IllegalArgumentException：参数数量错误

Question

I got IllegalArgumentException: wrong number of arguments when I call method.invoke() and I am using EasyMock. In my code invoke() has only one argument.

Code:

 if (applicationContext != null
                && applicationContext.containsBean(className)) {
            Object obj = applicationContext.getBean(className);
            String temp[] = signature.split(",");
            Object[] arguments = new Object[temp.length];
            Class[] parameterTypes = new Class[temp.length];

            for (int i = 0; i < temp.length; i++) {
                if(temp[i] != null && !temp[i].isEmpty()) {
                Class cls = Class.forName(temp[i]);
                parameterTypes[i] = cls;
                if (temp[i].startsWith("java.lang.")) {
                    arguments[i] = body[i];
                } else {
                    try {
                        arguments[i] = mapper.readValue(body[i], cls);
                    } catch (Exception e) {
                        // e.printStackTrace();
                        arguments[i] = body[i];
                    }
                }
                }
            }
            Method m = null;
            if(null !=signature && !signature.isEmpty()) {

                m = obj.getClass().getMethod(method, parameterTypes);
            } else {
                m = obj.getClass().getMethod(method);
            }

            Object response = m.invoke(obj);
            return response;
        } else {
            throw new Exception("ApplicationContext not properly set");
        }

EasyMock Test :

 Object obj = new Object();
String[] body ={ "body" };
EasyMock.expect(applicationContext.containsBean("Object")).andReturn(true);
EasyMock.expect(applicationContext.getBean("Object")).andReturn(obj);
EasyMock.replay(applicationContext);

moduleInvocation.invokeService("Object", "equals", "java.lang.Object", "responseType",body );
EasyMock.verify(applicationContext);

Answer 1

You never pass the arguments array into Method#invoke . Your line

Object response = m.invoke(obj);

should be

Object response = m.invoke(obj, arguments);

Answer 2

You need to pass arguments variable in invoke method as per the default signature Method#invoke(obj,args). Please see below link :

http://grepcode.com/file/repository.grepcode.com/java/root/jdk/openjdk/6-b14/java/lang/reflect/Method.java#Method.invoke%28java.lang.Object%2Cjava.lang.Object%5B%5D%29