Java tutorial
/** * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.apache.hadoop.eclipse.servers; import java.net.URI; import java.net.URISyntaxException; import java.util.HashSet; import java.util.Iterator; import java.util.Map; import java.util.Set; import java.util.SortedMap; import java.util.TreeMap; import java.util.Map.Entry; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.eclipse.server.ConfProp; import org.apache.hadoop.eclipse.server.HadoopServer; import org.eclipse.jface.dialogs.IMessageProvider; import org.eclipse.jface.wizard.WizardPage; import org.eclipse.swt.SWT; import org.eclipse.swt.custom.ScrolledComposite; import org.eclipse.swt.events.ModifyEvent; import org.eclipse.swt.events.ModifyListener; import org.eclipse.swt.events.SelectionEvent; import org.eclipse.swt.events.SelectionListener; import org.eclipse.swt.graphics.Image; import org.eclipse.swt.layout.GridData; import org.eclipse.swt.layout.GridLayout; import org.eclipse.swt.widgets.Button; import org.eclipse.swt.widgets.Composite; import org.eclipse.swt.widgets.Control; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Event; import org.eclipse.swt.widgets.Group; import org.eclipse.swt.widgets.Label; import org.eclipse.swt.widgets.Listener; import org.eclipse.swt.widgets.TabFolder; import org.eclipse.swt.widgets.TabItem; import org.eclipse.swt.widgets.Text; /** * Wizard for editing the settings of a Hadoop location * * The wizard contains 3 tabs: General, Tunneling and Advanced. It edits * parameters of the location member which either a new location or a copy of * an existing registered location. */ public class HadoopLocationWizard extends WizardPage { Image circle; /** * The location effectively edited by the wizard. This location is a copy * or a new one. */ private HadoopServer location; /** * The original location being edited by the wizard (null if we create a * new instance). */ private HadoopServer original; /** * New Hadoop location wizard */ public HadoopLocationWizard() { super("Hadoop Server", "New Hadoop Location", null); this.original = null; this.location = new HadoopServer(); this.location.setLocationName(""); } /** * Constructor to edit the parameters of an existing Hadoop server * * @param server */ public HadoopLocationWizard(HadoopServer server) { super("Create a new Hadoop location", "Edit Hadoop Location", null); this.original = server; this.location = new HadoopServer(server); } /** * Performs any actions appropriate in response to the user having pressed * the Finish button, or refuse if finishing now is not permitted. * * @return the created or updated Hadoop location */ public HadoopServer performFinish() { try { if (this.original == null) { // New location Display.getDefault().syncExec(new Runnable() { public void run() { ServerRegistry.getInstance().addServer(HadoopLocationWizard.this.location); } }); return this.location; } else { // Update location final String originalName = this.original.getLocationName(); this.original.load(this.location); Display.getDefault().syncExec(new Runnable() { public void run() { ServerRegistry.getInstance().updateServer(originalName, HadoopLocationWizard.this.location); } }); return this.original; } } catch (Exception e) { e.printStackTrace(); setMessage("Invalid server location values", IMessageProvider.ERROR); return null; } } /** * Validates the current Hadoop location settings (look for Hadoop * installation directory). * */ private void testLocation() { setMessage("Not implemented yet", IMessageProvider.WARNING); } /** * Location is not complete (and finish button not available) until a host * name is specified. * * @inheritDoc */ @Override public boolean isPageComplete() { { String locName = location.getConfProp(ConfProp.PI_LOCATION_NAME); if ((locName == null) || (locName.length() == 0) || locName.contains("/")) { setMessage("Bad location name: " + "the location name should not contain " + "any character prohibited in a file name.", WARNING); return