣌୅
139. ͦ͜ʹ޲͚ͨ४උͱͯ͠
 4USFBN
     "1*Λ
 शಘ͍ͯͩ͘͠͞
140. -FU`T
     4UVEZ
 4USFBN
     "1*
     
141. Ξϯέʔτޚڠྗ͓ئ͍͠·͢
 IUUQCJUMZKKVH
     
142. +BWBຊ֨ೖ໳Λ
 ങͬͯͩ͘͞Δํ͸
 ͥͻ࿩͔͚͍ͯͩ͘͠͞