Java生成带参数的微信二维码
在Java中生成带参数的微信二维码,可以通过调用微信提供的二维码生成接口来实现，以下是详细的实现步骤：
（图片来源网络，侵删）
准备工作
你需要有一个已认证的微信公众号,并获取到以下信息：
- AppID
- AppSecret
获取access_token
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import org.json.JSONObject;
public class WeChatUtil {
private static final String APPID = "你的AppID";
private static final String APPSECRET = "你的AppSecret";
public static String getAccessToken() throws IOException {
String url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid="
+ APPID + "&secret=" + APPSECRET;
HttpURLConnection connection = (HttpURLConnection) new URL(url).openConnection();
connection.setRequestMethod("GET");
BufferedReader reader = new BufferedReader(new InputStreamReader(connection.getInputStream()));
String line;
StringBuilder response = new StringBuilder();
while ((line = reader.readLine()) != null) {
response.append(line);
}
reader.close();
JSONObject jsonObject = new JSONObject(response.toString());
return jsonObject.getString("access_token");
}
}
生成带参数的二维码
微信提供了两种类型的二维码：
- 临时二维码（expire_seconds参数指定有效期）
- 永久二维码（scene_id参数指定场景值）
1 生成临时二维码
import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.URL;
import org.json.JSONObject;
public class WeChatQRCode {
public static String createTemporaryQRCode(int expireSeconds, String sceneStr) throws IOException {
String accessToken = WeChatUtil.getAccessToken();
JSONObject json = new JSONObject();
JSONObject actionInfo = new JSONObject();
JSONObject scene = new JSONObject();
scene.put("scene_str", sceneStr); // 使用字符串场景值
actionInfo.put("scene", scene);
actionInfo.put("action_name", "QR_STR_SCENE");
json.put("expire_seconds", expireSeconds);
json.put("action_info", actionInfo);
String url = "https://api.weixin.qq.com/cgi-bin/qrcode/create?access_token=" + accessToken;
HttpURLConnection connection = (HttpURLConnection) new URL(url).openConnection();
connection.setRequestMethod("POST");
connection.setDoOutput(true);
connection.setRequestProperty("Content-Type", "application/json");
connection.getOutputStream().write(json.toString().getBytes());
BufferedReader reader = new BufferedReader(new InputStreamReader(connection.getInputStream()));
String line;
StringBuilder response = new StringBuilder();
while ((line = reader.readLine()) != null) {
response.append(line);
}
reader.close();
JSONObject responseJson = new JSONObject(response.toString());
return responseJson.getString("ticket");
}
}
2 生成永久二维码
public static String createPermanentQRCode(int sceneId) throws IOException {
String accessToken = WeChatUtil.getAccessToken();
JSONObject json = new JSONObject();
JSONObject actionInfo = new JSONObject();
JSONObject scene = new JSONObject();
scene.put("scene_id", sceneId); // 使用整数场景值
actionInfo.put("scene", scene);
actionInfo.put("action_name", "QR_SCENE");
json.put("action_info", actionInfo);
String url = "https://api.weixin.qq.com/cgi-bin/qrcode/create?access_token=" + accessToken;
HttpURLConnection connection = (HttpURLConnection) new URL(url).openConnection();
connection.setRequestMethod("POST");
connection.setDoOutput(true);
connection.setRequestProperty("Content-Type", "application/json");
connection.getOutputStream().write(json.toString().getBytes());
BufferedReader reader = new BufferedReader(new InputStreamReader(connection.getInputStream()));
String line;
StringBuilder response = new StringBuilder();
while ((line = reader.readLine()) != null) {
response.append(line);
}
reader.close();
JSONObject responseJson = new JSONObject(response.toString());
return responseJson.getString("ticket");
}
使用ticket获取二维码图片
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
public class QRCodeImage {
public static void getQRCodeImage(String ticket, String savePath) throws IOException {
String url = "https://mp.weixin.qq.com/cgi-bin/showqrcode?ticket=" + ticket;
HttpURLConnection connection = (HttpURLConnection) new URL(url).openConnection();
connection.setRequestMethod("GET");
InputStream inputStream = connection.getInputStream();
FileOutputStream outputStream = new FileOutputStream(savePath);
byte[] buffer = new byte[1024];
int bytesRead;
while ((bytesRead = inputStream.read(buffer)) != -1) {
outputStream.write(buffer, 0, bytesRead);
}
inputStream.close();
outputStream.close();
}
}
完整示例
public class Main {
public static void main(String[] args) {
try {
// 生成临时二维码，有效期30分钟，场景值为"test123"
String temporaryTicket = WeChatQRCode.createTemporaryQRCode(1800, "test123");
QRCodeImage.getQRCodeImage(temporaryTicket, "temporary_qrcode.png");
System.out.println("临时二维码已生成: temporary_qrcode.png");
// 生成永久二维码，场景值为12345
String permanentTicket = WeChatQRCode.createPermanentQRCode(12345);
QRCodeImage.getQRCodeImage(permanentTicket, "permanent_qrcode.png");
System.out.println("永久二维码已生成: permanent_qrcode.png");
} catch (IOException e) {
e.printStackTrace();
}
}
}
注意事项
- 二维码的scene_str或scene_id是自定义参数,用于区分不同的二维码场景
- 临时二维码有效期最长为30天（2592000秒）
- 永久二维码的scene_id目前只支持1-100000的整数
- 生成的ticket需要URL编码后才能用于获取二维码图片
- 微信接口调用频率有限制,需要注意不要频繁调用
使用第三方库简化
如果你不想自己实现HTTP请求部分,可以使用如Apache HttpClient或OkHttp等第三方库来简化代码：
// 使用OkHttp的示例
public static String getAccessToken() throws IOException {
String url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid="
+ APPID + "&secret=" + APPSECRET;
OkHttpClient client = new OkHttpClient();
Request request = new Request.Builder().url(url).build();
try (Response response = client.newCall(request).execute()) {
if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);
String responseBody = response.body().string();
JSONObject jsonObject = new JSONObject(responseBody);
return jsonObject.getString("access_token");
}
}
就是在Java中生成带参数的微信二维码的完整实现方法。
（图片来源网络，侵删）
（图片来源网络，侵删）
