DATACMNS-710 - Replace ObjectInstantiatorClassGenerator
Deprecate ObjectInstantiatorClassGenerator and provide a replacement ClassGeneratingEntityInstantiator which doesn't retain a reference to the context class loader. Original pull request: #128.
This commit is contained in:
Phillip Webb
committed by
Oliver Gierke
Oliver Gierke
parent
b60f5d84ec
commit
8156c2a151
@@ -15,31 +15,10 @@
|
||||
*/
|
||||
package org.springframework.data.convert;
|
||||
|
||||
import static org.springframework.asm.Opcodes.*;
|
||||
|
||||
import java.lang.reflect.Constructor;
|
||||
import java.lang.reflect.Modifier;
|
||||
import java.security.AccessController;
|
||||
import java.security.PrivilegedAction;
|
||||
import java.util.ArrayList;
|
||||
import java.util.Arrays;
|
||||
import java.util.HashMap;
|
||||
import java.util.List;
|
||||
import java.util.Map;
|
||||
|
||||
import org.springframework.asm.ClassWriter;
|
||||
import org.springframework.asm.MethodVisitor;
|
||||
import org.springframework.asm.Opcodes;
|
||||
import org.springframework.asm.Type;
|
||||
import org.springframework.data.mapping.PersistentEntity;
|
||||
import org.springframework.data.mapping.PersistentProperty;
|
||||
import org.springframework.data.mapping.PreferredConstructor;
|
||||
import org.springframework.data.mapping.PreferredConstructor.Parameter;
|
||||
import org.springframework.data.mapping.model.MappingInstantiationException;
|
||||
import org.springframework.data.mapping.model.ParameterValueProvider;
|
||||
import org.springframework.data.util.TypeInformation;
|
||||
import org.springframework.util.Assert;
|
||||
import org.springframework.util.ClassUtils;
|
||||
|
||||
/**
|
||||
* An {@link EntityInstantiator} that can generate byte code to speed-up dynamic object instantiation. Uses the
|
||||
@@ -50,15 +29,14 @@ import org.springframework.util.ClassUtils;
|
||||
* @author Thomas Darimont
|
||||
* @author Oliver Gierke
|
||||
* @since 1.10
|
||||
* @deprecated since 1.11 in favor of {@link ClassGeneratingEntityInstantiator}
|
||||
*/
|
||||
public enum BytecodeGeneratingEntityInstantiator implements EntityInstantiator {
|
||||
|
||||
INSTANCE;
|
||||
|
||||
private static final ObjectInstantiatorClassGenerator GENERATOR = ObjectInstantiatorClassGenerator.INSTANCE;
|
||||
private final ClassGeneratingEntityInstantiator delegate = new ClassGeneratingEntityInstantiator();
|
||||
|
||||
private volatile Map<TypeInformation<?>, EntityInstantiator> entityInstantiators = new HashMap<TypeInformation<?>, EntityInstantiator>(
|
||||
32);
|
||||
|
||||
/* (non-Javadoc)
|
||||
* @see org.springframework.data.convert.EntityInstantiator#createInstance(org.springframework.data.mapping.PersistentEntity, org.springframework.data.mapping.model.ParameterValueProvider)
|
||||
@@ -67,434 +45,15 @@ public enum BytecodeGeneratingEntityInstantiator implements EntityInstantiator {
|
||||
public <T, E extends PersistentEntity<? extends T, P>, P extends PersistentProperty<P>> T createInstance(E entity,
|
||||
ParameterValueProvider<P> provider) {
|
||||
|
||||
EntityInstantiator instantiator = this.entityInstantiators.get(entity.getTypeInformation());
|
||||
|
||||
if (instantiator == null) {
|
||||
instantiator = potentiallyCreateAndRegisterEntityInstantiator(entity);
|
||||
}
|
||||
|
||||
return instantiator.createInstance(entity, provider);
|
||||
}
|
||||
|
||||
/**
|
||||
* @param entity
|
||||
* @return
|
||||
*/
|
||||
private synchronized EntityInstantiator potentiallyCreateAndRegisterEntityInstantiator(PersistentEntity<?, ?> entity) {
|
||||
|
||||
Map<TypeInformation<?>, EntityInstantiator> map = this.entityInstantiators;
|
||||
EntityInstantiator instantiator = map.get(entity.getTypeInformation());
|
||||
|
||||
if (instantiator != null) {
|
||||
return instantiator;
|
||||
}
|
||||
|
||||
instantiator = createEntityInstantiator(entity);
|
||||
|
||||
map = new HashMap<TypeInformation<?>, EntityInstantiator>(map);
|
||||
map.put(entity.getTypeInformation(), instantiator);
|
||||
|
||||
this.entityInstantiators = map;
|
||||
|
||||
return instantiator;
|
||||
}
|
||||
|
||||
/**
|
||||
* @param entity
|
||||
* @return
|
||||
*/
|
||||
private EntityInstantiator createEntityInstantiator(PersistentEntity<?, ?> entity) {
|
||||
|
||||
if (shouldUseReflectionEntityInstantiator(entity)) {
|
||||
return ReflectionEntityInstantiator.INSTANCE;
|
||||
}
|
||||
|
||||
try {
|
||||
return new EntityInstantiatorAdapter(createObjectInstantiator(entity));
|
||||
} catch (Throwable ex) {
|
||||
return ReflectionEntityInstantiator.INSTANCE;
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* @param entity
|
||||
* @return
|
||||
*/
|
||||
private boolean shouldUseReflectionEntityInstantiator(PersistentEntity<?, ?> entity) {
|
||||
|
||||
Class<?> type = entity.getType();
|
||||
|
||||
if (type.isInterface() //
|
||||
|| type.isArray() //
|
||||
|| !Modifier.isPublic(type.getModifiers()) //
|
||||
|| (type.isMemberClass() && !Modifier.isStatic(type.getModifiers())) //
|
||||
|| ClassUtils.isCglibProxyClass(type)) { //
|
||||
return true;
|
||||
}
|
||||
|
||||
PreferredConstructor<?, ?> persistenceConstructor = entity.getPersistenceConstructor();
|
||||
if (persistenceConstructor == null || !Modifier.isPublic(persistenceConstructor.getConstructor().getModifiers())) {
|
||||
return true;
|
||||
}
|
||||
|
||||
return false;
|
||||
}
|
||||
|
||||
/**
|
||||
* Creates a dynamically generated {@link ObjectInstantiator} for the given {@link InstantiatorKey}. There will always
|
||||
* be exactly one {@link ObjectInstantiator} instance per {@link PersistentEntity}.
