/*
* Copyright 2012-2017 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.springframework.boot.autoconfigure.condition;
import java.security.AccessControlException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.BeanClassLoaderAware;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.BeanFactoryAware;
import org.springframework.beans.factory.config.ConfigurableBeanFactory;
import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
import org.springframework.boot.autoconfigure.AutoConfigurationImportFilter;
import org.springframework.boot.autoconfigure.AutoConfigurationMetadata;
import org.springframework.boot.autoconfigure.condition.ConditionMessage.Style;
import org.springframework.context.annotation.Condition;
import org.springframework.context.annotation.ConditionContext;
import org.springframework.core.Ordered;
import org.springframework.core.annotation.Order;
import org.springframework.core.type.AnnotatedTypeMetadata;
import org.springframework.util.ClassUtils;
import org.springframework.util.MultiValueMap;
/**
* {@link Condition} and {@link AutoConfigurationImportFilter} that checks for the
* presence or absence of specific classes.
*
* @author Phillip Webb
* @see ConditionalOnClass
* @see ConditionalOnMissingClass
*/
@Order(Ordered.HIGHEST_PRECEDENCE)
class OnClassCondition extends SpringBootCondition
implements AutoConfigurationImportFilter, BeanFactoryAware, BeanClassLoaderAware {
private BeanFactory beanFactory;
private ClassLoader beanClassLoader;
@Override
public boolean[] match(String[] autoConfigurationClasses,
AutoConfigurationMetadata autoConfigurationMetadata) {
ConditionEvaluationReport report = getConditionEvaluationReport();
ConditionOutcome[] outcomes = getOutcomes(autoConfigurationClasses,
autoConfigurationMetadata);
boolean[] match = new boolean[outcomes.length];
for (int i = 0; i < outcomes.length; i++) {
match[i] = (outcomes[i] == null || outcomes[i].isMatch());
if (!match[i] && outcomes[i] != null) {
logOutcome(autoConfigurationClasses[i], outcomes[i]);
if (report != null) {
report.recordConditionEvaluation(autoConfigurationClasses[i], this,
outcomes[i]);
}
}
}
return match;
}
private ConditionEvaluationReport getConditionEvaluationReport() {
if (this.beanFactory != null
&& this.beanFactory instanceof ConfigurableBeanFactory) {
return ConditionEvaluationReport
.get((ConfigurableListableBeanFactory) this.beanFactory);
}
return null;
}
private ConditionOutcome[] getOutcomes(String[] autoConfigurationClasses,
AutoConfigurationMetadata autoConfigurationMetadata) {
// Split the work and perform half in a background thread. Using a single
// additional thread seems to offer the best performance. More threads make
// things worse
int split = autoConfigurationClasses.length / 2;
OutcomesResolver firstHalfResolver = createOutcomesResolver(
autoConfigurationClasses, 0, split, autoConfigurationMetadata);
OutcomesResolver secondHalfResolver = new StandardOutcomesResolver(
autoConfigurationClasses, split, autoConfigurationClasses.length,
autoConfigurationMetadata, this.beanClassLoader);
ConditionOutcome[] secondHalf = secondHalfResolver.resolveOutcomes();
ConditionOutcome[] firstHalf = firstHalfResolver.resolveOutcomes();
ConditionOutcome[] outcomes = new ConditionOutcome[autoConfigurationClasses.length];
System.arraycopy(firstHalf, 0, outcomes, 0, firstHalf.length);
System.arraycopy(secondHalf, 0, outcomes, split, secondHalf.length);
return outcomes;
}
private OutcomesResolver createOutcomesResolver(String[] autoConfigurationClasses,
int start, int end, AutoConfigurationMetadata autoConfigurationMetadata) {
OutcomesResolver outcomesResolver = new StandardOutcomesResolver(
autoConfigurationClasses, start, end, autoConfigurationMetadata,
this.beanClassLoader);
try {
return new ThreadedOutcomesResolver(outcomesResolver);
}
catch (AccessControlException ex) {
return outcomesResolver;
}
}
@Override
public ConditionOutcome getMatchOutcome(ConditionContext context,
AnnotatedTypeMetadata metadata) {
ClassLoader classLoader = context.getClassLoader();
ConditionMessage matchMessage = ConditionMessage.empty();
List<String> onClasses = getCandidates(metadata, ConditionalOnClass.class);
if (onClasses != null) {
List<String> missing = getMatches(onClasses, MatchType.MISSING, classLoader);
if (!missing.isEmpty()) {
return ConditionOutcome
.noMatch(ConditionMessage.forCondition(ConditionalOnClass.class)
.didNotFind("required class", "required classes")
.items(Style.QUOTE, missing));
}
matchMessage = matchMessage.andCondition(ConditionalOnClass.class)
.found("required class", "required classes").items(Style.QUOTE,
getMatches(onClasses, MatchType.PRESENT, classLoader));
}
List<String> onMissingClasses = getCandidates(metadata,
ConditionalOnMissingClass.class);
if (onMissingClasses != null) {
List<String> present = getMatches(onMissingClasses, MatchType.PRESENT,
