java微信小程序 获取二维码

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 com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.wx.scooter.tool.CheckTool;
import com.wx.scooter.tool.Constant;
import com.wx.scooter.tool.HttpTool;

public class TestQR {
public static void main(String[] args) throws Exception {
//获取token
String result1 = HttpTool.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();

948d
out.close();
} else {
System.out.println("获取access_token错误");
}
}
}