org.eclipse.persistence.internal.descriptors.InstantiationPolicy Maven / Gradle / Ivy
Show all versions of eclipselink Show documentation
/*
* Copyright (c) 1998, 2020 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0 which is available at
* http://www.eclipse.org/legal/epl-2.0,
* or the Eclipse Distribution License v. 1.0 which is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
*/
// Contributors:
// Oracle - initial API and implementation from Oracle TopLink
package org.eclipse.persistence.internal.descriptors;
import java.io.Serializable;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import org.eclipse.persistence.descriptors.ClassDescriptor;
import org.eclipse.persistence.exceptions.DescriptorException;
import org.eclipse.persistence.exceptions.ValidationException;
import org.eclipse.persistence.internal.core.descriptors.CoreInstantiationPolicy;
import org.eclipse.persistence.internal.helper.Helper;
import org.eclipse.persistence.internal.security.PrivilegedAccessHelper;
import org.eclipse.persistence.internal.sessions.AbstractSession;
/**
* Purpose: Allows customization of how an object is created/instantiated.
*
* So, here is how it works:
*
* If there is no method specified
* - all the other settings are ignored and
* - the descriptor class's default constructor is invoked.
* If a factory is specified
* - the factoryClass and factoryClassMethod are ignored and
* - the method is invoked on the factory.
* If neither a factory nor a factoryClass are specified
* - the factoryClassMethod is ignored and
* - the method is invoked on the descriptor class (as a static).
* If only the factoryClass is specified
* - the factory is created by invoking the factoryClass' default (zero-argument) constructor and
* - the method is invoked on the resulting factory.
* If both the factoryClass and the factoryClassMethod are specified
* - the factory is created by invoking the factoryClassMethod on the factoryClass (as a static) and
* - the method is invoked on the resulting factory.
*
* The only thing we can't support in the current configuration is invoking a static on some,
* client-specified, factoryClass to build new instances of the descriptor class; and it's debatable
* whether that is desirable...
*
* It might be reasonable to rework this into a number of different classes that implement
* an interface...
*/
public class InstantiationPolicy extends CoreInstantiationPolicy implements Cloneable, Serializable {
/**
* The method invoked on either the descriptor class (in which case it is static) or
* the factory (in which case it is not static) to build a new instance of the descriptor class.
*/
protected String methodName;
/** The method is resolved during initialization, and it is not serialized. */
protected transient Method method;
/**
* The class of the factory. The factory is instantiated by either invoking this class's default
* (zero-argument) constructor or the factoryMethod specified below.
*/
protected Class factoryClass;
protected String factoryClassName;
/**
* Static method invoked on the factoryClass to get the factory instance. If this is null, the
* factory class's default (zero-argument) constructor is invoked.
*/
protected String factoryMethodName;
/**
* The object factory. This can be specified directly by the client, or it can be built dynamically
* using the the factoryClass and, optionally, the factoryMethodName.
*/
protected Object factory;
/** Backpointer to descriptor. */
protected ClassDescriptor descriptor;
/** Must be transient because java.lang.Constructor is not serializable. */
private transient Constructor defaultConstructor;
/**
* Default constructor
*/
public InstantiationPolicy() {
super();
}
/**
* Build and return a new instance, using the appropriate mechanism.
*/
@Override
public Object buildNewInstance() throws DescriptorException {
// PERF: Just check method-name.
if (this.methodName == null) {
return buildNewInstanceUsingDefaultConstructor();
} else {
return buildNewInstanceUsingFactory();
}
}
/**
* Build and return a new instance, using the default (zero-argument) constructor.
