Sample to demonstrate Http GET and POST from MIDlet
/*** Chapter 5 Sample to demonstrate Http GET and POST from 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());
System.out.println("Protocol for this connection is " + hc.getProtocol()); // It better be HTTP:)
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());
}
}
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