public Method getJavaMethod(Class<?> clazz, String methodName, Class... parameterTypes) {
        String clazzName = clazz.getName();
        String methodKey = buildMethodKey(clazzName, methodName, parameterTypes);

        Method method = methodCache.get(methodKey);
        if (null == method) {
            getFastClass(clazz);// 分析一次clazz,这时会跟新methodCache
            return methodCache.get(methodKey);
        } else {
            return method;
        }
    }
public Method getJavaMethod ( Class < ? > clazz , String methodName , Class ... parameterTypes ) { String clazzName = clazz . getName ( ) ; String methodKey = buildMethodKey ( clazzName , methodName , parameterTypes ) ; Method method = methodCache . get ( methodKey ) ; if ( null == method ) { getFastClass ( clazz ) ; return methodCache . get ( methodKey ) ; } else { return method ; } }
根据信息查询Method，已经有cache实现。

@param clazz
@param methodName
@param parameterTypes
@return