Java 获取微信小程序wxacode.getUnlimited生成二维码

悠悠 2021-11-04 09:42 763阅读 0赞

为了直接扫描一个二维码就进入小程序并完成部分业务操作, 需要用到微信小程序提供的二维码接口 wxacode.getUnlimited  
微信文档连接[https://developers.weixin.qq.com/miniprogram/dev/api-backend/open-api/qr-code/wxacode.getUnlimited.html][https_developers.weixin.qq.com_miniprogram_dev_api-backend_open-api_qr-code_wxacode.getUnlimited.html]

在获取TOKEN之后,替换请求地址中ACCESS\_TOKEN.

随后,发送POST请求并获取流,代码如下:

# http请求返回图片流工具类 #

import java.io.ByteArrayOutputStream;
    import java.io.IOException;
    import java.io.InputStream;
    import java.nio.charset.Charset;
    
    import org.apache.commons.collections.Buffer;
    import org.apache.http.HttpEntity;
    import org.apache.http.client.methods.CloseableHttpResponse;
    import org.apache.http.client.methods.HttpPost;
    import org.apache.http.entity.StringEntity;
    import org.apache.http.impl.client.CloseableHttpClient;
    import org.apache.http.impl.client.HttpClients;
    
    /**
     * 测试httpclient 4.0 1. 重新设计了HttpClient 4.0 API架构，彻底从内部解决了所有 HttpClient 3.x 已知的架构缺陷代码。 2. HttpClient 4.0 提供了更简洁，更灵活，更明确的API。 3. HttpClient 4.0 引入了很多模块化的结构。 4.
     * HttpClient 4.0性能方面得到了不小的提升，包括更少的内存使用，通过使用HttpCore模块更高效完成HTTP传输。 5. 通过使用 协议拦截器(protocol interceptors), HttpClient 4.0实现了 交叉HTTP（cross-cutting HTTP protocol）
     * 协议 6. HttpClient 4.0增强了对连接的管理，更好的处理持久化连接，同时HttpClient 4.0还支持连接状态 7. HttpClient 4.0增加了插件式（可插拔的）的 重定向（redirect） 和 验证（authentication）处理。 8. HttpClient
     * 4.0支持通过代理发送请求，或者通过一组代理发送请求。 9. 更灵活的SSL context 自定义功能在HttpClient 4.0中得以实现。 10. HttpClient 4.0减少了在省城HTTP请求 和 解析HTTP响应 过程中的垃圾信息。 11. HttpClient团队鼓励所有的项目升级成
     * HttpClient 4.0
     *
     * 
     */
    public class HttpClientUtils {
    
    	/* 发送 post请求 用HTTPclient 发送请求*/
    	public byte[] post(String URL, String json) {
    		String obj = null;
    		InputStream inputStream = null;
    		Buffer reader = null;
    		byte[] data = null;
    		// 创建默认的httpClient实例.
    		CloseableHttpClient httpclient = HttpClients.createDefault();
    		// 创建httppost
    		HttpPost httppost = new HttpPost(URL);
    		httppost.addHeader("Content-type", "application/json; charset=utf-8");
    		httppost.setHeader("Accept", "application/json");
    		try {
    			StringEntity s = new StringEntity(json, Charset.forName("UTF-8")); 
    			s.setContentEncoding("UTF-8");
    			httppost.setEntity(s);
    			CloseableHttpResponse response = httpclient.execute(httppost);
    			try {
    				// 获取相应实体
    				HttpEntity entity = response.getEntity();
    				if (entity != null) {
    					inputStream = entity.getContent();
    					data = readInputStream(inputStream);
    				}
    				return data;
    			} finally {
    				response.close();
    			}
    		} catch (Exception e) {
    			e.printStackTrace();
    		} finally {
    			// 关闭连接,释放资源
    			try {
    				httpclient.close();
    			} catch (IOException e) {
    				e.printStackTrace();
    			}
    		}
    		return data;
    	}
     
        /**  将流 保存为数据数组
    	 * @param inStream
    	 * @return
    	 * @throws Exception
    	 */
    	public static byte[] readInputStream(InputStream inStream) throws Exception {
    		ByteArrayOutputStream outStream = new ByteArrayOutputStream();
    		// 创建一个Buffer字符串
    		byte[] buffer = new byte[1024];
    		// 每次读取的字符串长度，如果为-1，代表全部读取完毕
    		int len = 0;
    		// 使用一个输入流从buffer里把数据读取出来
    		while ((len = inStream.read(buffer)) != -1) {
    			// 用输出流往buffer里写入数据，中间参数代表从哪个位置开始读，len代表读取的长度
    			outStream.write(buffer, 0, len);
    		}
    		// 关闭输入流
    		inStream.close();
    		// 把outStream里的数据写入内存
    		return outStream.toByteArray();
    	}
    }

### Controller ###

/**
    	 * @author sunran
    	 * @param request
    	 * @param response
    	 */
    	@RequestMapping(value = "/getUnlimited", produces = "application/json;charset=UTF-8")
    	@ResponseBody
    	public Object pullCouponByToken1(HttpServletRequest request, HttpServletResponse response) {
    		ResultResp result = new ResultResp();
    		try {
    			String reqBody = Barriers.getContent(request);
    			logger.info("====请求 pullCouponByToken ====>" + reqBody);
    			
    			Test2 test = new Test2(); 
    			String accessToken = test.getAccessToken(); 
    			String url = "https://api.weixin.qq.com/wxa/getwxacodeunlimit?access_token="+accessToken; 
    			
    			HttpClientUtils client = new HttpClientUtils(url);
    			Map<String,Object> map = Maps.newHashMap();
    			map.put("scene", "a=1");
    			map.put("width", 280);
    			String jsonString = JSON.toJSONString(map);
    			
    			byte[] data  = client.post(url, jsonString);
    			
    			result.setCode(ResponseCodeType.SUCCESS.getCode() + "");
    			result.setData(data);
    			result.setMsg("OK");
    		} catch (Exception e) {
    			e.printStackTrace();
    			result.setCode(ResponseCode.FAILD.getCode());
    			result.setMsg("调用接口异常！");
    		}
    		return JSON.toJSONString(result);
    	}

返回出来base64 需要转换  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM2NzI1Mjgy_size_16_color_FFFFFF_t_70]  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM2NzI1Mjgy_size_16_color_FFFFFF_t_70 1]

### 转换完成 ###

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM2NzI1Mjgy_size_16_color_FFFFFF_t_70 2]

[https_developers.weixin.qq.com_miniprogram_dev_api-backend_open-api_qr-code_wxacode.getUnlimited.html]: https://developers.weixin.qq.com/miniprogram/dev/api-backend/open-api/qr-code/wxacode.getUnlimited.html
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM2NzI1Mjgy_size_16_color_FFFFFF_t_70]: /images/20211104/01f102e9a72e45da95f7dbf7c3088bd0.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM2NzI1Mjgy_size_16_color_FFFFFF_t_70 1]: /images/20211104/8a535a6f859c4361bc8ccd1216c6daba.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM2NzI1Mjgy_size_16_color_FFFFFF_t_70 2]: https://img-blog.csdnimg.cn/20190809163658853.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM2NzI1Mjgy,size_16,color_FFFFFF,t_70