UnitDef.java

package com.xrosstools.xunit.def;

import java.util.LinkedHashMap;

import com.xrosstools.xunit.ApplicationPropertiesAware;
import com.xrosstools.xunit.BehaviorType;
import com.xrosstools.xunit.Unit;
import com.xrosstools.xunit.UnitPropertiesAware;
import com.xrosstools.xunit.impl.DefaultUnitImpl;

public class UnitDef {
	protected UnitDefRepo repo;
	private String name;
	private BehaviorType type;
	private String description;
	private boolean singleton;
	private Unit instance;
	private String className;
	private String referenceName;
	private String key;
	private LinkedHashMap<String, String> properties;
	
	public void setUnitDefRepo(UnitDefRepo repo){
		this.repo = repo;
	}
	
	public BehaviorType getType() {
		return type;
	}

	public void setType(BehaviorType type) {
		this.type = type;
	}

	public String getKey() {
		return key;
	}

	public void setKey(String key) {
		this.key = key;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public String getDescription() {
		return description;
	}

	public void setDescription(String description) {
		this.description = description;
	}

	public boolean isSingleton() {
		return singleton;
	}

	public void setSingleton(boolean singleton) {
		this.singleton = singleton;
	}

	public String getClassName() {
		return className;
	}

	public void setClassName(String className) {
		this.className = className;
	}

	public String getReferenceName() {
		return referenceName;
	}

	public void setReferenceName(String referenceName) {
		this.referenceName = referenceName;
	}
	
	public void setProperties(LinkedHashMap<String, String> properties) {
		this.properties = properties;
	}

	private boolean isEmpty(String str){
		if(str == null || str.trim().length() == 0)
			return true;
		return str.trim().equalsIgnoreCase("default");
	}
	
	protected Unit createDefault(){
		return new DefaultUnitImpl(this);
	}

	protected Unit createInstance() throws Exception{
		if(!isEmpty(className)){
			Unit unit = (Unit)Class.forName(className).newInstance();
			if(unit instanceof ApplicationPropertiesAware){
				ApplicationPropertiesAware aware = (ApplicationPropertiesAware)unit;
				// Make a copy
				aware.setApplicationProperties(new LinkedHashMap<String, String>(repo.getApplicationProperties()));
			}
			
			if(unit instanceof UnitPropertiesAware){
				UnitPropertiesAware aware = (UnitPropertiesAware)unit;
				// Make a copy
				aware.setUnitProperties(new LinkedHashMap<String, String>(properties));
			}
			return unit;
		}
		
		if(!isEmpty(referenceName))
			return repo.getUnit(referenceName);
		return createDefault();
	}
	
	/**
	 * if it is singleton, we should return the only instance
	 * @return
	 * @throws Exception 
	 */
	public final Unit getInstance() throws Exception{
		if(singleton)
			if(instance != null)
				return instance;
			else
				return instance = createInstance();
		
		return createInstance();
	}
	
	/**
	 * Just a helper method to let subclass create child unit.
	 * The parent  
	 */
	public static Unit getInstance(UnitDef def) throws Exception{
		return  def == null ? null : def.getInstance();
	}	
}