Merge pull request #271 from InvalidCo/list_getitem_indexerror

for...in iteration of list interfaces

jnius/reflect.py

@@ -7,7 +7,8 @@
 
 from .jnius import (
     JavaClass, MetaJavaClass, JavaMethod, JavaStaticMethod,
-    JavaField, JavaStaticField, JavaMultipleMethod, find_javaclass
+    JavaField, JavaStaticField, JavaMultipleMethod, find_javaclass,
+    JavaException
 )
 
 
@@ -218,9 +219,22 @@ def autoclass(clsname):
 
         classDict[name] = JavaMultipleMethod(signatures)
 
+    def _getitem(self, index):
+        try:
+            return self.get(index)
+        except JavaException as e:
+            # initialize the subclass before getting the Class.forName
+            # otherwise isInstance does not know of the subclass
+            mock_exception_object = autoclass(e.classname)()
+            if Class.forName("java.lang.IndexOutOfBoundsException").isInstance(mock_exception_object):
+                # python for...in iteration checks for end of list by waiting for IndexError
+                raise IndexError()
+            else:
+                raise
+
     for iclass in c.getInterfaces():
         if iclass.getName() == 'java.util.List':
-            classDict['__getitem__'] = lambda self, index: self.get(index)
+            classDict['__getitem__'] = _getitem
             classDict['__len__'] = lambda self: self.size()
             break
 

tests/test_reflect.py

@@ -14,3 +14,10 @@ def test_stack(self):
         stack.push('world')
         self.assertEqual(stack.pop(), 'world')
         self.assertEqual(stack.pop(), 'hello')
+
+    def test_list_iteration(self):
+        ArrayList = autoclass('java.util.ArrayList')
+        words = ArrayList()
+        words.add('hello')
+        words.add('world')
+        self.assertEqual(['hello', 'world'], [word for word in words])