Cannot find the class file for org.eclipse.swt.widgets.XXX

Question

I am using Eclipse Indigo and cannot compile some code which used to work fine before in Ganymede. I am not able to import any of these classes:

import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.CTabFolder;
import org.eclipse.swt.custom.CTabItem;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Composite;

I tried searching for SWT in the Eclipse Marketplace but could not find the library. Also, I read other articles which say to rebuild my project (which I did) and others recommend to download "the JAR." Does anyone know what JAR I need to download? Or how to fix my build path so it includes these SWT libraries?

Classpath (DannyGui should be there twice):

<?xml version="1.0" encoding="UTF-8"?>
<classpath>
<classpathentry kind="src" path="com.danny.DannyGui.plugin/src"/>
<classpathentry exported="true" kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-1.6"/>
<classpathentry exported="true" kind="lib" path="C:/DannyGui/DannyGui/com.danny.DannyGui.plugin/third_party_libs/JFreeChart/swtgraphics2d.jar"/>
<classpathentry exported="true" kind="lib" path="C:/DannyGui/DannyGui/com.danny.DannyGui.plugin/third_party_libs/antlr/stringtemplate-3.2.jar"/>
<classpathentry exported="true" kind="lib" path="C:/DannyGui/DannyGui/com.danny.DannyGui.plugin/third_party_libs/antlr/antlr-2.7.7.jar"/>
<classpathentry exported="true" kind="lib" path="C:/DannyGui/DannyGui/com.danny.DannyGui.plugin/third_party_libs/antlr/antlr-3.1.3.jar"/>
<classpathentry exported="true" kind="lib" path="C:/DannyGui/DannyGui/com.danny.DannyGui.plugin/third_party_libs/antlr/antlr-runtime-3.1.3.jar"/>
<classpathentry exported="true" kind="lib" path="C:/DannyGui/DannyGui/com.danny.DannyGui.plugin/third_party_libs/antlr/gunit.jar"/>
<classpathentry exported="true" kind="lib" path="C:/DannyGui/DannyGui/com.danny.DannyGui.plugin/third_party_libs/JacORB/wrapper-3.1.0.jar"/>
<classpathentry exported="true" kind="lib" path="C:/DannyGui/DannyGui/com.danny.DannyGui.plugin/third_party_libs/JacORB/antlr-2.7.2.jar"/>
<classpathentry exported="true" kind="lib" path="C:/DannyGui/DannyGui/com.danny.DannyGui.plugin/third_party_libs/JacORB/avalon-framework-4.1.5.jar"/>
<classpathentry exported="true" kind="lib" path="C:/DannyGui/DannyGui/com.danny.DannyGui.plugin/third_party_libs/JacORB/backport-util-concurrent.jar"/>
<classpathentry exported="true" kind="lib" path="C:/DannyGui/DannyGui/com.danny.DannyGui.plugin/third_party_libs/JacORB/idl.jar"/>
<classpathentry exported="true" kind="lib" path="C:/DannyGui/DannyGui/com.danny.DannyGui.plugin/third_party_libs/JacORB/jacorb.jar"/>
<classpathentry exported="true" kind="lib" path="C:/DannyGui/DannyGui/com.danny.DannyGui.plugin/third_party_libs/JacORB/logkit-1.2.jar"/>
<classpathentry exported="true" kind="lib" path="C:/DannyGui/DannyGui/com.danny.DannyGui.plugin/third_party_libs/JacORB/picocontainer-1.2.jar"/>
<classpathentry exported="true" kind="lib" path="C:/DannyGui/DannyGui/com.danny.DannyGui.plugin/third_party_libs/JFreeChart/gnujaxp.jar"/>
<classpathentry exported="true" kind="lib" path="C:/DannyGui/DannyGui/com.danny.DannyGui.plugin/third_party_libs/JFreeChart/iText-2.1.3.jar"/>
<classpathentry exported="true" kind="lib" path="C:/DannyGui/DannyGui/com.danny.DannyGui.plugin/third_party_libs/JFreeChart/jcommon-1.0.15.jar"/>
<classpathentry exported="true" kind="lib" path="C:/DannyGui/DannyGui/com.danny.DannyGui.plugin/third_party_libs/JFreeChart/jfreechart-1.0.12.jar"/>
<classpathentry exported="true" kind="lib" path="C:/DannyGui/DannyGui/com.danny.DannyGui.plugin/third_party_libs/JFreeChart/jfreechart-1.0.12-experimental.jar"/>
<classpathentry exported="true" kind="lib" path="C:/DannyGui/DannyGui/com.danny.DannyGui.plugin/third_party_libs/JFreeChart/jfreechart-1.0.12-swt.jar"/>
<classpathentry exported="true" kind="lib" path="C:/DannyGui/DannyGui/com.danny.DannyGui.plugin/third_party_libs/JFreeChart/junit.jar"/>
<classpathentry exported="true" kind="lib" path="C:/DannyGui/DannyGui/com.danny.DannyGui.plugin/third_party_libs/JFreeChart/servlet.jar"/>
<classpathentry exported="true" kind="lib" path="C:/DannyGui/DannyGui/com.danny.DannyGui.plugin/third_party_libs/log4j/log4j-1.2.15.jar"/>
<classpathentry kind="output" path="bin"/>
</classpath>

Thanks in advance.

I should add, here is my actual error: The project was not built since its build path is incomplete. Cannot find the class file for org.eclipse.swt.widgets.Composite. Fix the build path then try building this project. The project was not built since its build path is incomplete. Cannot find the class file for org.eclipse.swt.widgets.Composite. Fix the build path then try building this project. — Danny Lacks
could you post the contents of your project's .classpath file? — Konstantin Komissarchik
I stand corrected, I just imported my project into Ganymede and I get the same error. So, you are probably on to something, could be the classpath... — Danny Lacks

Konstantin Komissarchik Konstantin Komissarchik · Accepted Answer · 2011-07-15T19:52:57

The posted .classpath file does not contain anything from where SWT classes can be loaded. This project wouldn't build as is in any version of Eclipse.

It sounds like you are trying to build as stand-alone SWT app (as opposed to say an Eclipse plugin). Standalone apps need SWT library on the classpath. You don't look for SWT on Eclipse Marketplace as you are not looking for a plugin to extend your Eclipse. You are looking for a library for your project to depend on. You download SWT as a zip that you extract somewhere on your system. The zip contains .jar file and native libraries that are part of SWT implementation.

Rather than giving you a direct link, I will show you how to find it. Start at the Eclipse Platform download site:

http://download.eclipse.org/eclipse/downloads/

Ignore development builds. Look under latest releases. Right now, that would be 3.7. Follow that link to a build page. Look for SWT towards the bottom. Download the zip that's right for you system. Extract it and add a reference to the included jar from your project's classpath.

Cannot find the class file for org.eclipse.swt.widgets.XXX

2 Answers