HttpsURLConnection上传文件流

项目需要对接外部接口，将图片文件流发送到外部接口，下面代码就是HttpsURLConnection如何上传文件流：

/**
 * HttpsURLConnection上传文件流
 *
 * @param args
 * @throws Exception
 */
public static void main(String[] args) throws Exception {
//本地图片
        java.io.File file = new java.io.File("/Users/jikukalun/Pictures/id1.jpg");
        FileInputStream fileInputStream = new FileInputStream(file);
//对接外部接口
        String urlString = "************";

        URL url = new URL(urlString);
        HttpsURLConnection con = (HttpsURLConnection) url.openConnection();
// 设置是否向httpUrlConnection输出，因为这个是post请求，参数要放在
// http正文内，因此需要设为true, 默认情况下是false;
        con.setDoOutput(true);
// 设置是否从httpUrlConnection读入，默认情况下是true;
        con.setDoInput(true);
// 设定请求的方法为"POST"，默认是GET
        con.setRequestMethod("POST");
// Post 请求不能使用缓存
        con.setUseCaches(false);
// 设定传送的内容类型是可序列化的java对象
// (如果不设此项,在传送序列化对象时,当WEB服务默认的不是这种类型时可能抛java.io.EOFException)
// con.setRequestProperty("Content-type", "application/x-java-serialized-object");
        OutputStream out = con.getOutputStream();

//读取本地图片文件流
        FileInputStream inputStream = new FileInputStream(file);
byte[] data = new byte[2048];
int len = 0;
int sum = 0;
while ((len = inputStream.read(data)) != -1) {
//将读取到的本地文件流读取到HttpsURLConnection,进行上传
            out.write(data, 0, len);
            sum = len + sum;
        }

        System.out.println("上传图片大小为:" + sum);

        out.flush();
        inputStream.close();
        out.close();

int code = con.getResponseCode();  //获取post请求返回状态
        System.out.println("code=" + code + " url=" + url);
if (code == 200) {
            InputStream inputStream2 = con.getInputStream();
            ByteArrayOutputStream bos = new ByteArrayOutputStream();
while ((len = inputStream2.read(data)) != -1) {
                bos.write(data, 0, len);
            }
            inputStream2.close();
            String content = bos.toString();
            bos.close();
            System.out.println("result =" + content);
//将返回的json格式的字符串转化为json对象
            JSONObject json = JSONObject.parseObject(content);
try {
                System.out.println("name=" + json.getString("name") + ", people=" + json.getString("people") + ", sex=" + json.getString("sex")
                        + ", id_number=" + json.getString("id_number") + ", type=" + json.getString("type") + ", address=" + json.getString("address")
                        + ", birthday=" + json.getString("birthday"));
            } catch (JSONException e) {
                e.printStackTrace();
            }
        }
//断开HttpsURLConnection连接
        con.disconnect();
    }

引用jar包：

import com.alibaba.fastjson.JSONException;
import com.alibaba.fastjson.JSONObject;
import javax.net.ssl.HttpsURLConnection;
import java.io.*;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;