1.小程序前端获取微信 openId 以及订单号 传给后台
2,后台根据 openId 和订单号进行签名 post 微信统一下单接口
3.后台获取微信返回的xml字符串 解析 二次签名以后返回给前端
4.前端调起支付微信支付 API
二次签名的时候使用 appId nonceStr package signType timeStamp 这五个key生成签名(这里无视微信官方文档 以及注意 appId 的大小写)
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.util.Map;
import java.util.Random;
public class WXPayUtil {
//生成随机字符串
public static String getNonce_str() {
String base = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
Random random = new Random();
StringBuilder sb = new StringBuilder();
for (int i = 0; i < 15; i++) {
int number = random.nextInt(base.length());
sb.append(base.charAt(number));
}
return sb.toString();
}
//map转xml 加上签名信息
public static String map2Xml(Map<String,Object> map) throws UnsupportedEncodingException {
StringBuffer sb = new StringBuffer();
StringBuilder sb2 = new StringBuilder();
sb2.append("");
for (String key : map.keySet()) {
sb.append(key);
sb.append('=');
sb.append(map.get(key));
sb.append('&');
// sb2是用来做请求的xml参数
sb2.append("<" + key + ">");
// sb2.append("<![CDATA[" + map.get(key) + "]]>");
sb2.append(map.get(key));
sb2.append("</" + key + ">");
}
sb.append(System.getenv("signKey"));
String sign = MD5.getMessageDigest(sb.toString().getBytes()).toUpperCase();
sb2.append("");
sb2.append(sign);
sb2.append("");
sb2.append("");
return sb2.toString();
}
//解析微信返回return_code SUCCESS或FILE
//根据微信返回resultXml再次生成签名
public static String getSign(Map<String,Object> map) {
StringBuffer sb = new StringBuffer();
for (String key : map.keySet()) {
sb.append(key);
sb.append('=');
sb.append(map.get(key));
sb.append('&');
}
sb.append(System.getenv("signKey"));
System.out.println("第二次签名内容:" + sb);
System.out.println("第二次签名SING:" + MD5.getMessageDigest(sb.toString().getBytes()).toUpperCase());
return MD5.getMessageDigest(sb.toString().getBytes()).toUpperCase();
}
//解析微信返回return_code SUCCESS或FILE
public static String getReturnCode(String resultXml) {
String nonceStr;
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder builder;
try {
builder = dbf.newDocumentBuilder();
InputStream inputStream = new ByteArrayInputStream(resultXml.getBytes());
org.w3c.dom.Document doc = builder.parse(inputStream); //
// 下面开始读取
org.w3c.dom.Element root = doc.getDocumentElement(); // 获取根元素
NodeList nl = root.getElementsByTagName("return_code");
org.w3c.dom.Element el = (org.w3c.dom.Element) nl.item(0);
org.w3c.dom.Node nd = el.getFirstChild();
nonceStr = nd.getNodeValue();
return nonceStr;
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
//解析微信返回return_msg
public static String getReturn_msg(String resultXml) {
String nonceStr;
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder builder;
try {
builder = dbf.newDocumentBuilder();
InputStream inputStream = new ByteArrayInputStream(resultXml.getBytes());
org.w3c.dom.Document doc = builder.parse(inputStream); //
// 下面开始读取
org.w3c.dom.Element root = doc.getDocumentElement(); // 获取根元素
NodeList nl = root.getElementsByTagName("return_msg");
org.w3c.dom.Element el = (org.w3c.dom.Element) nl.item(0);
org.w3c.dom.Node nd = el.getFirstChild();
nonceStr = nd.getNodeValue();
return nonceStr;
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
//解析微信返回appid
public static String getAppId(String resultXml) {
String nonceStr;
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder builder;
try {
builder = dbf.newDocumentBuilder();
InputStream inputStream = new ByteArrayInputStream(resultXml.getBytes());
org.w3c.dom.Document doc = builder.parse(inputStream); //
// 下面开始读取
org.w3c.dom.Element root = doc.getDocumentElement(); // 获取根元素
NodeList nl = root.getElementsByTagName("appid");
org.w3c.dom.Element el = (org.w3c.dom.Element) nl.item(0);
org.w3c.dom.Node nd = el.getFirstChild();
nonceStr = nd.getNodeValue();
return nonceStr;
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
//解析微信返回mch_id
public static String getMchId(String resultXml) {
String nonceStr;
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder builder;
try {
builder = dbf.newDocumentBuilder();
InputStream inputStream = new ByteArrayInputStream(resultXml.getBytes());
org.w3c.dom.Document doc = builder.parse(inputStream); //
// 下面开始读取
org.w3c.dom.Element root = doc.getDocumentElement(); // 获取根元素
NodeList nl = root.getElementsByTagName("mch_id");
org.w3c.dom.Element el = (org.w3c.dom.Element) nl.item(0);
org.w3c.dom.Node nd = el.getFirstChild();
nonceStr = nd.getNodeValue();
return nonceStr;
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
//解析微信返回nonce_str
public static String getNonceStr(String resultXml) {
String nonceStr;
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder builder;
try {
builder = dbf.newDocumentBuilder();
InputStream inputStream = new ByteArrayInputStream(resultXml.getBytes());
org.w3c.dom.Document doc = builder.parse(inputStream); //
// 下面开始读取
org.w3c.dom.Element root = doc.getDocumentElement(); // 获取根元素
NodeList nl = root.getElementsByTagName("nonce_str");
org.w3c.dom.Element el = (org.w3c.dom.Element) nl.item(0);
org.w3c.dom.Node nd = el.getFirstChild();
nonceStr = nd.getNodeValue();
return nonceStr;
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
//解析微信返回prepay_id
public static String getPrepayId(String resultXml) {
String nonceStr;
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder builder;
try {
builder = dbf.newDocumentBuilder();
InputStream inputStream = new ByteArrayInputStream(resultXml.getBytes());
org.w3c.dom.Document doc = builder.parse(inputStream); //
// 下面开始读取
org.w3c.dom.Element root = doc.getDocumentElement(); // 获取根元素
NodeList nl = root.getElementsByTagName("prepay_id");
org.w3c.dom.Element el = (org.w3c.dom.Element) nl.item(0);
org.w3c.dom.Node nd = el.getFirstChild();
nonceStr = nd.getNodeValue();
return nonceStr;
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
}