001    /*
002    @license.text@
003     */
004    package biz.hammurapi.config;
005    
006    import biz.hammurapi.metrics.MeasurementCollector;
007    import biz.hammurapi.metrics.MeasurementConsumer;
008    
009    /**
010     * Base class for components. Implements some standard functions.
011     * Measurement collection is delegated if measurement consumer is set.
012     * @author Pavel Vlasov
013     * @revision $Revision$
014     */
015    public abstract class ComponentBase implements Component, Context, MeasurementConsumer, MeasurementCollector {
016    
017            protected Object owner;
018            
019            private PathNavigator pathNavigator=new PathNavigator(this) {
020    
021                    protected Object getParent() {
022                            return owner;
023                    }
024    
025                    protected Object getChild(String name) {
026                            return ComponentBase.this.getChild(name);
027                    }
028                    
029            };
030            
031            /**
032             * Override this method if component has subcomponents.
033             * @param name
034             * @return
035             */
036            protected Object getChild(String name) {
037                    return null;
038            }
039    
040            public void setOwner(Object owner) {            
041                    this.owner=owner;
042            }
043    
044            public Object get(String name) {
045                    return pathNavigator.get(name);
046            }
047    
048            private MeasurementConsumer measurementConsumer;
049            
050            public void setMeasurementConsumer(MeasurementConsumer measurementConsumer) {
051                    this.measurementConsumer = measurementConsumer;         
052                    if (measurementConsumer instanceof Component) {
053                            ((Component) getMeasurementConsumer()).setOwner(this);
054                    }
055            }
056            
057            public MeasurementConsumer getMeasurementConsumer() {
058                    return measurementConsumer;
059            }
060            
061            public void addMeasurement(String name, double value, long time) {
062                    if (measurementConsumer!=null) {
063                            measurementConsumer.addMeasurement(name, value, time==0 ? System.currentTimeMillis() : time);
064                    }               
065            }
066            
067            /**
068             * Finds component owner of particular type.
069             * @param ownerType
070             * @return Owner which is an instance of specified type or null if no such owner is found.
071             */
072            public Object getOwner(Class ownerType) {
073                    if (owner==null || ownerType.isInstance(owner)) {
074                            return owner;
075                    }
076                    
077                    if (owner instanceof ComponentBase) {
078                            return ((ComponentBase) owner).getOwner(ownerType);
079                    }
080                    
081                    if (owner instanceof GenericContainer) {
082                            return ((GenericContainer) owner).getOwner(ownerType);
083                    }
084                    
085                    return null;
086            }
087    }