EDIT

import java.io.IOException;

import java.net.URL;

import org.eclipse.core.runtime.IStatus;

import org.eclipse.core.runtime.Status;

import org.eclipse.swt.events.SelectionAdapter;

import org.eclipse.swt.events.SelectionEvent;

import eu.etaxonomy.taxeditor.model.ImageResources;

import eu.etaxonomy.taxeditor.model.MessagingUtils;

import eu.etaxonomy.taxeditor.store.internal.TaxeditorStorePlugin;

import eu.etaxonomy.taxeditor.workbench.WorkbenchUtility;

        Composite textAndButton = formFactory.createComposite(getLayoutComposite(), style);

        addControl(textAndButton);

        textAndButton.setLayout(LayoutConstants.LAYOUT(2, false));

        textAndButton.setLayoutData(LayoutConstants.FILL_HORIZONTALLY());

      //uri text

        initText(formFactory, null, textHeight, null, false, style, textAndButton);

      //button

        btnOpenBrowser = formFactory.createButton(textAndButton, "", SWT.NONE); //$NON-NLS-1$

        btnOpenBrowser.setImage(ImageResources.getImage(ImageResources.WEB));

        btnOpenBrowser.setToolTipText(Messages.UriWithLabelElement_OPEN_EXTERNAL_BROWSER);

        btnOpenBrowser.addSelectionListener(new SelectionAdapter() {

            @Override

            public void widgetSelected(SelectionEvent e) {

                String errorTitle = Messages.UriWithLabelElement_INVALID_URL;

                String errorText = Messages.UriWithLabelElement_COULD_NOT_OPEN_BROWSER;

                DOI doi= parseText();

                if(doi!=null){

                    try {

                        WorkbenchUtility.openWebpage(new URL(doi.asURI()));

                    } catch (IOException pie) {

                        MessagingUtils.informationDialog(errorTitle, new Status(IStatus.WARNING, TaxeditorStorePlugin.PLUGIN_ID, errorText, pie));

                    } catch (IllegalArgumentException iae) {

                        MessagingUtils.informationDialog(errorTitle, new Status(IStatus.WARNING, TaxeditorStorePlugin.PLUGIN_ID, errorText, iae));

                    }

                }

                else{

                    MessagingUtils.informationDialog(errorTitle, new Status(IStatus.WARNING, TaxeditorStorePlugin.PLUGIN_ID, errorText, null));

                }

            }

        });

        btnOpenBrowser.setLayoutData(LayoutConstants.RIGHT());