基于标准的http来实现Android多文件上传

1. 多文件上传MyUploader类的实现：

/**
 * 
 * 同步上传多个文件
 * 基于标准的http实现，需要在非UI线程中调用，以免阻塞UI。
 *
 */
public class MyUploader {
    private static final String TAG = "MyUploader";

    // ////////////////////同步上传多个文件/////////
        /**
         * 同步上传File
         * 
         * @param Url
         * @param fullFileName
         *            : 全路径，ex. /sdcard/f/yh.jpg
         * @param fileName
         *            : file name,ex. yh.jpg
         * @return 服务器的响应结果(字符串形式)
         */
        public String MyUploadMultiFileSync(String Url,List<String> fileList,Map<String,String> params) {
            String reulstCode = "";
            String end = "rn";
            String twoHyphens = "--";
            String boundary = "--------boundary";

            try {
                URL url = new URL(actionUrl);
                HttpURLConnection con = (HttpURLConnection) url.openConnection();
                // 允许Input、Output，不使用Cache
                con.setDoInput(true);
                con.setDoOutput(true);
                con.setUseCaches(false);
                // 设置传送的method=POST
                con.setRequestMethod("POST");
                // setRequestProperty
                con.setRequestProperty("Connection","Keep-Alive");
                con.setRequestProperty("Charset","UTF-8");
                // con.setRequestProperty("Content-Type",// "application/x-www-form-urlencoded");
                con.setRequestProperty("Content-Type","multipart/form-data;boundary=" + boundary);

                StringBuffer s = new StringBuffer();
                // 设置DataOutputStream
                DataOutputStream dos = new DataOutputStream(con.getOutputStream());

                for (int i = 0; i < fileList.size(); i++) {

                    String filePath = fileList.get(i);

                    int endFileIndex = filePath.lastIndexOf("/");
                    String fileName = filePath.substring(endFileIndex + 1);
                    Log.i(TAG,"filename= " + fileName);
                    // set 头部
                    StringBuilder sb = new StringBuilder();

                    sb.append(twoHyphens);
                    sb.append(boundary);
                    sb.append(end);
                    sb.append("Content-Disposition: form-data; ");
                    sb.append("name=" + """ + "upload_file" +i + """);
                    sb.append(";filename=");
                    sb.append(""" + fileName + """);
                    sb.append(end);

                    sb.append("Content-Type: ");
                    sb.append("image/jpeg");
                    sb.append(end);
                    sb.append(end);

                    // 1. write sb
                    dos.writeBytes(sb.toString());

                    // 取得文件的FileInputStream
                    FileInputStream fis = new FileInputStream(filePath);
                    // 设置每次写入1024bytes
                    int bufferSize = 1024;
                    byte[] buffer = new byte[bufferSize];

                    int length = -1;
                    // 从文件读取数据至缓冲区
                    while ((length = fis.read(buffer)) != -1) {
                        dos.write(buffer,length);
                    }
                    dos.writeBytes(end);
                    fis.close();

                    dos.writeBytes(end);
                    dos.writeBytes(end);

                    //dos.writeBytes(end);
                    //dos.flush();
                    // close streams
                    //fis.close();
                }

                // set 尾部
                StringBuilder sb2 = new StringBuilder();

                if (params != null && !params.isEmpty()) {
                    for (String key : params.keySet()) {
                        String value = params.get(key);
                        sb2.append(twoHyphens);
                        sb2.append(boundary);
                        sb2.append(end);
                        sb2.append("Content-Disposition: form-data; ");
                        sb2.append("name=" + """);
                        sb2.append(key + """);
                        sb2.append(end);
                        sb2.append(end);
                        sb2.append(value);
                        sb2.append(end);
                    }
                }
                sb2.append(twoHyphens + boundary + end);
                dos.writeBytes(sb2.toString());
                dos.flush();
                Log.i(TAG,"sb2:" + sb2.toString());

                // 取得Response内容
                InputStream is = con.getInputStream();
                int ch;
                StringBuffer b = new StringBuffer();
                while ((ch = is.read()) != -1) {
                    b.append((char) ch);
                }
                reulstCode = b.toString().trim();
                // 关闭
                dos.close();
            } catch (IOException e) {
                Log.i(TAG,"IOException: " + e);
                e.printStackTrace();
            }

            return reulstCode;
        }
}

2. 调用方法：

public void uploadThreadTest() {
        new Thread(new Runnable() {
            @Override
            public void run() {

                try {
                    upload();
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }

        }).start();

    }

    private void upload() {
        String url = "https://httpbin.org/post";
        List<String> fileList = getCacheFiles();

        if (fileList == null) {
            myHandler.sendEmptyMessage(-1);
        }else {
            MyUploader myUpload = new MyUploader();
            //同步请求，直接返回结果，根据结果来判断是否成功。
            String reulstCode = myUpload.MyUploadMultiFileSync(url,fileList,null);
            Log.i(TAG,"upload reulstCode: " + reulstCode);
            myHandler.sendEmptyMessage(0);

        }
    }

    private List<String> getCacheFiles() {
        List<String> fileList = new ArrayList<String>();
        File catchPath = mContext.getCacheDir();

        if (catchPath!=null && catchPath.isDirectory()) {

            File[] files = catchPath.listFiles();
            if (files == null || files.length<1) {
                return null;
            }
            for (int i = 0; i < files.length; i++) {
                if (files[i].isFile() && files[i].getAbsolutePath().endsWith(".jpg")) {
                    fileList.add(files[i].getAbsolutePath());
                }

            }
            return fileList;

        }
        return null;


    }
    ////////////handler/////
    private Handler myHandler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            Log.i(TAG,"handleMessage msg===" + msg);
            if (msg.what == -1) {
                Toast.makeText(mContext,"not find file!",Toast.LENGTH_LONG).show();
                return;
            }else {
                Toast.makeText(mContext,"upload success!",Toast.LENGTH_LONG).show();
            }

        }

    };

3 项目demo代码地址：