implementation 'com.squareup.okhttp3:okhttp:3.10.0'implementation 'com.squareup.okio:okio:1.12.0'

忽略https请求：
res->xml->network_security_config.xml

<?xml version="1.0" encoding="utf-8"?>
<network-security-config xmlns:android="http://schemas.android.com/apk/res/android"><base-config cleartextTrafficPermitted="true" />
</network-security-config>

清单文件中添加：

<application
android:networkSecurityConfig="@xml/network_security_config"
application/>

上传文件代码

 OkHttpClient client = new OkHttpClient();MediaType type = MediaType.parse("application/octet-stream");//“text/xml;charset=utf-8”File file1 = new File(path + fileName);RequestBody fileBody = RequestBody.create(type, file1);Request request = new Request.Builder().url("http://192.168.0.107:8087/fileupload/fileupload/").addHeader("User-Agent", "android").header("Content-Type", "text/html; charset=utf-8;").post(fileBody).build();client.newCall(request).enqueue(new Callback() {@Overridepublic void onFailure(Call call, IOException e) {e.printStackTrace();}@Overridepublic void onResponse(Call call, Response response) throws IOException {runOnUiThread(new Runnable() {@Overridepublic void run() {Toast.makeText(Main2Activity.this, "成功", Toast.LENGTH_SHORT).show();}});}});