一、java后台
1、maven引入
<!--微信支付-->
<dependency>
<groupId>com.github.wxpay</groupId>
<artifactId>wxpay-sdk</artifactId>
<version>0.0.3</version>
</dependency>
<dependency>
<groupId>org.jdom</groupId>
<artifactId>jdom</artifactId>
<version>2.0.2</version>
</dependency>
2、java代码
WxUtils类
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.HttpClients;
import org.jdom2.Document;
import org.jdom2.Element;
import org.jdom2.JDOMException;
import org.jdom2.input.SAXBuilder;
import org.springframework.stereotype.Component;
import org.springframework.stereotype.Service;
import javax.servlet.http.HttpServletRequest;
import java.io.*;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.*;
@Component
public class WxUtils {
/**
* 执行 POST 方法的 HTTP 请求
*
* @param url
* @param parameters
* @return
* @throws IOException
*/
public String executeHttpPost(String url, SortedMap<String, Object> parameters) throws IOException {
HttpClient client = HttpClients.createDefault();
HttpPost request = new HttpPost(url);
request.setHeader("Content-type", "application/xml");
request.setHeader("Accept", "application/xml");
request.setEntity(new StringEntity(transferMapToXml(parameters), "UTF-8"));
HttpResponse response = client.execute(request);
return readResponse(response);
}
/**
* 第一次签名
*
* @param parameters 数据为服务器生成，下单时必须的字段排序签名
* @param key
* @return
*/
public String createSign(SortedMap<String, Object> parameters, String key) {
StringBuffer sb = new StringBuffer();
Set es = parameters.entrySet();//所有参与传参的参数按照accsii排序（升序）
Iterator it = es.iterator();
while (it.hasNext()) {
Map.Entry entry = (Map.Entry) it.next();
String k = (String) entry.getKey();
Object v = entry.getValue();
if (null != v && !"".equals(v)
&& !"sign".equals(k) && !"key".equals(k)) {
sb.append(k + "=" + v + "&");
}
}
sb.append("key=" + key);
return encodeMD5(sb.toString());
}
/**
* 第二次签名
*
* @param result 数据为微信返回给服务器的数据（XML 的 String），再次签名后传回给客户端（APP）使用
* @param key 密钥
* @return
* @throws IOException
*/
public Map createSign2(String result, String key) throws IOException {
SortedMap<String, Object> map = new TreeMap<>(transferXmlToMap(result));
Map app = new HashMap();
System.out.println(map);
app.put("appId", map.get("appid"));
app.put("nonceStr", map.get("nonce_str"));
app.put("package", "prepay_id="+map.get("prepay_id"));
app.put("signType", "MD5");
app.put("timeStamp",String.valueOf(new Date().getTime() / 1000) ); // 时间为秒，JDK 生成的是毫秒，故除以 1000
app.put("sign", createSign(new TreeMap<>(app), key));
return app;
}
/**
* 验证签名是否正确
*
* @return boolean
* @throws Exception
*/
public boolean checkSign(SortedMap<String, Object> parameters, String key) throws Exception {
String signWx = parameters.get("sign").toString();
if (signWx == null) return false;
parameters.remove("sign"); // 需要去掉原 map 中包含的 sign 字段再进行签名
String signMe = createSign(parameters, key);
return signWx.equals(signMe);
}
/**
* 读取 request body 内容作为字符串
*
* @param request
* @return
* @throws IOException
*/
public String readRequest(HttpServletRequest request) throws IOException {
InputStream inputStream;
StringBuffer sb = new StringBuffer();
inputStream = request.getInputStream();
String str;
BufferedReader in = new BufferedReader(new InputStreamReader(inputStream, "UTF-8"));
while ((str = in.readLine()) != null) {
sb.append(str);
}
in.close();
inputStream.close();
return sb.toString();
}
/**
* 读取 response body 内容为字符串
*/
public String readResponse(HttpResponse response) throws IOException {
BufferedReader in = new BufferedReader(
new InputStreamReader(response.getEntity().getContent()));
String result = new String();
String line;
while ((line = in.readLine()) != null) {
result += line;
}
return result;
}
/**
* 将 Map 转化为 XML
*
* @param map
* @return
*/
public String transferMapToXml(SortedMap<String, Object> map) {
StringBuffer sb = new StringBuffer();
sb.append("<xml>");
for (String key : map.keySet()) {
sb.append("<").append(key).append(">")
.append(map.get(key))
.append("</").append(key).append(">");
}
return sb.append("</xml>").toString();
}
/**
* 将 XML 转化为 map
*
* @param strxml
* @return
* @throws org.jdom2.JDOMException
* @throws IOException
*/
public Map transferXmlToMap(String strxml) throws IOException {
strxml = strxml.replaceFirst("encoding=\".*\"", "encoding=\"UTF-8\"");
if (null == strxml || "".equals(strxml)) {
return null;
}
Map m = new HashMap();
InputStream in = new ByteArrayInputStream(strxml.getBytes("UTF-8"));
