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J2ME Development using Eclipse
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Java Application Descriptor Editor
This document describes EclipseME's built-in Java Application Descriptor (JAD) editor.
Overview
J2ME distributions consist of a JAR file containing the software, and a JAD file containing information for the J2ME container describing the contents of the source file.
EclipseME has a built-in JAD editor that handles the details of formatting the JAD file for you. Using the JAD editor, you can make all the required entries to allow your MIDlet to be properly supported. The information that makes up the JAD file is spread across several tabs, along the bottom of the editor window, for convenience.
Required Tab
The first tab on the JAD editor window is labeled Required
The items on this tab are:
| Item | Contents |
| Midlet Jar URL | The URL from which the JAR file can be loaded. By default, this field will be set to the name of the Midlet Suite project. Changing the name of the jar file will automatically cause a rebuild of the deployed jar with the new name. A full URL may be specified in this field, in which case the final component of the URL will be used when building the JAR name. |
| Midlet Name | The name of the MIDlet suite that identifies the MIDlets to the user. Individual MIDlets can also have names. See the Midlets tab below for that information. |
| Midlet Vendor | The organization that provides the MIDlet suite. |
| Midlet Version | The version number of the MIDlet suite. The format is <major>.<minor>.<micro> as described in the Java Product Versioning Specification. the J2ME container can use this for install and upgrade purposes, as well as for communication with the user. |
| Microedition Configuration | The J2ME Configuration (CLDC version) required by this MIDlet suite. The contents of this pull-down will depend on the CLDC versions supported by the Wireless Toolkit that you are using for this project. |
| Microedition Profile | The J2ME profile required by this MIDlet suite. As with the Microedition Configuration, the contents of this pull-down will depend on the profile versions supported by the Wireless Toolkit that you are using for this project. |
Note that the EclipseME plug-in automatically provides the MIDLet-Jar-Size item required by the J2ME specification, so you are not required to enter this information.
Midlets tab
The second tab on the JAD editor window is labeled Midlets. On this tab, you must have one entry for each MIDlet in your MIDlet suite. If you selected the Add to Application Descriptor option when you created the MIDlet class, an entry is automatically made for you. If not, you must use the Add button to add an entry for your MIDlet.
In versions of EclipseME prior to 0.5.0, pressing the Add presented a dialog into which you entered the relevant information. Beginning with version 0.5.0, this panel operates more like a spreadsheet. Pressing the Add button creates a new row, and the items in the list can be directly edited in-place.
The columns on this tab are:
| Item | Contents |
| Name | Name of the MIDlet. If there are multiple MIDlets in your suite, when the user invokes the suite, the J2ME device will typically prompt the user for the specific MIDlet to be executed. This entry provides the name that will be shown to the user. |
| Icon | Path to the PNG file within the JAR file that contains the icon for this MIDlet. |
| Class | The MIDlet class itself. This is the class you created derived from javax.microedition.midlet.MIDlet. |
To edit the name or the icon path, simply click in the cell and enter the
new value. To change the class, click in the cell. When you do this, a
button will appear.
Pressing the button will display a dialog box that will allow you to choose
the appropriate class for the midlet.
Optional tab
The third tab on the JAD editor window is labeled Optional. On this tab you can make entries that are defined in the J2ME specification, but which are not required.
The items on this tab are:
| Item | Contents |
| Midlet Permissions | Permissions that your MIDlet must have in order to operate correctly. Permissions are usually only provided for signed MIDlets. |
| Optional Midlet Permissions | Permissions that your MIDlet would like, but can work without. |
| Midlet Data Size | The minimum number of bytes of persistent data required by the MIDlet. The device may provide additional storage according to its own policy. The default is zero. |
| Midlet Description | The description of the MIDlet suite. |
| Midlet Icon | The name of a PNG file within the JAR file used to represent the MIDlet suite. It is the icon used by the Java Application Manager to identify the suite. This icon is for the suite as a whole, as distinct from the individual MIDlet icons you can set up on the Midlets Tab. |
| Midlet Information URL | A URL for information further describing the MIDlet suite. |
Over the Air tab
The fourth tab on the JAD editor window is labeled Over the Air. On this tab you can make entries that are related to Over-the-Air provisioning.
The items on this tab are:
| Item | Contents |
| Midlet Delete Confirm | A text message provided to the user when prompted to confirm deletion of the MIDlet suite. |
| Midlet Delete Notify | The URL to which a POST request is sent to confirm successful deletion of this MIDlet suite. |
| Midlet Install Notify | The URL to which a POST request is sent to confirm successful installation of this MIDlet suite. |
User Defined tab
The fifth tab on the JAD editor window is labeled User Defined. On this tab you can make custom entries relating to your particular MIDlet.
The columns on this tab are:
| Item | Contents |
| Key | The key string used to retrieve the value. |
| Value | The value associated with the key. |