false; } } { String master = location.getConfProp(ConfProp.PI_JOB_TRACKER_HOST); if ((master == null) || (master.length() == 0)) { setMessage("Bad master host name: " + "the master host name refers to the machine " + "that runs the Job tracker.", WARNING); return false; } } { String jobTracker = location.getConfProp(ConfProp.JOB_TRACKER_URI); String[] strs = jobTracker.split(":"); boolean ok = (strs.length == 2); if (ok) { try { int port = Integer.parseInt(strs[1]); ok = (port >= 0) && (port < 65536); } catch (NumberFormatException nfe) { ok = false; } } if (!ok) { setMessage("The job tracker information (" + ConfProp.JOB_TRACKER_URI.name + ") is invalid. " + "This usually looks like \"host:port\"", WARNING); return false; } } { String fsDefaultURI = location.getConfProp(ConfProp.FS_DEFAULT_URI); try { URI uri = new URI(fsDefaultURI); } catch (URISyntaxException e) { setMessage( "The default file system URI is invalid. " + "This usually looks like \"hdfs://host:port/\" " + "or \"file:///dir/\"", WARNING); } } setMessage("Define the location of a Hadoop infrastructure " + "for running MapReduce applications."); return true; } /** * Create the wizard */ /* @inheritDoc */ public void createControl(Composite parent) { setTitle("Define Hadoop location"); setDescription("Define the location of a Hadoop infrastructure " + "for running MapReduce applications."); Composite panel = new Composite(parent, SWT.FILL); GridLayout glayout = new GridLayout(2, false); panel.setLayout(glayout); TabMediator mediator = new TabMediator(panel); { GridData gdata = new GridData(GridData.FILL_BOTH); gdata.horizontalSpan = 2; mediator.folder.setLayoutData(gdata); } this.setControl(panel /* mediator.folder */); { final Button btn = new Button(panel, SWT.NONE); btn.setText("&Load from file"); btn.setEnabled(false); btn.setToolTipText("Not yet implemented"); btn.addListener(SWT.Selection, new Listener() { public void handleEvent(Event e) { // TODO } }); } { final Button validate = new Button(panel, SWT.NONE); validate.setText("&Validate location"); validate.setEnabled(false); validate.setToolTipText("Not yet implemented"); validate.addListener(SWT.Selection, new Listener() { public void handleEvent(Event e) { testLocation(); } }); } } private interface TabListener { void notifyChange(ConfProp prop, String propValue); } /* * Mediator pattern to keep tabs synchronized with each other and with the * location state. */ private class TabMediator { TabFolder folder; private Set<TabListener> tabs = new HashSet<TabListener>(); TabMediator(Composite parent) { folder = new TabFolder(parent, SWT.NONE); tabs.add(new TabMain(this)); tabs.add(new TabAdvanced(this)); } /** * Access to current configuration settings * * @param propName the property name * @return the current property value */ String get(String propName) { return location.getConfProp(propName); } String get(ConfProp prop) { return location.getConfProp(prop); } /** * Implements change notifications from any tab: update the location * state and other tabs * * @param source origin of the notification (one of the tree tabs) * @param propName modified property * @param propValue new value */ void notifyChange(TabListener source, final ConfProp prop, final String propValue) { // Ignore notification when no change String oldValue = location.getConfProp(prop); if ((oldValue != null) && oldValue.equals(propValue)) return; location.setConfProp(prop, propValue); Display.getDefault().syncExec(new Runnable() { public void run() { getContainer().updateButtons(); } }); this.fireChange(source, prop, propValue); /* * Now we deal with dependencies between settings */ final String jobTrackerHost = location.getConfProp(ConfProp.PI_JOB_TRACKER_HOST); final String jobTrackerPort = location.getConfProp(ConfProp.PI_JOB_TRACKER_PORT); final String nameNodeHost = location.getConfProp(ConfProp.PI_NAME_NODE_HOST); final String nameNodePort = location.getConfProp(ConfProp.PI_NAME_NODE_PORT); final boolean