java原生
public class AccessingAllClassesInPackage {
public Set<Class> findAllClassesUsingClassLoader(String packageName) {
InputStream stream = ClassLoader.getSystemClassLoader().getResourceAsStream(packageName.replaceAll("[.]", "/"));
BufferedReader reader = new BufferedReader(new InputStreamReader(stream));
return reader.lines()
.filter(line -> line.endsWith(".class"))
.map(line -> getClass(line, packageName))
.collect(Collectors.toSet());
}
private Class getClass(String className, String packageName) {
try {
return Class.forName(packageName + "." + className.substring(0, className.lastIndexOf('.')));
} catch (ClassNotFoundException e) {
// handle the exception
}
return null;
}
}
ImmutableSet<ClassPath.ClassInfo> classes = ClassPath.from(ClassLoader.getSystemClassLoader()).getTopLevelClasses();
for (ClassPath.ClassInfo classInfo : classes) {
Class<?> clss = classInfo.load();
}
Reflections reflections = new Reflections(packageName, new SubTypesScanner(false));
Set<Class> classes = reflections.getSubTypesOf(Object.class)
.stream()
.collect(Collectors.toSet());
spring
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.core.io.support.ResourcePatternResolver;
import org.springframework.core.type.ClassMetadata;
import org.springframework.core.type.classreading.CachingMetadataReaderFactory;
import org.springframework.core.type.classreading.MetadataReaderFactory;
import org.springframework.util.ClassUtils;
private static final ResourcePatternResolver RESOURCE_PATTERN_RESOLVER = new PathMatchingResourcePatternResolver();
private static final MetadataReaderFactory METADATA_READER_FACTORY = new CachingMetadataReaderFactory();
private Set<Class<?>> scanClasses(String packagePatterns, Class<?> assignableType) throws IOException {
Set<Class<?>> classes = new HashSet<>();
String[] packagePatternArray = tokenizeToStringArray(packagePatterns, ConfigurableApplicationContext.CONFIG_LOCATION_DELIMITERS);
for (String packagePattern : packagePatternArray) {
Resource[] resources = RESOURCE_PATTERN_RESOLVER.getResources(ResourcePatternResolver.CLASSPATH_ALL_URL_PREFIX
+ ClassUtils.convertClassNameToResourcePath(packagePattern) + "/**/*.class");
for (Resource resource : resources) {
try {
ClassMetadata classMetadata = METADATA_READER_FACTORY.getMetadataReader(resource).getClassMetadata();
Class<?> clazz = Resources.classForName(classMetadata.getClassName());
if (assignableType == null || assignableType.isAssignableFrom(clazz)) {
classes.add(clazz);
}
} catch (Throwable e) {
LOGGER.warn(() -> "Cannot load the '" + resource + "'. Cause by " + e.toString());
}
}
}
return classes;
}
mybatis
import org.apache.ibatis.io.ResolverUtil;
ResolverUtil<Class<?>> resolverUtil = new ResolverUtil<>();
resolverUtil.find(new ResolverUtil.IsA(TypeHandler.class), packageName);
Set<Class<? extends Class<?>>> handlerSet = resolverUtil.getClasses();
ServiceLoader
ServiceLoader<IMyServiceLoader> serviceLoader = ServiceLoader.load(IMyServiceLoader.class);
for (IMyServiceLoader myServiceLoader : serviceLoader){
System.out.println(myServiceLoader);
}
参考
