The document discusses the Java Virtual Machine (JVM) in 3 paragraphs: 1) It defines the JVM as a process that runs Java programs and handles memory and resource management similarly to an operating system. The JVM executes Java bytecode through an abstraction layer separating programs from hardware. 2) It explains how the JVM loads classes through classloaders and instantiates objects, allocating memory for each object. Garbage collection reclaims memory from objects no longer in use. 3) Web application servers like WAS are built on the JVM to run servlets and JSPs, allowing dynamic web content through Java code executed similarly to desktop programs on the JVM. The JVM provides a stable,

1. ჎ఁ࿌ ੭෧ၴ౅ ၦጄ ዾ ༘ ၰ௴ ྤ൑ఋဪ JVM ໞື
2014. 11
Darion Kim

2. ୾௴ ௛ૐ?
Darion Kim (଀጑ૺ)
ಀ࿝༺ඊቔൟ ࿨ૐ໴ ༘໐
พ
ၴᆼ ቛཅ(ቛጁၡ ཅ, God of
Integration)
hnki0104@me.com
https://www.facebook.com/
groups/serverside (၌ၦྤ๢)

3. ၦ බ໏൐ ක౷
Freshman࿝઎ ෡ᆺఁఋ.
(for YMS, JHJ)

4. ၦු JVM࿝ ఝጄ໏ ྤ
གྷ੿୾ གྷఁ࿌ ੭෧ၴ
ึ౹ၔ ࿥ૺଆხൢ …

5. ྾໵౵൝ఁఋ.
႗ఝ ࿌ഒ઎ ࿈ૺዻ
ხ ྨઔཀఁఋ.

6. ྤ൑ఋဪ JVM ໞື
ၕ ൢ୾ ย ა๗ਜ਼ ౗
໮ཀఁଆ?

7. ຫ೥౹ၔ JVMၕ ශ
ೡધ ࿈ૺዾଆဠ?

8. JVM
=
Java Virtual Machine

9. ૯ ఋၗิሽ௴ ඳჰ
ၿ ࿌ഒ઎ ࿈ૺዻధ
ೡૐဠ. ΢΢

10. ႔௴ ࿌಩઎ ࿈ૺዾ
ଆဠ?

11. ጮགྷ ይച૯ೱ
(Program) ၔ ྤໞဠ?

12. ይച૯ೱၕ ཇጌዻඓ
ይചໞ༺(Process)ਜ਼
ແໜ౛ఁఋ.

13. Ⴓధ ၴໞᎁ ໕඗ዻඓ?
ಀ༺ሙ(Disk)࿝ ၰ௴ ይച૯ೱ ኒၩ
(File)ၕ ཇጌዽఋ.
ይച૯ೱ ኒၩၦ ඈක൘(Memory) ႕
ႁ౗ඓ໏ ይചໞ༺ጷ ౗࿌ ይചໞ໏
(CPU)൐ ຫဧዽఋ.

14. ૯൜ၒച౅ ૯഍ยଆ
ဠ?
Disk
Program.exe Loading
CPU
Process
Memory

15. Process௴ Disk, File, Memory,
CPUဉ શഏ౗࿌ ၰ஫ဠ.
ૺ࿍ጄ౞ໞဠ.

16. JVM
=
Process
ၦೡધ ਜ਼ႜዽఋඓ

17. JVM౅ Process ᅧ೿
ཇጌዾ༘ ၰઔ஫ဠ.

18. ࿝ၦ~ ఋ౹ ྤགྷඓ
໏… ^^

19. java -cp ೡၦ๐೻൘ ඈၨሜ೭༺

20. Ⴓధ ၴໞᎁ ໕඗ዻඓ?
ಀ༺ሙ࿝ ၰ௴ java ይച૯ೱ࿝ ඈၨ
ሜ೭༺൐ ხႜዻ࿥ ཇጌዽఋ.
-cp စ໩ၕ ჎࿌ ೡၦ๐೻൘౅ ხႜዻ
࿥ ཇጌዽఋ.
ೡၦ๐೻൘௴ ಀആቔ൘, *.jar, *.zip ኒ
ၩ ႗ఝઠചၦఋ.