*/
protected Object buildNewInstanceUsingDefaultConstructor() throws DescriptorException {
// NoSuchMethodError is not an Exception instance so Throwable is required
return PrivilegedAccessHelper.callDoPrivilegedWithThrowable(
() -> (defaultConstructor != null ? defaultConstructor : getDefaultConstructor()).newInstance((Object[])null),
(t) -> {
if (t instanceof DescriptorException) {
return (DescriptorException) t;
} else if (t instanceof InvocationTargetException) {
return DescriptorException.targetInvocationWhileConstructorInstantiation(getDescriptor(), (InvocationTargetException) t);
} else if (t instanceof IllegalAccessException) {
return DescriptorException.illegalAccessWhileConstructorInstantiation(getDescriptor(), (IllegalAccessException) t);
} else if (t instanceof InstantiationException) {
return DescriptorException.instantiationWhileConstructorInstantiation(getDescriptor(), (InstantiationException) t);
} else if (t instanceof NoSuchMethodError) {
// This exception is not documented but gets thrown.
return DescriptorException.noSuchMethodWhileConstructorInstantiation(getDescriptor(), t);
} else if (t instanceof NullPointerException) {
// Some JVMs will throw a NULL pointer exception here
return DescriptorException.nullPointerWhileConstructorInstantiation(getDescriptor(), t);
}
// This indicates unexpected problem in the code
return new RuntimeException(String.format(
"Invocation of default %s constructor failed", getDescriptor().getJavaClass().getName()), t);
}
);
}
/**
* Build and return a new instance, using the factory.
* The factory can be null, in which case the method is a static method defined by the descriptor class.
*/
protected Object buildNewInstanceUsingFactory() throws DescriptorException {
return PrivilegedAccessHelper.callDoPrivilegedWithException(
() -> PrivilegedAccessHelper.invokeMethod(getMethod(), getFactory(), new Object[0]),
(ex) -> {
if (ex instanceof IllegalAccessException) {
return DescriptorException.illegalAccessWhileMethodInstantiation(getMethod().toString(), getDescriptor(), ex);
} else if (ex instanceof InvocationTargetException) {
return DescriptorException.targetInvocationWhileMethodInstantiation(getMethod().toString(), getDescriptor(), ex);
} else if (ex instanceof NullPointerException) {
// Some JVMs will throw a NULL pointer exception here
return DescriptorException.nullPointerWhileMethodInstantiation(getMethod().toString(), getDescriptor(), ex);
}
// This indicates unexpected problem in the code
return new RuntimeException(String.format(
"Invocation of factory %s class %s method failed", getFactory().getClass().getName(), getMethod().getName()), ex);
}
);
}
/**
* INTERNAL:
* Clones the InstantiationPolicy
*/
@Override
public Object clone() {
try {
// clones itself
return super.clone();
} catch (Exception exception) {
throw new AssertionError(exception);
}
}
/**
* Return the default (zero-argument) constructor for the descriptor class.
*/
protected Constructor getDefaultConstructor() throws DescriptorException {
// Lazy initialize, because the constructor cannot be serialized
if (defaultConstructor == null) {
this.setDefaultConstructor(this.buildDefaultConstructor());
}
return defaultConstructor;
}
/**
* Build and return the default (zero-argument) constructor for the descriptor class.
*/
protected Constructor buildDefaultConstructor() throws DescriptorException {
return this.buildDefaultConstructorFor(this.getDescriptor().getJavaClass());
}
/**
* Build and return the default (zero-argument) constructor for the specified class.
*/
protected Constructor buildDefaultConstructorFor(final Class javaClass) throws DescriptorException {
return PrivilegedAccessHelper.callDoPrivilegedWithException(
() -> PrivilegedAccessHelper.getDeclaredConstructorFor(javaClass, new Class[0], true),
(ex) -> DescriptorException.noSuchMethodWhileInitializingInstantiationPolicy(javaClass.getName() + ".", getDescriptor(), ex)
);
}
protected ClassDescriptor getDescriptor() {
return descriptor;
}
public String getFactoryMethodName() {
return factoryMethodName;
}
public Object getFactory() {
return factory;
}
public Class getFactoryClass() {
return factoryClass;
}
public String getFactoryClassName() {
if ((factoryClassName == null) && (factoryClass != null)) {
factoryClassName = factoryClass.getName();
}
return factoryClassName;
}
protected Method getMethod() {
return method;
}
public String getMethodName() {
return methodName;
}
/**
* If necessary, initialize the factory and the method.
