生成小程序二维码，并上传oss

最近在做小程序，有个需求是生成小程序的二维码，扫二维码，进入到小程序指定页面。

1、获取token

获取小程序二维码之前，首先需要获取access_token。access_token是有时效性的2小时，每获取一次上次的的access_token就会失效。我们把请求到的access_token放到redis，失效时间设置为2小时，每次请求token，先从redis取，取不到则请求微信获取access_token。

 @Autowired
 private StringRedisTemplate stringRedisTemplate;


public String getToken(String appId,String secret) {
        Token instanceToken = getAccessToken(appId);
        return instanceToken == null ? "" : instanceToken.getAccess_token();
    }

    public Token getAccessToken(String appid) {
        Token instanceToken = null;
        try {

            String tokenJson = stringRedisTemplate.get(ConstantRedis.REDIS_KEY.WECHAT_ACCESS_TOKEN.generateFullKey(appid));
            if (!StringUtils.isEmpty(tokenJson)) {
                instanceToken = JSON.parseObject(tokenJson, Token.class);
            }
           
            if (instanceToken == null || StringUtils.isEmpty(instanceToken.getAccess_token()) || instanceToken.isExpire()) {
                instanceToken = WechatAPI.getToken(appid,secret);
                
                if (instanceToken == null || StringUtils.isEmpty(instanceToken.getAccess_token())) {
                    return null;
                }

                stringRedisTemplate.set(ConstantRedis.REDIS_KEY.WECHAT_ACCESS_TOKEN.generateFullKey(appid), instanceToken, 7200L);
            }
        } catch (IOException ex) {
            logger.error("getAccessToken exception...{}", ex);
        }
        return instanceToken;
    }

public class WechatAPI {

   privite static final String WECHAT_URI = "https://api.weixin.qq.com";

    /**
     * 调用微信SDK请求获取access_token
     * @param appid
     * @param secret
     * @return
     */
    public static Token getToken(String appid, String secret) {
        HttpUriRequest httpUriRequest = RequestBuilder.get()
                .setUri(WECHAT_URI + "/cgi-bin/token")
                .addParameter("grant_type", "client_credential")
                .addParameter("appid", appid)
                .addParameter("secret", secret)
                .build();
        Token token = MyHttpClient.executeJsonResult(httpUriRequest, Token.class);
        token.setCreate_time_millis(System.currentTimeMillis());
        return token;
    }
}

package com.wechat.client;

import org.apache.http.client.ResponseHandler;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpUriRequest;
import org.apache.http.client.protocol.HttpClientContext;
import org.apache.http.impl.client.CloseableHttpClient;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;

public class MyHttpClient {

    private static final int maxTotal = 100;
    private static final int maxPerRouter = 10;
    private static final int timeout = 6000;
    private static final int retryExecutionCount = 1;

    private static final Logger logger = LoggerFactory.getLogger(MyHttpClient.class);

    protected static CloseableHttpClient httpClient = HttpClientFactory.createHttpClient(maxTotal, maxPerRouter, timeout, retryExecutionCount);

    public static void init(int maxTotal, int maxPerRoute) {
        try {
            httpClient.close();
            httpClient = HttpClientFactory.createHttpClient(maxTotal, maxPerRoute, timeout, retryExecutionCount);
        } catch (IOException e) {
            logger.error("init exception...", e);
        }
    }

    public static CloseableHttpResponse execute(HttpUriRequest request) {
        try {
            return httpClient.execute(request, HttpClientContext.create());
        } catch (Exception e) {
            e.printStackTrace();
            logger.error("CloseableHttpResponse exception...", e);
        }
        return null;
    }

    public static  T execute(HttpUriRequest request, ResponseHandler responseHandler) {
        try {
            T t = httpClient.execute(request, responseHandler, HttpClientContext.create());
            return t;
        } catch (Exception e) {
            e.printStackTrace();
            logger.error("execute exception...", e);
        }
        return null;
    }

    public static  T executeJsonResult(HttpUriRequest request, Class clazz) {
        return execute(request, JsonResponseHandler.createResponseHandler(clazz));
    }
}

