org.mockito.internal.creation.bytebuddy.SubclassByteBuddyMockMaker Maven / Gradle / Ivy
/*
* Copyright (c) 2016 Mockito contributors
* This program is made available under the terms of the MIT License.
*/
package org.mockito.internal.creation.bytebuddy;
import static org.mockito.internal.util.StringUtil.join;
import java.lang.reflect.Modifier;
import org.mockito.creation.instance.Instantiator;
import org.mockito.exceptions.base.MockitoException;
import org.mockito.internal.configuration.plugins.Plugins;
import org.mockito.internal.util.Platform;
import org.mockito.invocation.MockHandler;
import org.mockito.mock.MockCreationSettings;
/**
* Subclass based mock maker.
*
* This mock maker tries to create a subclass to represent a mock. It uses the given mock settings, that contains
* the type to mock, extra interfaces, and serialization support.
*
*
* The type to mock has to be not final and not part of the JDK. THe created mock will implement extra interfaces
* if any. And will implement Serializable if this settings is explicitly set.
*/
public class SubclassByteBuddyMockMaker implements ClassCreatingMockMaker {
private final BytecodeGenerator cachingMockBytecodeGenerator;
public SubclassByteBuddyMockMaker() {
this(new SubclassInjectionLoader());
}
public SubclassByteBuddyMockMaker(SubclassLoader loader) {
cachingMockBytecodeGenerator =
new TypeCachingBytecodeGenerator(new SubclassBytecodeGenerator(loader), false);
}
@Override
public T createMock(MockCreationSettings settings, MockHandler handler) {
Class mockedProxyType = createMockType(settings);
Instantiator instantiator = Plugins.getInstantiatorProvider().getInstantiator(settings);
T mockInstance = null;
try {
mockInstance = instantiator.newInstance(mockedProxyType);
MockAccess mockAccess = (MockAccess) mockInstance;
mockAccess.setMockitoInterceptor(new MockMethodInterceptor(handler, settings));
return ensureMockIsAssignableToMockedType(settings, mockInstance);
} catch (ClassCastException cce) {
throw new MockitoException(
join(
"ClassCastException occurred while creating the mockito mock :",
" class to mock : " + describeClass(settings.getTypeToMock()),
" created class : " + describeClass(mockedProxyType),
" proxy instance class : " + describeClass(mockInstance),
" instance creation by : " + instantiator.getClass().getSimpleName(),
"",
"You might experience classloading issues, please ask the mockito mailing-list.",
""),
cce);
} catch (org.mockito.creation.instance.InstantiationException e) {
throw new MockitoException(
"Unable to create mock instance of type '"
+ mockedProxyType.getSuperclass().getSimpleName()
+ "'",
e);
}
}
@Override
public Class createMockType(MockCreationSettings settings) {
try {
return cachingMockBytecodeGenerator.mockClass(
MockFeatures.withMockFeatures(
settings.getTypeToMock(),
settings.getExtraInterfaces(),
settings.getSerializableMode(),
settings.isStripAnnotations(),
settings.getDefaultAnswer()));
} catch (Exception bytecodeGenerationFailed) {
throw prettifyFailure(settings, bytecodeGenerationFailed);
}
}
private static T ensureMockIsAssignableToMockedType(
MockCreationSettings settings, T mock) {
// Force explicit cast to mocked type here, instead of
// relying on the JVM to implicitly cast on the client call site.
// This allows us to catch earlier the ClassCastException earlier
Class typeToMock = settings.getTypeToMock();
return typeToMock.cast(mock);
}
private RuntimeException prettifyFailure(
MockCreationSettings mockFeatures, Exception generationFailed) {
if (mockFeatures.getTypeToMock().isArray()) {
throw new MockitoException(
join("Mockito cannot mock arrays: " + mockFeatures.getTypeToMock() + ".", ""),
generationFailed);
}
if (Modifier.isPrivate(mockFeatures.getTypeToMock().getModifiers())) {
throw new MockitoException(
join(
"Mockito cannot mock this class: " + mockFeatures.getTypeToMock() + ".",
"Most likely it is due to mocking a private class that is not visible to Mockito",
""),
generationFailed);
}
throw new MockitoException(
join(
"Mockito cannot mock this class: " + mockFeatures.getTypeToMock() + ".",
"",
"Mockito can only mock non-private & non-final classes.",
"If you're not sure why you're getting this error, please report to the mailing list.",
"",
Platform.warnForVM(
"IBM J9 VM",
"Early IBM virtual machine are known to have issues with Mockito, please upgrade to an up-to-date version.\n",
"Hotspot",
Platform.isJava8BelowUpdate45()
? "Java 8 early builds have bugs that were addressed in Java 1.8.0_45, please update your JDK!\n"
: ""),
Platform.describe(),
"",
"Underlying exception : " + generationFailed),
generationFailed);
}
private static String describeClass(Class type) {
return type == null
? "null"
: "'"
+ type.getCanonicalName()
+ "', loaded by classloader : '"
+ type.getClassLoader()
+ "'";
}
private static String describeClass(Object instance) {
return instance == null ? "null" : describeClass(instance.getClass());
}
@Override
public MockHandler getHandler(Object mock) {
if (!(mock instanceof MockAccess)) {
return null;
}
return ((MockAccess) mock).getMockitoInterceptor().getMockHandler();
}
@Override
public void resetMock(Object mock, MockHandler newHandler, MockCreationSettings settings) {
((MockAccess) mock).setMockitoInterceptor(new MockMethodInterceptor(newHandler, settings));
}
@Override
public TypeMockability isTypeMockable(final Class type) {
return new TypeMockability() {
@Override
public boolean mockable() {
return !type.isPrimitive()
&& !Modifier.isFinal(type.getModifiers())
&& !TypeSupport.INSTANCE.isSealed(type);
}
@Override
public String nonMockableReason() {
if (mockable()) {
return "";
}
if (type.isPrimitive()) {
return "primitive type";
}
if (Modifier.isFinal(type.getModifiers())) {
return "final class";
}
if (TypeSupport.INSTANCE.isSealed(type)) {
return "sealed class";
}
return join("not handled type");
}
};
}
@Override
public void clearAllCaches() {
cachingMockBytecodeGenerator.clearAllCaches();
}
}