classLoader);
if (!present.isEmpty()) {
return ConditionOutcome.noMatch(
ConditionMessage.forCondition(ConditionalOnMissingClass.class)
.found("unwanted class", "unwanted classes")
.items(Style.QUOTE, present));
}
matchMessage = matchMessage.andCondition(ConditionalOnMissingClass.class)
.didNotFind("unwanted class", "unwanted classes").items(Style.QUOTE,
getMatches(onMissingClasses, MatchType.MISSING, classLoader));
}
return ConditionOutcome.match(matchMessage);
}
private List<String> getCandidates(AnnotatedTypeMetadata metadata,
Class<?> annotationType) {
MultiValueMap<String, Object> attributes = metadata
.getAllAnnotationAttributes(annotationType.getName(), true);
List<String> candidates = new ArrayList<>();
if (attributes == null) {
return Collections.emptyList();
}
addAll(candidates, attributes.get("value"));
addAll(candidates, attributes.get("name"));
return candidates;
}
private void addAll(List<String> list, List<Object> itemsToAdd) {
if (itemsToAdd != null) {
for (Object item : itemsToAdd) {
Collections.addAll(list, (String[]) item);
}
}
}
private List<String> getMatches(Collection<String> candidates, MatchType matchType,
ClassLoader classLoader) {
List<String> matches = new ArrayList<>(candidates.size());
for (String candidate : candidates) {
if (matchType.matches(candidate, classLoader)) {
matches.add(candidate);
}
}
return matches;
}
@Override
public void setBeanFactory(BeanFactory beanFactory) throws BeansException {
this.beanFactory = beanFactory;
}
@Override
public void setBeanClassLoader(ClassLoader classLoader) {
this.beanClassLoader = classLoader;
}
private enum MatchType {
PRESENT {
@Override
public boolean matches(String className, ClassLoader classLoader) {
return isPresent(className, classLoader);
}
},
MISSING {
@Override
public boolean matches(String className, ClassLoader classLoader) {
return !isPresent(className, classLoader);
}
};
private static boolean isPresent(String className, ClassLoader classLoader) {
if (classLoader == null) {
classLoader = ClassUtils.getDefaultClassLoader();
}
try {
forName(className, classLoader);
return true;
}
catch (Throwable ex) {
return false;
}
}
private static Class<?> forName(String className, ClassLoader classLoader)
throws ClassNotFoundException {
if (classLoader != null) {
return classLoader.loadClass(className);
}
return Class.forName(className);
}
public abstract boolean matches(String className, ClassLoader classLoader);
}
private interface OutcomesResolver {
ConditionOutcome[] resolveOutcomes();
}
private static final class ThreadedOutcomesResolver implements OutcomesResolver {
private final Thread thread;
private volatile ConditionOutcome[] outcomes;
private ThreadedOutcomesResolver(final OutcomesResolver outcomesResolver) {
this.thread = new Thread(new Runnable() {
@Override
public void run() {
ThreadedOutcomesResolver.this.outcomes = outcomesResolver
.resolveOutcomes();
}
});
this.thread.start();
}
@Override
public ConditionOutcome[] resolveOutcomes() {
try {
this.thread.join();
}
catch (InterruptedException ex) {
Thread.currentThread().interrupt();
}
return this.outcomes;
}
}
private final class StandardOutcomesResolver implements OutcomesResolver {
private final String[] autoConfigurationClasses;
private final int start;
private final int end;
private final AutoConfigurationMetadata autoConfigurationMetadata;
private final ClassLoader beanClassLoader;
private StandardOutcomesResolver(String[] autoConfigurationClasses, int start,
int end, AutoConfigurationMetadata autoConfigurationMetadata,
ClassLoader beanClassLoader) {
this.autoConfigurationClasses = autoConfigurationClasses;
this.start = start;
this.end = end;
this.autoConfigurationMetadata = autoConfigurationMetadata;
this.beanClassLoader = beanClassLoader;
}
@Override
public ConditionOutcome[] resolveOutcomes() {
return getOutcomes(this.autoConfigurationClasses, this.start, this.end,
this.autoConfigurationMetadata);
}
private ConditionOutcome[] getOutcomes(final String[] autoConfigurationClasses,
int start, int end, AutoConfigurationMetadata autoConfigurationMetadata) {
ConditionOutcome[] outcomes = new ConditionOutcome[end - start];
for (int i = start; i < end; i++) {
String autoConfigurationClass = autoConfigurationClasses[i];
Set<String> candidates = autoConfigurationMetadata
.getSet(autoConfigurationClass, "ConditionalOnClass");
if (candidates != null) {
outcomes[i - start] = getOutcome(candidates);
}
}
return outcomes;
}
private ConditionOutcome getOutcome(Set<String> candidates) {
try {
List<String> missing = getMatches(candidates, MatchType.MISSING,
this.beanClassLoader);
if (!missing.isEmpty()) {
return ConditionOutcome.noMatch(
ConditionMessage.forCondition(ConditionalOnClass.class)
.didNotFind("required class", "required classes")
.items(Style.QUOTE, missing));
}
}
catch (Exception ex) {
// We'll get another chance later
}
return null;
}
}
}