Java 9: what is there beyond modularization
0 likes582 views
A quick overview of language and API changes in the upcoming Java 9
![亳仄亠 Process API
Source: http://blog.takipi.com/java-9-the-ultimate-feature-list/ 39
Process proc = Runtime.getRuntime()
.exec(new String[]{"/bin/sh",
"-c", "echo $PPID"});
if (proc.waitFor()==0) {
InputStream in = proc.getInputStream();
int available = in.available();
byte[] outputBytes = new byte[available];
in.read(outputBytes);
String pid = new String(outputBytes);
System.out.println("Your pid is " + pid)
}
System.out.println("Your pid is "
+ ProcessHandle.current().getPid());](https://image.slidesharecdn.com/jdk9previewrujeeconf-170529075209/85/Java-9-what-is-there-beyond-modularization-34-320.jpg)
![Stack walking API
仍仂: Throwable::getStackTrace 亳 Thread::getStackTrace
StackTraceElement[] stack = Thread.currentThread().getStackTrace();
弌舒仍仂:
StackFrame[] stack =new StackWalker().walk((s) ->
s.collect(Collectors.toArray()));
仂于亶 从仍舒 StackWalker
54](https://image.slidesharecdn.com/jdk9previewrujeeconf-170529075209/85/Java-9-what-is-there-beyond-modularization-43-320.jpg)
![JShell
舒亰于亳于舒(亠/仍) 于 舒仄从舒
仗仂亠从舒 Kulla
仂亰于仂仍磳 仗仂仗仂弍仂于舒
亳仆舒从亳 弍亠亰 仆舒仗亳舒仆亳
亰舒从仂仆亠仆仆仂亶 仗仂亞舒仄仄
仂仄仂亞舒亠 仂弍舒 磶从 Java
class HelloWorld {
public static void main(String[] args) {
System.out.println("Hello World!");
}
}
66](https://image.slidesharecdn.com/jdk9previewrujeeconf-170529075209/85/Java-9-what-is-there-beyond-modularization-47-320.jpg)
More Related Content
What's hot (20)
Similar to Java 9: what is there beyond modularization (20)
Java 9: what is there beyond modularization
- 1. Java 9 - 仆亠 仂仍从仂 仄仂亟仍亳 于舒仆 仍仂于 1 @JohnWings ivankrylov.java@gmail.com
- 2. 亠仄 弍亟亠仄 亞仂于仂亳 于舒 仍舒亶亟舒 仗仂 仆舒 (Azul Systems) 亰仄亠仆亠仆亳 于 磶从亠 仂于亠 舒弍亳仆亠 仄亠仂亟 亟仍 从仂仍仍亠从亳亶 仂于仂亠 于 Stream API Spin Loop Hints Process API HTTP/2 JVM changes Stack Walking API 弍亰仂 仗仂亳 JEP仂于 JShell 2 Ivan Krylov
- 3. Zing: 亳舒仍仆舒 Java-仄舒亳仆舒 亟仍 从仗仆仂亞仂 弍亳亰仆亠舒 仍舒于仆舒 亠仍 - 仍亠仆亳亠 仗仂从舒亰舒亠仍亠亶 仆从亳仂仆亳仂于舒仆亳 于亳舒仍仆仂亶 Java-仄舒亳仆 亟仍 仗亠亟仗亳亳亶 仂于亶 JIT 从仂仄仗亳仍仂 仆舒 弍舒亰亠 LLVM 弌弍仂从舒 仄仂舒 弍仂仍亠 仆亠 于仍亳磳 仆舒 仗仂亳亰于仂亟亳亠仍仆仂 仗亳仍仂亢亠仆亳亶 亠亠仆仆舒 仗仂弍仍亠仄舒 "仗仂亞亠于舒" 从亳 亠亳亰仄亠仆仆舒 仗仂亳亰于仂亟亳亠仍仆仂 - 仆亠 仗仂仂 弍仂, 舒 弌 弍仂 丿亳仂舒亶舒 亠舒 仗亳仄亠仆亠仆亳: 仂 亳仆亠舒从亳于仆 仗亳仍仂亢亠仆亳亶 亟仂 亰舒亟舒, 从亳亳仆 从仂 于亠仄亠仆亳 仂从仍亳从舒 仂 仄亳从仂亠于亳仂于 亟仂 仗亳仍仂亢亠仆亳亶, 亠弍ﾑ亳 弍仂仍亳 仂弍亠仄仂于 仗舒仄亳 丕舒仆磳 仆亠仂弍仂亟亳仄仂 于 弍仂仍亳仆于亠 亳亰于亠仆 "从仂仍亠亶" 于 于舒亠仄 从仂亟亠 3
- 4. Zulu (Embedded): 仂亞亟舒 仆亢仆 亠亠仆亳 亟仍 于仂亠仆仆 亳亠仄 100% 仂从亶 从仂亟 - 亠仆仂仍仂亞亳, 仂仆仂于舒仆仆舒 仆舒 OpenJDK 弌亠亳亳亳仂于舒仆舒 仆舒 仂于仄亠亳仄仂 亳 仂仂于亠于亳亠 Java SE 仂从舒亰舒亠仍亳 仆从亳仂仆亳仂于舒仆亳, 亳亟亠仆亳仆亠 OpenJDK 亳 Oracle Java SE 仂从仂从仍舒仆舒 仗仂亟亟亠亢从舒 亠仍亳亰舒亳 亟仍 Linux x86, ARM32, ARM64, PPC32, MIPS, 舒 舒从亢亠 Windows 亳 Mac OS 4
