Android HTTP uploads files and submits parameters through post (via Assembly Protocol)

Httpurlconnection conn = NULL;

Dataoutputstream outstream = NULL;
Try {
String boundary = "--------------------------- 7da1_7580612"; // data demarcation line

String multipart_form_data = "multipart/form-Data ";

URL url = new URL (Const. url );

// Upload the Form file
Stringbuilder emailsb = new stringbuilder ();
Emailsb. append ("--");
Emailsb. append (Boundary );
Emailsb. append ("\ r \ n ");
Emailsb. append ("content-Disposition: Form-data; name = \" email \ "\ r \ n ");
Emailsb. append (email );
Emailsb. append ("\ r \ n ");

Stringbuilder bitmapsb = new stringbuilder ();
Bitmapsb. append ("--");
Bitmapsb. append (Boundary );
Bitmapsb. append ("\ r \ n ");
Bitmapsb. append ("content-Disposition: Form-data; name = \" image \ "; filename = \" image \ "\ r \ n ");
Bitmapsb. append ("Content-Type: image/PNG \ r \ n ");

Byte [] end_data = ("--" + boundary + "-- \ r \ n"). getbytes (); // data end mark

File file = new file ("/mnt/sdcard/111.png ");
Fileinputstream fileis = new fileinputstream (File );

Long contentlenght = emailsb. tostring (). getbytes (). Length + end_data.length

+ Bitmapsb. tostring (). getbytes (). Length + file. Length () + "\ r \ n". getbytes (). length;

Conn = (httpurlconnection) URL. openconnection ();
Conn. setdoinput (true); // allow input
Conn. setdooutput (true); // allow output
Conn. setusecaches (false); // do not use caches
Conn. setrequestmethod ("Post ");
Conn. setrequestproperty ("connection", "keep-alive ");
Conn. setrequestproperty ("Content-Type", multipart_form_data + "; boundary =" + boundary );
Conn. setrequestproperty ("Content-Length", long. tostring (contentlenght ));


Outstream = new dataoutputstream (conn. getoutputstream ());

Outstream. Write (emailsb. tostring (). getbytes ());

Outstream. Write (bitmapsb. tostring (). getbytes ());

Byte [] buffer = new byte [1024];
Int Len = 0;
While (LEN = fileis. Read (buffer ))! =-1 ){

Outstream. Write (buffer, 0, Len );
}
Outstream. Write ("\ r \ n". getbytes ());


Outstream. Write (end_data );
Outstream. Flush ();
Int CAH = conn. getresponsecode ();
If (CAH! = 200 ){

System. Out. println ("Upload Failed ");

Return;
}
Inputstream is = conn. getinputstream ();
Int ch;
Stringbuilder result = new stringbuilder ();
While (CH = is. Read ())! =-1 ){

Result. append (char) CH );
}
System. Out. println ("Result:" + result. tostring ());
} Catch (ioexception e ){
// Todo auto-generated Catch Block
E. printstacktrace ();
}
Finally {

Try {

If (outstream! = NULL ){

Outstream. Close ();

}
} Catch (ioexception e ){
// Todo auto-generated Catch Block
E. printstacktrace ();
}

If (Conn! = NULL ){

Conn. Disconnect ();

Conn = NULL;

}

}

It is rarely used to upload files using the httpurlconnection post form, which is troublesome.

 

The principle is: analyze the data format uploaded by the file, and then construct the corresponding string sent to the server according to the format.

The format is as follows: httppost123 is a self-constructed string, which can be any other string.

---------- Httppost123 (\ r \ n)
Content-Disposition: Form-data; name = "IMG"; filename = "t.txt" (\ r \ n)
Content-Type: Application/octet-stream (\ r \ n)

(\ R \ n)

Sdfsdfsdfsdfsdf (\ r \ n)
---------- Httppost123 (\ r \ n)
Content-Disposition: Form-data; name = "text" (\ r \ n)

(\ R \ n)

Text tttt (\ r \ n)
---------- Httppost123 -- (\ r \ n)
(\ R \ n)

 

The above (\ r \ n) indicates that each data must end with (\ r \ n.