|
||||
* <p>
|
||||
*
|
||||
* @param entity
|
||||
* @return
|
||||
*/
|
||||
private ObjectInstantiator createObjectInstantiator(PersistentEntity<?, ?> entity) {
|
||||
|
||||
try {
|
||||
return (ObjectInstantiator) GENERATOR.generateCustomInstantiatorClass(entity).newInstance();
|
||||
} catch (Exception e) {
|
||||
throw new RuntimeException(e);
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Adapter to forward an invocation of the {@link EntityInstantiator} API to an {@link ObjectInstantiator}.
|
||||
*
|
||||
* @author Thomas Darimont
|
||||
* @author Oliver Gierke
|
||||
*/
|
||||
private static class EntityInstantiatorAdapter implements EntityInstantiator {
|
||||
|
||||
private static final Object[] EMPTY_ARRAY = new Object[0];
|
||||
|
||||
private final ObjectInstantiator instantiator;
|
||||
|
||||
/**
|
||||
* Creates a new {@link EntityInstantiatorAdapter} for the given {@link ObjectInstantiator}.
|
||||
*
|
||||
* @param instantiator must not be {@literal null}.
|
||||
*/
|
||||
public EntityInstantiatorAdapter(ObjectInstantiator instantiator) {
|
||||
this.instantiator = instantiator;
|
||||
}
|
||||
|
||||
/*
|
||||
* (non-Javadoc)
|
||||
* @see org.springframework.data.convert.EntityInstantiator#createInstance(org.springframework.data.mapping.PersistentEntity, org.springframework.data.mapping.model.ParameterValueProvider)
|
||||
*/
|
||||
@Override
|
||||
@SuppressWarnings("unchecked")
|
||||
public <T, E extends PersistentEntity<? extends T, P>, P extends PersistentProperty<P>> T createInstance(E entity,
|
||||
ParameterValueProvider<P> provider) {
|
||||
|
||||
Object[] params = extractInvocationArguments(entity.getPersistenceConstructor(), provider);
|
||||
|
||||
try {
|
||||
return (T) instantiator.newInstance(params);
|
||||
} catch (Exception e) {
|
||||
throw new MappingInstantiationException(entity, Arrays.asList(params), e);
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Extracts the arguments required to invoce the given constructor from the given {@link ParameterValueProvider}.
|
||||
*
|
||||
* @param constructor can be {@literal null}.
|
||||
* @param provider can be {@literal null}.
|
||||
* @return
|
||||
*/
|
||||
private <P extends PersistentProperty<P>, T> Object[] extractInvocationArguments(
|
||||
PreferredConstructor<? extends T, P> constructor, ParameterValueProvider<P> provider) {
|
||||
|
||||
if (provider == null || constructor == null || !constructor.hasParameters()) {
|
||||
return EMPTY_ARRAY;
|
||||
}
|
||||
|
||||
List<Object> params = new ArrayList<Object>();
|
||||
|
||||
for (Parameter<?, P> parameter : constructor.getParameters()) {
|
||||
params.add(provider.getParameterValue(parameter));
|
||||
}
|
||||
|
||||
return params.toArray();
|
||||
}
|
||||
return this.delegate.createInstance(entity, provider);
|
||||
}
|
||||
|
||||
/**
|
||||
* @author Thomas Darimont
|
||||
* @deprecated
|
||||
*/
|
||||
public interface ObjectInstantiator {
|
||||
|
||||
Object newInstance(Object... args);
|
||||
}
|
||||
|
||||
/**
|
||||
* Generates a new {@link ObjectInstantiator} class for the given custom class.
|
||||
* <p>
|
||||
* This code generator will generate a custom factory class implementing the {@link ObjectInstantiator} interface for
|
||||
* every publicly accessed constructor variant.
