Scripting for the JVM using Groovy. Adil Khan Sr. Application Developer /Java Group Biomedical Informatics

Transcription

1 Scripting for the JVM using Groovy Adil Khan Sr. Application Developer /Java Group Biomedical Informatics

2 Outline

3 What is Groovy? Outline

4 Outline What is Groovy? Why would we want to use it?

5 Outline What is Groovy? Why would we want to use it? A taste of the features.

6 Outline What is Groovy? Why would we want to use it? A taste of the features. Some examples in the BMI world.

7 Outline What is Groovy? Why would we want to use it? A taste of the features. Some examples in the BMI world. Other Features

8 What is Groovy?

9 What is Groovy? Released in 2003 ~ Java 1.4

10 What is Groovy? Released in 2003 ~ Java 1.4 Scripting language that is a Superset of Java.

11 What is Groovy? Released in 2003 ~ Java 1.4 Scripting language that is a Superset of Java. Great for Designing Domain Specific Languages (DSL).

12 What is Groovy? Released in 2003 ~ Java 1.4 Scripting language that is a Superset of Java. Great for Designing Domain Specific Languages (DSL). Seamless Integration with Java. (Groovy is Java)

13 What is Groovy? Released in 2003 ~ Java 1.4 Scripting language that is a Superset of Java. Great for Designing Domain Specific Languages (DSL). Seamless Integration with Java. (Groovy is Java) Natural for Java Developers /Access to all java libraries.

14 What is Groovy? Released in 2003 ~ Java 1.4 Scripting language that is a Superset of Java. Great for Designing Domain Specific Languages (DSL). Seamless Integration with Java. (Groovy is Java) Natural for Java Developers /Access to all java libraries. Natural for Scripters who want to learn/use Java.

15 What is Groovy? Released in 2003 ~ Java 1.4 Scripting language that is a Superset of Java. Great for Designing Domain Specific Languages (DSL). Seamless Integration with Java. (Groovy is Java) Natural for Java Developers /Access to all java libraries. Natural for Scripters who want to learn/use Java. Potential avenue for non-java developers who need access to java api/libraries

16 What is Groovy (Ctd.) Numerous ways to run groovy. Interactive console like Ruby, Python Shell Scripts: #!/usr/bin/env groovy GroovyShell Helper class java groovy.lang.groovyshell path_to/myscript.groovy Plugins for Eclipse/Netbeans etc. The designers goals is to have a language that gets out of the way and allows you to be productive.

17 A Taste Hello World Java: Hello World Groovy: Note lack of parenthesis, semicolons, modifiers and Typing.

18 More useful Example Java (6) Print contents of a file: With Groovy:

19 More useful Example Java (6) Print contents of a file: With Groovy:

20 More useful Example (Ctd) java.io.file class with a Groovy Nature. Groovy enhances existing java Objects. Use of closures /Functional programming. A more java like example:

21 Baked in Features

22 Baked in Features A quick overview of some basic built in features.

23 Baked in Features A quick overview of some basic built in features. Collections

24 Baked in Features A quick overview of some basic built in features. Collections {G}Strings

25 Baked in Features A quick overview of some basic built in features. Collections {G}Strings Templating

26 Baked in Features A quick overview of some basic built in features. Collections {G}Strings Templating Switch

27 Baked in Features A quick overview of some basic built in features. Collections {G}Strings Templating Switch Builders / Slurpers

28 Lists : Collections

29 Lists : Collections

30 Maps : Collections (Ctd)

31 Maps : Collections (Ctd)

32 Collections (Ctd) Range Using the.. operator

33 Collections (Ctd) Range Using the.. operator

34 {G}Strings Powerful extensions to the java.lang.string class. Evaluate expressions and here documents ( ).

35 {G}Strings Powerful extensions to the java.lang.string class. Evaluate expressions and here documents ( ).

36 Templating Templating engine allows for quick building of text. Good use case of building sql statements, or any dynamic text.

37 Templating Templating engine allows for quick building of text. Good use case of building sql statements, or any dynamic text.

38 Templating Templating engine allows for quick building of text. Good use case of building sql statements, or any dynamic text.

39 Switch Can use any object in the condition

40 Switch Can use any object in the condition

41 Switch Can use any object in the condition

42 Builders Built in ability to generate/parse JSON/XML Declarative Nature of groovy simplifies the task.

43 Builders Built in ability to generate/parse JSON/XML Declarative Nature of groovy simplifies the task.

44 Builders Built in ability to generate/parse JSON/XML Declarative Nature of groovy simplifies the task.

45 Builders (Ctd) Using MarkupBuilder to generate XML

46 Builders (Ctd) Using MarkupBuilder to generate XML

47 Builders (Ctd) Using MarkupBuilder to generate XML

48 Slurpers Using the Slurpers to build an object graph from Json/XML

49 Slurpers (Ctd) Xml example.

50 Potential Uses for Java Group

51 Potential Uses for Java Group Testing : unit/integration Ease of parsing/generating xml/json is very useful in integration tests.

52 Potential Uses for Java Group Testing : unit/integration Ease of parsing/generating xml/json is very useful in integration tests. Simplifying Utils classes.

53 Potential Uses for Java Group Testing : unit/integration Ease of parsing/generating xml/json is very useful in integration tests. Simplifying Utils classes. Build/Deployment scripts.

54 Potential Uses for Java Group Testing : unit/integration Ease of parsing/generating xml/json is very useful in integration tests. Simplifying Utils classes. Build/Deployment scripts. System Administration

55 Potential Uses for Java Group Testing : unit/integration Ease of parsing/generating xml/json is very useful in integration tests. Simplifying Utils classes. Build/Deployment scripts. System Administration DSLs

56 Testing Java with Groovy Creating Mock/Stub objects that simulate request/response for unit testing. Requirements specific testing using frameworks such as Spock (BDD) Unit Testing baked in groovy.util.groovytestcase Use case of using groovy constructs to simplify loops/parameters to java code.

57 Simplifying Utils Classes

58 Simplifying Utils Classes

59 Simplifying Utils Classes

60 Simplifying Utils Classes

61 Simplifying Utils Classes

62 Build/Monitor Scripts Invoke Groovy Scripts in Ant using the <groovy> tag. Use Groovy to monitor tomcat/application status *.

63 Build/Monitor Scripts Invoke Groovy Scripts in Ant using the <groovy> tag. Use Groovy to monitor tomcat/application status *.

64 Build/Monitor Scripts Invoke Groovy Scripts in Ant using the <groovy> tag. Use Groovy to monitor tomcat/application status *. *

65 Other Topics to Research DSLs-Powerful feature of Groovy to build specific languages for specific tasks. Web Application Frameworks like Grails could be useful for rapid prototyping of ideas. Developers with scripting/non-java background can get easier access to existing java code base.

66 Q/A