获取jar包中某一目录下实现了接口的所有类

  最近要写一个获取所有实现了Runnable接口的类，然而写完后发现项目没打包成可运行jar包时可以正常运行，一旦打包后就无法运行了。经过资料搜索，自己实现了一个。代码如下：

import java.io.File;import java.io.IOException;import java.util.ArrayList;import java.util.Enumeration;import java.util.List;import java.util.jar.JarEntry;import java.util.jar.JarFile;import lombok.extern.log4j.Log4j;@SuppressWarnings("unchecked")@Log4jpublic class ClassUtils {public static List<Class> getAllImplClassesByInterface(Class c,String packageName) {List<Class> returnClassList = new ArrayList<Class>();if (c.isInterface()) {// 判断是否是接口try {List<Class> allClass = getClassesByPackageName(packageName);// 根据jar包中某一目录获取该目录下所有类for (int i = 0; i < allClass.size(); i++) {if (c.isAssignableFrom(allClass.get(i))) {// (自身类.class).isAssignableFrom(自身类或子类.class)if (!c.equals(allClass.get(i))) {returnClassList.add(allClass.get(i));}}}} catch (ClassNotFoundException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();}}return returnClassList;}private static List<Class> getClassesByPackageName(String packageName)throws IOException, ClassNotFoundException {File file = new File(System.getProperty("user.dir"));String path = file.getAbsolutePath();// 当前目录下绝对路径JarFile jarFile = new JarFile(path + "/MySpider_News.jar");// 要获取的jar包Enumeration<JarEntry> entrys = jarFile.entries();List<Class> classes = new ArrayList<Class>();while (entrys.hasMoreElements()) {JarEntry jarEntry = entrys.nextElement();if (jarEntry.getName().endsWith(".class")) {if (jarEntry.getName().contains("$"))continue;String className = jarEntry.getName().substring(0,jarEntry.getName().length() - 6).replaceAll("/", ".");if (className.contains(packageName))classes.add(Class.forName(className));}}return classes;}}