colocate = location.getConfProp(ConfProp.PI_COLOCATE_MASTERS).equalsIgnoreCase("yes"); final String jobTrackerURI = location.getConfProp(ConfProp.JOB_TRACKER_URI); final String fsDefaultURI = location.getConfProp(ConfProp.FS_DEFAULT_URI); final String socksServerURI = location.getConfProp(ConfProp.SOCKS_SERVER); final boolean socksProxyEnable = location.getConfProp(ConfProp.PI_SOCKS_PROXY_ENABLE) .equalsIgnoreCase("yes"); final String socksProxyHost = location.getConfProp(ConfProp.PI_SOCKS_PROXY_HOST); final String socksProxyPort = location.getConfProp(ConfProp.PI_SOCKS_PROXY_PORT); Display.getDefault().syncExec(new Runnable() { public void run() { switch (prop) { case PI_JOB_TRACKER_HOST: { if (colocate) notifyChange(null, ConfProp.PI_NAME_NODE_HOST, jobTrackerHost); String newJobTrackerURI = String.format("%s:%s", jobTrackerHost, jobTrackerPort); notifyChange(null, ConfProp.JOB_TRACKER_URI, newJobTrackerURI); break; } case PI_JOB_TRACKER_PORT: { String newJobTrackerURI = String.format("%s:%s", jobTrackerHost, jobTrackerPort); notifyChange(null, ConfProp.JOB_TRACKER_URI, newJobTrackerURI); break; } case PI_NAME_NODE_HOST: { String newHDFSURI = String.format("hdfs://%s:%s/", nameNodeHost, nameNodePort); notifyChange(null, ConfProp.FS_DEFAULT_URI, newHDFSURI); // Break colocation if someone force the DFS Master if (!colocate && !nameNodeHost.equals(jobTrackerHost)) notifyChange(null, ConfProp.PI_COLOCATE_MASTERS, "no"); break; } case PI_NAME_NODE_PORT: { String newHDFSURI = String.format("hdfs://%s:%s/", nameNodeHost, nameNodePort); notifyChange(null, ConfProp.FS_DEFAULT_URI, newHDFSURI); break; } case PI_SOCKS_PROXY_HOST: { String newSocksProxyURI = String.format("%s:%s", socksProxyHost, socksProxyPort); notifyChange(null, ConfProp.SOCKS_SERVER, newSocksProxyURI); break; } case PI_SOCKS_PROXY_PORT: { String newSocksProxyURI = String.format("%s:%s", socksProxyHost, socksProxyPort); notifyChange(null, ConfProp.SOCKS_SERVER, newSocksProxyURI); break; } case JOB_TRACKER_URI: { String[] strs = jobTrackerURI.split(":", 2); String host = strs[0]; String port = (strs.length == 2) ? strs[1] : ""; notifyChange(null, ConfProp.PI_JOB_TRACKER_HOST, host); notifyChange(null, ConfProp.PI_JOB_TRACKER_PORT, port); break; } case FS_DEFAULT_URI: { try { URI uri = new URI(fsDefaultURI); if (uri.getScheme().equals("hdfs")) { String host = uri.getHost(); String port = Integer.toString(uri.getPort()); notifyChange(null, ConfProp.PI_NAME_NODE_HOST, host); notifyChange(null, ConfProp.PI_NAME_NODE_PORT, port); } } catch (URISyntaxException use) { // Ignore the update! } break; } case SOCKS_SERVER: { String[] strs = socksServerURI.split(":", 2); String host = strs[0]; String port = (strs.length == 2) ? strs[1] : ""; notifyChange(null, ConfProp.PI_SOCKS_PROXY_HOST, host); notifyChange(null, ConfProp.PI_SOCKS_PROXY_PORT, port); break; } case PI_COLOCATE_MASTERS: { if (colocate) notifyChange(null, ConfProp.PI_NAME_NODE_HOST, jobTrackerHost); break; } case PI_SOCKS_PROXY_ENABLE: { if (socksProxyEnable) { notifyChange(null, ConfProp.SOCKET_FACTORY_DEFAULT, "org.apache.hadoop.net.SocksSocketFactory"); } else { notifyChange(null, ConfProp.SOCKET_FACTORY_DEFAULT, "org.apache.hadoop.net.StandardSocketFactory"); } break; } } } }); } /** * Change notifications on properties (by name). A property might not be * reflected as a ConfProp enum. If it is, the notification is forwarded * to the ConfProp notifyChange method. If not, it is processed here. * * @param source * @param propName * @param propValue */ void notifyChange(TabListener source, String propName, String propValue) { ConfProp prop = ConfProp.getByName(propName); if (prop != null) notifyChange(source, prop, propValue); location.setConfProp(propName, propValue); } /** * Broadcast a property change to all registered tabs. If a tab is * identified as the source of the change, this tab will not be notified. * * @param source TODO * @param prop * @param value */ private void