我们可以通过如下的方法实现小程序太阳码生成。
获取小程序的access_token
设置path、with相关参数
调用getwxacodeunlimit接口,并将返回图片存储到本地
public static String getAccessToken(String appid, String appsecret)
{
String requestUrl = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid="+appid+"&secret="+appsecret+"";
String accessToken = null;
try
{
String response = HttpClientUtil.getInstance().sendHttpsGet(
requestUrl, null);
JSONObject json = JSONObject.parseObject(response);
accessToken = String.valueOf(json.get("access_token"));
}
catch (Exception e)
{
logger.error("getAccessToken error", e);
}
return accessToken;
}说明：调用微信API接口传入小程序的appid和appsecret参数即可。
public static String generatLimitSunCode(WxScanCodeParam param) throws Exception
{
String token =param.getAccessToken();
Map<String, String> params = new HashMap<>();
params.put("path", param.getPath());
params.put("width", "430");
CloseableHttpClient httpClient = HttpClientBuilder.create().build();
HttpPost httpPost = new HttpPost("https://api.weixin.qq.com/wxa/getwxacode?access_token="+token);
httpPost.addHeader(HTTP.CONTENT_TYPE, "application/json");
String body = JSON.toJSONString(params);
StringEntity entity = new StringEntity(body);
entity.setContentType("image/jpg");
httpPost.setEntity(entity);
HttpResponse response = httpClient.execute(httpPost);
int statusCode = response.getStatusLine().getStatusCode();
if (statusCode == HttpStatus.SC_OK)
{
HttpEntity entity2 = response.getEntity();
if(!entity2.getContentType().getValue().equals("image/jpeg"))
{
String result = EntityUtils.toString(entity2, "UTF-8");
logger.error("generate sun code error,http execute result:" + result);
return null;
}
}
else
{
logger.error("generate sun code error,http execute result:" + statusCode);
}
InputStream inputStream = response.getEntity().getContent();
// 保存图片到本地
int flag = saveImg(inputStream, param.getFilePath(), name);
if (flag == 0)
{
throw new SysException("保存图片[" + name + "]失败");
}
else
{
logger.info("太阳码[{}]生成成功", name);
}
return param.getFilePath() + File.separatorChar + name;
}path：扫码进入的小程序页面路径，最大长度 128 字节，不能为空；例如:pages/index/index
access_token：小程序授权token
需要特殊注意,本方案生成的小程序太阳码与二维码的总数不能超过10万个，微信没有提供对应的Api接口查询的使用的数量，一旦超过了数量，将会导致小程序失效，且微信目前无法重置查询次数，适合于生成数量少的场景。
如同第一种的方案
/**
* 生成无限制的小程序码
* @param param
* @return
* @throws Exception
*/
public static String generatUnlimitSunCode(WxScanCodeParam param) throws Exception
{
String token =param.getAccessToken();
Map<String, String> params = new HashMap<>();
params.put("scene", param.getScene());
params.put("page", param.getPath());
params.put("width", "430");
CloseableHttpClient httpClient = HttpClientBuilder.create().build();
HttpPost httpPost = new HttpPost("https://api.weixin.qq.com/wxa/getwxacodeunlimit?access_token="+token);
httpPost.addHeader(HTTP.CONTENT_TYPE, "application/json");
String body = JSON.toJSONString(params);
StringEntity entity = new StringEntity(body);
entity.setContentType("image/jpg");
httpPost.setEntity(entity);
HttpResponse response = httpClient.execute(httpPost);
int statusCode = response.getStatusLine().getStatusCode();
if (statusCode == HttpStatus.SC_OK)
{
HttpEntity entity2 = response.getEntity();
if(!entity2.getContentType().getValue().equals("image/jpeg"))
{
String result = EntityUtils.toString(entity2, "UTF-8");
logger.error("generate sun code error,http execute result:" + result);
return null;
}
}
else
{
logger.error("generate sun code error,http execute result:" + statusCode);
}
InputStream inputStream = response.getEntity().getContent();
//太阳码写标题
String content=param.getWriteContent();
if(StringUtil.isNotEmpty(content) && param.isWrite())
{
inputStream = ImageUtil.addImageTitle(param.getWriteContent(), inputStream, 450, 450);
}
String name = param.getFileName()+".jpg";//文件名加后缀，跟上面对应
int flag = saveImg(inputStream, param.getFilePath(), name);// 保存图片
if (flag == 0)
{
throw new SysException("保存图片[" + name + "]失败");
}
else
{
logger.info("太阳码[{}]生成成功", name);
}
return param.getFilePath() + File.separatorChar + name;
}scene：最大32个可见字符,参数格式可以自行定义a&b或者a=1&b=2都行
access_token：小程序授权token
由于scene参数的长度只支持32位字符，如果参数超过了32位，我们将如何合处理？
改问题的解决方案为：设计一张小程序参数表，将生成的参数存储到表中，生成小程序是scene参数设置此表表的主键，小程序扫码后，先请求后台通过scene参数获取小程序的具体参数。
如下示例：
