查找同一包下实现了接口的所有的类

package com.cbf4file;

import java.io.File;
import java.io.IOException;
import java.net.URL;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.List;

public class ClassUtils {


public static List<Class> getAllClassByInterface(Class c){
List<Class> returnClassList = new ArrayList<Class>();

if(c.isInterface()){
String packageName = c.getPackage().getName();
try{
List<Class> allClass = getClasses(packageName);
for(int i=0; i<allClass.size(); i++){
if(c.isAssignableFrom(allClass.get(i))){
if(!c.equals(allClass.get(i))){
returnClassList.add(allClass.get(i));
}
}
}
}catch(ClassNotFoundException e){
e.printStackTrace();
}catch(IOException e){
e.printStackTrace();
}
}
return returnClassList;
}





public static List<Class> getClasses(String packageName) throws ClassNotFoundException,IOException{

ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
String path = packageName.replace(".", "/");

Enumeration<URL> resources = classLoader.getResources(path);
List<File> dirs = new ArrayList<File>();
while(resources.hasMoreElements()){
URL resource = resources.nextElement();
dirs.add(new File(resource.getFile()));
}
ArrayList<Class> classes = new ArrayList<Class>();
for(File directory :dirs){
classes.addAll(findClasses(directory,packageName));
}
return classes;
}

private static List<Class> findClasses(File directory,String packageName) throws ClassNotFoundException{

List<Class> classes = new ArrayList<Class>();
if(!directory.exists()){
return classes;
}

File[] files = directory.listFiles();
for(File file : files){
if(file.isDirectory()){
assert !file.getName().contains(".");
classes.addAll(findClasses(file,packageName+"."+file.getName()));
}else if(file.getName().endsWith(".class")){
classes.add(Class.forName(packageName+"."+file.getName().substring(0,file.getName().length() -6)));
}
}
return classes;
}

}