Android + PHP无法上传图像

我正在使用 localhost for php。

import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import android.util.Log;
public class ImageUpload {
    HttpURLConnection _httpurlconnection;
    DataOutputStream _dos;
    DataInputStream _dis;
    String _serverurl="http://192.168.1.11/project/imageupload.php";
    String _lineend= "'r'n";
    String _twohyphens= "--";
    String _boundry="*****";
    int _bytesread, _bytesavailable, _buffersize;
    byte[] _buffer;
    int _maxbuffersize = 1 * 1024 * 1024;
    public void uploadImage(String _filepath) {
        try {
            FileInputStream _fis = new FileInputStream(new File(_filepath));
            URL _url = new URL(_serverurl);
            _httpurlconnection = (HttpURLConnection) _url.openConnection();
            _httpurlconnection.setDoInput(true);
            _httpurlconnection.setDoOutput(true);
            _httpurlconnection.setUseCaches(false);
            _httpurlconnection.setRequestMethod("POST");
            _httpurlconnection.setRequestProperty("Connection", "Keep-Alive");
            _httpurlconnection.setRequestProperty("Connection-Type",
                    "multipart/form-data;boundry=" + _boundry);
            _dos = new DataOutputStream(_httpurlconnection.getOutputStream());
            _dos.writeBytes(_twohyphens + _boundry + _lineend);
            _dos.writeBytes("Content-Disposition: form-data; name='"uploadedfile'";filename='""
                + _filepath + "'"" + _lineend);
            _dos.writeBytes(_lineend);
            _bytesavailable = _fis.available();
            _buffersize = Math.min(_bytesavailable, _maxbuffersize);
            _buffer = new byte[_buffersize];
            _bytesread = _fis.read(_buffer, 0, _buffersize);

            while (_bytesread > 0) {

                _dos.write(_buffer, 0, _buffersize);
                _bytesavailable = _fis.available();
                _buffersize = Math.min(_bytesavailable, _maxbuffersize);
                _bytesread = _fis.read(_buffer, 0, _buffersize);
            }
            _dos.writeBytes(_lineend);
            _dos.writeBytes(_twohyphens + _boundry + _twohyphens + _lineend);
            int responsecode = _httpurlconnection.getResponseCode();
            String responsemessage = _httpurlconnection.getResponseMessage();
            _fis.close();
            _dos.flush();
            _dos.close();
            BufferedReader br=new BufferedReader(new InputStreamReader(_httpurlconnection.getInputStream()));
            String line;
            while((line=br.readLine())!=null)
            {
                Log.i("----------------",">>"+line);
            }
            br.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

这是我的PHP代码。

<?php
$target_path  = "/var/www/project";
$target_path = $target_path . basename( $_FILES['uploadedfile']['name']);
if(move_uploaded_file($_FILES['uploadedfile']['tmp_name'], $target_path)) {
 echo "The file ".  basename( $_FILES['uploadedfile']['name']).
 " has been uploaded";
} else{
 echo "There was an error uploading the file, please try again!";
}
?>

但是我收到通知：未定义的索引：第 5 行上传的文件。谁能帮我解决这个问题？