To get the required Eclipse tooling for plug-in development you have two options. You can download a special version of Eclipse to develop plug-ins or your can upgrade an existing Eclipse Java IDE.

Both approaches require that you have Java already installed.

Browse to the Eclipse download site and download the Eclipse Classic package.

Extract the downloaded file to your harddisk. Avoid having special characters or spaces in the path to your extract Eclipse.

In case you have downloaded the Eclipse Java IDE (or any other non RCP flavor) distribution you can use the Eclipse update manager to install the plug-ins required for RCP development.

To open the update manager select Help → Install new Software....

Install General Purpose Tools → Eclipse Plug-in Development Environment → Eclipse RCP Plug-in Developer Resources from the Eclipse update site for your release. This would be for example http://download.eclipse.org/releases/kepler for the Eclipse 4.3. release. You may have to remove the Group items by category flag to see all available features.

We will create a plug-in which contributes a menu entry to the standard Eclipse menu.

Create a new plug-in project called com.vogella.plugin.first via File → New → Project → Plug-in Development → Plug-in Project.

Enter the data as depicted in the following screenshots.

Select the Hello, World Command! template and press the Next button.

The last page of the wizard allows you to customize the values of the wizard. You can leave the default values and press the Finish button.

Eclipse may ask you if you want to switch to the plug-in development perspective. Answer Yes if you are prompted.

As result the following project is created.

Eclipse allows you to start a new Eclipse IDE with your plug-in included.

For this, select either your project folder or your MANIFEST.MF file, right-click on it and select Run-As → Eclipse Application.

A new Eclipse workbench starts. This runtime Eclipse has your new menu entry included. If you select this menu entry a message box will be displayed.

You have several options to make your plug-in available in your Eclipse IDE. You can:

The following describes all approaches.

You can install your plug-in directly into your running Eclipse IDE.

The Eclipse plug-in export wizard has an option for this. Open the export wizard via File → Export → Plug-in Development → Deployable plug-ins and fragments.

In the export wizard dialog select in this case Install into host. Repository. This is depicted in the following screenshot.

If you export your plug-in locally you can put it into the Eclipse dropins folder of your Eclipse installation. After a restart of your Eclipse your plug-in should be available and ready for use.

Open again the export wizard via File → Export → Plug-in Development → Deployable plug-ins and fragments.

Select the plug-in you want to export and the folder to which this plug-in should get exported.

Press the Finish button. This creates a jar file with the exported plug-in in the selected directory.

Copy this jar to the dropins directory in your Eclipse installation directory and re-start Eclipse.

After a restart of Eclipse your plug-in is available in your Eclipse installation and ready to be used.

You can also create an update site for your plug-in. An update site consists of static files which can be placed on a fileserver or a webserver. Other users can install Eclipse plug-in from this update site.

This requires that you create a feature project for the plug-in. You can export this feature project and use the Eclipse update manager to install the feature (with the plug-in).

You also need a category as the Eclipse update manager shows by default only features with a category. While the user can de-select this grouping you should always include a category for your exported feature to make it easy for the user to install your feature.

Create a feature project for your plug-in and add your plug-in to this feature. You create a feature project via File → New → Other... → Plug-in Development → Feature Project.

Create the feature project similar to the following screenshots.

In your feature project create via the menu entry File → New → Other... → Plug-in development → Category Definition a new category definition.

Press the New Category button and create a category with a name which describes your functionality. Add your feature to this category.

You can create an update site for your feature in a local directory on your machine. For this, select File → Export → Deployable features.

To use your category, switch to the Options tab and select the path to your category.xml file in the Categorize repository option.

Use the Eclipse update manager via Help → Install new software to install this new feature into your Eclipse IDE.

Use the update manager and point to your local directory and select and install your feature. In case you don't see your feature, try deselecting the Group items by category flag. In this case you have forgotten to use your category during the export.

Restart the Eclipse IDE after the installation. After a restart of Eclipse your plug-in should now be available in your Eclipse installation and ready to be used.

In this example we will add a new context menu entry to the Package Explorer part. The context menu is displayed if the user select a file in the package explorer via a right mouse click. We will offer the option to create a HTML page from a Java source file.

To contribute to an existing menu or toolbar you need to know the corresponding ID. This ID can be found via the Menu Spy. See Eclipse Source Code Guide for details.

This tutorial uses Eclipse Commands. See Eclipse Commands Tutorial to learn how to work with commands.