fireChange(TabListener source, ConfProp prop, String value) { for (TabListener tab : tabs) { if (tab != source) tab.notifyChange(prop, value); } } } /** * Create a SWT Text component for the given {@link ConfProp} text * configuration property. * * @param listener * @param parent * @param prop * @return */ private Text createConfText(ModifyListener listener, Composite parent, ConfProp prop) { Text text = new Text(parent, SWT.SINGLE | SWT.BORDER); GridData data = new GridData(GridData.FILL_HORIZONTAL); text.setLayoutData(data); text.setData("hProp", prop); text.setText(location.getConfProp(prop)); text.addModifyListener(listener); return text; } /** * Create a SWT Checked Button component for the given {@link ConfProp} * boolean configuration property. * * @param listener * @param parent * @param prop * @return */ private Button createConfCheckButton(SelectionListener listener, Composite parent, ConfProp prop, String text) { Button button = new Button(parent, SWT.CHECK); button.setText(text); button.setData("hProp", prop); button.setSelection(location.getConfProp(prop).equalsIgnoreCase("yes")); button.addSelectionListener(listener); return button; } /** * Create editor entry for the given configuration property. The editor is * a couple (Label, Text). * * @param listener the listener to trigger on property change * @param parent the SWT parent container * @param prop the property to create an editor for * @param labelText a label (null will defaults to the property name) * * @return a SWT Text field */ private Text createConfLabelText(ModifyListener listener, Composite parent, ConfProp prop, String labelText) { Label label = new Label(parent, SWT.NONE); if (labelText == null) labelText = prop.name; label.setText(labelText); return createConfText(listener, parent, prop); } /** * Create an editor entry for the given configuration name * * @param listener the listener to trigger on property change * @param parent the SWT parent container * @param propName the name of the property to create an editor for * @param labelText a label (null will defaults to the property name) * * @return a SWT Text field */ private Text createConfNameEditor(ModifyListener listener, Composite parent, String propName, String labelText) { { ConfProp prop = ConfProp.getByName(propName); if (prop != null) return createConfLabelText(listener, parent, prop, labelText); } Label label = new Label(parent, SWT.NONE); if (labelText == null) labelText = propName; label.setText(labelText); Text text = new Text(parent, SWT.SINGLE | SWT.BORDER); GridData data = new GridData(GridData.FILL_HORIZONTAL); text.setLayoutData(data); text.setData("hPropName", propName); text.setText(location.getConfProp(propName)); text.addModifyListener(listener); return text; } /** * Main parameters of the Hadoop location: * <li> host and port of the Map/Reduce master (Job tracker) * <li> host and port of the DFS master (Name node) * <li> SOCKS proxy */ private class TabMain implements TabListener, ModifyListener, SelectionListener { TabMediator mediator; Text locationName; Text textJTHost; Text textNNHost; Button colocateMasters; Text textJTPort; Text textNNPort; Text userName; Button useSocksProxy; Text socksProxyHost; Text socksProxyPort; TabMain(TabMediator mediator) { this.mediator = mediator; TabItem tab = new TabItem(mediator.folder, SWT.NONE); tab.setText("General"); tab.setToolTipText("General location parameters"); tab.setImage(circle); tab.setControl(createControl(mediator.folder)); } private Control createControl(Composite parent) { Composite panel = new Composite(parent, SWT.FILL); panel.setLayout(new GridLayout(2, false)); GridData data; /* * Location name */ { Composite subpanel = new Composite(panel, SWT.FILL); subpanel.setLayout(new GridLayout(2, false)); data = new GridData(); data.horizontalSpan = 2; data.horizontalAlignment = SWT.FILL; subpanel.setLayoutData(data); locationName = createConfLabelText(this, subpanel, ConfProp.PI_LOCATION_NAME, "&Location