Question

I am working on the Android app. I searched a lot posts before create this question. I would like to use socket in java to upload files from android phone. What kind of app should it be in server side? Supposing write the server side in java.What kind of project should it be?
about java application, I only know the server host — tomcat.

Answer 1

In your case (as server has tomcat) If you have url of the server then you can use HttpURLConnection to upload any file to server. and in server end logic should be written to receive the file
Example

HttpURLConnection connection = null;
DataOutputStream outputStream = null;
DataInputStream inputStream = null;

String pathToOurFile = "/sdcard/file_to_send.mp3"; //complete path of file from your android device
String urlServer = "http://192.168.10.1/handle_upload.do";// complete path of server
String lineEnd = "\r\n";
String twoHyphens = "--";
String boundary =  "*****";

int bytesRead, bytesAvailable, bufferSize;
byte[] buffer;
int maxBufferSize = 1*1024*1024;

try
{
FileInputStream fileInputStream = new FileInputStream(new File(pathToOurFile) );

URL url = new URL(urlServer);
connection = (HttpURLConnection) url.openConnection();

// Allow Inputs & Outputs
connection.setDoInput(true);
connection.setDoOutput(true);
connection.setUseCaches(false);

// Enable POST method
connection.setRequestMethod("POST");

connection.setRequestProperty("Connection", "Keep-Alive");
connection.setRequestProperty("Content-Type", "multipart/form-data;boundary="+boundary);

outputStream = new DataOutputStream( connection.getOutputStream() );
outputStream.writeBytes(twoHyphens + boundary + lineEnd);
outputStream.writeBytes("Content-Disposition: form-data; name=\"uploadedfile\";filename=\"" + pathToOurFile +"\"" + lineEnd);
outputStream.writeBytes(lineEnd);

bytesAvailable = fileInputStream.available();
bufferSize = Math.min(bytesAvailable, maxBufferSize);
buffer = new byte[bufferSize];

// Read file
bytesRead = fileInputStream.read(buffer, 0, bufferSize);

while (bytesRead > 0)
{
outputStream.write(buffer, 0, bufferSize);
bytesAvailable = fileInputStream.available();
bufferSize = Math.min(bytesAvailable, maxBufferSize);
bytesRead = fileInputStream.read(buffer, 0, bufferSize);
}

outputStream.writeBytes(lineEnd);
outputStream.writeBytes(twoHyphens + boundary + twoHyphens + lineEnd);

// Responses from the server (code and message)
serverResponseCode = connection.getResponseCode();
serverResponseMessage = connection.getResponseMessage();

fileInputStream.close();
outputStream.flush();
outputStream.close();
}
catch (Exception ex)
{
//Exception handling
}