|
||||
* <p>
|
||||
* Given a class {@code ObjCtor1ParamString} like:
|
||||
*
|
||||
* <pre>
|
||||
* {
|
||||
* @code
|
||||
* public class ObjCtor1ParamString extends ObjCtorNoArgs {
|
||||
*
|
||||
* public final String param1;
|
||||
*
|
||||
* public ObjCtor1ParamString(String param1) {
|
||||
* this.param1 = param1;
|
||||
* }
|
||||
* }
|
||||
* }
|
||||
* </pre>
|
||||
*
|
||||
* The following factory class {@code ObjCtor1ParamString_Instantiator_asdf} is generated:
|
||||
*
|
||||
* <pre>
|
||||
* {
|
||||
* @code
|
||||
* public class ObjCtor1ParamString_Instantiator_asdf implements ObjectInstantiator {
|
||||
*
|
||||
* public Object newInstance(Object... args) {
|
||||
* return new ObjCtor1ParamString((String) args[0]);
|
||||
* }
|
||||
* }
|
||||
* }
|
||||
* </pre>
|
||||
*
|
||||
* @author Thomas Darimont
|
||||
*/
|
||||
enum ObjectInstantiatorClassGenerator {
|
||||
|
||||
INSTANCE;
|
||||
|
||||
private static final String INIT = "<init>";
|
||||
private static final String TAG = "_Instantiator_";
|
||||
private static final String JAVA_LANG_OBJECT = "java/lang/Object";
|
||||
private static final String CREATE_METHOD_NAME = "newInstance";
|
||||
|
||||
private static final String[] IMPLEMENTED_INTERFACES = new String[] { Type
|
||||
.getInternalName(ObjectInstantiator.class) };
|
||||
|
||||
private final ByteArrayClassLoader classLoader;
|
||||
|
||||
private ObjectInstantiatorClassGenerator() {
|
||||
|
||||
this.classLoader = AccessController.doPrivileged(new PrivilegedAction<ByteArrayClassLoader>() {
|
||||
public ByteArrayClassLoader run() {
|
||||
return new ByteArrayClassLoader(ClassUtils.getDefaultClassLoader());
|
||||
}
|
||||
});
|
||||
}
|
||||
|
||||
/**
|
||||
* Generate a new class for the given {@link InstantiatorKey}.
|
||||
*
|
||||
* @param key
|
||||
* @return
|
||||
*/
|
||||
public Class<?> generateCustomInstantiatorClass(PersistentEntity<?, ?> entity) {
|
||||
|
||||
String className = generateClassName(entity);
|
||||
byte[] bytecode = generateBytecode(className, entity);
|
||||
|
||||
return classLoader.loadClass(className, bytecode);
|
||||
}
|
||||
|
||||
/**
|
||||
* @param key
|
||||
* @return
|
||||
*/
|
||||
private String generateClassName(PersistentEntity<?, ?> entity) {
|
||||
return entity.getType().getName() + TAG + Integer.toString(entity.hashCode(), 36);
|
||||
}
|
||||
|
||||
/**
|
||||
* Generate a new class for the given {@link InstantiatorKey}.
|
||||
*
|
||||
* @param key
|
||||
* @return
|
||||
*/
|
||||
public byte[] generateBytecode(String internalClassName, PersistentEntity<?, ?> entity) {
|
||||
|
||||
ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS);
|
||||
|
||||
cw.visit(Opcodes.V1_6, ACC_PUBLIC + ACC_SUPER, internalClassName.replace('.', '/'), null, JAVA_LANG_OBJECT,
|
||||
IMPLEMENTED_INTERFACES);
|
||||
|
||||
visitDefaultConstructor(cw);
|
||||
|
||||
visitCreateMethod(cw, entity);
|
||||
|
||||
cw.visitEnd();
|
||||
|
||||
return cw.toByteArray();
|
||||
}
|
||||
|
||||
private void visitDefaultConstructor(ClassWriter cw) {
|
||||
|
||||
MethodVisitor mv = cw.visitMethod(ACC_PUBLIC, INIT, "()V", null, null);
|
||||
mv.visitCode();
|
||||
mv.visitVarInsn(ALOAD, 0);
|
||||
mv.visitMethodInsn(INVOKESPECIAL, JAVA_LANG_OBJECT, INIT, "()V", false);
|
||||
mv.visitInsn(RETURN);
|
||||
mv.visitMaxs(0, 0); // (0, 0) = computed via ClassWriter.COMPUTE_MAXS
|
||||
mv.visitEnd();
|
||||
}
|
||||
|
||||
/**
|
||||
* Inserts the bytecode definition for the create method for the given {@link PersistentEntity}.
|
||||
*
|
||||
* @param cw
|
||||
* @param entity
|
||||
*/
|
||||
private void visitCreateMethod(ClassWriter cw, PersistentEntity<?, ?> entity) {
|
||||
|
||||
String entityTypeResourcePath = Type.getInternalName(entity.getType());
|
||||
|
||||
MethodVisitor mv = cw.visitMethod(ACC_PUBLIC + ACC_VARARGS, CREATE_METHOD_NAME,
|
||||
"([Ljava/lang/Object;)Ljava/lang/Object;", null, null);
|
||||
mv.visitCode();
|
||||
mv.visitTypeInsn(NEW, entityTypeResourcePath);
|
||||
mv.visitInsn(DUP);
|
||||
|
||||
Constructor<?> ctor = entity.getPersistenceConstructor().getConstructor();
|
||||
Class<?>[] parameterTypes = ctor.getParameterTypes();
|
||||
for (int i = 0; i < parameterTypes.length; i++) {
|
||||
mv.visitVarInsn(ALOAD, 1);
|
||||
|
||||
visitArrayIndex(mv, i);
|
||||
|
||||
mv.visitInsn(AALOAD);
|
||||
|
||||
if (parameterTypes[i].isPrimitive()) {
|
||||
insertUnboxInsns(mv, Type.getType(parameterTypes[i]).toString().charAt(0), "");
|
||||
} else {
|
||||
mv.visitTypeInsn(CHECKCAST, Type.getInternalName(parameterTypes[i]));
|
||||
}
|
||||
}
|
||||
mv.visitMethodInsn(INVOKESPECIAL, entityTypeResourcePath, INIT, Type.getConstructorDescriptor(ctor), false);
|
||||
|
||||
mv.visitInsn(ARETURN);
|
||||
mv.visitMaxs(0, 0); // (0, 0) = computed via ClassWriter.COMPUTE_MAXS
|
||||
mv.visitEnd();
|
||||
}
|
||||
|
||||
/**
|
||||
* Insert an appropriate value on the stack for the given index value {@code idx}.
