io.vanillabp.springboot.utils.ClasspathScanner Maven / Gradle / Ivy
package io.vanillabp.springboot.utils;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.function.Predicate;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
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.classreading.CachingMetadataReaderFactory;
import org.springframework.core.type.classreading.MetadataReader;
import org.springframework.util.ClassUtils;
import org.springframework.util.SystemPropertyUtils;
public class ClasspathScanner {
private static Logger logger = LoggerFactory.getLogger(ClasspathScanner.class);
private static final Map cache = new HashMap<>();
private ClasspathScanner() {
// static class: hide public constructor
}
private static ResourcePatternResolver getResourcePatternResolver(
final ResourceLoader resourceLoader) {
if (resourceLoader == null) {
return new PathMatchingResourcePatternResolver();
} else {
return new PathMatchingResourcePatternResolver(resourceLoader);
}
}
@SafeVarargs
public static List allResources(
final Predicate... filters) throws Exception {
return allResources(null, null, filters);
}
@SafeVarargs
public static List allResources(
final ResourceLoader resourceLoader,
final Predicate... filters) throws Exception {
return allResources(resourceLoader, null, filters);
}
@SafeVarargs
public static List allResources(
final String basePath,
final Predicate... filters) throws Exception {
return allResources(null, basePath, filters);
}
@SafeVarargs
public static List allResources(
final ResourceLoader resourceLoader,
final String basePath,
final Predicate... filters) throws Exception {
final var searchPath = ResourcePatternResolver.CLASSPATH_ALL_URL_PREFIX
+ (basePath == null ? "" : basePath)
+ "/**/*";
final Resource[] resources;
synchronized (cache) {
final var cachedResources = cache.get(searchPath);
if (cachedResources != null) {
resources = cachedResources;
} else {
resources = getResourcePatternResolver(resourceLoader).getResources(searchPath);
}
}
final List result = new LinkedList<>();
for (final var resource : resources) {
if (resource.isReadable()) {
boolean complies = true;
for (Predicate filter : filters) {
if (!filter.test(resource)) {
complies = false;
break;
}
}
if (complies) {
result.add(resource);
}
}
}
return result;
}
@SafeVarargs
public static List> allClasses(
final String basePackage,
final Predicate... filters) throws Exception {
return allClasses(null, basePackage, filters);
}
@SafeVarargs
public static List> allClasses(
final ResourceLoader resourceLoader,
final String basePackage,
final Predicate... filters) throws Exception {
final var packageSearchPath = ResourcePatternResolver.CLASSPATH_ALL_URL_PREFIX + resolveBasePackage(basePackage)
+ "/**/*.class";
final List> classes = new LinkedList<>();
final var resourcePatternResolver = getResourcePatternResolver(null);
final var metadataReaderFactory = new CachingMetadataReaderFactory(resourcePatternResolver);
final Resource[] resources;
synchronized (cache) {
final var cachedResources = cache.get(packageSearchPath);
if (cachedResources != null) {
resources = cachedResources;
} else {
resources = resourcePatternResolver.getResources(packageSearchPath);
}
}
for (Resource resource : resources) {
if (resource.isReadable()) {
final var metadataReader = metadataReaderFactory.getMetadataReader(resource);
boolean complies = true;
for (Predicate filter : filters) {
if (!filter.test(metadataReader)) {
complies = false;
break;
}
}
if (complies) {
try {
Class c = Class.forName(metadataReader.getClassMetadata().getClassName());
classes.add(c);
} catch (NoClassDefFoundError e) {
logger.debug("NoClassDefFoundError: it might be an optional dependency", e);
}
}
}
}
return classes;
}
private static String resolveBasePackage(final String basePackage) {
return ClassUtils.convertClassNameToResourcePath(SystemPropertyUtils.resolvePlaceholders(basePackage));
}
}