Spring Framework Integration

1
Spring Framework Integration

• Lance Berry CIS 764 Fall 2006

2
The Spring Model
3
Spring Integration with Other Components
Spring Framework
AOP
AspectJ
BeanFactory
POJO
Hibernate
Interface
POJI
Struts
4
Aspect Oriented Programming (AOP)

• What is AOP?
• AOP is an extension to Object-Oriented
  Programming.
• Closely resembles Java Servlet Filters
• AOP allows a developer to add testing or
  validation external to a class
• Spring Supports both a native AOP and hooks into
  the AspectJ AOP Framework.

5
Aspect Oriented Programming Definitions and Terms

• Aspect modularization of a concern across
  multiple objects (called Cross-Cut Concerns in
  AOP).
• Advice Action taken by an Aspect
• Joinpoint (called point cut in AOP) Point
  defined during execution.
• Target (or advised object) Object being
  advised
• AOP proxy Object created to implement Aspect
  contracts and the primary method used in Springs
  AOP implementation.
• Weaving linking Aspects with other application
  types and objects.

6
Types of Advice

• Before processing before method invocation.
  Good for security or preprocessing validation.
• After -- processing after method invocation.
  Good for verification or checking processing
  method accuracy
• Around Before and after method invocation.
  Good for checking changed values.
• Throws After method invocation, but only if an
  exception was raised
• Introduction special type of Advice that
  Introduces implementations to an object
  dynamically.

7
Example Spring AspectJ Using Before and After
Advice
8
MessageWriter Code

• public class MessageWriterpublic void
  writeMessage()
• System.out.println(foobar)
• public void foo()
• System.out.println(foo!)

9
MessageWrapper Code

• public aspect MessageWrapper
• private String prefix
• private String suffix
• public void setPrefix(String prefix)
• this.prefixprefix
• public void setSuffix(String suffix)
• this.suffixsuffix
• pointcut doWriting()
• execution( MessageWriter.writeMessage())
• before() doWriting()
• System.out.println(prefix)
• after() doWriting()
• Sytem.out.printlng(suffix)

10
AspectJ.XML

• lt?xml version1.0 encodingUTF-8?gtlt!DOCTYPE
  beans PUBLIC -//SPRING/DTD BEAN//EN
  http//www.springframework.org/dtd/spring-beans.d
  tdgt
• ltbeansgt
• ltbean idaspect
• classMessageWrapper factory-methodaspectOf
  gt
• ltproperty nameprefixgt
• ltvaluegtHa Ha!lt/valuegt
• lt/propertygt
• ltproperty namesuffixgt
• ltvaluegtHo Ho!lt/valuegt
• lt/propertygt
• lt/beangt
• lt/beansgt

11
Putting It All Together

• import org.springframework.context.ApplicationCont
  ext
• import org.springframework.context.support.FileSys
  temXmlAPplicationContext
• Public class AspectJExample
• public static void main(String args)
• Application context ctx new
  FileSystemXmlApplicationContext(AspectJ.xm)
• MessageWriter writer new MessageWriter()
• writer.writeMessage()
• writer.foo()

12
The Output

• Ha Ha!foobar!Ho Ho!foo

13
Hibernate Integration
14
The End