|
||||
*
|
||||
* @param mv
|
||||
* @param idx
|
||||
*/
|
||||
private static void visitArrayIndex(MethodVisitor mv, int idx) {
|
||||
|
||||
if (idx >= 0 && idx < 6) {
|
||||
mv.visitInsn(ICONST_0 + idx);
|
||||
return;
|
||||
}
|
||||
|
||||
mv.visitLdcInsn(idx);
|
||||
}
|
||||
|
||||
/**
|
||||
* Insert any necessary cast and value call to convert from a boxed type to a primitive value.
|
||||
* <p>
|
||||
* Taken from Spring Expression 4.1.2 {@code org.springframework.expression.spel.CodeFlow#insertUnboxInsns}.
|
||||
*
|
||||
* @param mv the method visitor into which instructions should be inserted
|
||||
* @param ch the primitive type desired as output
|
||||
* @param stackDescriptor the descriptor of the type on top of the stack
|
||||
*/
|
||||
private static void insertUnboxInsns(MethodVisitor mv, char ch, String stackDescriptor) {
|
||||
|
||||
switch (ch) {
|
||||
case 'Z':
|
||||
if (!stackDescriptor.equals("Ljava/lang/Boolean")) {
|
||||
mv.visitTypeInsn(CHECKCAST, "java/lang/Boolean");
|
||||
}
|
||||
mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Boolean", "booleanValue", "()Z", false);
|
||||
break;
|
||||
case 'B':
|
||||
if (!stackDescriptor.equals("Ljava/lang/Byte")) {
|
||||
mv.visitTypeInsn(CHECKCAST, "java/lang/Byte");
|
||||
}
|
||||
mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Byte", "byteValue", "()B", false);
|
||||
break;
|
||||
case 'C':
|
||||
if (!stackDescriptor.equals("Ljava/lang/Character")) {
|
||||
mv.visitTypeInsn(CHECKCAST, "java/lang/Character");
|
||||
}
|
||||
mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Character", "charValue", "()C", false);
|
||||
break;
|
||||
case 'D':
|
||||
if (!stackDescriptor.equals("Ljava/lang/Double")) {
|
||||
mv.visitTypeInsn(CHECKCAST, "java/lang/Double");
|
||||
}
|
||||
mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Double", "doubleValue", "()D", false);
|
||||
break;
|
||||
case 'F':
|
||||
if (!stackDescriptor.equals("Ljava/lang/Float")) {
|
||||
mv.visitTypeInsn(CHECKCAST, "java/lang/Float");
|
||||
}
|
||||
mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Float", "floatValue", "()F", false);
|
||||
break;
|
||||
case 'I':
|
||||
if (!stackDescriptor.equals("Ljava/lang/Integer")) {
|
||||
mv.visitTypeInsn(CHECKCAST, "java/lang/Integer");
|
||||
}
|
||||
mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Integer", "intValue", "()I", false);
|
||||
break;
|
||||
case 'J':
|
||||
if (!stackDescriptor.equals("Ljava/lang/Long")) {
|
||||
mv.visitTypeInsn(CHECKCAST, "java/lang/Long");
|
||||
}
|
||||
mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Long", "longValue", "()J", false);
|
||||
break;
|
||||
case 'S':
|
||||
if (!stackDescriptor.equals("Ljava/lang/Short")) {
|
||||
mv.visitTypeInsn(CHECKCAST, "java/lang/Short");
|
||||
}
|
||||
mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Short", "shortValue", "()S", false);
|
||||
break;
|
||||
default:
|
||||
throw new IllegalArgumentException("Unboxing should not be attempted for descriptor '" + ch + "'");
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* A {@link ClassLoader} that can load classes from {@code byte[]} representations.
|
||||
*
|
||||
* @author Thomas Darimont
|
||||
*/
|
||||
private class ByteArrayClassLoader extends ClassLoader {
|
||||
|
||||
public ByteArrayClassLoader(ClassLoader parent) {
|
||||
super(parent);
|
||||
}
|
||||
|
||||
/**
|
||||
* Tries to load a class given {@code byte[]}.
|
||||
*
|
||||
* @param name must not be {@literal null}
|
||||
* @param bytes must not be {@literal null}
|
||||
* @return
|
||||
*/
|
||||
public Class<?> loadClass(String name, byte[] bytes) {
|
||||
|
||||
Assert.notNull(name, "name must not be null");
|
||||
Assert.notNull(bytes, "bytes must not be null");
|
||||
|
||||
try {
|
||||
Class<?> clazz = findClass(name);
|
||||
if (clazz != null) {
|
||||
return clazz;
|
||||
}
|
||||
} catch (ClassNotFoundException ignore) {}
|
||||
|
||||
return defineClass(name, bytes, 0, bytes.length);
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
@@ -0,0 +1,501 @@
|
||||
package org.springframework.data.convert;
|
||||
/*
|
||||
* Copyright 2015 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.