Create a new plug-in project called de.vogella.plugin.htmlconverter. Do not use a template.

Select the Dependencies tab of the file plugin.xml and add the following dependencies to your plug-in.

Add a command with the ID de.vogella.plugin.htmlconverter.convert and the default handler de.vogella.plugin.htmlconverter.handler.ConvertHandler to your plug-in.

Add this command to the menu via the extension point org.eclipse.ui.menus and use as the "locationURI" popup:org.eclipse.jdt.ui.PackageExplorer. Set the label to "Create HTML" for this contribution.

The resulting file plugin.xml should look like the following.

<?xml version="1.0" encoding="UTF-8"?>
<?eclipse version="3.4"?>
<plugin>
  <extension point="org.eclipse.ui.menus">
    <menuContribution locationURI="popup:org.eclipse.jdt.ui.PackageExplorer">
      <command commandId="de.vogella.plugin.htmlconverter.convert"
        label="Create HTML" style="push">
      </command>
    </menuContribution>
  </extension>
  <extension point="org.eclipse.ui.commands">
    <command defaultHandler="de.vogella.plugin.htmlconverter.handler.ConvertHandler"
      id="de.vogella.plugin.htmlconverter.convert" name="Convert">
    </command>
  </extension>

</plugin> 

Eclipse allows to save additional information for each file. You can use the IResource interface and the setPersistentProperty() and getPersistentProperty() methods. With these functions you can save Strings on files. We use these functions to save a directory for Java source files which already were exported via HTML.

Create the following ConvertHandler class.

package de.vogella.plugin.htmlconverter.handler;

import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;

import org.eclipse.core.commands.AbstractHandler;
import org.eclipse.core.commands.ExecutionEvent;
import org.eclipse.core.commands.ExecutionException;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.QualifiedName;
import org.eclipse.jdt.core.ICompilationUnit;
import org.eclipse.jdt.core.JavaModelException;
import org.eclipse.jface.dialogs.MessageDialog;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.swt.widgets.DirectoryDialog;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.ui.handlers.HandlerUtil;

public class ConvertHandler extends AbstractHandler {
  private QualifiedName path = new QualifiedName("html", "path");

  @Override
  public Object execute(ExecutionEvent event) throws ExecutionException {
    Shell shell = HandlerUtil.getActiveShell(event);
    ISelection sel = HandlerUtil.getActiveMenuSelection(event);
    IStructuredSelection selection = (IStructuredSelection) sel;

    Object firstElement = selection.getFirstElement();
    if (firstElement instanceof ICompilationUnit) {
      createOutput(shell, firstElement);

    } else {
      MessageDialog.openInformation(shell, "Info",
          "Please select a Java source file");
    }
    return null;
  }

  private void createOutput(Shell shell, Object firstElement) {
    String directory;
    ICompilationUnit cu = (ICompilationUnit) firstElement;
    IResource res = cu.getResource();
    boolean newDirectory = true;
    directory = getPersistentProperty(res, path);

    if (directory != null && directory.length() > 0) {
      newDirectory = !(MessageDialog.openQuestion(shell, "Question",
          "Use the previous output directory?"));
    }
    if (newDirectory) {
      DirectoryDialog fileDialog = new DirectoryDialog(shell);
      directory = fileDialog.open();

    }
    if (directory != null && directory.length() > 0) {
      setPersistentProperty(res, path, directory);
      write(directory, cu);
    }
  }

  protected String getPersistentProperty(IResource res, QualifiedName qn) {
    try {
      return res.getPersistentProperty(qn);
    } catch (CoreException e) {
      return "";
    }
  }

  protected void setPersistentProperty(IResource res, QualifiedName qn,
      String value) {
    try {
      res.setPersistentProperty(qn, value);
    } catch (CoreException e) {
      e.printStackTrace();
    }
  }

  private void write(String dir, ICompilationUnit cu) {
    try {
      cu.getCorrespondingResource().getName();
      String test = cu.getCorrespondingResource().getName();
      // Need
      String[] name = test.split("\\.");
      String htmlFile = dir + "\\" + name[0] + ".html";
      FileWriter output = new FileWriter(htmlFile);
      BufferedWriter writer = new BufferedWriter(output);
      writer.write("<html>");
      writer.write("<head>");
      writer.write("</head>");
      writer.write("<body>");
      writer.write("<pre>");
      writer.write(cu.getSource());
      writer.write("</pre>");
      writer.write("</body>");
      writer.write("</html>");
      writer.flush();
    } catch (JavaModelException e) {
    } catch (IOException e) {
      e.printStackTrace();
    }

  }
} 

If you start this plug-in you should be able to create HTML output from a Java source file.

