How to programmatically new a java class which implements sepecified interface in eclipse plugin development

Friends,

Now we are developing a eclipse plugin, it contains a action to generated a service interface and it's impl stub.

Now the interface is generated, I want to u开发者_如何学JAVAse eclipse JDT to create a java class which implements sepecified interface, but don't know how.

The info we have: the interface name, the impl class name, the packagename, the java project contains them.

Thanks in advance for your kindly help.

A quick scan of how the new class wizard does it, it seems that there is no public easy to use API for this. You can have a look at org.eclipse.jdt.ui.wizards.NewTypeWizardPage.createType(IProgressMonitor) method to see how JDT itself creates new classes.

It should be possible to extend the org.eclipse.jdt.ui.wizards.NewTypeWizardPage, so you can leverage the createType() method.

Probably the minimal steps you would have to do is simply generate source content into the correctly placed IFile. ex:

public Object execute(ExecutionEvent event) throws ExecutionException {
    final String PACKAGE_PATH = "z.ex/src/z/ex/go";
    final String CONTENT = "package z.ex.go;\n"
            + "public class RunAway {\npublic static void main(String[] args) {\n"
            + "System.out.println(\"Run Away\");\n}\n}\n";
    final IWorkspaceRoot root = ResourcesPlugin.getWorkspace().getRoot();
    final IResource packageResource = root.findMember(PACKAGE_PATH);
    if (packageResource instanceof IFolder) {
        IFolder packageFolder = (IFolder) packageResource;
        final IFile file = packageFolder.getFile("RunAway.java");
        try {
            if (!file.exists()) {
                file.create(new ByteArrayInputStream(CONTENT.getBytes()),
                        true, new NullProgressMonitor());
            } else {
                file.setContents(
                        new ByteArrayInputStream(CONTENT.getBytes()),
                        IFile.FORCE | IFile.KEEP_HISTORY,
                        new NullProgressMonitor());
            }
        } catch (CoreException e) {
            e.printStackTrace();
        }
    }
    return null;
}

See AbstractNewClassWizard for a smaller example that is similar to NewTypeWizardPage and uses some of the JDT APIs.

You can use the new class wizard to create classes.

This will prompt the user for the class name, et cetera. You can initialize the values of the wizard page. Below I am setting the source folder only (and tell the wizard that it cannot be changed, thus the second false parameter). You might want to set the interface and possible the package as well.

    OpenNewClassWizardAction wizard = new OpenNewClassWizardAction();
    wizard.setOpenEditorOnFinish(false);
    NewClassWizardPage page = new NewClassWizardPage();
    page.setPackageFragmentRoot(sourceFolder, false);
    wizard.setConfiguredWizardPage(page);
    wizard.run();
    return (IType) wizard.getCreatedElement();

Hope that helps!

Create the entire java file using the JDT - AST. First create the AST and then write it to a java file. It might look as hefty work, but its the best one. You will have complete control.