name:"); } /* * Map/Reduce group */ { Group groupMR = new Group(panel, SWT.SHADOW_NONE); groupMR.setText("Map/Reduce Master"); groupMR.setToolTipText("Address of the Map/Reduce master node " + "(the Job Tracker)."); GridLayout layout = new GridLayout(2, false); groupMR.setLayout(layout); data = new GridData(); data.verticalAlignment = SWT.FILL; data.horizontalAlignment = SWT.CENTER; data.widthHint = 250; groupMR.setLayoutData(data); // Job Tracker host Label label = new Label(groupMR, SWT.NONE); label.setText("Host:"); data = new GridData(GridData.BEGINNING, GridData.CENTER, false, true); label.setLayoutData(data); textJTHost = createConfText(this, groupMR, ConfProp.PI_JOB_TRACKER_HOST); data = new GridData(GridData.FILL, GridData.CENTER, true, true); textJTHost.setLayoutData(data); // Job Tracker port label = new Label(groupMR, SWT.NONE); label.setText("Port:"); data = new GridData(GridData.BEGINNING, GridData.CENTER, false, true); label.setLayoutData(data); textJTPort = createConfText(this, groupMR, ConfProp.PI_JOB_TRACKER_PORT); data = new GridData(GridData.FILL, GridData.CENTER, true, true); textJTPort.setLayoutData(data); } /* * DFS group */ { Group groupDFS = new Group(panel, SWT.SHADOW_NONE); groupDFS.setText("DFS Master"); groupDFS.setToolTipText("Address of the Distributed FileSystem " + "master node (the Name Node)."); GridLayout layout = new GridLayout(2, false); groupDFS.setLayout(layout); data = new GridData(); data.horizontalAlignment = SWT.CENTER; data.widthHint = 250; groupDFS.setLayoutData(data); colocateMasters = createConfCheckButton(this, groupDFS, ConfProp.PI_COLOCATE_MASTERS, "Use M/R Master host"); data = new GridData(); data.horizontalSpan = 2; colocateMasters.setLayoutData(data); // Job Tracker host Label label = new Label(groupDFS, SWT.NONE); data = new GridData(); label.setText("Host:"); label.setLayoutData(data); textNNHost = createConfText(this, groupDFS, ConfProp.PI_NAME_NODE_HOST); // Job Tracker port label = new Label(groupDFS, SWT.NONE); data = new GridData(); label.setText("Port:"); label.setLayoutData(data); textNNPort = createConfText(this, groupDFS, ConfProp.PI_NAME_NODE_PORT); } { Composite subpanel = new Composite(panel, SWT.FILL); subpanel.setLayout(new GridLayout(2, false)); data = new GridData(); data.horizontalSpan = 2; data.horizontalAlignment = SWT.FILL; subpanel.setLayoutData(data); userName = createConfLabelText(this, subpanel, ConfProp.PI_USER_NAME, "&User name:"); } // SOCKS proxy group { Group groupSOCKS = new Group(panel, SWT.SHADOW_NONE); groupSOCKS.setText("SOCKS proxy"); groupSOCKS .setToolTipText("Address of the SOCKS proxy to use " + "to connect to the infrastructure."); GridLayout layout = new GridLayout(2, false); groupSOCKS.setLayout(layout); data = new GridData(); data.horizontalAlignment = SWT.CENTER; data.horizontalSpan = 2; data.widthHint = 250; groupSOCKS.setLayoutData(data); useSocksProxy = createConfCheckButton(this, groupSOCKS, ConfProp.PI_SOCKS_PROXY_ENABLE, "Enable SOCKS proxy"); data = new GridData(); data.horizontalSpan = 2; useSocksProxy.setLayoutData(data); // SOCKS proxy host Label label = new Label(groupSOCKS, SWT.NONE); data = new GridData(); label.setText("Host:"); label.setLayoutData(data); socksProxyHost = createConfText(this, groupSOCKS, ConfProp.PI_SOCKS_PROXY_HOST); // SOCKS proxy port label = new Label(groupSOCKS, SWT.NONE); data = new GridData(); label.setText("Port:"); label.setLayoutData(data); socksProxyPort = createConfText(this, groupSOCKS, ConfProp.PI_SOCKS_PROXY_PORT); } // Update the state of all widgets according to the current values! reloadConfProp(ConfProp.PI_COLOCATE_MASTERS); reloadConfProp(ConfProp.PI_SOCKS_PROXY_ENABLE); reloadConfProp(ConfProp.PI_JOB_TRACKER_HOST); return panel; } /** * Reload the given configuration property value * * @param prop */ private void reloadConfProp(ConfProp prop) { this.notifyChange(prop, location.getConfProp(prop)); } public void notifyChange(ConfProp prop, String