Adding DOM Elements to XML file

创建于 2015年04月15日 14:42

My objective is to programatically add dom elements to a web.xml file, like servlets, servlet-mappings and filters.

First using intellij idea dev-kit plugin I have generated to dom model for web.xml 2.4 xsd file

Then I wrote following peice of code to get hold of web.xml file inside the project directory. And try to add new servlet dom element to it.

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

    
@Override
    public void actionPerformed(AnActionEvent anActionEvent) {
        Project project = anActionEvent.getProject();
        PsiFile[] filesByName = FilenameIndex.getFilesByName(anActionEvent.getProject(), "web.xml", GlobalSearchScopesCore.directoryScope(anActionEvent.getProject(), anActionEvent.getProject().getBaseDir(), true));
        XmlFile xmlFile = (XmlFile) filesByName[0];

        DomManagerImpl domManager = (DomManagerImpl) DomManager.getDomManager(anActionEvent.getProject());
        domManager.registerFileDescription(new DomFileDescription(WebApp.class, "web-app"));

        DomElement rootElement = domManager.getFileElement(xmlFile).getRootElement();

        if((rootElement instanceof WebApp)) {
            final WebApp webapp = (WebApp) rootElement;


            ApplicationManager.getApplication().runWriteAction(new Runnable() {
                @Override
                public void run() {
                    Servlet servlet = webapp.addServlet();
                    servlet.getServletName().setStringValue("ussdReceiver");
                    servlet.getServletClass().setStringValue("UssdMoReceiver");
                }
            });


            JOptionPane.showMessageDialog(null, "Hello world - " + webapp.getServletMappings().get(0).getUrlPattern().getRawText());
        }


    }

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

How ever when I run the event which trigger this action. I get following exception.

java.lang.NullPointerException
at com.intellij.psi.impl.source.tree.ChangeUtil.decodeInformation(ChangeUtil.java:91)
at com.intellij.psi.impl.source.tree.ChangeUtil.decodeInformation(ChangeUtil.java:83)
at com.intellij.psi.impl.source.tree.CompositePsiElement.addAfter(CompositePsiElement.java:162)
at com.intellij.util.xml.impl.DomInvocationHandler.addEmptyTag(DomInvocationHandler.java:828)
at com.intellij.util.xml.impl.DomInvocationHandler.addCollectionChild(DomInvocationHandler.java:795)
at com.intellij.util.xml.impl.AddChildInvocation.invoke(AddChildInvocation.java:43)
at com.intellij.util.xml.impl.DomInvocationHandler.invoke(DomInvocationHandler.java:689)
at com.intellij.myframework.model.WebApp$$EnhancerByCGLIB$$d89a8446.addServlet(<generated>)
at TestPsi$1.run(TestPsi.java:49)
at com.intellij.openapi.application.impl.ApplicationImpl.runWriteAction(ApplicationImpl.java:938)
at TestPsi.actionPerformed(TestPsi.java:46)
at com.intellij.openapi.actionSystem.impl.ChameleonAction.actionPerformed(ChameleonAction.java:54)
at com.intellij.openapi.actionSystem.ex.ActionUtil.performActionDumbAware(ActionUtil.java:164)
at com.intellij.openapi.actionSystem.impl.ActionMenuItem$ActionTransmitter$1.run(ActionMenuItem.java:312)
at com.intellij.openapi.wm.impl.FocusManagerImpl.runOnOwnContext(FocusManagerImpl.java:926)
at com.intellij.openapi.wm.impl.IdeFocusManagerImpl.runOnOwnContext(IdeFocusManagerImpl.java:124)
at com.intellij.openapi.actionSystem.impl.ActionMenuItem$ActionTransmitter.actionPerformed(ActionMenuItem.java:282)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2022)
at com.intellij.openapi.actionSystem.impl.ActionMenuItem.fireActionPerformed(ActionMenuItem.java:109)
at com.intellij.ui.plaf.beg.BegMenuItemUI.doClick(BegMenuItemUI.java:512)
at com.intellij.ui.plaf.beg.BegMenuItemUI.access$300(BegMenuItemUI.java:44)
at com.intellij.ui.plaf.beg.BegMenuItemUI$MyMouseInputHandler.mouseReleased(BegMenuItemUI.java:532)
at java.awt.Component.processMouseEvent(Component.java:6525)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
at java.awt.Component.processEvent(Component.java:6290)
at java.awt.Container.processEvent(Container.java:2234)
at java.awt.Component.dispatchEventImpl(Component.java:4881)
at java.awt.Container.dispatchEventImpl(Container.java:2292)

What is the proper way to achieve this. What am I missing here.

1 条评论

Peter Gromov

创建于 2015年04月16日 07:05

It's not the latest IDEA 14.0.x, is it? (line numbers don't seem to match) Which IDEA build are you running your plugin in? Or, what's in "ChangeUtil.java:91" line in that version?

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