Add script to find duplicate classes across JARs

This commit is dedicated to Phillip Hanslovsky.

Author: ctrueden

find-duplicate-classes.py

@@ -0,0 +1,42 @@
+#!/bin/env python
+
+import os, subprocess
+
+def extract_classes(f):
+    lines = subprocess.check_output(['jar', 'tf', f]).split()
+    result = set()
+    for line in lines:
+        v = line.decode('utf-8').strip()
+        if v.endswith('.class'):
+            result.add(v)
+    return result
+
+print('Reading JAR files... ', end='', flush=True)
+paths = []
+for root, dirs, files in os.walk("."):
+   for name in files:
+       if not name.lower().endswith('.jar'): continue
+       paths.append(os.path.join(root, name))
+
+classes = {}
+count = 0
+perc = ''
+for path in paths:
+    count += 1
+    classes[path] = extract_classes(path)
+    print('\b' * len(perc), end='')
+    perc = str(round(100 * count / len(paths))) + '%    '
+    print(perc, end='', flush=True)
+
+exceptions = ['module-info.class']
+print('Scanning for duplicate classes..')
+for jar1 in classes:
+    for jar2 in classes:
+        if jar1 == jar2: continue
+        dups = classes[jar1].intersection(classes[jar2])
+        for exc in exceptions:
+            if exc in dups: dups.remove(exc)
+        if len(dups) > 0:
+            print(f'==> {jar1} and {jar2} have duplicates! E.g. {next(iter(dups))}')
+
+print('Done!')