/**
* Copyright 2013 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.util;
import java.lang.reflect.Field;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.batch.api.BatchProperty;
import javax.batch.runtime.context.JobContext;
import javax.batch.runtime.context.StepContext;
import javax.inject.Inject;
import com.ibm.jbatch.container.artifact.proxy.InjectionReferences;
import com.ibm.jbatch.container.exception.BatchContainerRuntimeException;
import com.ibm.jbatch.container.exception.IllegalBatchPropertyException;
import com.ibm.jbatch.jsl.model.Property;
public class DependencyInjectionUtility {
private final static String sourceClass = DependencyInjectionUtility.class.getName();
private final static Logger logger = Logger.getLogger(sourceClass);
public static void injectReferences(Object artifact, InjectionReferences injectionRefs) {
if (logger.isLoggable(Level.FINE)) {
logger.fine("Injecting references into: " + artifact);
logger.fine("InjectionReferences = " + injectionRefs);
}
Map<String, Field> propertyMap = findPropertyFields(artifact);
if (injectionRefs.getProps() != null) {
injectProperties(artifact, injectionRefs.getProps(), propertyMap);
}
injectBatchContextFields(artifact, injectionRefs.getJobContext(),
injectionRefs.getStepContext());
if (logger.isLoggable(Level.FINE)) {
logger.exiting(sourceClass, "injectReferences");
}
}
/**
*
* @param props
* The properties directly associated with this batch artifact.
*/
private static void injectProperties(Object artifact , List<Property> props, Map<String, Field> propertyFieldMap) {
//check if jsl properties are null or if
//the propertyMap is null. this means there are no annotated fields with @BatchProperty
if (props == null || propertyFieldMap == null) {
return;
}
// go through each field marked with @BatchProperty
for (Entry<String, Field> batchProperty : propertyFieldMap.entrySet()) {
String propValue = getPropertyValue(props, batchProperty.getKey());
// if a property is supplied in the job xml inject the given value
// into
// the field otherwise the default value will remain
try {
if (!(propValue == null)) {
batchProperty.getValue().set(artifact, propValue);
} else {
//DO NOTHING so that the Java initialized value is used as the default for unresolved properties
}
} catch (IllegalArgumentException e) {
throw new IllegalBatchPropertyException("The given property value is not an instance of the declared field.", e);
} catch (IllegalAccessException e) {
throw new BatchContainerRuntimeException(e);
}
}
}
/**
*
* @param props list of properties from job xml
* @param name name of the property
* @return null if no matching property found
*/
public static String getPropertyValue(List<Property> props, String name) {
if (props == null) {
return null;
}
for (Property prop : props) {
if (name.equals(prop.getName())) {
String propValue = prop.getValue();
if ("".equals(propValue)){
return null;
} else {
return propValue;
}
}
}
return null;
}
/**
*
* @param artifact
* An instance of the batch artifact
* @return an ArrayList<Field> of fields annotated with @JobContext
*/
private static void injectBatchContextFields(Object artifact, JobContext jobCtx, StepContext stepCtx) {
// Go through declared field annotations
for (final Field field : artifact.getClass().getDeclaredFields()) {
AccessController.doPrivileged(new PrivilegedAction<Object>() {
public Object run() {
field.setAccessible(true); // ignore java accessibility
return null;
}
});
Inject injectAnnotation = field.getAnnotation(Inject.class);
if (injectAnnotation != null) {
if (logger.isLoggable(Level.FINER)) {
logger.log(Level.FINER, "Found Context on (Object, field)", new Object[] { artifact, field.getName() });
}
try {
// check the field for the context type
if (JobContext.class.isAssignableFrom(field.getType())) {
field.set(artifact, jobCtx);
} else if (StepContext.class.isAssignableFrom(field.getType())) {
field.set(artifact, stepCtx);
}
} catch (IllegalArgumentException e) {
throw new BatchContainerRuntimeException(e);
} catch (IllegalAccessException e) {
throw new BatchContainerRuntimeException(e);
}
}
}
}
/**
*
* @param delegate
* An instance of the batch artifact
* @return A map of Fields annotated with @BatchProperty.
*/
private static Map<String, Field> findPropertyFields(Object delegate) {
HashMap<String, Field> propertyMap = null;
// Go through declared field annotations
for (final Field field : delegate.getClass().getDeclaredFields()) {
AccessController.doPrivileged(new PrivilegedAction<Object>() {
public Object run() {
field.setAccessible(true); // ignore java accessibility
return null;
}
});
BatchProperty batchPropertyAnnotation = field.getAnnotation(BatchProperty.class);
if (batchPropertyAnnotation != null) {
if (propertyMap == null) {
propertyMap = new HashMap<String, Field>();
}
// If a name is not supplied the batch property name defaults to
// the field name
String batchPropName = null;
if (batchPropertyAnnotation.name().equals("")) {
batchPropName = field.getName();
} else {
batchPropName = batchPropertyAnnotation.name();
}
// Check if we have already used this name for a property.
if (propertyMap.containsKey(batchPropName)) {
throw new IllegalBatchPropertyException("There is already a batch property with this name: " + batchPropName);
}
propertyMap.put(batchPropName, field);
}
}
return propertyMap;
}
}