Java Tutorial/J2ME/Servlet Invoke
An example MIDlet to invoke a CGI script
/* License
*
* Copyright 1994-2004 Sun Microsystems, Inc. All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistribution of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* * Redistribution in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* Neither the name of Sun Microsystems, Inc. or the names of contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* This software is provided "AS IS," without a warranty of any kind. ALL
* EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING
* ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
* OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN MICROSYSTEMS, INC. ("SUN")
* AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE
* AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
* DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR ANY LOST
* REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL,
* INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY
* OF LIABILITY, ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE,
* EVEN IF SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
*
* You acknowledge that this software is not designed, licensed or intended
* for use in the design, construction, operation or maintenance of any
* nuclear facility.
*/
import java.io.IOException;
import java.io.InputStream;
import javax.microedition.io.Connector;
import javax.microedition.io.HttpConnection;
import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.TextBox;
import javax.microedition.midlet.MIDlet;
/**
* An example MIDlet to invoke a CGI script.
*/
public class FirstMidletServlet extends MIDlet {
private Display display;
String url = "http://127.0.0.1/HelloServlet";
public FirstMidletServlet() {
display = Display.getDisplay(this);
}
/**
* Initialization. Invoked when we activate the MIDlet.
*/
public void startApp() {
try {
invokeServlet(url);
} catch (IOException e) {
System.out.println("IOException " + e);
e.printStackTrace();
}
}
/**
* Pause, discontinue ....
*/
public void pauseApp() {
}
/**
* Destroy must cleanup everything.
*/
public void destroyApp(boolean unconditional) {
}
/**
* Prepare connection and streams then invoke servlet.
*/
void invokeServlet(String url) throws IOException {
HttpConnection c = null;
InputStream is = null;
StringBuffer b = new StringBuffer();
TextBox t = null;
try {
c = (HttpConnection) Connector.open(url);
c.setRequestMethod(HttpConnection.GET);
c.setRequestProperty("IF-Modified-Since", "20 Jan 2001 16:19:14 GMT");
c.setRequestProperty("User-Agent",
"Profile/MIDP-1.0 Configuration/CLDC-1.0");
c.setRequestProperty("Content-Language", "en-CA");
is = c.openDataInputStream();
int ch;
while ((ch = is.read()) != -1) {
b.append((char) ch);
// System.out.println((char)ch);
}
t = new TextBox("First Servlet", b.toString(), 1024, 0);
} finally {
if (is != null) {
is.close();
}
if (c != null) {
c.close();
}
}
display.setCurrent(t);
}
}
MIDlet and Servlet
/* License
*
* Copyright 1994-2004 Sun Microsystems, Inc. All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistribution of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* * Redistribution in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* Neither the name of Sun Microsystems, Inc. or the names of contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* This software is provided "AS IS," without a warranty of any kind. ALL
* EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING
* ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
* OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN MICROSYSTEMS, INC. ("SUN")
* AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE
* AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
* DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR ANY LOST
* REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL,
* INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY
* OF LIABILITY, ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE,
* EVEN IF SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
*
* You acknowledge that this software is not designed, licensed or intended
* for use in the design, construction, operation or maintenance of any
* nuclear facility.
*/
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import javax.microedition.io.Connector;
import javax.microedition.io.HttpConnection;
import javax.microedition.lcdui.Choice;
import javax.microedition.lcdui.rumand;
import javax.microedition.lcdui.rumandListener;
import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Displayable;
import javax.microedition.lcdui.List;
import javax.microedition.lcdui.TextBox;
import javax.microedition.lcdui.TextField;
import javax.microedition.midlet.MIDlet;
import javax.microedition.midlet.MIDletStateChangeException;
public class SecondMidletServlet extends MIDlet implements CommandListener {
Display display = null;
List menu = null;
TextBox input = null;
String user = null;
String url = "http://developer.java.sun.ru/servlet/RequestServlet";
static final Command backCommand = new Command("Back", Command.BACK, 0);
static final Command submitCommand = new Command("Submit", Command.OK, 2);
static final Command exitCommand = new Command("Exit", Command.STOP, 3);
String currentMenu = null;
public SecondMidletServlet() {
}
public void startApp() throws MIDletStateChangeException {
display = Display.getDisplay(this);
menu = new List("Invoke Servlet", Choice.IMPLICIT);
menu.append("Add a user", null);
menu.addCommand(exitCommand);
menu.setCommandListener(this);
mainMenu();
}
public void pauseApp() {
}
public void destroyApp(boolean unconditional) {
notifyDestroyed();
}
void mainMenu() {
display.setCurrent(menu);
}
public void addName() {
input = new TextBox("Enter first name:", "", 5, TextField.ANY);
input.addCommand(submitCommand);
input.addCommand(backCommand);
input.setCommandListener(this);
input.setString("");
display.setCurrent(input);
}
void invokeServlet(String url) throws IOException {
HttpConnection c = null;
InputStream is = null;
OutputStream os = null;
StringBuffer b = new StringBuffer();
TextBox t = null;
try {
c = (HttpConnection) Connector.open(url);
c.setRequestMethod(HttpConnection.POST);
c.setRequestProperty("IF-Modified-Since", "20 Jan 2001 16:19:14 GMT");
c.setRequestProperty("User-Agent",
"Profile/MIDP-1.0 Configuration/CLDC-1.0");
c.setRequestProperty("Content-Language", "en-CA");
os = c.openOutputStream();
String str = "name=" + user;
byte postmsg[] = str.getBytes();
System.out.println("Length: " + str.getBytes());
for (int i = 0; i < postmsg.length; i++) {
os.write(postmsg[i]);
}
// or you can easily do:
// os.write(("name="+user).getBytes());
os.flush();
is = c.openDataInputStream();
int ch;
while ((ch = is.read()) != -1) {
b.append((char) ch);
System.out.print((char) ch);
}
t = new TextBox("Second Servlet", b.toString(), 1024, 0);
t.addCommand(backCommand);
t.setCommandListener(this);
} finally {
if (is != null) {
is.close();
}
if (os != null) {
os.close();
}
if (c != null) {
c.close();
}
}
display.setCurrent(t);
}
public void commandAction(Command c, Displayable d) {
String label = c.getLabel();
if (label.equals("Exit")) {
destroyApp(true);
} else if (label.equals("Back")) {
mainMenu();
} else if (label.equals("Submit")) {
user = input.getString();
try {
invokeServlet(url);
} catch (IOException e) {
}
} else {
addName();
}
}
}
