private static boolean isSingleType(final String parameterType) {
        return parameterType.startsWith("java");
    }
is single type.<br>
single type is package[java.xxx or [Ljava.xxx]

@param parameterType parameter type.
@return type is single type
shenyu-plugin/shenyu-plugin-proxy/shenyu-plugin-rpc/shenyu-plugin-sofa/src/main/java/org/apache/shenyu/plugin/sofa/param/SofaParamResolveServiceImpl.java