Question

这是客户端代码，在客户端，服务器响应代码GIVES ERROR 500.on服务器端console.log方法显示未定义

     public class HttpUpload extends AsyncTask<Void, Integer, Integer> {

     private Context context;
     private String imgPath;
     int serverResponseCode = 0;


     public HttpUpload(Context context, String imgPath) {
    super();
    this.context = context;
    this.imgPath = imgPath;
    }


    @Override
    protected Integer doInBackground(Void... params) {

    String upLoadServerUri = "http://192.168.10.182:8080/uploadimage";


    HttpURLConnection conn = null;
    DataOutputStream dos = null;
    String lineEnd = "\r\n";
    String twoHyphens = "--";
    String boundary = "*****";
    int bytesRead, bytesAvailable, bufferSize;
    byte[] buffer;
    int maxBufferSize = 1 * 1024 * 1024;
    File sourceFile = new File(imgPath);
    if (!sourceFile.isFile()) {
        Log.e("uploadFile", "Source File Does not exist");
        return 0;
    }
    try { // open a URL connection to the Servlet
        FileInputStream fileInputStream = new FileInputStream(sourceFile);
        Log.i("uploadFile", "" + fileInputStream);
        URL url = new URL(upLoadServerUri);
        conn = (HttpURLConnection) url.openConnection(); // Open a HTTP  connection to  the URL
        conn.setDoInput(true); // Allow Inputs
        conn.setDoOutput(true); // Allow Outputs
        conn.setUseCaches(false); // Don't use a Cached Copy
        conn.setRequestMethod("POST");
        conn.setRequestProperty("Connection", "Keep-Alive");
        conn.setRequestProperty("ENCTYPE", "multipart/form-data");
        conn.setRequestProperty("Content-Type", "multipart/form-data;boundary=" + boundary);
        conn.setRequestProperty("uploaded_file",imgPath );
        dos = new DataOutputStream(conn.getOutputStream());

        dos.writeBytes(twoHyphens + boundary + lineEnd);
        dos.writeBytes("Content-Disposition: form-data; name=\"uploaded_file\";filename=\""+ imgPath + "\"" + lineEnd);
        dos.writeBytes(lineEnd);

        bytesAvailable = fileInputStream.available(); // create a buffer of  maximum size

        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)
        serverResponseCode = conn.getResponseCode();
        String serverResponseMessage = conn.getResponseMessage();

        Log.i("uploadFile", "HTTP Response is : " + serverResponseMessage + ": " + serverResponseCode);

        //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) {

        e.printStackTrace();

        Log.e("Upload file to server Exception", "Exception : " + e.getMessage(), e);
    }
    return null;
    }
    }

这是req.files显示为undefined

的服务器代码

    var express = require('express');
    var logger = require('morgan');
    var bodyParser = require('body-parser');
    var request = require('request');

    var app = express();
    var port     = process.env.PORT || 8080;
    var config = require("./config");
    var requests = require("./model")(config);

    app.use(logger('dev'));
    app.use(bodyParser.json());
    app.use(bodyParser.urlencoded({ extended: true }));

    app.post('/uploadimage',function(req,res){
    console.log("recieved files"+req.files);


    });
    app.use(function(req, res, next) {
     var err = new Error('Not Found');
    err.status = 404;
    next(err);
    });

    if (app.get('env') === 'development') {
    app.use(function(err, req, res, next) {
    res.status(err.status || 500);
    res.render('error', {
    message: err.message,
    error: err
    });
    });
    }

    app.use(function(err, req, res, next) {
    res.status(err.status || 500);
    res.render('error', {
    message: err.message,
    error: {}
    });
    });

    app.listen(port);

    console.log('The App runs on port ' + port);

Answer 1

你错过了一个能够解析multipart/form-data个请求的中间件。 body-parser模块当前未提供一个模块。您可以为multipart/form-data查看multer之类的内容。

Answer 2

您可以使用multer来实现这一目标。

定义中间件如下

var filename;
var multer1 = multer({ dest: './public/uploads/images/',
   onFileUploadComplete: function (file) {
     filename = file.name;
   }
});

dest是您要存储文件的目标位置。上传完成后，您可以将文件名作为file.name。在路由器中使用上面的中间件。

app.post('/uploadimage', multer1, function(req, res){
        res.end(filename);
});

不要忘记在文件开头导入multer

var multer  = require('multer');

将文件从android发送到nodejs时，req.files是未定义的

2 个答案: