如果用Spring那套RestTemplate不能获取，或者获取了生成的图片文件是无法打开的，大小是150多k的（当宽度为430的时候，应该是55k左右），可以看看我的方法

package com.wx.scooter;import java.io.File;import java.io.FileOutputStream;import java.io.InputStream;import java.util.HashMap;import java.util.Map;import org.apache.http.HttpResponse;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.HttpClientBuilder;import org.apache.http.protocol.HTTP;import org.springframework.http.HttpEntity;import org.springframework.http.HttpHeaders;import org.springframework.http.HttpMethod;import org.springframework.http.MediaType;import org.springframework.http.ResponseEntity;import org.springframework.web.client.RestTemplate;import com.alibaba.fastjson.JSON;import com.alibaba.fastjson.JSONObject;import com.wx.scooter.tool.CheckTool;import com.wx.scooter.tool.Constant;public class TestQR {    public static void main2(String[] args) throws Exception {        //获取token        String result1 = get("https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid="+Constant.NATIVE_APP_ID+"&secret="+Constant.NATIVE_APP_SECRET);        String access_token = JSONObject.parseObject(result1).getString("access_token");        if(CheckTool.isString(access_token)) {            System.out.println("token为");            System.out.println(access_token);            Map<String, Object> params = new HashMap<>();            params.put("scene", "test");            params.put("page", "pages/index/index");            params.put("width", 430);            CloseableHttpClient  httpClient = HttpClientBuilder.create().build();            HttpPost httpPost = new HttpPost("https://api.weixin.qq.com/wxa/getwxacodeunlimit?access_token="+access_token);            httpPost.addHeader(HTTP.CONTENT_TYPE, "application/json");            String body = JSON.toJSONString(params);            StringEntity entity;            entity = new StringEntity(body);            entity.setContentType("image/png");            httpPost.setEntity(entity);            HttpResponse response;            response = httpClient.execute(httpPost);            InputStream inputStream = response.getEntity().getContent();            File targetFile = new File("D:\");              if(!targetFile.exists()){                    targetFile.mkdirs();                }                   FileOutputStream out = new FileOutputStream("D:\upload\5.png");            byte[] buffer = new byte[8192];            int bytesRead = 0;            while((bytesRead = inputStream.read(buffer, 0, 8192)) != -1) {                out.write(buffer, 0, bytesRead);            }            out.flush();            out.close();        } else {            System.out.println("获取access_token错误");        }    }    /**     * 发送get请求     * @param url     * @return     */    public static String get(String url) {        RestTemplate restTemplate = new RestTemplate();        HttpHeaders headers = new HttpHeaders();        headers.setContentType(MediaType.APPLICATION_JSON_UTF8);        HttpEntity<String> entity = new HttpEntity<String>(url, headers);        ResponseEntity<String> responseEntity = restTemplate.exchange(url, HttpMethod.GET, entity, String.class);        return responseEntity.getBody();    }}