Create Class objects from an Array of File Objects

Question

Hi There,
I'm having extreme difficulty in trying to convert an array of file objects to Class objects. My problem is as follows: I'm using Jfilechooser to select a directory and get an array of files of which are all .class files. I want to create Class objects from these .class files. Therefore, i can extract all the constructor, method and field information. I eventually want this class information to display in a JTree. Very similar to the explorer used in Netbeans. I've already created some code below, but it seems to be throwing a NoSuchMethodError exception. Can anyone please help??
Thanks in advance,
Vikash
/* the following is the class im using */
class FileClassLoader extends ClassLoader {
private File file;
public FileClassLoader (File ff) {
this.file = ff;
protected synchronized Class loadClass() throws ClassNotFoundException {
Class c = null;
try {
// Get size of class file
int size = (int)file.length();
// Reserve space to read
byte buff[] = new byte[size];
// Get stream to read from
FileInputStream fis = new FileInputStream(file);
DataInputStream dis = new DataInputStream (fis);
// Read in data
dis.readFully (buff);
// close stream
dis.close();
// get class name and remove ".class"
String classname = null;
String filename = file.getName();
int i = filename.lastIndexOf('.');
if(i>0 && i<filename.length()-1) {
classname = filename.substring(0,i);
// create class object from bytes
c = defineClass (classname, buff, 0, buff.length);
resolveClass (c);
} catch (java.io.IOException e) {
e.printStackTrace();
return c;
} // end of method loadClass
} // end of class FileClassLoader
/* The above class is used in the following button action in my gui */
/* At the moment im trying to output the data to standard output */
private void SelectPackage_but2ActionPerformed(java.awt.event.ActionEvent evt) {
final JFileChooser f = new JFileChooser();
f.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
int rVal = f.showOpenDialog(Remedy.this);
// selects directory
File dir = f.getSelectedFile();
// gets a list of files within the directory
File[] allfiles = dir.listFiles();
// for loop to filter out all the .class files
for (int k=0; k < allfiles.length; k++) {
if (allfiles[k].getName().endsWith(".class")) {
try {
System.out.println("File name: " + allfiles[k].getName()); // used for debugging
FileClassLoader loader = new FileClassLoader(allfiles[k]);
Class cl = loader.loadClass();
//Class cl = null;
Class[] interfaces = cl.getInterfaces();
java.lang.reflect.Method[] methods = cl.getDeclaredMethods();
java.lang.reflect.Field[] fields = cl.getDeclaredFields();
System.out.println("Class Name: " + cl.getName());
//print out methods
for (int m=0; m < methods.length; m++) {
System.out.println("Method: " + methods[m].getName());
// print out fields
for (int fld=0; fld < fields.length; fld++) {
System.out.println("Field: " + fields[fld].getName());
} catch (Exception e) {
e.printStackTrace();
} // end of if loop
} // end of for loop
packageName2.setText(dir.getPath());
}

Answer 1

It's throwing the exeption on the line:
FileClassLoader loader = new FileClassLoader(allfiles[k]);
I'm sure its something to do with the extended class i've created. but i cant seem to figure it out..
Thanks if you can figure it out