*/
public void initialize(AbstractSession session) throws DescriptorException {
if (this.isUsingDefaultConstructor()) {
// May not have a constructor as may be abstract or interface so only lazy init.
return;
}
try {
this.initializeMethod();
if (!(Modifier.isStatic(getMethod().getModifiers()))) {
// If the factory has been specified directly, do not overwrite it
if (this.getFactory() == null) {
this.setFactory(this.buildFactory());
}
}
} catch (DescriptorException ex) {
session.getIntegrityChecker().handleError(ex);
}
}
protected Object buildFactory() throws DescriptorException {
// If there is no factory class specified, there is no factory;
// we will be using a static method defined by the descriptor class...
if (this.getFactoryClass() == null) {
return null;
}
// If there is a factory class specified but no factory method name,
// instantiate the factory using the default constructor
if (this.getFactoryMethodName() == null) {
return this.buildFactoryUsingDefaultConstructor();
}
// If both the factory class and the factory method name have been specified,
// instantiate the factory by invoking the static factory method
return this.buildFactoryUsingStaticMethod();
}
/**
* Build and return the factory, using its default constructor.
*/
protected Object buildFactoryUsingDefaultConstructor() throws DescriptorException {
final Constructor factoryDefaultConstructor = buildFactoryDefaultConstructor();
// NoSuchMethodError is not an Exception instance so Throwable is required
return PrivilegedAccessHelper.callDoPrivilegedWithThrowable(
() -> PrivilegedAccessHelper.invokeConstructor(factoryDefaultConstructor, null),
(t) -> {
if (t instanceof InvocationTargetException) {
return DescriptorException.targetInvocationWhileConstructorInstantiationOfFactory(getDescriptor(), (InvocationTargetException) t);
} else if (t instanceof IllegalAccessException) {
return DescriptorException.illegalAccessWhileConstructorInstantiationOfFactory(getDescriptor(), (IllegalAccessException) t);
} else if (t instanceof InstantiationException) {
return DescriptorException.instantiationWhileConstructorInstantiationOfFactory(getDescriptor(), (InstantiationException) t);
} else if (t instanceof NoSuchMethodError) {
// This exception is not documented but gets thrown.
return DescriptorException.noSuchMethodWhileConstructorInstantiationOfFactory(getDescriptor(), t);
} else if (t instanceof NullPointerException) {
// Some JVMs will throw a NULL pointer exception here
return DescriptorException.nullPointerWhileConstructorInstantiationOfFactory(getDescriptor(), t);
}
// This indicates unexpected problem in the code
return new RuntimeException(String.format("Invocation of %s factory constructor failed", factoryClassName), t);
}
);
}
/**
* Build and return the default (zero-argument) constructor for the factory class.
*/
protected Constructor buildFactoryDefaultConstructor() throws DescriptorException {
return this.buildDefaultConstructorFor(this.getFactoryClass());
}
/**
* Build and return the factory, using the specified static method.
*/
protected Object buildFactoryUsingStaticMethod() throws DescriptorException {
final Method factoryMethod = buildMethod(getFactoryClass(), factoryMethodName, new Class[0]);
return PrivilegedAccessHelper.callDoPrivilegedWithException(
() -> PrivilegedAccessHelper.invokeMethod(factoryMethod, null, null),
(ex) -> {
final String factoryMethodName = getFactoryMethodName();
if (ex instanceof IllegalAccessException) {
return DescriptorException.illegalAccessWhileMethodInstantiationOfFactory(factoryMethodName, getDescriptor(), ex);
} else if (ex instanceof InvocationTargetException) {
return DescriptorException.targetInvocationWhileMethodInstantiationOfFactory(factoryMethodName, getDescriptor(), ex);
} else if (ex instanceof NullPointerException) {
// Some JVMs will throw a NULL pointer exception here
return DescriptorException.nullPointerWhileMethodInstantiationOfFactory(factoryMethodName, getDescriptor(), ex);
}
// This indicates unexpected problem in the code
return new RuntimeException(String.format("Invocation of %s factory method failed", factoryMethodName), ex);
}
);
}
/**
* Initialize the method.
* It is either a static on the descriptor class, or it is a non-static on the factory.
*/
protected void initializeMethod() throws DescriptorException {
Class tempClass;
if (this.getFactory() != null) {
tempClass = this.getFactory().getClass();
} else if (this.getFactoryClass() == null) {
tempClass = this.getDescriptor().getJavaClass();
} else {
tempClass = this.getFactoryClass();
}
this.setMethod(this.buildMethod(tempClass, this.getMethodName(), new Class[0]));
}
/**
* Build the specified method.
