com.ibm.jbatch.container.jsl.impl.JobMergeHelper Maven / Gradle / Ivy
/**
* Copyright 2012 International Business Machines Corp.
*
* See the NOTICE file distributed with this work for additional information
* regarding copyright ownership. Licensed under the Apache License,
* Version 2.0 (the "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.ibm.jbatch.container.jsl.impl;
import com.ibm.jbatch.container.jsl.ExecutionElement;
import com.ibm.jbatch.jsl.model.Flow;
import com.ibm.jbatch.jsl.model.JSLJob;
import com.ibm.jbatch.jsl.model.JSLProperties;
import com.ibm.jbatch.jsl.model.Listeners;
import com.ibm.jbatch.jsl.model.Split;
import com.ibm.jbatch.jsl.model.Step;
public class JobMergeHelper {
/**
* Merge s through a parent attribute reference.
* @param parent the referred to by the child
* @param child the with a parent reference, this object will be modified
*/
public void mergeParentJob(JSLJob parent, JSLJob child) {
//assert child really links to parent
if(!parent.getId().equals(child.getParent())) return;
//TODO: no merge attribute, what default behavior to have?
//merge lists
child.setProperties(mergeProperties(parent.getProperties(), child.getProperties()));
child.setListeners(mergeListeners(parent.getListeners(), child.getListeners()));
//add in any elements we don't already have
//n^2 performance. how big do we expect a JSL to be?
for(ExecutionElement pElem : parent.getExecutionElements()) {
boolean hasCollidingId = false;
ExecutionElement collidingChildElement = null;
for(ExecutionElement cElem : child.getExecutionElements()) {
if(pElem.getId().equals(cElem.getId())) { //id is required attribute, not null
hasCollidingId = true;
collidingChildElement = cElem;
}
}
if(hasCollidingId) {
//figure out how to merge the offending element
//what if same id on different element types?
if(pElem instanceof Flow ) mergeCollidingFlow( pElem, collidingChildElement);
if(pElem instanceof Step ) mergeCollidingStep( pElem, collidingChildElement);
if(pElem instanceof Split) mergeCollidingSplit(pElem, collidingChildElement);
} else {
child.getExecutionElements().add(pElem);
}
}
}
/**
* Merge two properties lists by combining all elements from parent into child.
* If child is null it will be instantiated, possibly empty.
* @param parentProps
* @param childProps is modified
* @return the modified childProps, or a new merged JSLProperties object if childProps
* was null.
*/
private JSLProperties mergeProperties(JSLProperties parentProps, JSLProperties childProps) {
if(parentProps == null) return childProps;
if(childProps == null) childProps = new JSLProperties();
childProps.getPropertyList().addAll(parentProps.getPropertyList());
//TODO: if we have to return anyway, why modify childProps at all? would be clearer
//if we were forced to use the return value
return childProps;
}
/**
* Merge two listeners lists by combining all elements from parent into child.
* If child is null it will be instantiated, possibly empty/
* @param parentListeners
* @param childListeners is modified
* @return the modified childListeners, or a new merged Listeners object if childListeners
* was null.
*/
private Listeners mergeListeners(Listeners parentListeners, Listeners childListeners) {
if(parentListeners == null) return childListeners;
if(childListeners == null) childListeners = new Listeners();
childListeners.getListenerList().addAll(parentListeners.getListenerList());
return childListeners;
}
public void mergeCollidingFlow(ExecutionElement parent, ExecutionElement child){}
/**
* Merge a parent that has the same id value as the child .
* Attributes - copy new ones, child takes precedence in collisions
*
* @param parent
* @param child
*/
public void mergeCollidingStep(ExecutionElement parent, ExecutionElement child){
}
public void mergeCollidingSplit(ExecutionElement parent, ExecutionElement child){}
}