org.hibernate.validator.internal.engine.resolver.TraversableResolvers Maven / Gradle / Ivy
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/*
* Hibernate Validator, declare and validate application constraints
*
* License: Apache License, Version 2.0
* See the license.txt file in the root directory or .
*/
package org.hibernate.validator.internal.engine.resolver;
import java.lang.invoke.MethodHandles;
import java.lang.reflect.Method;
import java.security.AccessController;
import java.security.PrivilegedAction;
import javax.validation.TraversableResolver;
import javax.validation.ValidationException;
import org.hibernate.validator.internal.util.ReflectionHelper;
import org.hibernate.validator.internal.util.logging.Log;
import org.hibernate.validator.internal.util.logging.LoggerFactory;
import org.hibernate.validator.internal.util.privilegedactions.GetMethod;
import org.hibernate.validator.internal.util.privilegedactions.LoadClass;
import org.hibernate.validator.internal.util.privilegedactions.NewInstance;
public class TraversableResolvers {
private static final Log LOG = LoggerFactory.make( MethodHandles.lookup() );
/**
* Class to load to check whether JPA is on the classpath.
*/
private static final String PERSISTENCE_CLASS_NAME = "javax.persistence.Persistence";
/**
* Method to check whether the found {@code Persistence} class is of the version 2
*/
private static final String PERSISTENCE_UTIL_METHOD = "getPersistenceUtil";
/**
* Class to instantiate in case JPA 2 is on the classpath.
*/
private static final String JPA_AWARE_TRAVERSABLE_RESOLVER_CLASS_NAME = "org.hibernate.validator.internal.engine.resolver.JPATraversableResolver";
private TraversableResolvers() {
}
/**
* Initializes and returns the default {@link TraversableResolver} depending on the environment.
*
* If JPA 2 is present in the classpath, a {@link JPATraversableResolver} instance is returned.
*
* Otherwise, it returns an instance of the default {@link TraverseAllTraversableResolver}.
*/
public static TraversableResolver getDefault() {
// check whether we have Persistence on the classpath
Class persistenceClass;
try {
persistenceClass = run( LoadClass.action( PERSISTENCE_CLASS_NAME, TraversableResolvers.class.getClassLoader() ) );
}
catch (ValidationException e) {
LOG.debugf(
"Cannot find %s on classpath. Assuming non JPA 2 environment. All properties will per default be traversable.",
PERSISTENCE_CLASS_NAME
);
return getTraverseAllTraversableResolver();
}
// check whether Persistence contains getPersistenceUtil
Method persistenceUtilGetter = run( GetMethod.action( persistenceClass, PERSISTENCE_UTIL_METHOD ) );
if ( persistenceUtilGetter == null ) {
LOG.debugf(
"Found %s on classpath, but no method '%s'. Assuming JPA 1 environment. All properties will per default be traversable.",
PERSISTENCE_CLASS_NAME,
PERSISTENCE_UTIL_METHOD
);
return getTraverseAllTraversableResolver();
}
// try to invoke the method to make sure that we are dealing with a complete JPA2 implementation
// unfortunately there are several incomplete implementations out there (see HV-374)
try {
Object persistence = run( NewInstance.action( persistenceClass, "persistence provider" ) );
ReflectionHelper.getValue( persistenceUtilGetter, persistence );
}
catch (Exception e) {
LOG.debugf(
"Unable to invoke %s.%s. Inconsistent JPA environment. All properties will per default be traversable.",
PERSISTENCE_CLASS_NAME,
PERSISTENCE_UTIL_METHOD
);
return getTraverseAllTraversableResolver();
}
LOG.debugf(
"Found %s on classpath containing '%s'. Assuming JPA 2 environment. Trying to instantiate JPA aware TraversableResolver",
PERSISTENCE_CLASS_NAME,
PERSISTENCE_UTIL_METHOD
);
try {
@SuppressWarnings("unchecked")
Class jpaAwareResolverClass = (Class)
run( LoadClass.action( JPA_AWARE_TRAVERSABLE_RESOLVER_CLASS_NAME, TraversableResolvers.class.getClassLoader() ) );
LOG.debugf(
"Instantiated JPA aware TraversableResolver of type %s.", JPA_AWARE_TRAVERSABLE_RESOLVER_CLASS_NAME
);
return run( NewInstance.action( jpaAwareResolverClass, "" ) );
}
catch (ValidationException e) {
LOG.logUnableToLoadOrInstantiateJPAAwareResolver( JPA_AWARE_TRAVERSABLE_RESOLVER_CLASS_NAME );
return getTraverseAllTraversableResolver();
}
}
/**
* Potentially wrap the {@link TraversableResolver} into a caching one.
*
* If {@code traversableResolver} is {@code TraverseAllTraversableResolver.INSTANCE}, we don't wrap it and it is
* returned directly. Same if the caching is explicitly disabled.
*
* If {@code traversableResolver} is an instance of our {@code JPATraversableResolver}, we wrap it with a caching
* wrapper specially tailored for the requirements of the spec. It is a very common case as it is used as soon as we
* have a JPA implementation in the classpath so optimizing this case is worth it.
*
* In all the other cases, we wrap the resolver for caching.
*
* Note that, in the {@code TraversableResolver} is wrapped, a new instance is returned each time and it should be
* used only for the duration of a validation call.
*
* @return The resolver for the duration of a validation call.
*/
public static TraversableResolver wrapWithCachingForSingleValidation(TraversableResolver traversableResolver,
boolean traversableResolverResultCacheEnabled) {
if ( TraverseAllTraversableResolver.class.equals( traversableResolver.getClass() ) || !traversableResolverResultCacheEnabled ) {
return traversableResolver;
}
else if ( JPA_AWARE_TRAVERSABLE_RESOLVER_CLASS_NAME.equals( traversableResolver.getClass().getName() ) ) {
return new CachingJPATraversableResolverForSingleValidation( traversableResolver );
}
else {
return new CachingTraversableResolverForSingleValidation( traversableResolver );
}
}
private static TraversableResolver getTraverseAllTraversableResolver() {
return new TraverseAllTraversableResolver();
}
/**
* Runs the given privileged action, using a privileged block if required.
*
* NOTE: This must never be changed into a publicly available method to avoid execution of arbitrary
* privileged actions within HV's protection domain.
*/
private static T run(PrivilegedAction action) {
return System.getSecurityManager() != null ? AccessController.doPrivileged( action ) : action.run();
}
}