android客户端将多部分表单数据解析为非ascii

Question

你能解释一下为什么 android 客户端将 multiparform 数据解析为非 ascii 聊天吗？虽然使用 postman 上传文件效果很好 这是我的 app.js 代码

var multipart = require('connect-multiparty');
var apiRoutes = require('./routes/apiRoutes');
app.set('views', path.join(__dirname, 'views'));
app.use(logger('dev'));
app.use(bodyParser.json({limit: '50mb'}));
app.use(bodyParser.urlencoded([{extended: false},{ uploadDir:path.join(__dirname, 'uploads') }, {parameterLimit:100000}, {limit: '50mb'}]));
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));
app.use(express.static(path.join(__dirname, 'uploads')));
app.use(multipart());
app.use(apiRoutes);

和 apiRoutes 指出我的上传功能包含简单的打印请求参数。使用 postman 它工作得很好

console.log("mediaChat called", req.body, req.files);

回应

mediaChat called { apiKey: '123' } { media: 
   { fieldName: 'media',
     originalFilename: 'default.png',
     path: '/tmp/KFnwsKGp-f4woTaBH6aPR-qa.png',
     headers: 
      { 'content-disposition': 'form-data; name="media"; filename="default.png"',
        'content-type': 'image/png' },
     size: 716,
     name: 'default.png',
     type: 'image/png' } }

这是我的 android 客户端代码(注意此代码使用 php $_FILE 工作文件但不使用 express)

com.info.acruss.wave;

import android.os.AsyncTask;
import android.util.Log;

import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

/**
 * Created by Naitik on 9/20/2016.
 */
public class UploadImage extends AsyncTask<Void, Void, String> {
    String CallingURL;
    URL url;
    OnTaskCompleted myListener;
    private static final String TAG = "UploadImage";
    int timeoutMilli = 60000;
    String sourceFileUri;
    String ApiKey,Type;

    public UploadImage(String sourceFileUri, String URL,String apiKey, String type,
                       OnTaskCompleted listener) {
        Log.e("Uploading", "API:" + URL);
        this.sourceFileUri = sourceFileUri;
        this.CallingURL = URL;
        this.myListener = listener;
        this.ApiKey=apiKey;
        this.Type=type;
        try {
            url = new URL(CallingURL);
            Log.e(TAG, "Url : " + CallingURL);
        } catch (MalformedURLException e) {
            e.printStackTrace();
        }
    }

    @Override
    protected String doInBackground(Void... params) {
        String fileName = sourceFileUri;
        HttpURLConnection conn = null;
        DataOutputStream dos = null;
        String lineEnd = "\r\n";
        String twoHyphens = "--";
        String boundary = "*****";
        int bytesRead, bytesAvailable, bufferSize;
        byte[] buffer;
        int maxBufferSize = 10 * 1024 * 1024;
        File sourceFile = new File(sourceFileUri);
        if (!sourceFile.isFile()) {
            Log.e("UploadImage", "Source File Does not exist";
            return null;
        }
        String serverResponseMessage = "";
        try {

            // open a URL connection to the Servlet
            FileInputStream fileInputStream = new FileInputStream(sourceFile);
            URL url = new URL(CallingURL);
            // Open a HTTP  connection to  the URL
            conn = (HttpURLConnection) url.openConnection();
            conn.setDoInput(true); // Allow Inputs
            conn.setDoOutput(true); // Allow Outputs
            conn.setUseCaches(false); // Don't use a Cached Copy
            conn.setRequestMethod("POST";
            conn.setReadTimeout(timeoutMilli);
            conn.setConnectTimeout(timeoutMilli);
            conn.setRequestProperty("Connection", "Keep-Alive";
            conn.setRequestProperty("ENCTYPE", "multipart/form-data";
            conn.setRequestProperty("Content-Type", "multipart/form-data;boundary=" + boundary);
            conn.setRequestProperty("media", fileName);
            conn.setRequestProperty("apiKey",ApiKey);
            conn.setRequestProperty("media_type",Type);
            conn.setRequestProperty("media", fileName);

            dos = new DataOutputStream(conn.getOutputStream());
            dos.writeBytes(twoHyphens + boundary + lineEnd);
            dos.writeBytes("Content-Disposition: form-data; name='media';filename='" + fileName + "'" + lineEnd);
               dos.writeBytes(lineEnd);
            // create a buffer of  maximum size
            bytesAvailable = fileInputStream.available();
            bufferSize = Math.min(bytesAvailable, maxBufferSize);
            buffer = new byte[bufferSize];

            // read file and write it into form...
            bytesRead = fileInputStream.read(buffer, 0, bufferSize);

            while (bytesRead > 0) {

                dos.write(buffer, 0, bufferSize);
                bytesAvailable = fileInputStream.available();
                bufferSize = Math.min(bytesAvailable, maxBufferSize);
                bytesRead = fileInputStream.read(buffer, 0, bufferSize);

            }

            // send multipart form data necesssary after file data...
            dos.writeBytes(lineEnd);
            dos.writeBytes(twoHyphens + boundary + twoHyphens + lineEnd);

            // Responses from the server (code and message)
            int serverResponseCode = conn.getResponseCode();

            BufferedReader br = new BufferedReader(new InputStreamReader(conn.getInputStream()));
            String line = "";
            StringBuilder responseOutput = new StringBuilder();
            while ((line = br.readLine()) != null) {
                responseOutput.append(line);
            }
            br.close();
            serverResponseMessage = responseOutput.toString();//output.toString();

            Log.e("uploadFile", "HTTP Response is : " + serverResponseMessage);
            if (serverResponseCode == 200) {
                //status code 200
                //status ok
            }
            //close the streams //
            fileInputStream.close();
            dos.flush();
            dos.close();

        } catch (MalformedURLException ex) {
            ex.printStackTrace();
            Log.e("Upload file to server", "error: " + ex.getMessage(), ex);
        } catch (Exception e) {
            Log.e("Upload file to server", "error: " + e.getMessage(), e);
            e.printStackTrace();
        }
        return serverResponseMessage;
    }

    @Override
    protected void onPostExecute(String result) {
        super.onPostExecute(result);
        Log.e("Result", "" + result);
        if (myListener != null)
            if (result != null) {
                myListener.onFileUploadComplete(result);
            } else {
                myListener.onFileUploadComplete("";
            }
    }

    public interface OnTaskCompleted {
        void onFileUploadComplete(String result);
    }
}

使用 android 这个显示如下有线响应

mediaChat called { null: '����\u0000\u0010JFIF\u0000\u0001\u0001\u0000\u0000\u0001\u0000\u0001\u0000\u0000��\u0000C\u0000\u0010\u000b\f\u000e\f\n\u0010\u000e\r\u000e\u0012\u0011\u0010\u0013\u0018(\u001a\u0018\u0016\u0016\u00181#%\u001d(:3=Mqypdx\\egc��\u0000C\u0001\u0011\u0012\u0012\u0018\u0015\u0018/\u001a\u001a/cB8Bccccccccccc....
�\u001f.[���_�\u0014)M���XIjX��7�`=�/�8`��ïDʚ\u0018�D���#�V#q~m�q10L�' }

我还尝试了 multer 和其他多部分处理程序，但注意到有效。 请帮助我走出这个 hell

Answer 1

服务器响应似乎被编码为 UTF-8。要正确解码和阅读，您可以尝试

BufferedReader br = new BufferedReader(new InputStreamReader(conn.getInputStream(), "UTF-8"));

为 InputStreamReader 指定编码部分将使用指定的编码方案解码和读取流，在本例中为 UTF-8。检查javadocs了解详情。