使用这种方式，没问题 public static String postByJson(String url, int connectTimeout, int readTimeout, Map<String, String> param, String json) { OutputStream out = null; InputStream in = null; HttpURLConnection httpConn = null; try { URL urlcon = new URL(url); httpConn = (HttpURLConnection) urlcon.openConnection(); httpConn.setDoInput(true); httpConn.setDoOutput(true); httpConn.setRequestMethod("POST"); httpConn.setUseCaches(false); httpConn.setRequestProperty("Content-Type", "application/json"); httpConn.setRequestProperty("Connection", "Keep-Alive");// 维持长连接 httpConn.setRequestProperty("Charset", "UTF-8"); httpConn.setRequestProperty("user-agent", "java.net.http"); httpConn.setConnectTimeout(connectTimeout); httpConn.setReadTimeout(readTimeout); httpConn.connect(); if (param != null && !param.isEmpty()) { StringBuilder sb = new StringBuilder(); for (Map.Entry<String, String> e : param.entrySet()) { if (e.getKey() != null && e.getKey().trim().length() > 0) { sb.append(e.getKey() + "=" + e.getValue() + "&"); } } out = httpConn.getOutputStream(); out.write(sb.substring(0, sb.length() - 1).getBytes("utf-8")); out.flush(); } else if (null != json) { out = httpConn.getOutputStream(); out.write(json.getBytes("UTF-8")); out.flush(); } InputStream is = httpConn.getInputStream(); byte[] bytes = new byte[1024]; int length = bytes.length; int remain = length; while (true) { int count = is.read(bytes, length - remain, remain); if (count == -1) { break; } remain -= count; if (remain == 0) { length = bytes.length + 1024; remain = 1024; byte[] c = new byte[length]; System.arraycopy(bytes, 0, c, 0, bytes.length); bytes = c; } } return new String(bytes, "utf-8").trim(); } catch (Exception e) { e.printStackTrace(); } finally { try { if (out != null) { out.close(); } if (in != null) { in.close(); } if (httpConn != null) { httpConn.disconnect(); } } catch (IOException e) { e.printStackTrace(); } } return ""; }

解决了吗？是什么原因？

新增永久素材接口， [代码]thumb_media_id[代码]这个封面字段需要先新增永久图片，返回的media_id就是这个thumb_media_id.

我做的时候，获取到的是B。

请问你使用是小程序的web-view中嵌入H5网页使用公众号支付吗？