How to use GET and POST methods in HTTP from a MIDlet-J2ME

//This example shows how to use GET and POST methods in HTTP from a MIDlet.

import java.io.*;

import javax.microedition.io.*;

import javax.microedition.lcdui.*;

import javax.microedition.midlet.*;

public class HttpTest1 extends MIDlet {

private Display display;

public HttpTest1() {

try {

//NOTE:Comment out the functionality which you don't want to test

getBirthdayFromNameUsingGet("John");

getBirthdayFromNameUsingPost("John");

}

catch (IOException e) {

System.out.println("IOException " + e.toString());

}

}

/**

* MIDlet lifecycle functions

*/

public void startApp() { }

public void pauseApp() {

}

public void destroyApp(boolean unconditional) {

}

/**

This function connects to web server and passes the parameter name to the

target in HTTP Get request. Upon successful connection, web server returns

birthday for 'name'.

This function also calls getConnectionInformation to retrieve properties of

HTTPConnection

**/

public void getBirthdayFromNameUsingGet(String name) throws IOException {

HttpConnection httpConn = null;

String url = "http://localhost:8080/examples/servlet/GetBirthday?name=" + name;

InputStream is = null;

OutputStream os = null;

try {

// Open an HTTP Connection object

httpConn = (HttpConnection)Connector.open(url);

// Setup HTTP Request

httpConn.setRequestMethod(HttpConnection.GET);

httpConn.setRequestProperty("User-Agent",

"Profile/MIDP-1.0 Confirguration/CLDC-1.0");

// This function retrieves the information of this connection

getConnectionInformation(httpConn);

/** Initiate connection and check for the response code. If the

response code is HTTP_OK then get the content from the target

**/

int respCode = httpConn.getResponseCode();

if (respCode == httpConn.HTTP_OK) {

StringBuffer sb = new StringBuffer();

os = httpConn.openOutputStream();

is = httpConn.openDataInputStream();

int chr;

while ((chr = is.read()) != -1)

sb.append((char) chr);

// Web Server just returns the birthday in mm/dd/yy format.

System.out.println(name+"'s Birthday is " + sb.toString());

}

else {

System.out.println("Error in opening HTTP Connection. Error#" + respCode);

}

} finally {

if(is!= null)

is.close();

if(os != null)

os.close();

if(httpConn != null)

httpConn.close();

}

}

/**

This function connects to web server and passes the parameter name to the

target in HTTP POST request. Upon successful connection, web server returns

birthday for 'name'.

This function also calls getConnectionInformation to retrieve properties of

HTTPConnection

**/

public void getBirthdayFromNameUsingPost(String name) throws IOException {

HttpConnection httpConn = null;

String url = "http://localhost:8080/examples/servlet/GetBirthday";

InputStream is = null;

OutputStream os = null;

try {

// Open an HTTP Connection object

httpConn = (HttpConnection)Connector.open(url);

// Setup HTTP Request to POST

httpConn.setRequestMethod(HttpConnection.POST);

httpConn.setRequestProperty("User-Agent",

"Profile/MIDP-1.0 Confirguration/CLDC-1.0");

httpConn.setRequestProperty("Accept_Language","en-US");

//Content-Type is must to pass parameters in POST Request

httpConn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");

// This function retrieves the information of this connection

getConnectionInformation(httpConn);

os = httpConn.openOutputStream();

String params;

params = "name=" + name;

os.write(params.getBytes());

/**Caution: os.flush() is controversial. It may create unexpected behavior

on certain mobile devices. Try it out for your mobile device **/

//os.flush();

// Read Response from the Server

StringBuffer sb = new StringBuffer();

is = httpConn.openDataInputStream();

int chr;

while ((chr = is.read()) != -1)

sb.append((char) chr);

// Web Server just returns the birthday in mm/dd/yy format.

System.out.println(name+"'s Birthday is " + sb.toString());

} finally {

if(is!= null)

is.close();

if(os != null)

os.close();

if(httpConn != null)

httpConn.close();

}

}

/*** After setup, attributes of the HttpConnection object can be retrived using

various get methods.

***/

void getConnectionInformation(HttpConnection hc) {

System.out.println("Request Method for this connection is " + hc.getRequestMethod());

System.out.println("URL in this connection is " + hc.getURL());

// It better be HTTP:)

System.out.println("Protocol for this connection is " + hc.getProtocol());

System.out.println("This object is connected to " + hc.getHost() + " host");

System.out.println("HTTP Port in use is " + hc.getPort());

System.out.println("Query parameter in this request are " + hc.getQuery());

}

}