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Eclipse Mobile Java Development Tools
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Creating a new Device Importer

In this section, you will be learning how to create a device importer for a non Unified Emulator Interface (UEI) compliant SDKs.


The device importer creation process is composed of the following tasks:

  1. Extend the org.eclipse.mtj.core.deviceimporter extension point;
  2. Implement the org.eclipse.mtj.core.sdk.device.IDeviceImporter interface;

Extending the org.eclipse.mtj.core.deviceimporter Extension Point

The 3 required extension fields must filled in:

  1. id : a fully-qualified identifier for this device importer implementation.
  2. priority : define the priority order for this importer. The priority may range from 1 to 99. The importers will be consulted in priority order starting with the lower numbered priority and working toward the highest numbered priority. The first device importer that requires a non-null result for a particular folder will "win" and no further importer instances will be consulted.
  3. class : the implementation of the org.eclipse.mtj.core.sdk.device.IDeviceImporter interface.

An optional displayable name for this particular device importer may also be defined on the name field.

On the example bellow you'll find the declaration of a deviceimporter named "ME4SE Device Importer":



"ME4SE Device Importer"


Implementing the org.eclipse.mtj.core.sdk.device.IDeviceImporter interface

The org.eclipse.mtj.core.sdk.device.IDeviceImporter interface has just one method to be implemented.

public List<IDevice> importDevices(File directory, IProgressMonitor monitor)
            throws CoreException, InterruptedException;

The implementor is responsible for, given an existing file system directory, return a list of org.eclipse.mtj.core.sdk.device.IDevice instances available in that directory.

On the example bellow you'll find the implementation of the IDeviceImporter for a "ME4SE" SDK:

public class ME4SEDeviceImporter extends JavaEmulatorDeviceImporter {

    // Various pieces of static information
    private static final String EMULATOR_JAR_PREFIX = "me4se"; //$NON-NLS-1$
    private static final String EMULATOR_JAR_SUFFIX = ".jar"; //$NON-NLS-1$

    // Properties file holding emulator/device information
    private static final String PROPS_FILE = ""; //$NON-NLS-1$

    /* (non-Javadoc)
     * @see org.eclipse.mtj.core.sdk.device.IDeviceImporter#importDevices(, org.eclipse.core.runtime.IProgressMonitor)
    public List<IDevice> importDevices(File directory, IProgressMonitor monitor) {
        ArrayList<IDevice> devices = null;

        try {
            File[] files = directory.listFiles(new FilenameFilter() {
                public boolean accept(File dir, String name) {
                    return name.startsWith(EMULATOR_JAR_PREFIX)
                            && name.endsWith(EMULATOR_JAR_SUFFIX);

            // We should probably look more deeply into the jar, but this should
            // do for now.
            if ((files != null) && (files.length > 0)) {
                IMIDPDevice device = createDevice(files[0]);

                if (device != null) {
                    devices = new ArrayList<IDevice>(1);
        } catch (Exception e) {
                    Messages.ME4SEDeviceImporter_importing_error, e);

        return devices;

     * Add the device libraries.
     * @param jarFile
     * @param classpath
     * @param importer
    private void addDeviceLibraries(File jarFile, IDeviceClasspath classpath,
            ILibraryImporter importer) {

        // Now add the player libraries
        String classpathString = getDeviceProperties().getProperty(
                JavaEmulatorDeviceProperties.CLASSPATH.toString(), //$NON-NLS-1$

        Map<String, String> replaceableParameters = new HashMap();
        replaceableParameters.put("me4sejar", jarFile.toString()); //$NON-NLS-1$

        classpathString = ReplaceableParametersProcessor
        String[] entries = classpathString.split(";"); //$NON-NLS-1$

        for (String entrie : entries) {
            IMIDPLibrary library = (IMIDPLibrary) importer
                    .createLibraryFor(new File(entrie));

            // Because of the structure of the libraries,
            // we need to hard-code the CLDC and MIDP API versions
            IMIDPAPI api = library.getAPI(MIDPAPIType.CONFIGURATION);
            if (api != null) {
                api.setVersion(new Version("1.1")); //$NON-NLS-1$
            api = library.getAPI(MIDPAPIType.PROFILE);
            if (api != null) {
                api.setVersion(new Version("2.0")); //$NON-NLS-1$


     * Create the new device instance for the specified ME4SE jar file.
     * @param jarFile
     * @return
    private IMIDPDevice createDevice(File jarFile) {
        ME4SEDevice device = new ME4SEDevice();

        device.setDescription("ME4SE Device"); //$NON-NLS-1$
        device.setDeviceProperties(new Properties());
        device.setGroupName("ME4SE"); //$NON-NLS-1$
        device.setName("ME4SE"); //$NON-NLS-1$
        device.setProtectionDomains(new String[0]);

        ISymbolSet dss = MTJCore.getSymbolSetFactory()
        ISymbolSet pss = MTJCore.getSymbolSetFactory()

        return device;

     * Get the device classpath based on the specified player.jar file.
     * @param jarFile
     * @return
    private IDeviceClasspath getDeviceClasspath(File jarFile) {
        IDeviceClasspath classpath = MTJCore.createNewDeviceClasspath();
        addDeviceLibraries(jarFile, classpath, MTJCore

        return classpath;

    /* (non-Javadoc)
     * @see org.eclipse.mtj.internal.core.sdk.device.JavaEmulatorDeviceImporter#getDevicePropertiesURL()
    protected URL getDevicePropertiesURL() {
        return Activator.getDefault().getBundle().getEntry(PROPS_FILE);

How to access the deviceimporter implementations

The developer can access the available implementations through the MTJCore facade method getDeviceFinder()

MTJ provides 3 implementations for the deviceimporter E.P., available in the following plug-ins:

  • org.eclipse.mtj.toolkit.uei responsible for importing all UEI compatible SDK's (id org.eclipse.mtj.toolkit.uei.importer)
  • org.eclipse.mtj.toolkit.mpowerplayer responsible for importing the MPowerPlayer SDK (id org.eclipse.mtj.toolkit.mpowerplayer.importer)
  • org.eclipse.mtj.toolkit.microemu responsible for importing the MicroEmu SDK (id org.eclipse.mtj.toolkit.microemu.importer)

  Published under the terms of the Eclipse Public License Version 1.0 ("EPL") Design by Interspire