propValue) { switch (prop) { case PI_JOB_TRACKER_HOST: { textJTHost.setText(propValue); break; } case PI_JOB_TRACKER_PORT: { textJTPort.setText(propValue); break; } case PI_LOCATION_NAME: { locationName.setText(propValue); break; } case PI_USER_NAME: { userName.setText(propValue); break; } case PI_COLOCATE_MASTERS: { if (colocateMasters != null) { boolean colocate = propValue.equalsIgnoreCase("yes"); colocateMasters.setSelection(colocate); if (textNNHost != null) { textNNHost.setEnabled(!colocate); } } break; } case PI_NAME_NODE_HOST: { textNNHost.setText(propValue); break; } case PI_NAME_NODE_PORT: { textNNPort.setText(propValue); break; } case PI_SOCKS_PROXY_ENABLE: { if (useSocksProxy != null) { boolean useProxy = propValue.equalsIgnoreCase("yes"); useSocksProxy.setSelection(useProxy); if (socksProxyHost != null) socksProxyHost.setEnabled(useProxy); if (socksProxyPort != null) socksProxyPort.setEnabled(useProxy); } break; } case PI_SOCKS_PROXY_HOST: { socksProxyHost.setText(propValue); break; } case PI_SOCKS_PROXY_PORT: { socksProxyPort.setText(propValue); break; } } } /* @inheritDoc */ public void modifyText(ModifyEvent e) { final Text text = (Text) e.widget; final ConfProp prop = (ConfProp) text.getData("hProp"); Display.getDefault().syncExec(new Runnable() { public void run() { mediator.notifyChange(TabMain.this, prop, text.getText()); } }); } /* @inheritDoc */ public void widgetDefaultSelected(SelectionEvent e) { this.widgetSelected(e); } /* @inheritDoc */ public void widgetSelected(SelectionEvent e) { final Button button = (Button) e.widget; final ConfProp prop = (ConfProp) button.getData("hProp"); Display.getDefault().syncExec(new Runnable() { public void run() { // We want to receive the update also! mediator.notifyChange(null, prop, button.getSelection() ? "yes" : "no"); } }); } } private class TabAdvanced implements TabListener, ModifyListener { TabMediator mediator; private Composite panel; private Map<String, Text> textMap = new TreeMap<String, Text>(); TabAdvanced(TabMediator mediator) { this.mediator = mediator; TabItem tab = new TabItem(mediator.folder, SWT.NONE); tab.setText("Advanced parameters"); tab.setToolTipText("Access to advanced Hadoop parameters"); tab.setImage(circle); tab.setControl(createControl(mediator.folder)); } private Control createControl(Composite parent) { ScrolledComposite sc = new ScrolledComposite(parent, SWT.BORDER | SWT.H_SCROLL | SWT.V_SCROLL); panel = new Composite(sc, SWT.NONE); sc.setContent(panel); sc.setExpandHorizontal(true); sc.setExpandVertical(true); sc.setMinSize(640, 480); GridLayout layout = new GridLayout(); layout.numColumns = 2; layout.makeColumnsEqualWidth = false; panel.setLayout(layout); panel.setLayoutData(new GridData(GridData.FILL, GridData.FILL, true, true, 1, 1)); // Sort by property name Configuration config = location.getConfiguration(); SortedMap<String, String> map = new TreeMap<String, String>(); Iterator<Entry<String, String>> it = config.iterator(); while (it.hasNext()) { Entry<String, String> entry = it.next(); map.put(entry.getKey(), entry.getValue()); } for (Entry<String, String> entry : map.entrySet()) { Text text = createConfNameEditor(this, panel, entry.getKey(), null); textMap.put(entry.getKey(), text); } sc.setMinSize(panel.computeSize(SWT.DEFAULT, SWT.DEFAULT)); return sc; } public void notifyChange(ConfProp prop, final String propValue) { Text text = textMap.get(prop.name); text.setText(propValue); } public void modifyText(ModifyEvent e) { final Text text = (Text) e.widget; Object hProp = text.getData("hProp"); final ConfProp prop = (hProp != null) ? (ConfProp) hProp : null; Object hPropName = text.getData("hPropName"); final String propName = (hPropName != null) ? (String) hPropName : null; Display.getDefault().syncExec(new Runnable() { public void run() { if (prop != null) mediator.notifyChange(TabAdvanced.this, prop, text.getText()); else mediator.notifyChange(TabAdvanced.this, propName, text.getText()); } }); } } }