Network Programming for android

Android Network Programming is divided into two types: socket-based and http-based.

Socket-based usage

Server:

Start a server socket ServerSocket svr = new ServerSocket (8989 );

Start listening for request Socket s = svr. accept ();

Obtain the input and output DataInputStream dis = new DataInputStream (s. getInputStream ());

DataOutputStream dos = new DataOutputStream (s. getOutputStream ());

Socket interaction is completed through a stream, that is, the transmitted byte stream, so any file can be transmitted on it. Remember to close it.

We use DataInputStream/DataOutputStream for packaging because we want them to read and write basic data types such as readInt (), writeInt (), readUTF (), writeUTF (), and so on.

Client:

Initiate a socket connection Socket s = new Socket ("192.168.1.200", 8989 );

Obtain the input and output DataInputStream dis = new DataInputStream (s. getInputStream ());

DataOutputStream dos = new DataOutputStream (s. getOutputStream ());

Then you can communicate with each other. Remember to close it.

Http-based

Generally, a request is sent to an application server. In this case, HttpURLConnection is required.

First obtain HttpURLConnection urlConn = new URL ("http://www.google.com"). openConnection ();

Set flag

UrlConn. setDoOutput (true); urlConn. setDoInput (true); // set DoOutput to true in case of post.

UrlConn. setRequestMethod ("POST ");

UrlConn. setUseCache (false); // you can specify whether the cache is used.

UrlConn. setRequestProperty ("Content-type", "application/x-www-form-urlencoded"); // set content-type

Obtain the output stream to facilitate sending information to the server.

DataOutputStream dos = new DataOutputStream (urlConn. getOutputStream ());

Write Request Parameters in the desired stream

Dos. writeBytes ("name =" + URLEncoder. encode ("chenmouren", "gb2312 ");

Dos. flush (); dos. close (); // close immediately after sending.

Get input stream and Data

BufferReader reader = new BufferedReader (new InputStreamReader (urlConn. getInputStream ()));

Reader. readLine (); // use! = Null to determine whether to end

Reader. close ();

After reading, remember to close connection urlConn. disconnect ();

The process Record ends here.