关于支付集成，请求后端是怎么签名 - JAVA

最近也是集成H5移动端的支付功能，但是不清楚后台是如何签名。
支付宝官网上自用的是wap支付，不知道什么地方有问题。

官网案例：http://demo.dcloud.net.cn/helloh5/payment/alipay.php?total=
这个URL返回的是：

service="mobile.securitypay.pay"&partner="2088801273866834"&_input_charset="UTF-8"&out_trade_no="20170508074253"&subject="DCloud项目捐赠"&payment_type="1"&seller_id="payservice@dcloud.io"&total_fee="10"&body="DCloud致力于打造HTML5最好的移动开发工具，包括终端的Runtime、云端的服务和IDE，同时提供各项配套的开发者服务。"&it_b_pay="1d"&notify_url="http%3A%2F%2Fdemo.dcloud.net.cn%2Fhelloh5%2Fpayment%2Fnotify.php"&show_url="http%3A%2F%2Fdemo.dcloud.net.cn%2Fhelloh5%2Fpayment%2F"&sign="WHr5p2AN1km754Q95%2BCPPdAXmJzGJN4llbSRk3CPQSqa%2FXgUfLVeSlzT8Cg2f0ReXoMDGFrhybRJeVs31YGes47LLPRL3%2F%2BmbGlX9sQVVqijE%2B2eThFJjdly9WH9WcsHp9iYmxTMjsHnvejFvVy3USVU1CpFW6ZLC8i3xPy9kzw%3D"&sign_type="RSA"

而我自己调用的环境是：

<form name="punchout_form" method="post" action="https://openapi.alipay.com/gateway.do?charset=UTF-8&method=alipay.trade.wap.pay&sign=UgYeeElAppSMXNveYZa0V%2BiIZrYcxJFgufKp7pTgmaomvIG4mgYpn1cGpLILXou1QWJ872h2WM%2FpNBI0SMbZsJQkkSd%2B6MR03tTNLRWrWILzTbTCGr9G1X7q5A6aVOLAe%2Bza43iO7nubI%2FOkMcR1VksOeyri2pb1upB3X40DdPs%3D&return_url=http%3A%2F%2Fmineibox.eicp.net%2Fyctm%2Fwallet%2Fpaycpt.do&notify_url=http%3A%2F%2Fmineibox.eicp.net%2Fyctm%2Fwallet%2Fpaycpt.do&version=1.0&app_id=2088512319466625&sign_type=RSA2&timestamp=2017-05-08+16%3A13%3A37&alipay_sdk=alipay-sdk-java-dynamicVersionNo&format=json"><input type="hidden" name="biz_content" value="{&quot;body&quot;:&quot;在线充值金币&quot;,&quot;out_trade_no&quot;:&quot;201758161229238&quot;,&quot;product_code&quot;:&quot;QUICK_WAP_PAY&quot;,&quot;subject&quot;:&quot;充值&quot;,&quot;timeout_express&quot;:&quot;2m&quot;,&quot;total_amount&quot;:&quot;1.00&quot;}"><input type="submit" value="立即支付" style="display:none" ></form><script>document.forms[0].submit();</script>

发现确实有问题，希望有大牛能帮帮忙。
多谢多谢