*/
protected Method buildMethod(Class methodClass, String methodName, Class[] methodParameterTypes) throws DescriptorException {
try {
return Helper.getDeclaredMethod(methodClass, methodName, methodParameterTypes);
} catch (NoSuchMethodException exception) {
throw DescriptorException.noSuchMethodWhileInitializingInstantiationPolicy(methodClass.getName() + "." + methodName, this.getDescriptor(), exception);
} catch (SecurityException exception) {
throw DescriptorException.securityWhileInitializingInstantiationPolicy(methodClass.getName() + "." + methodName, this.getDescriptor(), exception);
}
}
/**
* If no method name is specified, they we have to use the default (zero-argument) constructor.
*/
public boolean isUsingDefaultConstructor() {
return this.getMethodName() == null;
}
protected void setDefaultConstructor(Constructor defaultConstructor) {
this.defaultConstructor = defaultConstructor;
}
public void setDescriptor(ClassDescriptor descriptor) {
this.descriptor = descriptor;
}
protected void setFactoryMethodName(String factoryMethodName) {
this.factoryMethodName = factoryMethodName;
}
protected void setFactory(Object factory) {
this.factory = factory;
}
protected void setFactoryClass(Class factoryClass) {
this.factoryClass = factoryClass;
}
protected void setFactoryClassName(String factoryClassName) {
this.factoryClassName = factoryClassName;
}
protected void setMethod(Method method) {
this.method = method;
}
public void setMethodName(String methodName) {
this.methodName = methodName;
}
/**
* INTERNAL:
* Convert all the class-name-based settings in this InstantiationPolicy to actual class-based
* settings. This method is used when converting a project that has been built
* with class names to a project with classes.
* @param classLoader
*/
public void convertClassNamesToClasses(final ClassLoader classLoader) {
if (factoryClassName == null) {
return;
}
setFactoryClass(
PrivilegedAccessHelper.callDoPrivilegedWithException(
() -> PrivilegedAccessHelper.getClassForName(factoryClassName, true, classLoader),
(ex) -> ValidationException.classNotFoundWhileConvertingClassNames(factoryClassName, ex)
)
);
}
@Override
public String toString() {
String mName = null;
if (this.isUsingDefaultConstructor()) {
mName = "";
} else {
mName = this.getMethodName();
}
return Helper.getShortClassName(this) + "(" + mName + ")";
}
public void useDefaultConstructorInstantiationPolicy() {
setMethodName(null);
setFactory(null);
setFactoryClass(null);
setFactoryClassName(null);
setFactoryMethodName(null);
}
public void useFactoryInstantiationPolicy(Class factoryClass, String methodName) {
setMethodName(methodName);
setFactory(null);
setFactoryClass(factoryClass);
setFactoryClassName(factoryClass.getName());
setFactoryMethodName(null);
}
public void useFactoryInstantiationPolicy(Class factoryClass, String methodName, String factoryMethodName) {
setMethodName(methodName);
setFactory(null);
setFactoryClass(factoryClass);
setFactoryClassName(factoryClass.getName());
setFactoryMethodName(factoryMethodName);
}
@Override
public void useFactoryInstantiationPolicy(String factoryClassName, String methodName) {
setMethodName(methodName);
setFactory(null);
setFactoryClass(null);
setFactoryClassName(factoryClassName);
setFactoryMethodName(null);
}
public void useFactoryInstantiationPolicy(String factoryClassName, String methodName, String factoryMethodName) {
setMethodName(methodName);
setFactory(null);
setFactoryClass(null);
setFactoryClassName(factoryClassName);
setFactoryMethodName(factoryMethodName);
}
public void useFactoryInstantiationPolicy(Object factory, String methodName) {
setMethodName(methodName);
setFactory(factory);
setFactoryClass(null);
setFactoryClassName(null);
setFactoryMethodName(null);
}
public void useMethodInstantiationPolicy(String staticMethodName) {
setMethodName(staticMethodName);
setFactory(null);
setFactoryClass(null);
setFactoryClassName(null);
setFactoryMethodName(null);
}
}