|
||||
*/
|
||||
|
||||
import static org.springframework.asm.Opcodes.*;
|
||||
|
||||
import java.lang.reflect.Constructor;
|
||||
import java.lang.reflect.Modifier;
|
||||
import java.security.AccessController;
|
||||
import java.security.PrivilegedAction;
|
||||
import java.util.ArrayList;
|
||||
import java.util.Arrays;
|
||||
import java.util.HashMap;
|
||||
import java.util.List;
|
||||
import java.util.Map;
|
||||
|
||||
import org.springframework.asm.ClassWriter;
|
||||
import org.springframework.asm.MethodVisitor;
|
||||
import org.springframework.asm.Opcodes;
|
||||
import org.springframework.asm.Type;
|
||||
import org.springframework.data.mapping.PersistentEntity;
|
||||
import org.springframework.data.mapping.PersistentProperty;
|
||||
import org.springframework.data.mapping.PreferredConstructor;
|
||||
import org.springframework.data.mapping.PreferredConstructor.Parameter;
|
||||
import org.springframework.data.mapping.model.MappingInstantiationException;
|
||||
import org.springframework.data.mapping.model.ParameterValueProvider;
|
||||
import org.springframework.data.util.TypeInformation;
|
||||
import org.springframework.util.Assert;
|
||||
import org.springframework.util.ClassUtils;
|
||||
|
||||
/**
|
||||
* An {@link EntityInstantiator} that can generate byte code to speed-up dynamic object instantiation. Uses the
|
||||
* {@link PersistentEntity}'s {@link PreferredConstructor} to instantiate an instance of the entity by dynamically
|
||||
* generating factory methods with appropriate constructor invocations via ASM. If we cannot generate byte code for a
|
||||
* type, we gracefully fall-back to the {@link ReflectionEntityInstantiator}.
|
||||
*
|
||||
* @author Thomas Darimont
|
||||
* @author Oliver Gierke
|
||||
* @since 1.10
|
||||
*/
|
||||
public class ClassGeneratingEntityInstantiator implements EntityInstantiator {
|
||||
|
||||
private final ObjectInstantiatorClassGenerator generator;
|
||||
|
||||
private volatile Map<TypeInformation<?>, EntityInstantiator> entityInstantiators = new HashMap<TypeInformation<?>, EntityInstantiator>(
|
||||
32);
|
||||
|
||||
public ClassGeneratingEntityInstantiator() {
|
||||
this.generator = new ObjectInstantiatorClassGenerator();
|
||||
}
|
||||
|
||||
/* (non-Javadoc)
|
||||
* @see org.springframework.data.convert.EntityInstantiator#createInstance(org.springframework.data.mapping.PersistentEntity, org.springframework.data.mapping.model.ParameterValueProvider)
|
||||
*/
|
||||
@Override
|
||||
public <T, E extends PersistentEntity<? extends T, P>, P extends PersistentProperty<P>> T createInstance(E entity,
|
||||
ParameterValueProvider<P> provider) {
|
||||
|
||||
EntityInstantiator instantiator = this.entityInstantiators.get(entity.getTypeInformation());
|
||||
|
||||
if (instantiator == null) {
|
||||
instantiator = potentiallyCreateAndRegisterEntityInstantiator(entity);
|
||||
}
|
||||
|
||||
return instantiator.createInstance(entity, provider);
|
||||
}
|
||||
|
||||
/**
|
||||
* @param entity
|
||||
* @return
|
||||
*/
|
||||
private synchronized EntityInstantiator potentiallyCreateAndRegisterEntityInstantiator(
|
||||
PersistentEntity<?, ?> entity) {
|
||||
|
||||
Map<TypeInformation<?>, EntityInstantiator> map = this.entityInstantiators;
|
||||
EntityInstantiator instantiator = map.get(entity.getTypeInformation());
|
||||
|
||||
if (instantiator != null) {
|
||||
return instantiator;
|
||||
}
|
||||
|
||||
instantiator = createEntityInstantiator(entity);
|
||||
|
||||
map = new HashMap<TypeInformation<?>, EntityInstantiator>(map);
|
||||
map.put(entity.getTypeInformation(), instantiator);
|
||||
|
||||
this.entityInstantiators = map;
|
||||
|
||||
return instantiator;
|
||||
}
|
||||
|
||||
/**
|
||||
* @param entity
|
||||
* @return
|
||||
*/
|
||||
private EntityInstantiator createEntityInstantiator(PersistentEntity<?, ?> entity) {
|
||||
|
||||
if (shouldUseReflectionEntityInstantiator(entity)) {
|
||||
return ReflectionEntityInstantiator.INSTANCE;
|
||||
}
|
||||
|
||||
try {
|
||||
return new EntityInstantiatorAdapter(createObjectInstantiator(entity));
|
||||
} catch (Throwable ex) {
|
||||
return ReflectionEntityInstantiator.INSTANCE;
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* @param entity
|
||||
* @return
|
||||
*/
|
||||
private boolean shouldUseReflectionEntityInstantiator(PersistentEntity<?, ?> entity) {
|
||||
|
||||
Class<?> type = entity.getType();
|
||||
|
||||
if (type.isInterface() //
|
||||
|| type.isArray() //
|
||||
|| !Modifier.isPublic(type.getModifiers()) //
|
||||
|| (type.isMemberClass() && !Modifier.isStatic(type.getModifiers())) //
|
||||
|| ClassUtils.isCglibProxyClass(type)) { //
|
||||
return true;
|
||||
}
|
||||
|
||||
PreferredConstructor<?, ?> persistenceConstructor = entity.getPersistenceConstructor();
|
||||
if (persistenceConstructor == null || !Modifier.isPublic(persistenceConstructor.getConstructor().getModifiers())) {
|
||||
return true;
|
||||
}
|
||||
|
||||
return false;
|
||||
}
|
||||
|
||||
/**
|
||||
* Creates a dynamically generated {@link ObjectInstantiator} for the given {@link InstantiatorKey}. There will always
|
||||
* be exactly one {@link ObjectInstantiator} instance per {@link PersistentEntity}.
