sumscreen.java

NOKIA经典联网例子

// Copyright 2002 Nokia Corporation. 
// 
// THIS SOURCE CODE IS PROVIDED 'AS IS', WITH NO WARRANTIES WHATSOEVER, 
// EXPRESS OR IMPLIED, INCLUDING ANY WARRANTY OF MERCHANTABILITY, FITNESS 
// FOR ANY PARTICULAR PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE 
// OR TRADE PRACTICE, RELATING TO THE SOURCE CODE OR ANY WARRANTY OTHERWISE 
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// RIGHTS GRANTED HEREUNDER DOES NOT INFRINGE OR MAY NOT CAUSE INFRINGEMENT 
// OF ANY PATENT OR OTHER INTELLECTUAL PROPERTY RIGHTS OWNED OR CONTROLLED 
// BY THIRD PARTIES 
// 
// Furthermore, information provided in this source code is preliminary, 
// and may be changed substantially prior to final release. Nokia Corporation 
// retains the right to make changes to this source code at 
// any time, without notice. This source code is provided for informational 
// purposes only. 
// 
// Nokia and Nokia Connecting People are registered trademarks of Nokia
// Corporation.
// Java and all Java-based marks are trademarks or registered trademarks of
// Sun Microsystems, Inc.
// Other product and company names mentioned herein may be trademarks or
// trade names of their respective owners.
// 
// A non-exclusive, non-transferable, worldwide, limited license is hereby 
// granted to the Licensee to download, print, reproduce and modify the 
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package example.sum;

import javax.microedition.lcdui.*;
import java.io.IOException;


class SumScreen
    extends Form
    implements CommandListener, HttpPosterListener
{
    private final SumMIDlet midlet;
    private final HttpPoster httpPoster;
    private final TextField inputField;
    private final StringItem outputField;
    private final Command sendCommand;
    private final Command quitCommand;
    private volatile boolean readyForInput = true;


    SumScreen(SumMIDlet midlet,
              HttpPoster httpPoster)
    {
        super("Sum");
        this.midlet = midlet;
        this.httpPoster = httpPoster;

        inputField = new TextField("Input:", "1", 8, TextField.NUMERIC);
        append(inputField);
        outputField = new StringItem("Output:", "0");
        append(outputField);
        sendCommand = new Command("Send", Command.SCREEN, 2);
        addCommand(sendCommand);
        quitCommand = new Command("Quit", Command.EXIT, 2);
        addCommand(quitCommand);

        setCommandListener(this);
    }


    public void commandAction(Command c, Displayable d)
    {
        if (c == quitCommand)
        {
            midlet.sumScreenQuit();
        }
        else if (readyForInput)
        {
            if (c == sendCommand)
            {
                try
                {
                    String requestStr = inputField.getString();
                    httpPoster.sendRequest(requestStr, this);
                    readyForInput = false;
                }
                catch (IOException e)
                {
                    outputField.setText("Error");
                }
            }
        }
    }


    public void receiveHttpResponse(String response)
    {
        outputField.setText(response);
        readyForInput = true;
    }


    public void handleHttpError(String errorStr)
    {
        outputField.setText("Error");
        readyForInput = true;
    }
}