org.broadleafcommerce.common.extensibility.jpa.convert.inheritance.SingleTableInheritanceClassTransformer Maven / Gradle / Ivy
/*
* #%L
* BroadleafCommerce Common Libraries
* %%
* Copyright (C) 2009 - 2013 Broadleaf Commerce
* %%
* 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.
* #L%
*/
package org.broadleafcommerce.common.extensibility.jpa.convert.inheritance;
import javassist.ClassPool;
import javassist.bytecode.AnnotationsAttribute;
import javassist.bytecode.ClassFile;
import javassist.bytecode.ConstPool;
import javassist.bytecode.annotation.Annotation;
import javassist.bytecode.annotation.EnumMemberValue;
import javassist.bytecode.annotation.IntegerMemberValue;
import javassist.bytecode.annotation.StringMemberValue;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.broadleafcommerce.common.extensibility.jpa.convert.BroadleafClassTransformer;
import org.broadleafcommerce.common.extensibility.jpa.copy.AbstractClassTransformer;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.util.StringUtils;
import javax.persistence.DiscriminatorColumn;
import javax.persistence.DiscriminatorType;
import javax.persistence.Inheritance;
import javax.persistence.InheritanceType;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.lang.instrument.IllegalClassFormatException;
import java.security.ProtectionDomain;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Properties;
/**
*
* @author jfischer
*
*/
public class SingleTableInheritanceClassTransformer extends AbstractClassTransformer implements BroadleafClassTransformer {
public static final String SINGLE_TABLE_ENTITIES = "broadleaf.ejb.entities.override_single_table";
private static final Log LOG = LogFactory.getLog(SingleTableInheritanceClassTransformer.class);
protected List infos = new ArrayList();
public void compileJPAProperties(Properties props, Object key) throws Exception {
if (((String) key).equals(SINGLE_TABLE_ENTITIES)) {
String[] classes = StringUtils.tokenizeToStringArray(props.getProperty((String) key), ConfigurableApplicationContext.CONFIG_LOCATION_DELIMITERS);
for (String clazz : classes) {
String keyName;
int pos = clazz.lastIndexOf(".");
if (pos >= 0) {
keyName = clazz.substring(pos + 1, clazz.length());
} else {
keyName = clazz;
}
SingleTableInheritanceInfo info = new SingleTableInheritanceInfo();
info.setClassName(clazz);
String discriminatorName = props.getProperty("broadleaf.ejb."+keyName+".discriminator.name");
if (discriminatorName != null) {
info.setDiscriminatorName(discriminatorName);
String type = props.getProperty("broadleaf.ejb."+keyName+".discriminator.type");
if (type != null) {
info.setDiscriminatorType(DiscriminatorType.valueOf(type));
}
String length = props.getProperty("broadleaf.ejb."+keyName+".discriminator.length");
if (length != null) {
info.setDiscriminatorLength(Integer.parseInt(length));
}
}
infos.remove(info);
infos.add(info);
}
}
}
public byte[] transform(ClassLoader loader, String className, Class classBeingRedefined, ProtectionDomain protectionDomain, byte[] classfileBuffer) throws IllegalClassFormatException {
if (infos.isEmpty()) {
return null;
}
String convertedClassName = className.replace('/', '.');
SingleTableInheritanceInfo key = new SingleTableInheritanceInfo();
key.setClassName(convertedClassName);
int pos = infos.indexOf(key);
if (pos >= 0) {
try {
if (LOG.isDebugEnabled()) {
LOG.debug("Converting " + convertedClassName + " to a SingleTable inheritance strategy.");
}
SingleTableInheritanceInfo myInfo = infos.get(pos);
ClassFile classFile = new ClassFile(new DataInputStream(new ByteArrayInputStream(classfileBuffer)));
ConstPool constantPool = classFile.getConstPool();
AnnotationsAttribute annotationsAttribute = new AnnotationsAttribute(constantPool, AnnotationsAttribute.visibleTag);
List attributes = classFile.getAttributes();
Iterator itr = attributes.iterator();
while(itr.hasNext()) {
Object object = itr.next();
if (AnnotationsAttribute.class.isAssignableFrom(object.getClass())) {
AnnotationsAttribute attr = (AnnotationsAttribute) object;
Annotation[] items = attr.getAnnotations();
for (Annotation annotation : items) {
String typeName = annotation.getTypeName();
if (!typeName.equals(Inheritance.class.getName())) {
annotationsAttribute.addAnnotation(annotation);
}
}
itr.remove();
}
}
Annotation inheritance = new Annotation(Inheritance.class.getName(), constantPool);
ClassPool pool = ClassPool.getDefault();
pool.importPackage("javax.persistence");
pool.importPackage("java.lang");
EnumMemberValue strategy = (EnumMemberValue) Annotation.createMemberValue(constantPool, pool.makeClass("InheritanceType"));
strategy.setType(InheritanceType.class.getName());
strategy.setValue(InheritanceType.SINGLE_TABLE.name());
inheritance.addMemberValue("strategy", strategy);
annotationsAttribute.addAnnotation(inheritance);
if (myInfo.getDiscriminatorName() != null) {
Annotation discriminator = new Annotation(DiscriminatorColumn.class.getName(), constantPool);
StringMemberValue name = new StringMemberValue(constantPool);
name.setValue(myInfo.getDiscriminatorName());
discriminator.addMemberValue("name", name);
EnumMemberValue discriminatorType = (EnumMemberValue) Annotation.createMemberValue(constantPool, pool.makeClass("DiscriminatorType"));
discriminatorType.setType(DiscriminatorType.class.getName());
discriminatorType.setValue(myInfo.getDiscriminatorType().name());
discriminator.addMemberValue("discriminatorType", discriminatorType);
IntegerMemberValue length = new IntegerMemberValue(constantPool);
length.setValue(myInfo.getDiscriminatorLength());
discriminator.addMemberValue("length", length);
annotationsAttribute.addAnnotation(discriminator);
}
classFile.addAttribute(annotationsAttribute);
ByteArrayOutputStream bos = new ByteArrayOutputStream();
DataOutputStream os = new DataOutputStream(bos);
classFile.write(os);
os.close();
return bos.toByteArray();
} catch(Exception ex) {
ex.printStackTrace();
throw new IllegalClassFormatException("Unable to convert " + convertedClassName + " to a SingleTable inheritance strategy: " + ex.getMessage());
}
} else {
return null;
}
}
}