Rapid Java application development with JRebel

Transcript

1. Rapid  Java  Applica,on   Development     JUG.ru   25.02.2012  
3. Turnaround  Cycle   Make  a   change   Build,   deploy,   wait   Check   the   change  
4. Technology  Zoo  
5.                  dev  <<  PROD   Opera,ons   Standards   Vendors  
6. Turnaround  Cycle   Make  a   change   Build,   deploy,   wait   Check   the   change  
7. Naviga,on    Applica,on     deployment   Turnaround  Time  Sink   Container  boot  ,me   OOM  
8. Container  Startup  Time   hBp://dow.ngra.de/2010/12/14/jee-­‐oss-­‐container-­‐startup-­‐Jmes-­‐apples-­‐vs-­‐oranges/  
9. hBp://zeroturnaround.com/java-­‐ee-­‐producJvity-­‐report-­‐2011/  
10. Build   Package  everything  into  WAR/EAR   Package  modules  into  JARs   Compile  classes   Copy  sta,c  resources   Resolve  dependencies  
11. Exploded  Directory  Deployment  
12. JeBy  Launcher   public class Launcher { public static void main(String[] args) { Server server = new Server(); SelectChannelConnector connector = new SelectChannelConnector(); connector.setPort(8080); server.addConnector(connector); WebAppContext context = new WebAppContext("war", "/"); server.setHandler(context); server.start(); } }
13. “…I  know  about  JRebel,  but  I  cannot   pay  for  it,  so  I  tried  Maven…”                                                                                        -­‐  Stackoverflow  
14. This  works:   mvn  jeLy:run   others?  
15. getResource(“hello.html”)   read(“src/main/.../hello.html”)  
16. Build   Package  everything  into  WAR/EAR   Package  modules  into  JARs   Compile  classes   Copy  sta,c  resources   Resolve  dependencies  
17. Build   Package  everything  into  WAR/EAR   Package  modules  into  JARs   Compile  classes   Copy  sta,c  resources   Resolve  dependencies  
18. Why  Code  Reloading  is  Hard?   Externalized   Temporary   Serializable   DerivaJve   State  
19. MyObject   MyObject.class   OldClassLoader   NewClassLoader   MyObject.class   MyObject   Recreate  object  
20. Classes Libraries OldClassLoader NewClassLoader Sevlet New Classes New Libraries Sevlet Session Session init()   App State App State Serialize/deserialize  
21. Twin  ClassLoader  Issues   JVM Classes Libraries OldClassLoader NewClassLoader Objects and Code Classes Libraries Objects and Code OutOfMemoryError ClassCastException …
23. Old Component ClassLoader New Component ClassLoader Class Object Component State New Class New Object
24. MyObject MyObject.class   OldClassLoader Code   101000101   100010010   Debugger HotSwap   New  code   111000100   101010010   New  code   111000100   101010010   Make  changes  in  IDE   HotSwap  
25. JRebel  vs  HotSwap   HotSwap   JRebel   Changing  method  bodies   +   +   Adding/removing  methods   -­‐   +   Adding/removing  constructors   -­‐   +   Adding/removing  fields   -­‐   +   Adding/removing  classes   -­‐   +   Adding/removing  annotaJons   -­‐   +   Replacing  superclass   -­‐   -­‐   Adding/removing  implemented   interfaces   -­‐   -­‐  
26. MyObject MyObject.class   OldClassLoader Code   101000101   100010010   New  code   111000100   101010010   Make  changes  in  IDE   JRebel   Framework   Configura,on   (XML,  annota,ons,..)   JRebel  
27. in  acJon  
28. Oh  ...   The  Acid  is  Kicking  In   Take  a  break!