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* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 org.apache.cayenne.gen;
import java.io.Writer;
import java.util.Properties;
import org.apache.cayenne.CayenneRuntimeException;
import org.apache.cayenne.map.DataMap;
import org.apache.cayenne.map.ObjEntity;
import org.apache.velocity.Template;
import org.apache.velocity.VelocityContext;
import org.apache.velocity.app.VelocityEngine;
import org.apache.velocity.context.Context;
import org.apache.velocity.runtime.RuntimeConstants;
import org.apache.velocity.runtime.log.NullLogSystem;
import foundrylogic.vpp.VPPConfig;
/**
* Class generation engine for ObjEntities based on <a
* href="http://jakarta.apache.org/velocity/" target="_blank">Velocity templates </a>.
* Instance of ClassGenerationInfo is available inside Velocity template under the key
* "classGen".
*
* @deprecated since 3.0 template logic is merged into the code generation action.
*/
public class ClassGenerator {
public static final String VERSION_1_1 = "1.1";
public static final String VERSION_1_2 = "1.2";
protected String versionString;
protected Template classTemplate;
protected Context velCtxt;
protected ClassGenerationInfo classGenerationInfo; // only used for VERSION_1_1
/**
* Creates a new ClassGenerationInfo that uses a specified Velocity template.
*
* @since 1.2
* @param template to use
* @param versionString of cgen
* @throws Exception
*/
public ClassGenerator(String template, String versionString) throws Exception {
this.versionString = versionString;
if (!VERSION_1_1.equals(versionString)) {
throw new IllegalStateException(
"Illegal Version in generateClass(Writer,ObjEntity): "
+ versionString);
}
velCtxt = new VelocityContext();
classGenerationInfo = new ClassGenerationInfo();
velCtxt.put("classGen", classGenerationInfo);
initializeClassTemplate(template);
}
/**
* Creates a new ClassGenerationInfo that uses a specified Velocity template.
*
* @since 1.2
* @param template to use
* @param versionString of cgen
* @param vppConfig for configuring VelocityEngine and VelocityContext
* @throws Exception
*/
public ClassGenerator(String template, String versionString, VPPConfig vppConfig)
throws Exception {
this.versionString = versionString;
if (false == VERSION_1_2.equals(versionString)) {
throw new IllegalStateException(
"Illegal Version in generateClass(Writer,ObjEntity): "
+ versionString);
}
if (vppConfig != null) {
velCtxt = vppConfig.getVelocityContext();
}
else {
velCtxt = new VelocityContext();
}
initializeClassTemplate(template);
}
/**
* Sets up VelocityEngine properties, creates a VelocityEngine instance, and fetches a
* template using the VelocityEngine instance.
*
* @since 1.2
*/
private void initializeClassTemplate(String template) throws CayenneRuntimeException {
VelocityEngine velocityEngine = new VelocityEngine();
try {
// use ClasspathResourceLoader for velocity templates lookup
// if Cayenne URL is not null, load resource from this URL
Properties props = new Properties();
// null logger that will prevent velocity.log from being generated
props.put(RuntimeConstants.RUNTIME_LOG_LOGSYSTEM_CLASS, NullLogSystem.class
.getName());
props.put("resource.loader", "cayenne");
props.put("cayenne.resource.loader.class", ClassGeneratorResourceLoader.class
.getName());
velocityEngine.init(props);
}
catch (Exception ex) {
throw new CayenneRuntimeException("Can't initialize Velocity", ex);
}
try {
classTemplate = velocityEngine.getTemplate(template);
}
catch (Exception ex) {
throw new CayenneRuntimeException("Can't create template: " + template, ex);
}
}
/**
* Generates Java code for the ObjEntity. Output is written to the provided Writer.
*/
public void generateClass(Writer out, ObjEntity entity) throws Exception {
if (!VERSION_1_1.equals(versionString)) {
throw new IllegalStateException(
"Illegal Version in generateClass(Writer,ObjEntity): "
+ versionString);
}
classGenerationInfo.setObjEntity(entity);
classTemplate.merge(velCtxt, out);
}
/**
* Generates Java code for the ObjEntity. Output is written to the provided Writer.
*/
public void generateClass(
Writer out,
DataMap dataMap,
ObjEntity entity,
String fqnBaseClass,
String fqnSuperClass,
String fqnSubClass) throws Exception {
if (!VERSION_1_2.equals(versionString)) {
throw new IllegalStateException(
"Illegal Version in generateClass(Writer,ObjEntity,String,String,String): "
+ versionString);
}
if (null == dataMap) {
throw new IllegalStateException(
"DataMap MapClassGenerator constructor required for v1.2 templating.");
}
velCtxt.put("objEntity", entity);
velCtxt.put("stringUtils", StringUtils.getInstance());
velCtxt.put("entityUtils", new EntityUtils(
dataMap,
entity,
fqnBaseClass,
fqnSuperClass,
fqnSubClass));
velCtxt.put("importUtils", new ImportUtils());
classTemplate.merge(velCtxt, out);
}
// deprecated, delegated methods previously used internally in cayenne
/**
* @return Returns the classGenerationInfo in template.
*/
public ClassGenerationInfo getClassGenerationInfo() {
return classGenerationInfo;
}
}