cdmlibrary/src/main/java/eu/etaxonomy/cdm/aspectj/PropertyChangeAspect.aj

   1 package eu.etaxonomy.cdm.aspectj;
   2
   3 import java.lang.reflect.Field;
   4 import java.lang.reflect.InvocationTargetException;
   5
   6 import org.apache.log4j.Level;
   7 import org.apache.log4j.Logger;
   8 import org.aspectj.lang.Signature;
   9 import eu.etaxonomy.cdm.model.common.CdmBase;
  10
  11 /**
  12  * @author markus
  13  * Aspect class that adds a firePropertyChange call to all setter methods
  14  * which names start with "set" and that belong to subclasses form CdmBase
  15  * CdmBase defines the rest of the ProeprtyChangeSupport like listener registration
  16  */
  17 public aspect PropertyChangeAspect {
  18         static Logger logger = Logger.getLogger(PropertyChangeAspect.class);
  19
  20         pointcut execSetter(CdmBase cb): target(cb) && execution(void CdmBase+.set*(..) );
  21 //      /** *********** OLD ***********************/
  22 //      pointcut callSetter( CdmBase b ) : call( * CdmBase+.set*(..) ) && target( b );
  23
  24         /**
  25          * @param cb
  26          * Around aspect that will be weaven into the original setter methods of the CdmBase derived classes
  27          */
  28         void around( CdmBase cb ) : execSetter( cb )  {
  29                 //logger.setLevel(Level.DEBUG);
  30                 // get property that is set by setter method
  31                 Field property = getFieldOfSetter( thisJoinPointStaticPart.getSignature() );
  32                 property.setAccessible(true);
  33                 String propertyName = property.getName();
  34                 //logger.debug("execSetter: The property is ["+propertyName+"]");
  35                 try {
  36                         // use property attribute directly, not through get method.
  37                         // get method might modify things, like setting a UUID when called for the first time.
  38                         // Also get methods for booleans start with "is" or "has"
  39                         Object oldValue = property.get(cb);
  40                         proceed( cb );
  41                         cb.firePropertyChange( propertyName, oldValue, property.get(cb));
  42                 } catch (NoSuchMethodException e) {
  43                         e.printStackTrace();
  44                         proceed( cb );
  45                 }catch (IllegalArgumentException e) {
  46                         e.printStackTrace();
  47                         proceed( cb );
  48                 }catch (IllegalAccessException e) {
  49                         e.printStackTrace();
  50                         proceed( cb );
  51                 } catch (InvocationTargetException e) {
  52                         e.printStackTrace();
  53                         proceed( cb );
  54                 }
  55         }
  56
  57
  58                 /**
  59                  * @param signature
  60                  * Return the Field object that belongs to the signature of a setter method
  61                  * Removes first 3 characters of method name to find property name
  62                  */
  63                 private Field getFieldOfSetter( Signature signature ){
  64                         Field field = null;
  65                         String propertyName = "";
  66                         //logger.debug( "Getting the field name of setter ["+signature.getName() + "]" );
  67                         try{
  68                                 String methodName = signature.getName();
  69                                 propertyName = Character.toLowerCase(methodName.charAt(3)) + methodName.substring(4);
  70                                 field = signature.getDeclaringType().getDeclaredField( propertyName );
  71                         }catch( NoSuchFieldException e ){
  72                                 try{
  73                                         propertyName = "is"+propertyName.substring(0, 1).toUpperCase()+ propertyName.substring(1);
  74                                         field = signature.getDeclaringType().getDeclaredField( propertyName );
  75                                 }catch( NoSuchFieldException nsfe ){
  76                                         nsfe.printStackTrace();
  77                                 }
  78                         }
  79                         return field;
  80                 }
  81                 /**
  82                  * Fires a propertyChange Event
  83                  * @param cb  CdmBase that fires that Event
  84                  * @param property the property's name
  85                  * @param oldval the old value
  86                  * @param newval the new value
  87                   */
  88                 void fireLoggingPropertyChange( CdmBase cb,
  89                                 String property,
  90                                 Object oldval,
  91                                 Object newval) {
  92
  93                         //logger.debug( "PropertyChangeEvent: property [" + property + "], old value [" + oldval + "], new value [" + newval + "]");
  94                         // call firePropertyChange in original class. Method defined in CdmBase superclass!
  95                         cb.firePropertyChange( property,
  96                                         ( oldval == null ) ? oldval : oldval.toString(),
  97                                         ( newval == null ) ? newval : newval.toString());
  98                 }
  99
 100 }