为了使用Java调用微信服务号API以根据openid发送消息,你需要首先获取微信公众平台的access_token。以下是一段示例代码,展示了如何根据openid发送文本消息。
首先,在Java项目中添加以下依赖:
<!-- Maven --> <dependency> <groupId>com.squareup.okhttp3</groupId> <artifactId>okhttp</artifactId> <version>4.9.3</version> </dependency>
<!-- Gradle -->
implementation 'com.squareup.okhttp3:okhttp:4.9.3'
接下来,创建一个Java类,用于调用微信API:
import okhttp3.*; import java.io.IOException; public class WeChatService { private static final String APP_ID = "your_app_id"; private static final String APP_SECRET = "your_app_secret"; private static final String ACCESS_TOKEN_URL = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=" + APP_ID + "&secret=" + APP_SECRET; private static final String SEND_MESSAGE_URL = "https://api.weixin.qq.com/cgi-bin/message/custom/send?access_token="; public static void main(String[] args) { try { String accessToken = getAccessToken(); String openid = "user_openid"; String message = "Hello, this is a message from WeChat Service Account!"; sendMessage(accessToken, openid, message); } catch (IOException e) { e.printStackTrace(); } } private static String getAccessToken() throws IOException { OkHttpClient client = new OkHttpClient(); Request request = new Request.Builder().url(ACCESS_TOKEN_URL).build(); Response response = client.newCall(request).execute(); String responseBody = response.body().string(); // 此处需要解析JSON,获取access_token。你可以使用Gson、Jackson等库进行解析。 String accessToken = parseAccessToken(responseBody); return accessToken; } private static void sendMessage(String accessToken, String openid, String message) throws IOException { OkHttpClient client = new OkHttpClient(); MediaType JSON = MediaType.parse("application/json; charset=utf-8"); String jsonMessage = createJsonMessage(openid, message); RequestBody body = RequestBody.create(JSON, jsonMessage); Request request = new Request.Builder().url(SEND_MESSAGE_URL + accessToken).post(body).build(); Response response = client.newCall(request).execute(); System.out.println("Send message response: " + response.body().string()); } private static String createJsonMessage(String openid, String content) { return "{%"touser%":%"" + openid + "%",%"msgtype%":%"text%",%"text%":{%"content%":%"" + content + "%"}}"; } // 用于解析access_token的方法,你需要根据实际情况实现此方法 private static String parseAccessToken(String responseBody) { // 使用你选择的JSON解析库解析responseBody,获取access_token // 示例:return jsonObject.getString("access_token"); return ""; } }
请注意,你需要替换APP_ID和APP_SECRET为你自己的应用ID和密钥,以及替换user_openid为实际的用户openid。此代码示例仅发送文本消息,你可以根据需要修改createJsonMessage方法以发送其他类型的消息。同时,你需要实现parseAccessToken方法以从API响应中解