其实native动态支付就是调用微信的统一支付接口，在传trade_type时值为NATIVE即可。参考下个类。

package com.wingo.action.config;

import java.util.Map;
import java.util.SortedMap;
import java.util.TreeMap;

import com.wingo.util.CommonUtil;
import com.wingo.util.ConfigUtil;
import com.wingo.util.PayCommonUtil;
import com.wingo.util.XMLUtil;

/**
*
* @author 李欣桦
* @date 2015-1-5下午4:02:48
*
* 动态native支付
*/
public class NativeAction {
public static void main(String[] args) throws Exception {
SortedMap parameters = new TreeMap();
parameters.put(appid, ConfigUtil.APPID);
parameters.put(mch_id, ConfigUtil.MCH_ID);
parameters.put(nonce_str, PayCommonUtil.CreateNoncestr());
parameters.put(body, LEO测试NATIVE支付);
parameters.put(out_trade_no, 20140107001);
parameters.put(total_fee, 1);
parameters.put(spbill_create_ip,127.0.0.1);
parameters.put(notify_url, ConfigUtil.NOTIFY_URL);//支付成功后回调的action，与JSAPI相同
parameters.put(trade_type, NATIVE);
parameters.put(product_id, No.20140105003);//商品号要唯一
String sign = PayCommonUtil.createSign(UTF-8, parameters);
parameters.put(sign, sign);
String requestXML = PayCommonUtil.getRequestXml(parameters);
String result =CommonUtil.httpsRequest(ConfigUtil.UNIFIED_ORDER_URL, POST, requestXML);
System.out.println(result);
Map map = XMLUtil.doXMLParse(result);
String returnCode = map.get(return_code);
String resultCode = map.get(result_code);
if(returnCode.equalsIgnoreCase(SUCCESS)&&resultCode.equalsIgnoreCase(SUCCESS)){
String codeUrl = map.get(code_url);
//TODO 拿到codeUrl，写代码生成二维码
System.out.println(codeUrl=+codeUrl);
}
}
}