www.pudn.com > 20051122095286.zip > HttpMIDlet.java

package ora.ch6; 
 
import java.io.InputStream; 
import java.io.IOException; 
import java.io.OutputStream; 
import javax.microedition.io.Connector; 
import javax.microedition.io.HttpConnection; 
import javax.microedition.lcdui.Alert; 
import javax.microedition.lcdui.AlertType; 
import javax.microedition.lcdui.Command; 
import javax.microedition.lcdui.CommandListener; 
import javax.microedition.lcdui.Display; 
import javax.microedition.lcdui.Displayable; 
import javax.microedition.lcdui.Form; 
import javax.microedition.lcdui.StringItem; 
import javax.microedition.lcdui.TextField; 
import javax.microedition.midlet.MIDlet; 
import javax.microedition.midlet.MIDletStateChangeException; 
 
public class HttpMIDlet extends MIDlet 
                    implements CommandListener, Runnable { 
 
    private Display display; 
    private Form addressForm; 
    private Form connectForm; 
    private Form displayForm; 
    private TextField serverURL; 
    private StringItem messageLabel; 
    private StringItem errorLabel; 
    private Command okCommand; 
    private Command exitCommand; 
    private Command backCommand; 
 
    protected void startApp() throws MIDletStateChangeException { 
        if (display == null) { 
            initialize(); 
            display.setCurrent(addressForm); 
        } 
    } 
 
    protected void pauseApp() { 
    } 
 
    protected void destroyApp(boolean unconditional) 
                        throws MIDletStateChangeException { 
    } 
 
    public void commandAction(Command cmd, Displayable d) { 
        if (cmd == okCommand) { 
            Thread t = new Thread(this); 
            t.start(); 
            display.setCurrent(connectForm); 
        } else if (cmd == backCommand) { 
            display.setCurrent(addressForm); 
        } else if (cmd == exitCommand) { 
            try { 
                destroyApp(true); 
            } catch (MIDletStateChangeException ex) { 
            } 
            notifyDestroyed(); 
        } 
    } 
 
    public void run() { 
        InputStream is = null; 
        HttpConnection conn = null; 
 
        try { 
            String url = serverURL.getString(); 
            if (!url.startsWith("http://") &&  
			!url.startsWith("https://")) { 
                url = "http://" + url; 
            } 
            conn = (HttpConnection)Connector.open(url, Connector.READ_WRITE); 
        } catch (Exception ex) { 
		System.out.println(ex); 
		ex.printStackTrace(); 
            Alert alert = new Alert("Invalid Address", 
                        "The supplied address is invalid\n" + 
                        "Please correct it and try again.", null, 
                        AlertType.ERROR); 
            alert.setTimeout(Alert.FOREVER); 
            display.setCurrent(alert, addressForm); 
            return; 
        } 
 
        try { 
            // Fetch the required page, reading up 
            // to a maximum of 128 bytes 
            if (conn.getResponseCode() == HttpConnection.HTTP_OK) { 
                is = conn.openInputStream(); 
                final int MAX_LENGTH = 128; 
                byte[] buf = new byte[MAX_LENGTH]; 
                int total = 0; 
                while (total < MAX_LENGTH) { 
                    int count = is.read(buf, total, MAX_LENGTH - total); 
                    if (count < 0) { 
                        break; 
                    } 
                    total += count; 
                } 
                is.close(); 
                String reply = new String(buf, 0, total); 
                messageLabel.setText(reply); 
            } else { 
                messageLabel.setText("Failed: error " + conn.getResponseCode() + 
                                "\n" + conn.getResponseMessage()); 
            } 
             
            // Get the response code and print all the headers 
            System.out.println("Response code = " + conn.getResponseCode()); 
            System.out.println("Response message = " + conn.getResponseMessage()); 
            for (int i = 0; ; i++) { 
                String key = conn.getHeaderFieldKey(i); 
                String value = conn.getHeaderField(i); 
                if (key == null) { 
                    // Reached last header 
                    break; 
                } 
                System.out.println(key + " = " + value); 
            } 
            conn.close(); 
            display.setCurrent(displayForm); 
        } catch (IOException ex) { 
		System.out.println(ex); 
		ex.printStackTrace(); 
            Alert alert = new Alert("I/O Error", 
                        "An error occurred while communicating with the server.", 
                        null, AlertType.ERROR); 
            alert.setTimeout(Alert.FOREVER); 
            display.setCurrent(alert, addressForm); 
            return; 
        } finally { 
            // Close open streams 
           try { 
                if (is != null) { 
                    is.close(); 
                    is = null; 
                } 
            } catch (IOException ex1) { 
            } 
            try { 
                if (conn != null) { 
                    conn.close(); 
                    conn = null; 
                } 
            } catch (IOException ex1) { 
            } 
        } 
    } 
 
    private void initialize() { 
        display = Display.getDisplay(this); 
 
        // Commands 
        exitCommand = new Command("Exit", Command.EXIT, 0); 
        okCommand = new Command("OK", Command.OK, 0); 
        backCommand = new Command("Back", Command.BACK, 0); 
 
        // The address form 
        addressForm = new Form("HTTP Client"); 
        serverURL = new TextField("URL:", "", 256, TextField.ANY); 
        addressForm.append(serverURL); 
        addressForm.addCommand(okCommand); 
        addressForm.addCommand(exitCommand); 
        addressForm.setCommandListener(this); 
 
        // The connect form 
        connectForm = new Form("Connecting"); 
        messageLabel = new StringItem(null, "Connecting...\nPlease wait."); 
        connectForm.append(messageLabel); 
        connectForm.addCommand(backCommand); 
        connectForm.setCommandListener(this); 
 
        // The display form 
        displayForm = new Form("Server Reply"); 
        messageLabel = new StringItem(null, null); 
        displayForm.append(messageLabel); 
        displayForm.addCommand(backCommand); 
        displayForm.setCommandListener(this); 
    } 
}