|
||||
* <p>
|
||||
*
|
||||
* @param entity
|
||||
* @return
|
||||
*/
|
||||
private ObjectInstantiator createObjectInstantiator(PersistentEntity<?, ?> entity) {
|
||||
|
||||
try {
|
||||
return (ObjectInstantiator) this.generator.generateCustomInstantiatorClass(entity).newInstance();
|
||||
} catch (Exception e) {
|
||||
throw new RuntimeException(e);
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Adapter to forward an invocation of the {@link EntityInstantiator} API to an {@link ObjectInstantiator}.
|
||||
*
|
||||
* @author Thomas Darimont
|
||||
* @author Oliver Gierke
|
||||
*/
|
||||
private static class EntityInstantiatorAdapter implements EntityInstantiator {
|
||||
|
||||
private static final Object[] EMPTY_ARRAY = new Object[0];
|
||||
|
||||
private final ObjectInstantiator instantiator;
|
||||
|
||||
/**
|
||||
* Creates a new {@link EntityInstantiatorAdapter} for the given {@link ObjectInstantiator}.
|
||||
*
|
||||
* @param instantiator must not be {@literal null}.
|
||||
*/
|
||||
public EntityInstantiatorAdapter(ObjectInstantiator instantiator) {
|
||||
this.instantiator = instantiator;
|
||||
}
|
||||
|
||||
/*
|
||||
* (non-Javadoc)
|
||||
* @see org.springframework.data.convert.EntityInstantiator#createInstance(org.springframework.data.mapping.PersistentEntity, org.springframework.data.mapping.model.ParameterValueProvider)
|
||||
*/
|
||||
@Override
|
||||
@SuppressWarnings("unchecked")
|
||||
public <T, E extends PersistentEntity<? extends T, P>, P extends PersistentProperty<P>> T createInstance(E entity,
|
||||
ParameterValueProvider<P> provider) {
|
||||
|
||||
Object[] params = extractInvocationArguments(entity.getPersistenceConstructor(), provider);
|
||||
|
||||
try {
|
||||
return (T) instantiator.newInstance(params);
|
||||
} catch (Exception e) {
|
||||
throw new MappingInstantiationException(entity, Arrays.asList(params), e);
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Extracts the arguments required to invoce the given constructor from the given {@link ParameterValueProvider}.
|
||||
*
|
||||
* @param constructor can be {@literal null}.
|
||||
* @param provider can be {@literal null}.
|
||||
* @return
|
||||
*/
|
||||
private <P extends PersistentProperty<P>, T> Object[] extractInvocationArguments(
|
||||
PreferredConstructor<? extends T, P> constructor, ParameterValueProvider<P> provider) {
|
||||
|
||||
if (provider == null || constructor == null || !constructor.hasParameters()) {
|
||||
return EMPTY_ARRAY;
|
||||
}
|
||||
|
||||
List<Object> params = new ArrayList<Object>();
|
||||
|
||||
for (Parameter<?, P> parameter : constructor.getParameters()) {
|
||||
params.add(provider.getParameterValue(parameter));
|
||||
}
|
||||
|
||||
return params.toArray();
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* @author Thomas Darimont
|
||||
*/
|
||||
private static interface ObjectInstantiator {
|
||||
|
||||
Object newInstance(Object... args);
|
||||
}
|
||||
|
||||
/**
|
||||
* Generates a new {@link ObjectInstantiator} class for the given custom class.
|
||||
* <p>
|
||||
* This code generator will generate a custom factory class implementing the {@link ObjectInstantiator} interface for
|
||||
* every publicly accessed constructor variant.
