/*
* Copyright 2009-2012 the original author or authors.
*
* 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 org.apache.ibatis.submitted.automatic_lazy_loading;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Reader;
import java.lang.reflect.Method;
import java.sql.Connection;
import java.util.ArrayList;
import java.util.List;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.jdbc.ScriptRunner;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Assert;
import org.junit.BeforeClass;
import org.junit.Test;
public class AutomaticLazyLoadingTest {
private SqlSession sqlSession;
private static List<Method> noMethods;
private static List<Method> objectMethods;
@BeforeClass
public static void beforeClass()
throws Exception {
noMethods = new ArrayList<Method>();
objectMethods = new ArrayList<Method>();
objectMethods.add(Element.class.getMethod("hashCode"));
objectMethods.add(Element.class.getMethod("equals", Object.class));
objectMethods.add(Element.class.getMethod("toString"));
}
/**
* Load an element with 'default' configuration.
* Expect an exception when none of the 'object methods' is called.
*/
@Test
public void selectElementValue_default_nomethods()
throws Exception {
testScenario("default", true, noMethods);
}
/**
* Load an element with 'default' configuration.
* Expect no exception when one of the 'object methods' is called.
*/
@Test
public void selectElementValue_default_objectmethods()
throws Exception {
testScenario("default", false, objectMethods);
}
/**
* Load an element with 'disabled' configuration.
* Expect an exception when none of the 'object methods' is called.
*/
@Test
public void selectElementValue_disabled_nomethods()
throws Exception {
testScenario("disabled", true, noMethods);
}
/**
* Load an element with 'disabled' configuration.
* Expect an exception when one of the 'object methods' is called.
* (because calling object methods should not trigger lazy loading)
*/
@Test
public void selectElementValue_disabled_objectmethods()
throws Exception {
testScenario("disabled", true, objectMethods);
}
/**
* Load an element with 'enabled' configuration.
* Expect an exception when none of the 'object methods' is called.
*/
@Test
public void selectElementValue_enabled_nomethods()
throws Exception {
testScenario("enabled", true, noMethods);
}
/**
* Load an element with 'enabled' configuration.
* Expect no exception when one of the 'object methods' is called.
*/
@Test
public void selectElementValue_enabled_objectmethods()
throws Exception {
testScenario("enabled", false, objectMethods);
}
/**
* Load an element with default configuration and call toString.
* Expect that the toString triggers lazy loading which loads the nested Element
* is available after closing the session.
*/
private void testScenario(String aConfiguration, boolean anExpectingAnException, List<Method> aMethodsToCall)
throws Exception {
if (aMethodsToCall.isEmpty()) {
testScenario(aConfiguration, anExpectingAnException, (Method)null);
} else {
for (Method myMethod : aMethodsToCall) {
testScenario(aConfiguration, anExpectingAnException, myMethod);
}
}
}
/**
* Load an element with default configuration and call toString.
* Expect that the toString triggers lazy loading which loads the nested Element
* is available after closing the session.
*/
private void testScenario(String aConfiguration, boolean anExpectingAnException, Method aMethodToCall)
throws Exception {
openSession(aConfiguration);
Element myElement = selectElement();
String myMethodCallDescription;
if (aMethodToCall != null) {
Object[] myArguments = new Object[aMethodToCall.getParameterTypes().length];
aMethodToCall.invoke(myElement, myArguments);
myMethodCallDescription = aMethodToCall.toString();
} else {
myMethodCallDescription = "not called a method";
}
myElement = disableLazyLoaders(myElement);
closeSession();
try {
Assert.assertEquals("parent", myElement.getElement().getValue());
if (anExpectingAnException) {
Assert.fail("Excpected an exception, since " + myMethodCallDescription + " should not trigger lazy loading");
}
} catch(Exception anException) {
if (!anExpectingAnException) {
Assert.fail("Did not expect an exception, because " + myMethodCallDescription + " should trigger lazy loading");
}
}
}
/**
* Create a session with the specified configuration and initialized the database.
*/
private void openSession(String aConfig) throws Exception {
final String resource = "org/apache/ibatis/submitted/automatic_lazy_loading/ibatis-automatic-lazy-load-" + aConfig + ".xml";
Reader batisConfigReader = Resources.getResourceAsReader(resource);
SqlSessionFactory sqlSessionFactory;
try {
sqlSessionFactory = new SqlSessionFactoryBuilder().build(batisConfigReader);
} catch(Exception anException) {
throw new RuntimeException("Mapper configuration failed, expected this to work: " + anException.getMessage(), anException);
}
SqlSession session = sqlSessionFactory.openSession();
Connection conn = session.getConnection();
ScriptRunner runner = new ScriptRunner(conn);
runner.setLogWriter(null);
runner.setErrorLogWriter(null);
Reader createScriptReader = Resources.getResourceAsReader("org/apache/ibatis/submitted/automatic_lazy_loading/create.sql");
runner.runScript(createScriptReader);
sqlSession = sqlSessionFactory.openSession();
}
private void closeSession() {
if (sqlSession != null) {
sqlSession.close();
}
}
/**
* Select the child element.
*/
private Element selectElement() {
Element myElement = sqlSession.getMapper(ElementMapper.class).selectElementById("child");
Assert.assertNotNull("Test setup failure; Could not load element", myElement);
return myElement;
}
/**
* Disable lazy loaders by serializing / deserializing the element
*/
private Element disableLazyLoaders(Element anElement)
throws Exception {
ByteArrayOutputStream myBuffer = new ByteArrayOutputStream();
ObjectOutputStream myObjectOutputStream = new ObjectOutputStream(myBuffer);
myObjectOutputStream.writeObject(anElement);
myObjectOutputStream.close();
myBuffer.close();
ObjectInputStream myObjectInputStream = new ObjectInputStream(new ByteArrayInputStream(myBuffer.toByteArray()));
Element myResult = (Element)myObjectInputStream.readObject();
myObjectInputStream.close();
return myResult;
}
}