Currently our context menu is always displayed. We would like to show it only if a source file is selected. For this we will use a "visible-when" definition.

Add the org.eclipse.core.expressions plug-in as dependency to your plug-in. Select your menu contribution. Using the right mouse add the condition to the command that it should only be visible if a file is selected which represents a ICompilationUnit from the org.eclipse.jdt.core package.

For this exercise you use the predefined variable activeMenuSelection which contains the selection in the menu and iterate over it. If the selection can get adapted to ICompilationUnit then the contribution will be visible.

This will result in the following plugin.xml.

<?xml version="1.0" encoding="UTF-8"?>
<?eclipse version="3.4"?>
<plugin>
   <extension
         point="org.eclipse.ui.menus">
      <menuContribution
            locationURI="popup:org.eclipse.jdt.ui.PackageExplorer">
         <command
               commandId="de.vogella.plugin.htmlconverter.convert"
               label="Create HTML"
               style="push">
            <visibleWhen
                  checkEnabled="false">
               <with
                     variable="activeMenuSelection">
                  <iterate
                        ifEmpty="false"
                        operator="or">
                     <adapt
                           type="org.eclipse.jdt.core.ICompilationUnit">
                     </adapt>
                  </iterate>
               </with>
            </visibleWhen>
         </command>
      </menuContribution>
   </extension>
   <extension
         point="org.eclipse.ui.commands">
      <command
            defaultHandler="de.vogella.plugin.htmlconverter.handler.Convert"
            id="de.vogella.plugin.htmlconverter.convert"
            name="Convert">
      </command>
   </extension>

</plugin> 

If you now start your plug-in, the menu entry should only be visible if at least one compilation unit has been selected.

Adapters help to display information about objects in view without having to adjust the existing views. In this example we will create a small view which allows to select objects and use the properties view to display them.

Adapters are used on several places for example you can use an adapter to display your data in the outline view. See Outline View Example for an example how to do this.

We will simple use an adapter to show our data in the property view. Create a new plug-in project "de.vogella.plugin.adapter". Use the "Plug-in with a view" template with the following settings.

Add the dependency "org.eclipse.ui.views" in tab dependencies of plugin.xml.

Create the following data model.

package de.vogella.plugin.adapter.model;

public class Todo {
  private String summary;
  private String description;
  public String getSummary() {
    return summary;
  }
  public void setSummary(String summary) {
    this.summary = summary;
  }
  public String getDescription() {
    return description;
  }
  public void setDescription(String description) {
    this.description = description;
  }

} 

Change the code of SampleView.java to the following. After this change you should be able to run your project, open your view and see your todo items.

package de.vogella.plugin.adapter.views;

import org.eclipse.jface.viewers.ArrayContentProvider;
import org.eclipse.jface.viewers.ITableLabelProvider;
import org.eclipse.jface.viewers.LabelProvider;
import org.eclipse.jface.viewers.TableViewer;
import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.ui.ISharedImages;
import org.eclipse.ui.PlatformUI;
import org.eclipse.ui.part.ViewPart;

import de.vogella.plugin.adapter.model.Todo;

public class SampleView extends ViewPart {
  public static final String ID = "de.vogella.plugin.adapter.views.SampleView";

  private TableViewer viewer;

  class ViewLabelProvider extends LabelProvider implements
      ITableLabelProvider {
    public String getColumnText(Object obj, int index) {
      Todo todo = (Todo) obj;
      return todo.getSummary();
    }

    public Image getColumnImage(Object obj, int index) {
      return getImage(obj);
    }

    public Image getImage(Object obj) {
      return PlatformUI.getWorkbench().getSharedImages()
          .getImage(ISharedImages.IMG_OBJ_ELEMENT);
    }
  }

  
/**
   * This is a callback that will allow us to create the viewer and initialize
   * it.
   */
  public void createPartControl(Composite parent) {
    viewer = new TableViewer(parent, SWT.MULTI | SWT.H_SCROLL
        | SWT.V_SCROLL);
    viewer.setContentProvider(new ArrayContentProvider());
    viewer.setLabelProvider(new ViewLabelProvider());
    getSite().setSelectionProvider(viewer);
    viewer.setInput(getElements());

  }

  
/**
   * Passing the focus request to the viewer's control.
   */
  public void setFocus() {
    viewer.getControl().setFocus();
  }

  // Build up a simple data model
  private Todo[] getElements() {
    Todo[] todos = new Todo[2];
    Todo todo = new Todo();
    todo.setSummary("First Todo");
    todo.setDescription("A very good description");
    todos[0] = todo;
    todo = new Todo();
    todo.setSummary("Second Todo");
    todo.setDescription("Second super description");
    todos[1] = todo;
    return todos;
  }
} 

To displays its values in the property view, add the extension point "org.eclipse.core.runtime.adapters" to your project. The data of the extension point should be like the following.

