org.springframework.boot.BeanDefinitionLoader Maven / Gradle / Ivy
/*
* Copyright 2012-2019 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
*
* https://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;
import java.io.IOException;
import java.util.HashSet;
import java.util.Set;
import groovy.lang.Closure;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.BeanDefinitionStoreException;
import org.springframework.beans.factory.groovy.GroovyBeanDefinitionReader;
import org.springframework.beans.factory.support.BeanDefinitionReader;
import org.springframework.beans.factory.support.BeanDefinitionRegistry;
import org.springframework.beans.factory.support.BeanNameGenerator;
import org.springframework.beans.factory.xml.XmlBeanDefinitionReader;
import org.springframework.context.annotation.AnnotatedBeanDefinitionReader;
import org.springframework.context.annotation.ClassPathBeanDefinitionScanner;
import org.springframework.core.annotation.MergedAnnotations;
import org.springframework.core.annotation.MergedAnnotations.SearchStrategy;
import org.springframework.core.env.ConfigurableEnvironment;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.Resource;
import org.springframework.core.io.ResourceLoader;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.core.io.support.ResourcePatternResolver;
import org.springframework.core.type.filter.AbstractTypeHierarchyTraversingFilter;
import org.springframework.core.type.filter.TypeFilter;
import org.springframework.stereotype.Component;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
import org.springframework.util.StringUtils;
/**
* Loads bean definitions from underlying sources, including XML and JavaConfig. Acts as a
* simple facade over {@link AnnotatedBeanDefinitionReader},
* {@link XmlBeanDefinitionReader} and {@link ClassPathBeanDefinitionScanner}. See
* {@link SpringApplication} for the types of sources that are supported.
*
* @author Phillip Webb
* @see #setBeanNameGenerator(BeanNameGenerator)
*/
class BeanDefinitionLoader {
private final Object[] sources;
private final AnnotatedBeanDefinitionReader annotatedReader;
private final XmlBeanDefinitionReader xmlReader;
private BeanDefinitionReader groovyReader;
private final ClassPathBeanDefinitionScanner scanner;
private ResourceLoader resourceLoader;
/**
* Create a new {@link BeanDefinitionLoader} that will load beans into the specified
* {@link BeanDefinitionRegistry}.
* @param registry the bean definition registry that will contain the loaded beans
* @param sources the bean sources
*/
BeanDefinitionLoader(BeanDefinitionRegistry registry, Object... sources) {
Assert.notNull(registry, "Registry must not be null");
Assert.notEmpty(sources, "Sources must not be empty");
this.sources = sources;
this.annotatedReader = new AnnotatedBeanDefinitionReader(registry);
this.xmlReader = new XmlBeanDefinitionReader(registry);
if (isGroovyPresent()) {
this.groovyReader = new GroovyBeanDefinitionReader(registry);
}
this.scanner = new ClassPathBeanDefinitionScanner(registry);
this.scanner.addExcludeFilter(new ClassExcludeFilter(sources));
}
/**
* Set the bean name generator to be used by the underlying readers and scanner.
* @param beanNameGenerator the bean name generator
*/
void setBeanNameGenerator(BeanNameGenerator beanNameGenerator) {
this.annotatedReader.setBeanNameGenerator(beanNameGenerator);
this.xmlReader.setBeanNameGenerator(beanNameGenerator);
this.scanner.setBeanNameGenerator(beanNameGenerator);
}
/**
* Set the resource loader to be used by the underlying readers and scanner.
* @param resourceLoader the resource loader
*/
void setResourceLoader(ResourceLoader resourceLoader) {
this.resourceLoader = resourceLoader;
this.xmlReader.setResourceLoader(resourceLoader);
this.scanner.setResourceLoader(resourceLoader);
}
/**
* Set the environment to be used by the underlying readers and scanner.
* @param environment the environment
*/
void setEnvironment(ConfigurableEnvironment environment) {
this.annotatedReader.setEnvironment(environment);
this.xmlReader.setEnvironment(environment);
this.scanner.setEnvironment(environment);
}
/**
* Load the sources into the reader.