21. ૯൜ၒച౅ ૯഍ยଆ
Disk
ဠ?
java
Loading
CPU
JVM
Memory
Main.class
Main
Library
Library

22. JVM౅ Process ൬஫
ဠ.

23. ୵ଆხ ྤఁೡધ ዻ
གྷ௴ ึ౹ၔ ࿥ૺଆ
ხൢ …

24. ၴ~ ૯೻ඓ Ⴓధ ཉ౅
ၰ઎ ౹࿌ਜ਼ ยଆဠ?

25. JVM ྦᄠ࿝໏௴ ࿌
ಠၩ౹ၦ ข࿌ჲଆ
ဠ?

26. ૯೿ ဨ໓ Creatorဉ Class
ဉ Object, Instanceၡ ᅍ
ၦ൐ ྩྤ྽ ጁఁఋ.

27. Ⴓధ ၴໞᎁ ໕඗ዻඓ?
Creator = Ⴎම჎, ෡ച ࿥೻ึ ၮఁఋ.
Class(*.class)௴ Ⴎම჎ਜ਼ ൢ౷ ຄఝၮఁ
ఋ.
Class௴ Objectጷ ౛ఁఋ. = Instance
૯൥ၔ ຄఝ࿝ ແ඗എၕ ุ࿌பၒඓ ੮
ᅰਜ਼ ౛ఁఋ.

28. ૯൜ၒച౅ ૯഍ยଆ
ဠ?
Instance
Class Object
Creator

29. ၴ~ ఋགྷ Class, Object
൐ ૺ࿍ጄ჎ໞဠ.

30. ၦ႞ ႜ൥ച ྤ൑ఋ
ဪ JVM ໞືၒച ౹
࿌੣ఁఋ. ^^

31. ྤ൑ఋဪ JVM ໞື
ၕ ᆓື႕ၒച ૯഍
ฤఁఋ.

32. თဠዽ ઇၔ ༱઎
૯൝ఁఋ.

33. ႜጸዽ ૺ༜ ༺ኳၦ
พધ ཌྷၔ ึ౹ၔ ࿥
ૺଆხൢ …

34. ྤ൑ఋဪ JVM ໞື
Beautiful JVM World

35. ࿌ೡ! ྤඳઇ౅ ࿖
஫ဠ.

36. ྤఇఁఋ.
༝ၔ લཅ౹ၦ ၰཀ
ఁఋ.

37. JVM ໞື࿝௴ ੜၴ ધ၉
ၡ ࿦ዾ(Role)ၕ ਜ਼ხધ
ၰ௴ ੮ᅰਜ਼ ၰཀఁఋ.

38. ఋགྷ ዽ฀…
੮ᅰ௴ ੜၴ ધ၉ၡ ࿦
ዾ(Role)ၦ ၰཀఁఋ.

39. “ᅖႮ჎”ചཡ ຫ೥ၕ
ൢ౹഍ધ ጋఋඓ ຫ೥
ఖ઎ ൢ౹࿌྽ ዻઔ჊.

40. Ⴓధ ၴໞᎁ ໕඗ዻඓ?
ຫ೥ၕ ൢ౹഍ඓ ൽ൘, චቛ, ኖ, ఋ൘
ၡ ႜጸዽ ࿦ዾၕ ႜၡዽఋ.
ൽ൘ဉ චቛၦ ዻ୾ਜ਼ ྤఁඓ ຫ೥ၦ
ྤఁఋ.
ኖ઴ ఋ൘ਜ਼ ౞੭ਜ਼ ྤఁඓ ຫ೥ၦ ྤ
ఁఋ.

41. ૯൜ၒച౅ ໕඗ዻඓ?
ຫ೥ ૃම

42. ฀ဘ:
ဨ൘௴ OOP࿝໏ ຫ೥(੮ᅰ)ၕ
ຫ೥ఖხ ྨ઎ ແໜጁఁఋ.
ྦ૯೻ཊఁଆ?

43. ఋགྷ ༝ၔ લཅၕ
໴੭ጁఁఋ.