<extension
         point="org.eclipse.core.runtime.adapters">
      <factory
            adaptableType="de.vogella.plugin.adapter.model.Todo"
            class="de.vogella.plugin.adapter.TodoAdapterFactory">
         <adapter
               type="org.eclipse.ui.views.properties.IPropertySource">
         </adapter>
      </factory>
</extension> 

Implement the factory and the new class "TodoPropertySource" which implements "IPropertySource".

package de.vogella.plugin.adapter;

import org.eclipse.core.runtime.IAdapterFactory;
import org.eclipse.ui.views.properties.IPropertySource;

import de.vogella.plugin.adapter.model.Todo;

public class TodoAdapterFactory implements IAdapterFactory {

  @Override
  public Object getAdapter(Object adaptableObject, Class adapterType) {
    if (adapterType== IPropertySource.class && adaptableObject instanceof Todo){
      return new TodoPropertySource((Todo) adaptableObject);
    }
    return null;
  }

  @Override
  public Class[] getAdapterList() {
    return new Class[] { IPropertySource.class };
  }

} 

package de.vogella.plugin.adapter;

import org.eclipse.ui.views.properties.IPropertyDescriptor;
import org.eclipse.ui.views.properties.IPropertySource;
import org.eclipse.ui.views.properties.TextPropertyDescriptor;

import de.vogella.plugin.adapter.model.Todo;

public class TodoPropertySource implements IPropertySource {

  private final Todo todo;

  public TodoPropertySource(Todo todo) {
    this.todo = todo;
  }


  @Override
  public boolean isPropertySet(Object id) {
    return false;
  }

  @Override
  public Object getEditableValue() {
    return this;
  }

  @Override
  public IPropertyDescriptor[] getPropertyDescriptors() {

    return new IPropertyDescriptor[] {
        new TextPropertyDescriptor("summary", "Summary"),
        new TextPropertyDescriptor("description", "Description") };
  }

  @Override
  public Object getPropertyValue(Object id) {
    if (id.equals("summary")) {
      return todo.getSummary();
    }
    if (id.equals("description")) {
      return todo.getDescription();
    }
    return null;
  }

  @Override
  public void resetPropertyValue(Object id) {

  }

  @Override
  public void setPropertyValue(Object id, Object value) {
    String s = (String) value;
    if (id.equals("summary")) {
      todo.setSummary(s);
    }
    if (id.equals("description")) {
      todo.setDescription(s);
    }
  }

} 

If you run your workbench and open your View via Windows -> Show View -> Others -> Sample Category -> Sample View and the property view you should be able to view your data.

It's a comprehensive tool suite to debug, spy, spider, inspect and navigate Eclipse based application GUIs (Workbench or RCP). http://sourceforge.net/projects/yari/

VisualVM is a debugging tool which can be integrated into Eclipse. http://visualvm.java.net/eclipse-launcher.html

JVM Monitor is a Java profiler integrated with Eclipse to monitor CPU, threads and memory usage of Java applications. http://www.jvmmonitor.org/index.html

Source Code of Examples

http://wiki.eclipse.org/Eclipse_Plug-in_Development_FAQ Eclipse Plug-in Development FAQ

http://www.eclipse.org/articles/article.php?file=Article-Adapters/index.html Adapters in Eclipse

http://www.eclipse.org/articles/Article-Resource-deltas/resource-deltas.html How to react to Eclipse resource deltas

Using markers, annotations, and decorators in Eclipse (IBM) .

vogella Training Android and Eclipse Training from the vogella team

Android Tutorial Introduction to Android Programming

GWT Tutorial Program in Java and compile to JavaScript and HTML

Eclipse RCP Tutorial Create native applications in Java

JUnit Tutorial Test your application

Git Tutorial Put everything you have under distributed version control system