com.alibaba.nacos.common.packagescan.DefaultPackageScan Maven / Gradle / Ivy
/*
* Copyright 1999-2018 Alibaba Group Holding Ltd.
*
* 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 com.alibaba.nacos.common.packagescan;
import com.alibaba.nacos.common.packagescan.classreading.ClassReader;
import com.alibaba.nacos.common.packagescan.resource.PathMatchingResourcePatternResolver;
import com.alibaba.nacos.common.packagescan.resource.Resource;
import com.alibaba.nacos.common.packagescan.resource.ResourcePatternResolver;
import com.alibaba.nacos.common.packagescan.util.NestedIoException;
import com.alibaba.nacos.common.utils.ClassUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.IOException;
import java.io.InputStream;
import java.lang.annotation.Annotation;
import java.util.HashSet;
import java.util.Set;
/**
* Scan all appropriate Class object through the package name.
*
* @author hujun
*/
public class DefaultPackageScan implements PackageScan {
protected static final Logger LOGGER = LoggerFactory.getLogger(DefaultPackageScan.class);
private final PathMatchingResourcePatternResolver resourcePatternResolver = new PathMatchingResourcePatternResolver();
public DefaultPackageScan() {
}
/**
* Scan all appropriate Class object through the package name and Class object.
*
* @param pkg package name,for example, com.alibaba.nacos.common
* @param requestClass super class
* @param Class type
* @return a set contains Class
*/
@Override
public Set> getSubTypesOf(String pkg, Class requestClass) {
Set> set = new HashSet<>(16);
String packageSearchPath =
ResourcePatternResolver.CLASSPATH_ALL_URL_PREFIX + ClassUtils.convertClassNameToResourcePath(pkg) + '/'
+ "**/*.class";
try {
Resource[] resources = resourcePatternResolver.getResources(packageSearchPath);
for (Resource resource : resources) {
Class scanClass = getClassByResource(resource);
if (requestClass.isAssignableFrom(scanClass)) {
set.add((Class) scanClass);
}
}
} catch (IOException | ClassNotFoundException e) {
LOGGER.error("scan path: {} failed", packageSearchPath, e);
}
return set;
}
/**
* Scan all appropriate Class object through the package name and annotation.
*
* @param pkg package name,for example, com.alibaba.nacos.common
* @param annotation annotation
* @param Class type
* @return a set contains Class object
*/
@Override
public Set> getTypesAnnotatedWith(String pkg, Class annotation) {
Set> set = new HashSet<>(16);
String packageSearchPath =
ResourcePatternResolver.CLASSPATH_ALL_URL_PREFIX + ClassUtils.convertClassNameToResourcePath(pkg) + '/'
+ "**/*.class";
try {
Resource[] resources = resourcePatternResolver.getResources(packageSearchPath);
for (Resource resource : resources) {
Class scanClass = getClassByResource(resource);
if (scanClass.isAnnotationPresent(annotation)) {
set.add((Class) scanClass);
}
}
} catch (IOException | ClassNotFoundException e) {
LOGGER.error("scan path: {} failed", packageSearchPath, e);
}
return set;
}
private Class getClassByResource(Resource resource) throws IOException, ClassNotFoundException {
String className = getClassReader(resource).getClassName();
return Class.forName(ClassUtils.resourcePathToConvertClassName(className));
}
private static ClassReader getClassReader(Resource resource) throws IOException {
try (InputStream is = resource.getInputStream()) {
try {
return new ClassReader(is);
} catch (IllegalArgumentException ex) {
throw new NestedIoException("ASM ClassReader failed to parse class file - "
+ "probably due to a new Java class file version that isn't supported yet: " + resource, ex);
}
}
}
}