very very fast implementation of a converter Java -> Python class

tito · tito · commit dc4064f2033f · 2012-08-13T13:47:36.000+02:00
diff --git a/distribute.sh b/distribute.sh
@@ -525,6 +525,7 @@ function run_distribute() {
 	try cp -a $SRC_PATH/default.properties .
 	try cp -a $SRC_PATH/local.properties .
 	try cp -a $SRC_PATH/build.py .
+	try cp -a $SRC_PATH/java2python.py .
 	try cp -a $SRC_PATH/buildlib .
 	try cp -a $SRC_PATH/src .
 	try cp -a $SRC_PATH/templates .
diff --git a/src/java2python.py b/src/java2python.py
@@ -0,0 +1,102 @@
+import sys
+import subprocess
+
+def parse_signature(java, jni):
+    if not jni.startswith('  Signature: '):
+        print 'invalid signature'
+        return
+    jni = jni[13:]
+    javas = java.split()
+
+    if javas[0] in ('public', 'private', 'protected'):
+        javas.pop(0)
+
+    is_static = False
+    if javas[0] == 'static':
+        javas.pop(0)
+        is_static = True
+
+    if jni[0] == '(':
+        if javas[0][0] == '{':
+            return
+        if javas[0] in ('public', 'private', 'protected'):
+            javas.pop(0)
+        # method
+        if '(' in javas[0]:
+            # constructor
+            return ('constructor', '', jni)
+        else:
+            javas.pop(0)
+        name = javas[0].split('(')[0]
+        if is_static:
+            return ('staticmethod', name, jni)
+        return ('method', name, jni)
+    else:
+        # field
+        if javas[0] in ('public', 'private', 'protected'):
+            javas.pop(0)
+        name = javas[1].split(';')[0]
+        if is_static:
+            return ('staticfield', name, jni)
+        return ('field', name, jni)
+
+def parse(filename):
+    cmd = subprocess.Popen(['javap', '-s', filename], stdout=subprocess.PIPE)
+    stdout = cmd.communicate()[0]
+    lines = stdout.splitlines()[1:]
+
+    line = lines.pop(0)
+    if not line.startswith('public class') and not line.startswith('class'):
+        print '-> not a public class, exit.'
+        return []
+
+    javaclass = line[13:].split('{')[0].split(' ')[0]
+    pythonclass = javaclass.rsplit('.')[-1]
+
+    members = []
+    while len(lines) > 2:
+        javasignature = lines.pop(0)
+        jnisignature = lines.pop(0)
+        member = parse_signature(javasignature, jnisignature)
+        if member is None:
+            continue
+        members.append(member)
+
+    return (javaclass, pythonclass, members)
+
+
+def generate(defs):
+    javaclass, pythonclass, members = defs
+    output = '''
+from java import MetaJavaClass, JavaClass, JavaMethod, \\
+        JavaStaticMethod, JavaField, JavaStaticField
+
+class {0!r}(JavaClass):
+    __metaclass__ = MetaJavaClass
+    __javaclass__ = '{1!r}'
+
+'''.format(pythonclass, javaclass)
+
+    pyclasses = {
+            'method': 'JavaMethod',
+            'staticmethod': 'JavaStaticMethod',
+            'field': 'JavaField',
+            'staticfield': 'JavaStaticField' }
+
+    for member in members:
+        tp, name, sig = member
+        if tp == 'constructor':
+            output += '    __javaconstructor__ = {0!r}\n'.format(sig)
+            continue
+        cls = pyclasses[tp]
+        output += '    {0} = {1}({2!r})\n'.format(name, cls, sig)
+
+    return output
+
+
+
+if __name__ == '__main__':
+    filename = sys.argv[1]
+    if filename.endswith('.class'):
+        filename = filename[:-6]
+    print generate(parse(filename))