|
||||
* <p>
|
||||
* Given a class {@code ObjCtor1ParamString} like:
|
||||
*
|
||||
* <pre>
|
||||
* {
|
||||
* @code
|
||||
* public class ObjCtor1ParamString extends ObjCtorNoArgs {
|
||||
*
|
||||
* public final String param1;
|
||||
*
|
||||
* public ObjCtor1ParamString(String param1) {
|
||||
* this.param1 = param1;
|
||||
* }
|
||||
* }
|
||||
* }
|
||||
* </pre>
|
||||
*
|
||||
* The following factory class {@code ObjCtor1ParamString_Instantiator_asdf} is generated:
|
||||
*
|
||||
* <pre>
|
||||
* {
|
||||
* @code
|
||||
* public class ObjCtor1ParamString_Instantiator_asdf implements ObjectInstantiator {
|
||||
*
|
||||
* public Object newInstance(Object... args) {
|
||||
* return new ObjCtor1ParamString((String) args[0]);
|
||||
* }
|
||||
* }
|
||||
* }
|
||||
* </pre>
|
||||
*
|
||||
* @author Thomas Darimont
|
||||
*/
|
||||
static class ObjectInstantiatorClassGenerator {
|
||||
|
||||
private static final String INIT = "<init>";
|
||||
private static final String TAG = "_Instantiator_";
|
||||
private static final String JAVA_LANG_OBJECT = "java/lang/Object";
|
||||
private static final String CREATE_METHOD_NAME = "newInstance";
|
||||
|
||||
private static final String[] IMPLEMENTED_INTERFACES = new String[] {
|
||||
Type.getInternalName(ObjectInstantiator.class) };
|
||||
|
||||
private final ByteArrayClassLoader classLoader;
|
||||
|
||||
private ObjectInstantiatorClassGenerator() {
|
||||
|
||||
this.classLoader = AccessController.doPrivileged(new PrivilegedAction<ByteArrayClassLoader>() {
|
||||
public ByteArrayClassLoader run() {
|
||||
return new ByteArrayClassLoader(ClassUtils.getDefaultClassLoader());
|
||||
}
|
||||
});
|
||||
}
|
||||
|
||||
/**
|
||||
* Generate a new class for the given {@link InstantiatorKey}.
|
||||
*
|
||||
* @param key
|
||||
* @return
|
||||
*/
|
||||
public Class<?> generateCustomInstantiatorClass(PersistentEntity<?, ?> entity) {
|
||||
|
||||
String className = generateClassName(entity);
|
||||
byte[] bytecode = generateBytecode(className, entity);
|
||||
|
||||
return classLoader.loadClass(className, bytecode);
|
||||
}
|
||||
|
||||
/**
|
||||
* @param key
|
||||
* @return
|
||||
*/
|
||||
private String generateClassName(PersistentEntity<?, ?> entity) {
|
||||
return entity.getType().getName() + TAG + Integer.toString(entity.hashCode(), 36);
|
||||
}
|
||||
|
||||
/**
|
||||
* Generate a new class for the given {@link InstantiatorKey}.
|
||||
*
|
||||
* @param key
|
||||
* @return
|
||||
*/
|
||||
public byte[] generateBytecode(String internalClassName, PersistentEntity<?, ?> entity) {
|
||||
|
||||
ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS);
|
||||
|
||||
cw.visit(Opcodes.V1_6, ACC_PUBLIC + ACC_SUPER, internalClassName.replace('.', '/'), null, JAVA_LANG_OBJECT,
|
||||
IMPLEMENTED_INTERFACES);
|
||||
|
||||
visitDefaultConstructor(cw);
|
||||
|
||||
visitCreateMethod(cw, entity);
|
||||
|
||||
cw.visitEnd();
|
||||
|
||||
return cw.toByteArray();
|
||||
}
|
||||
|
||||
private void visitDefaultConstructor(ClassWriter cw) {
|
||||
|
||||
MethodVisitor mv = cw.visitMethod(ACC_PUBLIC, INIT, "()V", null, null);
|
||||
mv.visitCode();
|
||||
mv.visitVarInsn(ALOAD, 0);
|
||||
mv.visitMethodInsn(INVOKESPECIAL, JAVA_LANG_OBJECT, INIT, "()V", false);
|
||||
mv.visitInsn(RETURN);
|
||||
mv.visitMaxs(0, 0); // (0, 0) = computed via ClassWriter.COMPUTE_MAXS
|
||||
mv.visitEnd();
|
||||
}
|
||||
|
||||
/**
|
||||
* Inserts the bytecode definition for the create method for the given {@link PersistentEntity}.
|
||||
*
|
||||
* @param cw
|
||||
* @param entity
|
||||
*/
|
||||
private void visitCreateMethod(ClassWriter cw, PersistentEntity<?, ?> entity) {
|
||||
|
||||
String entityTypeResourcePath = Type.getInternalName(entity.getType());
|
||||
|
||||
MethodVisitor mv = cw.visitMethod(ACC_PUBLIC + ACC_VARARGS, CREATE_METHOD_NAME,
|
||||
"([Ljava/lang/Object;)Ljava/lang/Object;", null, null);
|
||||
mv.visitCode();
|
||||
mv.visitTypeInsn(NEW, entityTypeResourcePath);
|
||||
mv.visitInsn(DUP);
|
||||
|
||||
Constructor<?> ctor = entity.getPersistenceConstructor().getConstructor();
|
||||
Class<?>[] parameterTypes = ctor.getParameterTypes();
|
||||
for (int i = 0; i < parameterTypes.length; i++) {
|
||||
mv.visitVarInsn(ALOAD, 1);
|
||||
|
||||
visitArrayIndex(mv, i);
|
||||
|
||||
mv.visitInsn(AALOAD);
|
||||
|
||||
if (parameterTypes[i].isPrimitive()) {
|
||||
insertUnboxInsns(mv, Type.getType(parameterTypes[i]).toString().charAt(0), "");
|
||||
} else {
|
||||
mv.visitTypeInsn(CHECKCAST, Type.getInternalName(parameterTypes[i]));
|
||||
}
|
||||
}
|
||||
mv.visitMethodInsn(INVOKESPECIAL, entityTypeResourcePath, INIT, Type.getConstructorDescriptor(ctor), false);
|
||||
|
||||
mv.visitInsn(ARETURN);
|
||||
mv.visitMaxs(0, 0); // (0, 0) = computed via ClassWriter.COMPUTE_MAXS
|
||||
mv.visitEnd();
|
||||
}
|
||||
|
||||
/**
|
||||
* Insert an appropriate value on the stack for the given index value {@code idx}.
