cdmlib-model/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.Logger;
   7 import org.aspectj.lang.Signature;
   8 import eu.etaxonomy.cdm.model.common.CdmBase;
   9
  10 /**
  11  * @author markus
  12  * Aspect class that adds a firePropertyChange call to all setter methods
  13  * which names start with "set" and that belong to subclasses form CdmBase
  14  * CdmBase defines the rest of the ProeprtyChangeSupport like listener registration
  15  */
  16 public aspect PropertyChangeAspect {
  17         static Logger logger = Logger.getLogger(PropertyChangeAspect.class);
  18
  19 //      pointcut execAdder(CdmBase cb): target(cb) && execution(void CdmBase+.add*(..) );  //once implemented we may want to remove addToSetWithChangeEvent and remove... from CdmBase
  20
  21         /**
  22      * @param cb
  23      * Around aspect that will be weaven into the original setter methods of the CdmBase derived classes
  24      */
  25     after() returning(CdmBase cb): call(CdmBase+.new(..)) {
  26         //logger.warn(" new instance aop " + cb.getClass().getName());
  27         cb.fireOnCreateEvent(cb);
  28     }
  29
  30         pointcut execSetter(CdmBase cb): target(cb) && execution(void CdmBase+.set*(..) );
  31 //      /** *********** OLD ***********************/
  32 //      pointcut callSetter( CdmBase b ) : call( * CdmBase+.set*(..) ) && target( b );
  33
  34
  35
  36         /**
  37          * @param cb
  38          * Around aspect that will be weaven into the original setter methods of the CdmBase derived classes
  39          */
  40         void around( CdmBase cb ) : execSetter( cb )  {
  41                 //logger.setLevel(Level.DEBUG);
  42                 // get property that is set by setter method
  43                 Field property = getFieldOfSetter( thisJoinPointStaticPart.getSignature() );
  44                 if (property==null){
  45                         proceed( cb );
  46                 }else{
  47                         property.setAccessible(true);
  48                         String propertyName = property.getName();
  49                         //logger.debug("execSetter: The property is ["+propertyName+"]");
  50                         try {
  51                                 // use property attribute directly, not through get method.
  52                                 // get method might modify things, like setting a UUID when called for the first time.
  53                                 // Also get methods for booleans start with "is" or "has"
  54                                 Object oldValue = property.get(cb);
  55                                 proceed( cb );
  56                                 Object newValue = property.get(cb);
  57 //                              logger.error ("Prop: " + propertyName);
  58 //                              logger.warn("OLD:" + oldValue);
  59 //                              logger.warn("New:" + newValue);
  60                                 if (! isPersistentSet(newValue) && ! isPersistentSet(oldValue)  ){
  61                                         cb.firePropertyChange( propertyName, oldValue, newValue);
  62                                 }
  63                         } catch (NoSuchMethodException e) {
  64                                 e.printStackTrace();
  65                                 proceed( cb );
  66                         }catch (IllegalArgumentException e) {
  67                                 e.printStackTrace();
  68                                 proceed( cb );
  69                         }catch (IllegalAccessException e) {
  70                                 e.printStackTrace();
  71                                 proceed( cb );
  72                         } catch (InvocationTargetException e) {
  73                                 e.printStackTrace();
  74                                 proceed( cb );
  75                         }
  76                 }
  77         }
  78
  79         private boolean isPersistentSet(Object value){
  80                 if (value == null){
  81                         //logger.debug("(null) is not PS");
  82                         return false;
  83                 }else if (value.getClass().getSimpleName().equals("PersistentSet")){
  84                         logger.debug("Don't throw event for setter of Persistent Set");
  85                         return true;
  86                 }else{
  87                         //logger.warn(value.getClass().getSimpleName() + " is is not PS");
  88                         return false;
  89                 }
  90         }
  91
  92
  93         /**
  94          * @param signature
  95          * Return the Field object that belongs to the signature of a setter method
  96          * If no matching attribute can be found return null instead of throwing an NoSuchFieldException
  97          * Removes first 3 characters of method name to find property name
  98          */
  99         private Field getFieldOfSetter( Signature signature ){
 100                 Field field = null;
 101                 String propertyName = "";
 102                 //logger.debug( "Getting the field name of setter ["+signature.getName() + "]" );
 103                 try{
 104                         String methodName = signature.getName();
 105                         propertyName = Character.toLowerCase(methodName.charAt(3)) + methodName.substring(4);
 106                         field = signature.getDeclaringType().getDeclaredField( propertyName );
 107                 }catch( NoSuchFieldException e ){
 108                         try{
 109                                 propertyName = "is"+propertyName.substring(0, 1).toUpperCase()+ propertyName.substring(1);
 110                                 field = signature.getDeclaringType().getDeclaredField( propertyName );
 111                         }catch( NoSuchFieldException nsfe ){
 112                                 // can't find any matching attribute. catch error and return null
 113                                 return null;
 114                         }
 115                 }
 116                 return field;
 117         }
 118
 119         /**
 120          * Fires a propertyChange Event
 121          * @param cb  CdmBase that fires that Event
 122          * @param property the property's name
 123          * @param oldval the old value
 124          * @param newval the new value
 125           */
 126         void fireLoggingPropertyChange( CdmBase cb,
 127                         String property,
 128                         Object oldval,
 129                         Object newval) {
 130
 131                 //logger.debug( "PropertyChangeEvent: property [" + property + "], old value [" + oldval + "], new value [" + newval + "]");
 132                 // call firePropertyChange in original class. Method defined in CdmBase superclass!
 133                 cb.firePropertyChange( property,
 134                                 ( oldval == null ) ? oldval : oldval.toString(),
 135                                 ( newval == null ) ? newval : newval.toString());
 136         }
 137
 138 }