public List<String> getAllClassesInJarFile(String fileName) {
JarFile jarFile;
ArrayList<String> list = new ArrayList<String>();
try {
jarFile = new JarFile(fileName);
Enumeration<JarEntry> enums = jarFile.entries();
while (enums.hasMoreElements()) {
JarEntry jarEntry = enums.nextElement();
String entryName = jarEntry.getName();
if (!jarEntry.isDirectory() && entryName.endsWith(".class")) {
StringBuilder className = new StringBuilder();
for (String part : jarEntry.getName().split("/")) {
if (className.length() != 0)
className.append(".");
className.append(part);
if (part.endsWith(".class"))
className.setLength(className.length()
- ".class".length());
}
list.add(className.toString());
}
}
jarFile.close();
} catch (IOException e) {
e.printStackTrace();
}
return list;
}
This function can be connected with the other one, which checks if the class implement the specific interface:
@SuppressWarnings({ "rawtypes", "unchecked" })
public List<String> getAllClassesImplementingInterface(String fileName,
Class interf) {
List<String> listOfClassesToCheck = getAllClassesInJarFile(fileName);
List<String> listOfClasses = new ArrayList<String>();
File file = new File(fileName);
URL fileURL;
URLClassLoader ucl = null;
try {
fileURL = file.toURI().toURL();
String jarURL = "jar:" + fileURL + "!/";
URL urls[] = { new URL(jarURL) };
ucl = new URLClassLoader(urls);
} catch (MalformedURLException e1) {
e1.printStackTrace();
}
for (String className : listOfClassesToCheck) {
Class<?> c;
try {
c = Class.forName(className, true, ucl);
if (interf.isAssignableFrom(c)) {
listOfClasses.add(c.getName());
}
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SecurityException e) {
e.printStackTrace();
}
}
return listOfClasses;
}