|
||||
*
|
||||
* @param mv
|
||||
* @param idx
|
||||
*/
|
||||
private static void visitArrayIndex(MethodVisitor mv, int idx) {
|
||||
|
||||
if (idx >= 0 && idx < 6) {
|
||||
mv.visitInsn(ICONST_0 + idx);
|
||||
return;
|
||||
}
|
||||
|
||||
mv.visitLdcInsn(idx);
|
||||
}
|
||||
|
||||
/**
|
||||
* Insert any necessary cast and value call to convert from a boxed type to a primitive value.
|
||||
* <p>
|
||||
* Taken from Spring Expression 4.1.2 {@code org.springframework.expression.spel.CodeFlow#insertUnboxInsns}.
|
||||
*
|
||||
* @param mv the method visitor into which instructions should be inserted
|
||||
* @param ch the primitive type desired as output
|
||||
* @param stackDescriptor the descriptor of the type on top of the stack
|
||||
*/
|
||||
private static void insertUnboxInsns(MethodVisitor mv, char ch, String stackDescriptor) {
|
||||
|
||||
switch (ch) {
|
||||
case 'Z':
|
||||
if (!stackDescriptor.equals("Ljava/lang/Boolean")) {
|
||||
mv.visitTypeInsn(CHECKCAST, "java/lang/Boolean");
|
||||
}
|
||||
mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Boolean", "booleanValue", "()Z", false);
|
||||
break;
|
||||
case 'B':
|
||||
if (!stackDescriptor.equals("Ljava/lang/Byte")) {
|
||||
mv.visitTypeInsn(CHECKCAST, "java/lang/Byte");
|
||||
}
|
||||
mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Byte", "byteValue", "()B", false);
|
||||
break;
|
||||
case 'C':
|
||||
if (!stackDescriptor.equals("Ljava/lang/Character")) {
|
||||
mv.visitTypeInsn(CHECKCAST, "java/lang/Character");
|
||||
}
|
||||
mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Character", "charValue", "()C", false);
|
||||
break;
|
||||
case 'D':
|
||||
if (!stackDescriptor.equals("Ljava/lang/Double")) {
|
||||
mv.visitTypeInsn(CHECKCAST, "java/lang/Double");
|
||||
}
|
||||
mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Double", "doubleValue", "()D", false);
|
||||
break;
|
||||
case 'F':
|
||||
if (!stackDescriptor.equals("Ljava/lang/Float")) {
|
||||
mv.visitTypeInsn(CHECKCAST, "java/lang/Float");
|
||||
}
|
||||
mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Float", "floatValue", "()F", false);
|
||||
break;
|
||||
case 'I':
|
||||
if (!stackDescriptor.equals("Ljava/lang/Integer")) {
|
||||
mv.visitTypeInsn(CHECKCAST, "java/lang/Integer");
|
||||
}
|
||||
mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Integer", "intValue", "()I", false);
|
||||
break;
|
||||
case 'J':
|
||||
if (!stackDescriptor.equals("Ljava/lang/Long")) {
|
||||
mv.visitTypeInsn(CHECKCAST, "java/lang/Long");
|
||||
}
|
||||
mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Long", "longValue", "()J", false);
|
||||
break;
|
||||
case 'S':
|
||||
if (!stackDescriptor.equals("Ljava/lang/Short")) {
|
||||
mv.visitTypeInsn(CHECKCAST, "java/lang/Short");
|
||||
}
|
||||
mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Short", "shortValue", "()S", false);
|
||||
break;
|
||||
default:
|
||||
throw new IllegalArgumentException("Unboxing should not be attempted for descriptor '" + ch + "'");
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* A {@link ClassLoader} that can load classes from {@code byte[]} representations.
|
||||
*
|
||||
* @author Thomas Darimont
|
||||
*/
|
||||
private class ByteArrayClassLoader extends ClassLoader {
|
||||
|
||||
public ByteArrayClassLoader(ClassLoader parent) {
|
||||
super(parent);
|
||||
}
|
||||
|
||||
/**
|
||||
* Tries to load a class given {@code byte[]}.
|
||||
*
|
||||
* @param name must not be {@literal null}
|
||||
* @param bytes must not be {@literal null}
|
||||
* @return
|
||||
*/
|
||||
public Class<?> loadClass(String name, byte[] bytes) {
|
||||
|
||||
Assert.notNull(name, "name must not be null");
|
||||
Assert.notNull(bytes, "bytes must not be null");
|
||||
|
||||
try {
|
||||
Class<?> clazz = findClass(name);
|
||||
if (clazz != null) {
|
||||
return clazz;
|
||||
}
|
||||
} catch (ClassNotFoundException ignore) {}
|
||||
|
||||
return defineClass(name, bytes, 0, bytes.length);
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
@@ -55,7 +55,7 @@ public class EntityInstantiators {
|
||||
* @param customInstantiators must not be {@literal null}.
|
||||
*/
|
||||
public EntityInstantiators(Map<Class<?>, EntityInstantiator> customInstantiators) {
|
||||
this(BytecodeGeneratingEntityInstantiator.INSTANCE, customInstantiators);
|
||||
this(new ClassGeneratingEntityInstantiator(), customInstantiators);
|
||||
}
|
||||
|
||||
/**
|
||||
|
||||
Reference in New Issue
Block a user