* @return the number of loaded beans
*/
int load() {
int count = 0;
for (Object source : this.sources) {
count += load(source);
}
return count;
}
private int load(Object source) {
Assert.notNull(source, "Source must not be null");
if (source instanceof Class) {
return load((Class) source);
}
if (source instanceof Resource) {
return load((Resource) source);
}
if (source instanceof Package) {
return load((Package) source);
}
if (source instanceof CharSequence) {
return load((CharSequence) source);
}
throw new IllegalArgumentException("Invalid source type " + source.getClass());
}
private int load(Class source) {
if (isGroovyPresent() && GroovyBeanDefinitionSource.class.isAssignableFrom(source)) {
// Any GroovyLoaders added in beans{} DSL can contribute beans here
GroovyBeanDefinitionSource loader = BeanUtils.instantiateClass(source, GroovyBeanDefinitionSource.class);
load(loader);
}
if (isComponent(source)) {
this.annotatedReader.register(source);
return 1;
}
return 0;
}
private int load(GroovyBeanDefinitionSource source) {
int before = this.xmlReader.getRegistry().getBeanDefinitionCount();
((GroovyBeanDefinitionReader) this.groovyReader).beans(source.getBeans());
int after = this.xmlReader.getRegistry().getBeanDefinitionCount();
return after - before;
}
private int load(Resource source) {
if (source.getFilename().endsWith(".groovy")) {
if (this.groovyReader == null) {
throw new BeanDefinitionStoreException("Cannot load Groovy beans without Groovy on classpath");
}
return this.groovyReader.loadBeanDefinitions(source);
}
return this.xmlReader.loadBeanDefinitions(source);
}
private int load(Package source) {
return this.scanner.scan(source.getName());
}
private int load(CharSequence source) {
String resolvedSource = this.xmlReader.getEnvironment().resolvePlaceholders(source.toString());
// Attempt as a Class
try {
return load(ClassUtils.forName(resolvedSource, null));
}
catch (IllegalArgumentException | ClassNotFoundException ex) {
// swallow exception and continue
}
// Attempt as resources
Resource[] resources = findResources(resolvedSource);
int loadCount = 0;
boolean atLeastOneResourceExists = false;
for (Resource resource : resources) {
if (isLoadCandidate(resource)) {
atLeastOneResourceExists = true;
loadCount += load(resource);
}
}
if (atLeastOneResourceExists) {
return loadCount;
}
// Attempt as package
Package packageResource = findPackage(resolvedSource);
if (packageResource != null) {
return load(packageResource);
}
throw new IllegalArgumentException("Invalid source '" + resolvedSource + "'");
}
private boolean isGroovyPresent() {
return ClassUtils.isPresent("groovy.lang.MetaClass", null);
}
private Resource[] findResources(String source) {
ResourceLoader loader = (this.resourceLoader != null) ? this.resourceLoader
: new PathMatchingResourcePatternResolver();
try {
if (loader instanceof ResourcePatternResolver) {
return ((ResourcePatternResolver) loader).getResources(source);
}
return new Resource[] { loader.getResource(source) };
}
catch (IOException ex) {
throw new IllegalStateException("Error reading source '" + source + "'");
}
}
private boolean isLoadCandidate(Resource resource) {
if (resource == null || !resource.exists()) {
return false;
}
if (resource instanceof ClassPathResource) {
// A simple package without a '.' may accidentally get loaded as an XML
// document if we're not careful. The result of getInputStream() will be
// a file list of the package content. We double check here that it's not
// actually a package.
String path = ((ClassPathResource) resource).getPath();
if (path.indexOf('.') == -1) {
try {
return Package.getPackage(path) == null;
}
catch (Exception ex) {
// Ignore
}
}
}
return true;
}
private Package findPackage(CharSequence source) {
Package pkg = Package.getPackage(source.toString());
if (pkg != null) {
return pkg;
}
try {
// Attempt to find a class in this package
ResourcePatternResolver resolver = new PathMatchingResourcePatternResolver(getClass().getClassLoader());
Resource[] resources = resolver
.getResources(ClassUtils.convertClassNameToResourcePath(source.toString()) + "/*.class");
for (Resource resource : resources) {
String className = StringUtils.stripFilenameExtension(resource.getFilename());
load(Class.forName(source.toString() + "." + className));
break;
}
}
catch (Exception ex) {
// swallow exception and continue
}
return Package.getPackage(source.toString());
}
private boolean isComponent(Class type) {
// This has to be a bit of a guess. The only way to be sure that this type is
// eligible is to make a bean definition out of it and try to instantiate it.
if (MergedAnnotations.from(type, SearchStrategy.TYPE_HIERARCHY).isPresent(Component.class)) {
return true;
}
// Nested anonymous classes are not eligible for registration, nor are groovy
// closures
return !type.getName().matches(".*\\$_.*closure.*") && !type.isAnonymousClass()
&& type.getConstructors() != null && type.getConstructors().length != 0;
}
/**
* Simple {@link TypeFilter} used to ensure that specified {@link Class} sources are
* not accidentally re-added during scanning.
*/
private static class ClassExcludeFilter extends AbstractTypeHierarchyTraversingFilter {
private final Set classNames = new HashSet<>();
ClassExcludeFilter(Object... sources) {
super(false, false);
for (Object source : sources) {
if (source instanceof Class) {
this.classNames.add(((Class) source).getName());
}
}
}
@Override
protected boolean matchClassName(String className) {
return this.classNames.contains(className);
}
}
/**
* Source for Bean definitions defined in Groovy.
*/
@FunctionalInterface
protected interface GroovyBeanDefinitionSource {
Closure getBeans();
}
}