SAXBuilder builder = new SAXBuilder();
Document doc = null;
try {
doc = builder.build(in);
} catch (JDOMException e) {
throw new IOException(e.getMessage()); // 统一转化为 IO 异常输出
}
// 解析 DOM
Element root = doc.getRootElement();
List list = root.getChildren();
Iterator it = list.iterator();
while (it.hasNext()) {
Element e = (Element) it.next();
String k = e.getName();
String v = "";
List children = e.getChildren();
if (children.isEmpty()) {
v = e.getTextNormalize();
} else {
v = getChildrenText(children);
}
m.put(k, v);
}
//关闭流
in.close();
return m;
}
// 辅助 transferXmlToMap 方法递归提取子节点数据
private String getChildrenText(List<Element> children) {
StringBuffer sb = new StringBuffer();
if (!children.isEmpty()) {
Iterator<Element> it = children.iterator();
while (it.hasNext()) {
Element e = (Element) it.next();
String name = e.getName();
String value = e.getTextNormalize();
List<Element> list = e.getChildren();
sb.append("<" + name + ">");
if (!list.isEmpty()) {
sb.append(getChildrenText(list));
}
sb.append(value);
sb.append("</" + name + ">");
}
}
return sb.toString();
}
/**
* 生成 32 位随机字符串，包含：数字、字母大小写
*
* @return
*/
public String gen32RandomString() {
char[] dict = {'1', '2', '3', '4', '5', '6', '7', '8', '9', '0',
'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z'};
StringBuffer sb = new StringBuffer();
Random random = new Random();
for (int i = 0; i < 32; i++) {
sb.append(String.valueOf(dict[(int) (Math.random() * 36)]));
}
return sb.toString();
}
/**
* MD5 签名
*
* @param str
* @return 签名后的字符串信息
*/
public String encodeMD5(String str) {
try {
MessageDigest messageDigest = MessageDigest.getInstance("MD5");
byte[] inputByteArray = (str).getBytes();
messageDigest.update(inputByteArray);
byte[] resultByteArray = messageDigest.digest();
return byteArrayToHex(resultByteArray);
} catch (NoSuchAlgorithmException e) {
return null;
}
}
// 辅助 encodeMD5 方法实现
private String byteArrayToHex(byte[] byteArray) {
char[] hexDigits = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};
char[] resultCharArray = new char[byteArray.length * 2];
int index = 0;
for (byte b : byteArray) {
resultCharArray[index++] = hexDigits[b >>> 4 & 0xf];
resultCharArray[index++] = hexDigits[b & 0xf];
}
// 字符数组组合成字符串返回
return new String(resultCharArray);
}
}
统一下单接口
//统一下单接口
public Map createOrder(@PathVariable String ids, @CurrentPerson CurPersonInfo currentPerson) throws IOException {
SortedMap<String, Object> parameters = new TreeMap<String, Object>();
parameters.put("appid", APPID);
parameters.put("mch_id", MCH_ID);
parameters.put("device_info", "WEB"); // 默认 "WEB"
parameters.put("body", body);
parameters.put("nonce_str", wxUtils.gen32RandomString()); // 32 位随机字符串
parameters.put("notify_url", notifyUrl);
parameters.put("out_trade_no", ids);
parameters.put("sign_type", "MD5");
parameters.put("total_fee", 1); // 测试时，将支付金额设置为 1 分钱
parameters.put("spbill_create_ip", "127.0.0.1");
parameters.put("trade_type", "JSAPI");
System.out.println(currentPerson.getOpenId());
parameters.put("openid", currentPerson.getOpenId());
parameters.put("sign", wxUtils.createSign(parameters, KEY)); // sign 必须在最后
System.out.println(parameters);
String result = wxUtils.executeHttpPost(placeUrl, parameters); // 执行 HTTP 请求，获取接收的字符串（一段 XML）
Map resultInfo=wxUtils.createSign2(result, KEY);
System.out.println(resultInfo);
return resultInfo;
}
回调接口
@RequestMapping(value = "/callBack")
public String callBack(HttpServletRequest request, HttpServletResponse response) throws Exception {
// 预先设定返回的 response 类型为 xml
response.setHeader("Content-type", "application/xml");
// 读取参数，解析Xml为map
Map<String, String> map = wxUtils.transferXmlToMap(wxUtils.readRequest(request));
// 转换为有序 map，判断签名是否正确
boolean isSignSuccess = wxUtils.checkSign(new TreeMap<String, Object>(map), KEY);
if (isSignSuccess) {
// 签名校验成功，说明是微信服务器发出的数据
业务代码
return success();
} else {
// 签名校验失败（可能不是微信服务器发出的数据）
return fail();
}
}
String fail() {
return "<xml>\n" +
" <return_code><![CDATA[FAIL]]></return_code>\n" +
" <return_msg><![CDATA[]]></return_msg>\n" +
"</xml>";
}
String success() {
return "<xml>\n" +
" <return_code><![CDATA[SUCCESS]]></return_code>\n" +
" <return_msg><![CDATA[OK]]></return_msg>\n" +
"</xml>";
}
二、小程序调起支付代码
返回的参数为统一下单接口返回的
wx.requestPayment(
{
'timeStamp': data.timeStamp,
'nonceStr': data.nonceStr,
'package': data.package,
'signType': 'MD5',
'paySign': data.sign,
'success':function(res){
console.log(res)
},
'fail':function(res){
console.log(res)
}
})