44. ሜ೭༺ചధ(Classloader)
Beautiful JVM World
Classloader

45. Ⴓధ ၴໞᎁ ໕඗ዻඓ?
ሜ೭༺ചధ(Classloader)
࿦ዾ : JVM ၮૐ࿝໏ ሜ೭༺౹ၕ ചಉ
ዽఋ.
JVM ໞືၡ ༘බၿ ࿦ዾ

46. ૯൜ၒച౅ ໕඗ዻඓ?
Beautiful JVM World
Class
Classloader
Class
Class
Class Class

47. ചಉౘ ሜ೭༺௴ ੮
ᅰጷ ౙ༘ ၰཀఁఋ.

48. Ⴓధ ၴໞᎁ ໕඗ዻඓ?
Car a = new Car();
Car : ሜ೭༺
a : ੮ᅰ

49. ૯൜ၒച౅ ໕඗ዻඓ?
Beautiful JVM World
Class
Classloader
Car
Class
Class Class
a

50. ੮ᅰ൐ ࿥೻੭ ແໜ
ዻඓ

51. Ⴓధ ၴໞᎁ ໕඗ዻඓ?
Car a = new Car();
Car b = new Car();
House c = new House();
Food d = new Food();

52. ૯൜ၒച౅ ໕඗ዻඓ
Beautiful JVM World
Class
Classloader
Car
Class
Food House
a
b
c
d

53. ੮ᅰਜ਼ ඳዽఝച ൣ
ၦ ແໜ౗ඓ ࿌಩઎
ౙଆဠ?

54. ૯൜ၒച౅ ໕඗ዻඓ
Beautiful JVM World
Class
Classloader
Car
Object
Class
Object
Food House
a
b
c
d
Object
Object
Object
Object
Object
Object
Object
Object Object
Object
Object
Object
Object
Object
Object

55. JVM ໞືၡ ੮ᅰ ෘ
౅ਜ਼ ႙႙ ைྤჵఁ
ఋ.

56. ૯೻ఋਜ਼ …

57. ၦഄ઎ ౗ఋਜ਼ …

58. OOME(OutOf MemoryError)

59. ዻხൢ ႜື႕ၨ ື
ጼ࿝໏௴ OOMEਜ਼ ෧
ແዻხ ྨཀఁఋ.

60. ဒ ૯೾ଆဠ?

61. ವ ዻ୾ၡ ༝ၔ લ
ཅၕ ໴੭ጁఁఋ.

62. Garbage Collector
Beautiful JVM World
Class
Classloader
Car
Object
Class
Object
Food House
a
b
c
d
Object
Object
Object
Object
Object
Object Object
Object
Object
Object
finalize
Object
Object
Object
finalize
finalize
finalize
finalize
finalize
finalize finalize

63. Ⴓధ ၴໞᎁ ໕඗ዻඓ?
Garbage Collection : ੮ᅰਜ਼ ధ ၦື ᅒ
Ⴎਜ਼ ࿖ఋધ ንถ(finalize)ౘ ઠဨ
Garbage Collector࿝ ၡጄ ጭᆖ౛ఁఋ.
ყ ੮ᅰ൐ JVM ໞື࿝໏ ໴ඔ གྷሥఁ
ఋ.

64. ૯൜ၒച౅ ໕඗ዻඓ?
Beautiful JVM World
Class
Classloader
Object
Class
Food House
d
Object
Object Object
Object
Object
Object
Object
Object
Object
Car finalized

65. WAS(Web Application Server)
=
JVM
ၦೣ ແੜၔ ጄพ໮୾ဠ?

66. ൬ཀఁఋ.
WAS౅J2EE ༺ኳၕ ა
༘ዽ JVMၮఁఋ.

67. ૯൜ၒച౅ ໕඗ዻඓ?
Beautiful JVM World
AServlet
Classloader
FoodServlet House.jsp
Car.jsp
a
b
c
d
BServlet

68. JVM ໞືၔ ጃື
ྤ൑ఖૺൢ ዾଆဠ?

69. ႗ఝ ྤఇఁఋ.

70. Ⴎම჎ဉ Ⴎම჎ၡ ᆵ
ૐึ౹ၔ ุ໷ዽ ሜ೭
༺൐ ൢ౹༘ၰཀఁఋ.