- 5. 亳亠仆亳仂于仂仆仂亠 舒仗亳舒仆亳亠 于仂亟舒 Java 9Featurecomplete ZeroBugBounce Rampdownphase2 FinalReleaseCandidate 舒亶16 RampdownStartAllTestsRun GeneralAvailability 亊仆于17 个亠于17 个亠于17 舒17 ﾐ姿17 27ﾐ姿17 5 Ext.Featurecomplete 亠从16
- 6. 6 仂仍仂仂于舒仆亳亠 仗仂 JSR #376
- 7. 7
- 8. 9 interface I { private I foo() { return null; } // OK. void foo(int x); // OK. private void foo(String s); // Error: private method must declare body. private abstract void foo(int i, int j); // Error: private & abstract: bad combo. } 亳于舒仆亠 仄亠仂亟 于 亳仆亠亠亶舒
- 9. 亳于舒仆亠 仄亠仂亟 于 亳仆亠亠亶舒 13 public interface II { private void log(int x, int y, int z) { System.out.println("x="+x+" y="+y+" z="+z); } default int sum(int x, int y) { log(x,y,x+y); return x+y; } default int mul(int x, int y) { log(x,y,x*y); return x*y; } }
- 10. E鍖ectively-鍖nal 仗亠亠仄亠仆仆亠 于 try-with-resources 于舒亢亠仆亳 14 public static void main(String... args) { FileReader f = new FileReader("test.txt"); BufferedReader br = new BufferedReader(fr); try (br) { // do something } catch (Exception ex) { } } public static void main(String... args) { FileReader f = new FileReader(test.txt"); try (br = new BufferedReader(fr)) { // do something } catch (Exception ex) { } }
- 11. 仗仂仍亰仂于舒仆亳亠 @SafeVarargs 于 private 仄亠仂亟舒 15 class VarargsFinalOnly { @SafeVarargs void m(List<String>... args) { } }
- 12. Java 8 ./TypeInferrenceTest.java:7: error: cannot infer type arguments for HashMap<K,V> new HashMap<>() ^ reason: cannot use '<>' with anonymous inner classes where K,V are type-variables: K extends Object declared in class HashMap V extends Object declared in class HashMap 1 error Diamond 舒仆仂仆亳仄仆仄亳 从仍舒舒仄亳 16 class TypeInferrenceTest { Map<String, String> map = new HashMap<> () { { map.put("key", "value"); } }; }
- 13. 舒仗亠 仆舒 亳仗仂仍亰仂于舒仆亳亠 _ 于 亳仄亠仆舒 17 // -source 8: // warning: as of release 9, '_' is a keyword, // and may not be used as an identifier // -source 9: // error: as of release 9, '_' is a keyword, // and may not be used as an identifier class UnderscoreAsIdentifierWarning { String _ = null; }
- 14. 亞亳亠 仂弍仆仂于仍亠仆亳 磶从舒 (?) 舒亟仂亠仍仂 仗亳舒 亳仄 亳仗舒 于 亟亠从仍舒舒亳亳 仗亠亠仄亠仆仆仂亶? 18 var list = new ArrayList<String>(); JEP-286 Local-Variable Type Inference. 仂从舒 仂 仂仍从仂 从舒仆亟亳亟舒 var result = processNewCustomerAdded();
