オープントーン内部勉強会/ot-study-20151117

Transcript

1. ෮शJava 2015/11/17 2015೥Φʔϓϯτʔϯ಺෦ษڧձ ୈ14ճ Tetsuo Aoyagi
2. Agenda • ྺ࢙ͷ͓͞Β͍ • APIͷ঺հ
3. ؚ·Εͳ͍΋ͷ • Java EE • Stream API • Time API
4. ྺ࢙ͷ͓͞Β͍
5. ྺ࢙ͷ͓͞Β͍ • ஀ੜɿ1995೥ࠒ • ύύɿJames Gosling • ։ൃɿOracle (Sun Microsystems) • ࢓༷ɿJCP (Java Community Process)
6. ྺ࢙ͷ͓͞Β͍ JDK 1.1 J2SE 1.2 J2SE 1.3 J2SE 1.4 J2SE 5.0 Java SE 6.0 Java SE 7.0 Java SE 8.0 1995 2000 2005 2010 2015 Java SE 9.0 • generics • annotation • autoboxing • for-each • enum • static import • Մม௕Ҿ਺ • Swing • Collection API • try-with-resources • multi-catch • strings in switch • NIO2 • ࿨ྐྵ • Properties#loa d(Reader) • Stream API • Time API • lambda • default method JDK 1.0 1996.01 1997.02 1998.12 2000.05 2002.02 2004.09 2006.12 2011.07 2014.03 2016.09 • Applet • ֮͑ͯͳ͍.. • Logging API • NIO • regexp • exception chaining • assert
7. ྺ࢙ͷ͓͞Β͍ JDK 1.1 J2SE 1.2 J2SE 1.3 J2SE 1.4 J2SE 5.0 Java SE 6.0 Java SE 7.0 Java SE 8.0 1995 2000 2005 2010 2015 Java SE 9.0 JDK 1.0 1996.01 1997.02 1998.12 2000.05 2002.02 2004.09 2006.12 2011.07 2014.03 2016.09 Struts Seasar2 Spring Framework Struts2 Tomcat3 Tomcat8 OpenTone J2EE EJB JUnit Eclipse JBuilder Visual Age Scala Groovy Maven2 Maven1 Maven3 Ant Gradle Jenkins Hudson POJO JSF2 Hibernate iBatis JSF1 SAStruts JRuby Wicket JPA CDI Jakarta Project ivy Grails Clojure PoEAA CoC Rails DDD TDD BDD Android Refactoring IntelliJ Play Framework Backlog Redmine
8. 0 5 10 15 20 JDK1.1 J2SE1.2 J2SE1.3 J2SE1.4 J2SE5.0 Java SE6 Java SE7 Java SE8 1 4.1 4.6 9.5 14.4 15.8 16.5 17.7 1 3.9 4.4 9.3 13.6 14.8 15.7 16.9 1 2.5 2.9 7.3 12.6 14.2 14.4 14.4 1 3.3 3.8 8.7 12.9 14.2 14.9 15.8 loc package type method APIͷن໛ਪҠ
9. APIͷ঺հ
10. Service Provider Interface Java SE 6
11. Service Provider Interface • ʮαʔϏεʯΛಈతʹఏڙ͢Δ࢓૊Έ • ΠϯλʔϑΣΠεͰαʔϏεΛఆٛ • Ϋϥεύε͔ΒαʔϏεͷ࣮૷ΫϥεΛݕࡧ • ࣮૷ϑΝΠϧ໊Λهड़ͨ͠ϓϩόΠμߏ੒ϑΝ ΠϧΛ഑ஔ • META-INF/services/ΠϯλʔϑΣΠε໊
12. Service Provider Interface app.jar sample.Driver foo-driver.jar FooDriver sample.Driver sample.Driver META-INF/services bar-driver.jar BarDriver sample.Driver sample.Driver META-INF/services <<use>> <<use>> ྫɿσόΠεʹԠͨ͡υϥΠό੾ସ Interface͸ΞϓϦଆ Ͱఆٛ ࣮૷Ϋϥε͸ ֤jarͰఆٛ
13. Service Provider Interface import java.util.ServiceLoader; ServiceLoader.load(Driver.class) .forEach(d -> { if (d.accept(deviceName)) { d.connect(); // Ҏ߱ͷॲཧ.. } });
