jsapi微信支付v3版

请看清楚你的微信支付是v2还是v3，在这里整理的是v3的，v2的同学请忽略！

前期准备需要用的是商户证书，用的是p12的，设置api密钥(在微信商户端中设置)，还需要在微信公众号中设置jsapi授权目录；
1.微信授权获取用户openid
<a href="https://open.weixin.qq.com/connect/oauth2/authorize?appid=你的微信公众号appid&redirect_uri=授权完回调你的url&response_type=code&scope=snsapi_userinfo&state=1#wechat_redirect">点击测试</a>
2.授权回调接口，在接口中解析获取用户openid，如果已经授权的过的，我是通过解析获取到code然后再请求微信得到openid https://api.weixin.qq.com/sns/oauth2/access_token?appid=你的微信公众号appid&secret="+appsecret+"&code="+code+"&grant_type=authorization_code 3.用户下单提交，分两步，第一步通过统一下单接口获取prepay_id，第二步提交微信支付
前端代码：根据获取的openid提交后端

function wxpayCommit(){
$.ajax({
type : "POST",
url : "/wxpayCommit",
data :"openid=${openid}",
dataType : "json",
async : false,
success : function(obj) {

if(obj.prepay_id ==""){
return;
}

WeixinJSBridge.invoke('getBrandWCPayRequest',{
"appId" : obj.appid,
"timeStamp":obj.timeStamp,
"nonceStr" : obj.nonceStr,
"package" : "prepay_id="+obj.prepay_id,
"signType" : "MD5",
"paySign" : obj.paySign
},function(res){
alert(res.err_msg);
if(res.err_msg == "get_brand_wcpay_request:ok" ) {
window.location.href="/index";
}else{
alert("fail");
window.location.href="/wxpayCommit";

}
});
},
error : function(msg) {
alert("fail");

}
});

//统一下单接口获取prepay_id

注意中间遇到签名错误，是你的sign有问题，最好办法在微信官网在线生成签名的比对一样，马上找到错误

SortedMap<String, String> packageParams = new TreeMap<String, String>();
packageParams.put("appid", TenpayConfig.appid);
packageParams.put("mch_id", TenpayConfig.partner);
packageParams.put("nonce_str", WXUtil.getNonceStr());
packageParams.put("body", "测试");
packageParams.put("out_trade_no", 你的唯一订单号);
packageParams.put("total_fee","1"); 	  //银行币种
packageParams.put("spbill_create_ip",  request.remoteAddress); //订单生成的机器IP，指用户浏览器端IP
packageParams.put("notify_url", 回调的url);
packageParams.put("openid", openid);
packageParams.put("trade_type", "JSAPI");

RequestHandler reqHandler = new RequestHandler(null, null);
reqHandler.init(TenpayConfig.appid, TenpayConfig.appsecret, TenpayConfig.partnerkey);
String sign = reqHandler.createSign(packageParams);
packageParams.put("sign", sign);
String xml = toXml(packageParams);
String prepay_id = "";
String createOrderURL = "https://api.mch.weixin.qq.com/pay/unifiedorder";

//获取用户的
prepay_id = new GetWxOrderno().getPayNo2(createOrderURL, xml);
//生成paysign
SortedMap<String, String> payParams = new TreeMap<String, String>();
String non = WXUtil.getNonceStr();
String time = WXUtil.getTimeStamp();
payParams.put("appId", TenpayConfig.appid);
payParams.put("nonceStr", non);
payParams.put("timeStamp", time);
payParams.put("package", "prepay_id="+prepay_id);
payParams.put("signType", "MD5");
String paysign = reqHandler.createSign(payParams);

附上其他代码

public static String getNonceStr() {
Random random = new Random();
return MD5Util.MD5Encode(String.valueOf(random.nextInt(10000)),"GBK");
}

public static String getTimeStamp() {
return String.valueOf(System.currentTimeMillis() / 1000);
}

public static String getMchBillno(Stringmchid) {
SimpleDateFormat shortSdf =new SimpleDateFormat("yyyyMMdd");
String result = mchid+shortSdf.format(new Date())+String.valueOf(System.currentTimeMillis() / 1000);
returnresult;
}

public String createSign(SortedMap<String, String>packageParams) {
StringBuffer sb =new StringBuffer();
Set es = packageParams.entrySet();
Iterator it = es.iterator();
while (it.hasNext()) {
Map.Entry entry = (Map.Entry)it.next();
String k = (String)entry.getKey();
String v = (String)entry.getValue();
if (null !=v && !"".equals(v) && !"sign".equals(k)
&& !"key".equals(k)) {
sb.append(k +"=" +v +"&");
}
}
sb.append("key=" +this.getKey());//api密钥
String sign = MD5Util.MD5Encode(sb.toString(),this.charset)
.toUpperCase();
returnsign;
}

private static String toXml(SortedMap<String, String>params)
{
StringBuilder sb = new StringBuilder();
sb.append("<xml>");

for (Map.Entry<String, String>e :params.entrySet())
{
sb.append("<" +e.getKey() +">");
sb.append(e.getValue());
sb.append("</" +e.getKey() +">");
}
sb.append("</xml>");
returnsb.toString();
}

public static String getPayNo2(Stringurl,StringxmlParam)throws Exception{
KeyStore keyStore  = KeyStore.getInstance("PKCS12");
String prepay_id = "";
FileInputStream instream = new FileInputStream(new File("p12的证书路径"));
try {
keyStore.load(instream, TenpayConfig.partner.toCharArray());
} finally {
instream.close();
}
// Trust own CA and all self-signed certs
SSLContext sslcontext = SSLContexts.custom()
.loadKeyMaterial(keyStore, TenpayConfig.partner.toCharArray())
.build();
// Allow TLSv1 protocol only
SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory(
sslcontext,
new String[] { "TLSv1" },
null,
SSLConnectionSocketFactory.BROWSER_COMPATIBLE_HOSTNAME_VERIFIER);
CloseableHttpClient httpclient = HttpClients.custom()
.setSSLSocketFactory(sslsf)
.build();
try {
HttpPost httpost= HttpClientConnectionManager.getPostMethod(url);
httpost.setEntity(new StringEntity(xmlParam,"UTF-8"));
HttpResponse response = httpclient.execute(httpost);
String jsonStr = EntityUtils.toString(response.getEntity(),"UTF-8");
if(jsonStr.indexOf("FAIL")!=-1){
return "2";
}
Map map = doXMLParse(jsonStr);
prepay_id  = (String) map.get("prepay_id");
} finally {
httpclient.close();
}
returnprepay_id;
}