- 15. 个舒弍亳仆亠 仄亠仂亟 亟仍 从仂仍仍亠从亳亶 弌仂亰亟舒仆亳亠 仆亠亳亰仄亠仆仆 从仂仆亠亶仆亠仂于 19 Set<String> set = new HashSet<>(); set.add("a"); set.add("b"); set = Collections.unmodi鍖ableSet(set); Set<String> set = Collections.unmodi鍖ableSet( new HashSet<>(Arrays.asList("a", "b"))); Set<String> set = Collections.unmodi鍖ableSet( new HashSet<String>() {{ add("a"); add("b"); }}); Set<String> set = Collections.unmodi鍖ableSet( Stream.of("a", b").collect(toSet()) ); Set<String> set = Set.of("a", "b");
- 16. 个舒弍亳仆亠 仄亠仂亟 亟仍 从仂仍仍亠从亳亶 20 Set.of(a, b); List.of(a, b); Map.of(k1, v1); Map.of(k1, v1, k2, v2); Map.of(k1, v1, k2, v2, k3, v3); Map.ofEntries(entry(k1, v1), entry(k2, v2), .. entry (kn, vn));
- 17. 仂于仂亠 于 Stream API (1) 22 Stream::takeWhile while (predicate_on_stream_element) { <keep processing this ordered stream> }; Stream.of(3, 2, 1, 0, -1, 0, 1, 2, 3) .takeWhile(s -> s > 0) .forEach(System.out::println); 3 2 1
- 18. 仂于仂亠 于 Stream API (2) 23 Stream::dropWhile while (predicate_on_stream_element) { <skip element of this ordered stream> }; Stream.of(3, 2, 1, 0, -1, 0, 1, 2, 3) .dropWhile(s -> s > 0) .forEach(System.out::println); 0 -1 0 1 2 3
- 19. 仂于仂亠 于 Stream API (3) 24 Stream::Iterate 仗亠亟亳从舒仂仄 Stream.iterate(3, i -> i > 0, i -> i-1) .forEach(System.out::println); 3 2 1 于亠亳 亟仍 Java 8: Stream.iterate(3, i -> i-1) .limit(3) .forEach(System.out::println);
- 20. Stream API changes (4) 25 Stream::ofNullable 个舒从仂亳 亟仍 仂亟仆仂亞仂 仆亠仆仍亠于仂亞仂 仍亠仄亠仆舒 long a = Stream.ofNullable(1).count(); long b = Stream.ofNullable(null).count(); System.out.println(a); System.out.println(b); 1 0
- 21. Spin Loop Hint (JEP-285) 丶亠仍: latency (亳 仗仂亳亰于仂亟亳亠仍仆仂) 亠 API: 亠仂亟 j.l.Thread.onSpinWait() 舒 x86 亳仗仂仍亰亠 亳仆从亳 pause 仗仂仍亰亠 于 JSR 166 亟仍 JDK9 java/util/concurrent/locks/StampedLock.java java/util/concurrent/Phaser.java java/util/concurrent/SynchronousQueue.java class EventHandler { volatile boolean eventNoti鍖cationNotReceived; void waitForEventAndHandleIt() { while ( eventNoti鍖cationNotReceived ) { java.lang.Thread.onSpinWait(); } readAndProcessEvent(); } void readAndProcessEvent() { // Read event from some source and process it . . . } } 26
- 23. 仂亟亟亠亢从舒 SLH 于 Idea 28
- 24. Spin Loop Hint - source level 仂于仄亠亳仄仂 仂仗亳仄, 亠 从仂亟, 仂弍亳舒ﾑ亳亶 8-从仂亶 仗仂仍亰亶亠 Agrona library 亳仍亳 仗仂亟仄仂亳亠 于 java/org/agrona/hints/ThreadHints.java 仂亟亟亠亢从舒, 仆舒亳仆舒 Java 7 29 https://github.com/real-logic/Agrona/blob/master/src/main/java/org/agrona/hints/ThreadHints.java
- 25. 仂亟 亟仍 舒亰仆 于亠亳亶 Java 亳舒 于亠 仂仍从仂 仗仂亟 舒仄亶 舒亶 java 舒亰仆亠 舒亳舒从 丐仂仍亠 jar 舒亳于 (仆舒亳仆舒 9)
- 26. Multi-Release JARs (JEP-238) 31 仂亟 亟仍 JRE 于亠亳亳 仄亠仆亠 9 仂亟 亟仍 JRE 于亠亳亳 9 仂亟 亟仍 JRE 于亠亳亳 10 MANIFEST.MF: Multi-Release: true <root>/META-INF/versions/ ..