14. Service Provider Interface • γϯϓϧʹΠϯλʔϑΣΠεͱ࣮૷Λ෼཭Ͱ ͖Δ • ࣮૷ͷ੾Γସ͑΋༰қ(jarͷࠩସ͑) • JDBC 4.0 ͔Β͜ͷํࣜ • Class.forName(“υϥΠόΫϥε໊”)
15. Pluggable Annotation Processing API (JSR269) Java SE 6
16. Pluggable Annotation Processing API (JSR269) • ίϯύΠϧ࣌ʹɺιʔείʔυʹهड़͞ΕͨΞ ϊςʔγϣϯΛॲཧ͢Δ࢓૊Έ • ੒Ռ෺ͷੜ੒ • ιʔείʔυͷݕূ • ͍Ζ͍ΖͳOSSͰ΋࠾༻ • Lombok • Doma • Android Annotations
17. ίϯύΠϧ࣌ʹΞϊςʔγϣϯΛॲཧ͢Δ࢓૊Έ ੒Ռ෺ͷੜ੒ Τϥʔ Pluggable Annotation Processing API (JSR269) Annotation Processor class Compile Warning Error • ιʔεੜ੒ • Ϧιʔεੜ੒ • ιʔεݕূ • etc
18. Demonstration
19. Pluggable Annotation Processing API (JSR269) • ࡞ۀ࿙Εͷ৺഑͕ͳ͍ • ੒Ռ෺͕໨ʹݟ͑Δܗ(ιʔε౳)Ͱੜ੒͞ΕΔ ͷͰΘ͔Γ΍͍͢ • AOPɾϦϑϨΫγϣϯ౳Ͱͷ࣮ߦ࣌ղܾΑΓ ύϑΥʔϚϯε͕ظ଴Ͱ͖Δ • ݫ੍͍͠໿
20. java.lang.AutoCloseable Java SE 7
21. try-with-resources OutputStream o = null; try { o = Files.newOutputStream(path); // ͍Ζ͍Ζͳॲཧ.. } catch (IOException e) { handleException(e); } finally { if (o != null) { try { o.close(); } catch (IOException e) { handleException(e); } } } try (OutputStream o = Files.newOutputStream(path)) { // ͍Ζ͍Ζͳॲཧ.. } catch (IOException e) { handleException(e); }
22. Question
23. લఏ • HogeResourceReader͸ɺAutoCloseableΛ࣮૷͍ͯ͠Δ • read()͸ɺྫ֎HogeResourceReadExceptionΛthrow͢Δ • close()͸ɺྫ֎HogeResourceCloseExceptionΛthrow͢Δ
24. throw͞ΕΔͷ͸Ͳͬͪʁ A. HogeResourceReadException B. HogeResourceCloseException public void readHoge() throws Exception { try (HogeResourceReader r = HogeResourceReader.open()) { List<HogeResource> resources = r.read(); } catch (HogeResourceReadException e) { throw e; } catch (HogeResourceCloseException e) { throw e; } }
25. Answer
26. throw͞ΕΔͷ͸Ͳͬͪʁ A. HogeResourceReadException B. HogeResourceCloseException usage.java.lang.HogeResourceReadException at usage.java.lang.HogeResourceReader.read(HogeResourceReader.java:16) at usage.java.lang.TryWithResourcesTest.testTryWithResources1(TryWithResourcesTest.java:14) at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:78) at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:212) at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:68) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at com.intellij.rt.execution.application.AppMain.main(AppMain.java:140) Suppressed: usage.java.lang.HogeResourceCloseException at usage.java.lang.HogeResourceReader.close(HogeResourceReader.java:23) at usage.java.lang.TryWithResourcesTest.testTryWithResources1(TryWithResourcesTest.java:15) ... 26 more • ͨͩ͠ɺB΋ؚ·Εͯ·͢
27. ͦͷଞ Miscellaneous
28. ͦͷଞ Miscellaneous // ϓϦϛςΟϒϥούʔ // ࿦ཧԋࢉࢠ boolean x, y; Boolean.compare(x, y); // x == y Boolean.logicalAnd(x, y); // x && y Boolean.logicalOr(x, y); // x || y Boolean.logicalXor(x, y); // x ^ y // ූ߸ͳ͠੔਺΁ͷม׵ byte b = -1; Byte.toUnsignedInt(b); // 255 int i = -1; Integer.toUnsignedLong(b); // 4294967295 (0xffffffffL)
29. ͦͷଞ Miscellaneous // ࠃࡍԽυϝΠϯ import java.net.IDN; IDN.toASCII(“͜Ή.com”); // “xn—28jwe.com” // จࣈΤϯίʔσΟϯά import java.nio.charset.StandardCharsets; String message = ..; message.getBytes(StandardCharsets.UTF_8);
30. ͦͷଞ Miscellaneous // ཁૉͷ܁Γฦ͠ॲཧ List<Foo> list = getFooListFromSomewhere(); list.forEach(e -> { // ͍Ζ͍Ζͳॲཧ }); // จࣈྻ൑ఆɾૢ࡞ String s = “”; s.isEmpty(); // true String.join(“-“, “a”, “b”, “”, “c”, null, “d”); // “a-b--c-null-d” // System.getProperty(“line.separator”) ͱಉ͡ System.lineSeparator();
31. ͦͷଞ Miscellaneous // ฒ΂ସ͑ͦͷ1 import static java.util.Comparator.*; List<Integer> list = Arrays.asList(3, 1, 5, 7, 4); // 1, 3, 4, 5, 7 list.sort(naturalOrder()); // 7, 5, 4, 3, 1 list.sort(reverseOrder());
32. ͦͷଞ Miscellaneous // ฒ΂ସ͑ͦͷ2 List<Employee> list = new ArrayList<Employee>() { { // empNo, name, age add(new Employee(“00001”, “Taro Yamada”, 29)); add(new Employee(“00305”, null, 32)); .. } }; // 1. nameͷঢॱ(null͸ઌ಄΁), 2. empNoͷ߱ॱ(null͸຤ඌ΁) list.sort(comparing(Employee::getName, nullsFirst(naturalOrder())) .thenComparing(Employee::getEmpNo, nullsLast(reverseOrder())));
33. ͦͷଞ Miscellaneous // java.util.Objects Objects.equals(null, null); // true Objects.equals(null, “test”); // false; Objects.isNull(o); // nullͳΒtrue Objects.nonNull(o); // null͡Όͳ͚Ε͹true Objects.requireNonNull(o); // null͡Όͳ͚Ε͹o͕ฦ͞ΕΔ Objects.requireNonNull(null); // NullPointerException͕throw͞ΕΔ Objects.requireNonNull(o, “஋͕ઃఆ͞Ε͍ͯ·ͤΜ”); // nullͩͬͨΒϝοηʔδऔಘϝιου(͘͢͝ॏ͍ॲཧ)Ͱੜ੒ͨ͠ // ϝοηʔδΛઃఆͨ͠NullPointerException͕throw͞ΕΔ Objects.requireNonNull(o, this::createMessageUsingTooHeavyProcess);
34. ·ͱΊ • ঺հͨ͠ଟ͘͸৽͍͠΋ͷͰ͸͋Γ·ͤΜ • OracleͷެࣜυΩϡϝϯτʹࠓ೔ͷ಺༰͸΄ ΅ॻ͔Ε͍ͯ·͢ • http://docs.oracle.com/javase/jp/8/ • http://docs.oracle.com/javase/jp/8/docs/api/ • OSSϥΠϒϥϦΛ࢖Θͳ͍/࢖͑ͳ͍৔໘ͳͲ Ͱ໾ཱͭ΋ͷ͕͋Δ͔΋