org.springframework.boot.context.ConfigurationWarningsApplicationContextInitializer Maven / Gradle / Ivy
/*
* Copyright 2012-2015 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.
*/
package org.springframework.boot.context;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashSet;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Set;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.annotation.AnnotatedBeanDefinition;
import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
import org.springframework.beans.factory.support.BeanDefinitionRegistry;
import org.springframework.beans.factory.support.BeanDefinitionRegistryPostProcessor;
import org.springframework.context.ApplicationContextInitializer;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.core.Ordered;
import org.springframework.core.PriorityOrdered;
import org.springframework.core.annotation.AnnotationAttributes;
import org.springframework.core.type.AnnotationMetadata;
import org.springframework.util.ClassUtils;
import org.springframework.util.StringUtils;
/**
* {@link ApplicationContextInitializer} to report warnings for common misconfiguration
* mistakes.
*
* @author Phillip Webb
* @since 1.2.0
*/
public class ConfigurationWarningsApplicationContextInitializer
implements ApplicationContextInitializer {
private static final Log logger = LogFactory
.getLog(ConfigurationWarningsApplicationContextInitializer.class);
@Override
public void initialize(ConfigurableApplicationContext context) {
context.addBeanFactoryPostProcessor(
new ConfigurationWarningsPostProcessor(getChecks()));
}
/**
* Returns the checks that should be applied.
* @return the checks to apply
*/
protected Check[] getChecks() {
return new Check[] { new ComponentScanPackageCheck() };
}
/**
* {@link BeanDefinitionRegistryPostProcessor} to report warnings.
*/
protected final static class ConfigurationWarningsPostProcessor
implements PriorityOrdered, BeanDefinitionRegistryPostProcessor {
private Check[] checks;
public ConfigurationWarningsPostProcessor(Check[] checks) {
this.checks = checks;
}
@Override
public int getOrder() {
return Ordered.LOWEST_PRECEDENCE - 1;
}
@Override
public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory)
throws BeansException {
}
@Override
public void postProcessBeanDefinitionRegistry(BeanDefinitionRegistry registry)
throws BeansException {
for (Check check : this.checks) {
String message = check.getWarning(registry);
if (StringUtils.hasLength(message)) {
warn(message);
}
}
}
private void warn(String message) {
if (logger.isWarnEnabled()) {
logger.warn("\n\n** WARNING ** : " + message + "\n\n");
}
}
}
/**
* A single check that can be applied.
*/
protected interface Check {
/**
* Returns a warning if the check fails or {@code null} if there are no problems.
* @param registry the {@link BeanDefinitionRegistry}
* @return a warning message or {@code null}
*/
String getWarning(BeanDefinitionRegistry registry);
}
/**
* {@link Check} for {@code @ComponentScan} on problematic package.
*/
protected static class ComponentScanPackageCheck implements Check {
private static final Set PROBLEM_PACKAGES;
static {
Set packages = new HashSet();
packages.add("org.springframework");
packages.add("org");
PROBLEM_PACKAGES = Collections.unmodifiableSet(packages);
}
@Override
public String getWarning(BeanDefinitionRegistry registry) {
Set scannedPackages = getComponentScanningPackages(registry);
List problematicPackages = getProblematicPackages(scannedPackages);
if (problematicPackages.isEmpty()) {
return null;
}
return "Your ApplicationContext is unlikely to "
+ "start due to a @ComponentScan of "
+ StringUtils.collectionToDelimitedString(problematicPackages, ", ")
+ ".";
}
protected Set getComponentScanningPackages(
BeanDefinitionRegistry registry) {
Set packages = new LinkedHashSet();
String[] names = registry.getBeanDefinitionNames();
for (String name : names) {
BeanDefinition definition = registry.getBeanDefinition(name);
if (definition instanceof AnnotatedBeanDefinition) {
AnnotatedBeanDefinition annotatedDefinition = (AnnotatedBeanDefinition) definition;
addComponentScanningPackages(packages,
annotatedDefinition.getMetadata());
}
}
return packages;
}
private void addComponentScanningPackages(Set packages,
AnnotationMetadata metadata) {
AnnotationAttributes attributes = AnnotationAttributes.fromMap(metadata
.getAnnotationAttributes(ComponentScan.class.getName(), true));
if (attributes != null) {
addPackages(packages, attributes.getStringArray("value"));
addPackages(packages, attributes.getStringArray("basePackages"));
addClasses(packages, attributes.getStringArray("basePackageClasses"));
if (packages.isEmpty()) {
packages.add(ClassUtils.getPackageName(metadata.getClassName()));
}
}
}
private void addPackages(Set packages, String[] values) {
if (values != null) {
for (String value : values) {
packages.add(value);
}
}
}
private void addClasses(Set packages, String[] values) {
if (values != null) {
for (String value : values) {
packages.add(ClassUtils.getPackageName(value));
}
}
}
private List getProblematicPackages(Set scannedPackages) {
List problematicPackages = new ArrayList();
for (String scannedPackage : scannedPackages) {
if (isProblematicPackage(scannedPackage)) {
problematicPackages.add(getDisplayName(scannedPackage));
}
}
return problematicPackages;
}
private boolean isProblematicPackage(String scannedPackage) {
if (scannedPackage == null || scannedPackage.length() == 0) {
return true;
}
return PROBLEM_PACKAGES.contains(scannedPackage);
}
private String getDisplayName(String scannedPackage) {
if (scannedPackage == null || scannedPackage.length() == 0) {
return "the default package";
}
return "'" + scannedPackage + "'";
}
}
}