- 27. https://github.com/ivankrylov/onSpinWaitMultiReleaseJar onSpinWait Wrapper javac + make http://in.relation.to/2017/02/13/building-multi-release-jars-with-maven/ Get pid of jvm Maven Antrun + resources + maven-jar-plugin http://word-bits.鍖urg.com/multrelease-jars/ 亳仄亠 Multi-Release JARs 32
- 28. Garbage First 于从仍ﾑ亠仆 仗仂 仄仂仍舒仆亳 弌舒仄亶 仂于亠仄亠仆仆亶 GC 于 Hotspot 亠亞亳仂仆舒仍仆亶 仗舒舒仍仍亠仍仆亶 仂亟仆仂于亠仄亠仆仆亶 从仂仍仍亠从仂 亠亟从舒亰亠仄亠 仗舒亰 亳 于仂从舒 仗仂亳亰于仂亟亳亠仍仆仂! 仂 仄仂仍舒仆亳 => 亳弍从亳 于 GC 仆舒仂亟 弍亠亠 33
- 29. Garbage First 于从仍ﾑ亠仆 仗仂 仄仂仍舒仆亳 亅亞仂仆仂仄亳从舒 舒弍仂舒亠 仗仂-亟亞仂仄. 仂亞 仗仂磦亳 仂亳弍从亳 于 亳仆仂仆亳亰舒亳亳 仍亳 (亠(?)) 仆亠仂于仄亠亳仄仂亳 G1 于 Cassandra, Elasticsearch, Lucene, 亳 .仗,. (亳ﾐ姿 2015): https://groups.google.com/forum/#!topic/ mechanical-sympathy/JxsuVtIIOaY 34
- 30. 亠亠亢亳 仄亠仆 default GC, 仆亠 亠 仂仆 仍亳 亟仂 亳 仗仂 于舒 舒亳于舒仍亳 仆舒仂亶从亳 GC 仗仂 仄仂仍舒仆亳 亰舒仗舒亳亠 亟舒仆仆仄亳 亞仂仆仂仄亳从亳 亟仍 于舒亠亞仂 仗亳仍仂亢亠仆亳 亳 亠亟 于仆亠亟亠仆亳 (-XX:+PrintFlagsFinal) 仗仂仗亳亳亠 亳 于 亟亠仗仍仂亶仄亠仆 从亳仗舒 仍亳 于 亳 舒仆亠亠 磦仆仂 于弍亳舒仍亳 GC 亳 仍舒亞亳 GC 亳亠亞仂 仆亠 亳亰仄亠仆亳, 舒亠 从仂仍仍亠从仂 仆亠 亳亠亰仆 丐亠亳亶亠 G1. 亠 亟仂亢亳亟舒 Java 9. 35
- 31. 丱仂仂亳亶 仗仂于仂亟 亰仆舒 仗仂弍仂仍亠 仗仂 GC 亅从仗亠亳仄亠仆亳亶亠 G1 仍舒于仆仂亠 - 仗仂仆亳仄舒 仂仆仂于仆亠 仗亳仆亳仗 舒弍仂 GC 亠亢亟亠 于亠亞仂 - 仄亠亳从亳, 从仂仂仄亳 仂亠仆亳于舒ﾑ 舒仍亞仂亳仄 GC 丼仂 亠亠 仗仂亳舒: http://www.infoq.com/minibooks/java-garbage- collection 36
- 32. 亞亳亠 亳亰仄亠仆亠仆亳 于 GC Deprecate CMS Deprecate - 亰仆舒亳 亰舒仗亠亳, 仆仂 于 弍亟亠仄 (仗仂仍亠 9从亳) Shenandoah GC (JEP-189) 亠于亶 OpenJDK GC 仆亠 仂 舒从仍舒 弌仂亰亟舒仆亳亠 GC 亳仆亠亠亶舒 https://bugs.openjdk.java.net/browse/JDK-8163329 37
- 33. 弍仆仂于仍亠仆亳亠 Process API JEP 102: Process API Updates 仂于仂亠: 仂仍亳 pid 于仂亠亶 JVM 仂仍亳 仗亳仂从 仗仂亠仂于 亳亠仄 舒弍仂舒 亟亠亠于礆亳 仗仂亠仂于 supportsNormalTermination() ? Source: http://blog.takipi.com/java-9-the-ultimate-feature-list/ 38
- 34. 亳仄亠 Process API Source: http://blog.takipi.com/java-9-the-ultimate-feature-list/ 39 Process proc = Runtime.getRuntime() .exec(new String[]{"/bin/sh", "-c", "echo $PPID"}); if (proc.waitFor()==0) { InputStream in = proc.getInputStream(); int available = in.available(); byte[] outputBytes = new byte[available]; in.read(outputBytes); String pid = new String(outputBytes); System.out.println("Your pid is " + pid) } System.out.println("Your pid is " + ProcessHandle.current().getPid());
- 35. 40 丕仆亳亳从舒亳 JVM/GC 仍仂亞亞亳仆亞舒 丕仆亳亳从舒亳 仗仂 于亠仄 仗仂亟亳亠仄舒仄 jvm 6 仂于仆亠亶 + 亞亳 于仂亟 于 stdout / stderr / 舒亶仍 / 亰舒亳从仍亠仆仆亶 舒亶仍 仂弍仂仂仍亳 仗仂弍仍亠仄 仆亠从仂亠从仆仂亞仂 于于仂亟舒 仍仂亞仂于 11 亟亠从仂舒仂仂于 java -Xlog:help
- 37. 42 仂 仆亠 于亠 仂仗亳亳 仍亳 -XX:+PrintDeoptimizationDetails -XX:+PrintAOT -XX:+ThreadPriorityVerbose -XX:+PrintTieredEvents -XX:+PrintConcurrentLocks -XX:+PrintSharedSpaces -XX:+PrintSharedArchiveAndExit -XX:+PrintSharedDictionary -XX:+PrintMethodHandleStubs -XX:+PrintVMQWaitTime ...
