您能解释一下为什么Android客户端将多部分数据解析为非ASCII字符，而使用Postman上传文件却可以正常工作吗？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);
apiRoutes指向我的上传函数，包含简单的打印req参数。在使用postman时它运行良好。
console.log("mediaChat called", req.body, req.files);
响应
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' } }
这是我的安卓客户端代码（请注意，此代码可以与php $_FILE一起正常工作，但不能与express一起正常工作）
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时，以下是显示有线响应的方法：
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multipart处理程序，但什么都不起作用。 请帮助我摆脱这个困境。