71. ළ౅ ක്ધ ൢ౷ ሜ
೭༺ਜ਼ ᆊધၡ ุ໷
ዽ ሜ೭༺ၮఁఋ.

72. ุ໷ዽ ሜ೭༺ၡ ၡጄ ແໜ
ౘ ੮ᅰ౹ၦ JVM ໞືၕ
෥౵གྷ ࿌ხഀ઎ ጁఁఋ.

73. ࿌಩઎ ጄછጄ྽ ዻ
୾ဠ?

74. ይചኒၩൟ(Profiling)
ၕ ጄ྽ጁఁఋ.

75. ይചኒၩൟၕ ዻ഍ඓ
ሜ೭༺ചధဉ ᆵጄႦ
྽ ጁఁఋ.

76. Ⴓధ ၴໞᎁ ໕඗ዻඓ?
ဨ൘௴ ሜ೭༺ചధၡ ࿦ዾၕ ྩધ ၰཀఁఋ.
ሜ೭༺ചధ࿝ Hook Class൐ ႕ဧጁఁఋ.
ይചኒၩൟ ఝື ሜ೭༺ਜ਼ ചಉౙ ಕ ஀ྤᅘ࿌ ᆬႜ
ചჯၕ ཉ࿌௉ཀఁఋ.
ይചኒၩ ᆬႜၕ ༘ጌጁఁఋ. (ex:ඈ໴౵ ༘ጌགྷ੝ ᆬ
ႜ)
ይചኒၩൟ ఝື ሜ೭༺௴ ၴཅ࿝ ච໵࿝ ཉ࿌௉ၔ
ചჯၕ ၨხዻხ ජዻધ ዀ໴ဉ ౏ၩዻ઎ ጺ౏ጁఁఋ.

77. Hooking Class

78. ૯൜ၒച౅ ໕඗ዻඓ?
Beautiful JVM World
AServlet
Classloader
FoodServlet House.jsp
Crazy.jsp
maddest-a
maddest-b
c
d
BServlet
hook Profiler

79. ุ໷ዽ ሜ೭༺࿝໏ ແ
ໜౘ ੮ᅰ௴ ጭጹ, ႖ႉ,
ൠൠพఋ౅ ඳ໙ཀఁఋ.

80. ၦ ྤ൑ఋဪ JVM ໞື࿝
Memory Leak, Infinite Loop
ၡ ྭໞዅ൐ ጸຮགྷሥఁఋ.

81. છ૑࿟ ྤ൑ఋဪ JVM ໞື
࿝ OutOfMemoryError,
Process of Hanging઴ ੪ၔ Ⴖ
൥ၕ ਜ਼Ⴆఋ ვఁఋ.

82. JVM Ⴖ൥…

83. ૯೭໏ ይചኒၩൟၒച ဴ
ၨ ሜ೭༺ ෟ ੮ᅰ൐ ᅗྤ
႞੿ጄ྽ ዻ௴ ઇၮఁఋ.

84. ᅗྤ໏ ෥౵གྷ
႞੿ዻೡ~!

85. ይചኒၩൟၦ ࿌഍
ါઇ ੪ၒགྷ჊?

86. APM (Application
Performance Management)
໸ള໩ၕ ૐ൯ዻ࿥ ຫဧዻ
གྷඓ ੝ఎጁఁఋ.

87. ඳഭച ዻཇ഍ඓ JDK࿝ ዅ
ጀౘ JConsoleၦ୾ VisualVM
ၕ ຫဧዻགྷඓ ౛ఁఋ.

88. Ⴓధ ችጷౘ ይചኒၩൟၕ
ဴዻགྷඓ Java
Instrumentation ૺฅၕ ຫဧ
ዻ࿥ ૐጢዻགྷඓ ౛ఁఋ.

89. ྤ൑ఋဪ JVMໞືၔ
ဨ൘ਜ਼ ෥౵གྷ ᆓૐጄ
྽ ౗௴ ໞືၮఁఋ.

90. ၦື ၌ၦྤ๢࿰ཀఁఋ.