- 38. HTTP/2 亠亞仂亟仆 43
- 39. HTTP -> TCP 44 HTTP 0.9: The One-Line Protocol (1989) HTTP/1.0 (1996) HTTP/1.1: Internet Standard (1997) Keep alive; chunk encodings; byte- range requests, additional caching mechanisms, transfer encodings, and request pipelining HTTP/2.0 (since 2012) Ref: https://hpbn.co/brief-history-of-http/
- 41. 227: Unicode 7.0 & 267: Unicode 8.0 Unicode 于 Java 9 46
- 42. 弍亰仂 JEP-仂于. 舒亳从舒 258: HarfBuzz Font-Layout Engine 263: HiDPI Graphics on Windows and Linux 265: Marlin Graphics Renderer 262: TIFF Image I/O 257: Update JavaFX/Media to Newer Version of GStreamer (1.4.4) 251: Multi-Resolution Images 53
- 43. Stack walking API 仍仂: Throwable::getStackTrace 亳 Thread::getStackTrace StackTraceElement[] stack = Thread.currentThread().getStackTrace(); 弌舒仍仂: StackFrame[] stack =new StackWalker().walk((s) -> s.collect(Collectors.toArray())); 仂于亶 从仍舒 StackWalker 54
- 44. 弍亰仂 JEP-仂于. 仂亳亰于仂亟亳亠仍仆仂 197: Segmented Code Cache 165: Compiler Control 295: Ahead-of-Time Compilation 243: Java-Level JVM Compiler Interface 246: Leverage CPU Instructions for GHASH and RSA 254: Compact Strings 280: Indify String Concatenation 250: Store Interned Strings in CDS Archives 143: Improve Contended Locking 266: More Concurrency Updates 56
- 45. 弍亰仂 JEP-仂于. 亠亰仂仗舒仆仂 219: Datagram Transport Layer Security (DTLS) 229: Create PKCS12 Keystores by Default 244: TLS Application-Layer Protocol Negotiation Extension 249: OCSP Stapling for TLS 64
- 46. 弍亰仂 JEP-仂于. 丼仂 弍亠? 231: Remove Launch-Time JRE Version Selection 240: Remove the JVM TI hprof Agent 241: Remove the jhat Tool 65 仂仍亠亟于亳 仄仂亟仍仆仂亳 (JEP - 261) -Xbootclasspath -Xbootclasspath/p system property sun.boot.class.path
- 47. JShell 舒亰于亳于舒(亠/仍) 于 舒仄从舒 仗仂亠从舒 Kulla 仂亰于仂仍磳 仗仂仗仂弍仂于舒 亳仆舒从亳 弍亠亰 仆舒仗亳舒仆亳 亰舒从仂仆亠仆仆仂亶 仗仂亞舒仄仄 仂仄仂亞舒亠 仂弍舒 磶从 Java class HelloWorld { public static void main(String[] args) { System.out.println("Hello World!"); } } 66
- 50. Currency API (JSR-354) 亠 于仂亶亟亠 于 Java 9, 舒亰于亳于舒亠 仂亟亠仍仆仂 69
- 52. Deprecate finalize Deprecate Object.finalize with forRemoval=false Problem - objects resurrection Alternatives PhantomReference java.lang.ref.Cleaner (since 9) https://stuartmarks.wordpress.com/2017/04/17/deprecation-of-object- 鍖nalize/ 71