 

public class Token implements Serializable {

    private String access_token;
    private long expires_in;
    private long create_time_millis;

    private static final long MILLIS = 1000L;

    public String getAccess_token() {
        return access_token;
    }

    public void setAccess_token(String access_token) {
        this.access_token = access_token;
    }

    public long getExpires_in() {
        return expires_in;
    }

    public void setExpires_in(long expires_in) {
        this.expires_in = expires_in;
    }

    public long getCreate_time_millis() {
        return create_time_millis;
    }

    public void setCreate_time_millis(long create_time_millis) {
        this.create_time_millis = create_time_millis;
    }
}

2、有了access_token我们就可以请求微信SDK获取二维码了。

 public String getQrcode(QrcodeReq qrcodeReq) {

        InputStream inputStream = null;
        String fileName = "";
        String key = "qrcode"+qrcodeReq.getVideoId();
        try {
            String token = getToken(qrcodeReq.getAppId());
            logger.info("getQrcode  token:{}", token);
            fileName= "qrcode/qrcode"+qrcodeReq.getVideoId()+".png";

            RestTemplate rest = new RestTemplate();
            String url = "https://api.weixin.qq.com/wxa/getwxacodeunlimit?access_token=" + token;
            Map param = new HashMap<>();
            param.put("scene", "xxxxxxxxx");
          
            param.put("page", "pages/play/play");
            param.put("width", qrcodeReq.getWidth());
            param.put("auto_color", false);
            Map line_color = new HashMap<>();
            line_color.put("r", 0);
            line_color.put("g", 0);
            line_color.put("b", 0);
            param.put("line_color", line_color);
            logger.info("调用生成微信URL接口传参:" + param);
            MultiValueMap headers = new LinkedMultiValueMap<>();
            headers.add("Content-Type", "application/json");
            HttpEntity requestEntity = new HttpEntity(JSON.toJSON(param), headers);
            ResponseEntity entity = rest.exchange(url, HttpMethod.POST, requestEntity, byte[].class, new Object[0]);
            byte[] result = entity.getBody();
            String re = JsonUtil.decodeBase64(JSON.toJSONString(entity.getBody()));
            if (entity.getBody() !=null && !re.contains("errcode")){
                inputStream = new ByteArrayInputStream(result);
                String str = uploadService.putObject(fileName, inputStream);
            }else {
                logger.info("调用小程序生成微信永久小程序码URL接口返回结果:" + re);
            }
        }catch (Exception e){
            logger.error("getQrcode:{}",e);
        }finally {
            if (inputStream !=null){
                try {
                    inputStream.close();
                } catch (IOException e) {
                    logger.error("getQrcode:{}",e);
                }
            }
        }
        return fileName;
    }

3、上传oss

  public String putObject(String filename,InputStream inputStream) {

        // 上传Object.
        PutObjectResult result = null;
        try {
            result = client.putObject(defaultBucket, filename, inputStream);
        } catch (OSSException e) {
            logger.info("putObject putObject to oss error:{}",e);
        } catch (ClientException e) {
            logger.info("putObject putObject to oss error:{}",e);
        }
        String path = result.getETag();
        if (StringUtils.isEmpty(path)){
            return "";
        }else {
            return path;
        }
    }

4、有了二维码。总得测试一下，不然我好慌。

在微信开发这工具编译的左边的下拉框，是可以自定义编译的，启动页面和启动参数分别是请求生成二维码的page、scene。

小程序页面 js

 /**
   * 生命周期函数--监听页面加载
   */
  onLoad: function (options) {

     // 扫二维码
    if (options.scene) {

      let scene = decodeURIComponent(options.scene);
    
    // 
    }else{

    
    }

 

好了，获取小程序二维码就简单介绍到这了，有问题请留言吧  (^v^)