java 生成微信小程序二维码 base64 格式并携带参数 java 后端 完整代码

以下是Java生成微信小程序带参数二维码的完整代码： ```java import java.io.BufferedReader; import java.io.InputStream; import java.io.InputStreamReader; import java.net.HttpURLConnection; import java.net.URL; import java.net.URLEncoder; import java.util.HashMap; import java.util.Map; import org.apache.commons.codec.binary.Base64; import org.json.JSONObject; public class WxMaQrcodeUtils { private static final String API_URL = "https://api.weixin.qq.com/cgi-bin/wxaapp/createwxaqrcode"; private static final String PARAM_PAGE = "page"; private static final String PARAM_SCENE = "scene"; private static final String ACCESS_TOKEN_URL = "https://api.weixin.qq.com/cgi-bin/token"; /** * 获取access_token * * @param appid 小程序appid * @param secret 小程序secret * @return access_token */ public static String getAccessToken(String appid, String secret) { String accessToken = null; try { String url = ACCESS_TOKEN_URL + "?grant_type=client_credential&appid=" + appid + "&secret=" + secret; URL obj = new URL(url); HttpURLConnection con = (HttpURLConnection) obj.openConnection(); con.setRequestMethod("GET"); int responseCode = con.getResponseCode(); if (responseCode == HttpURLConnection.HTTP_OK) { InputStream inputStream = con.getInputStream(); BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream)); StringBuilder stringBuilder = new StringBuilder(); String line; while ((line = bufferedReader.readLine()) != null) { stringBuilder.append(line); } bufferedReader.close(); JSONObject jsonObject = new JSONObject(stringBuilder.toString()); accessToken = jsonObject.getString("access_token"); } } catch (Exception e) { e.printStackTrace(); } return accessToken; } /** * 生成小程序带参数二维码 * * @param accessToken 小程序access_token * @param page 小程序页面路径 * @param scene 小程序页面参数 * @return base64格式的二维码图片数据 */ public static String createQrcode(String accessToken, String page, String scene) { String base64Image = null; try { Map<String, Object> params = new HashMap<>(); params.put(PARAM_PAGE, page); params.put(PARAM_SCENE, scene); URL obj = new URL(API_URL + "?access_token=" + accessToken); HttpURLConnection con = (HttpURLConnection) obj.openConnection(); con.setRequestMethod("POST"); con.setRequestProperty("Content-Type", "application/json"); con.setDoOutput(true); con.getOutputStream().write(new JSONObject(params).toString().getBytes("UTF-8")); int responseCode = con.getResponseCode(); if (responseCode == HttpURLConnection.HTTP_OK) { InputStream inputStream = con.getInputStream(); byte[] imageBytes = new byte[inputStream.available()]; inputStream.read(imageBytes); inputStream.close(); base64Image = Base64.encodeBase64String(imageBytes); } } catch (Exception e) { e.printStackTrace(); } return base64Image; } public static void main(String[] args) { String appid = "your_appid"; String secret = "your_secret"; String accessToken = getAccessToken(appid, secret); String page = "pages/index/index"; String scene = "key=value"; String base64Image = createQrcode(accessToken, page, URLEncoder.encode(scene)); System.out.println(base64Image); } } ``` 注意，需要引入Apache Commons Codec库。 其中，getAccessToken方法用于获取小程序的access_token，createQrcode方法用于生成小程序带参数二维码并返回base64格式的图片数据。在main方法中调用以上两个方法即可生成小程序二维码。