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Can't read an XML file.

Greenhorn

Posts: 19

posted 12 years ago

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Hello,

I'm using GWT 2.4 on Windows 7
I'm trying to learn how to read in an xml file from the tutorial at DevGuideXML
It gives instruction on how to get the information from xml that is in a string.
Unfortunately it does not give any information about how to get the xml file into a string.
I found the answer to the following query at stackflow helpful Stackflow
I'm not sure where I should put the xml file in my project.
If I put the xml file in clients package or the server package I get a warning.
The warning occurs when I run the program, it says that it has not found the xml file.
If I put the xml file in the war package the warning stops but the file still does seem to be getting read

Where should I put the xml file?

Here is the contents of the xml file:

Here is my java code to read the xml file:

public class ParsingXML implements EntryPoint {
  static final String xmlurl = "myData.xml";
  private String xmlText = null;
  private Label fromLabel, subjectLabel, bodyLabel;
  private VerticalPanel vPanel;
 
  public void onModuleLoad() {
  httpGetFile(xmlurl, new AsyncCallback<String>() {
      public void onFailure(Throwable caught) {
        xmlText = "Error";
      }
      
      public void onSuccess(String xmlData) {
        xmlText = xmlData;
      }
    });
        
    fromLabel = new Label();
    subjectLabel = new Label();
    bodyLabel = new Label();
    vPanel = new VerticalPanel();
    Button button = new Button("Click Here");
    button.addClickHandler(new ClickHandler() {
      public void onClick(ClickEvent event) {
        parseMessage(xmlText);
        vPanel.add(fromLabel);
        vPanel.add(subjectLabel);
        vPanel.add(bodyLabel);
        RootPanel.get("slot2").add(vPanel);
      }
    });
    RootPanel.get("slot1").add(button);
  }
  
  public static void httpGetFile(final String url, final AsyncCallback<String> callback) {
    final RequestBuilder rb = new RequestBuilder(RequestBuilder.GET, url);
    rb.setCallback(new RequestCallback() {
      public void onResponseReceived(Request request, Response response) {
        try {
          final int responseCode = response.getStatusCode() / 100;
          if (url.startsWith("file:/") || (responseCode == 2)) {
            callback.onSuccess(response.getText());
          } else {
            callback.onFailure(new IllegalStateException("HttpError#" + response.getStatusCode() + " - " + response.getText()));
            }
        } catch (Throwable e) {
          callback.onFailure(e);
        }
      }
      public void onError(Request request, Throwable exception) {
        callback.onFailure(exception);
      }
    });
    try {
      rb.send();
    } catch (RequestException e) {
      callback.onFailure(e);
    }
  }
  
  private void parseMessage(String messageXml) {
    try {
      // parse the XML document into a DOM
      Document messageDom = XMLParser.parse(messageXml);
      
      // find the sender's display name in an attribute of the <from> tag.
      Node fromNode = messageDom.getElementsByTagName("from").item(0);
      String from = ((Element)fromNode).getAttribute("displayName");
      fromLabel.setText(from);
      
      // get the subject using Node's getNodeValue() function
      String subject = messageDom.getElementsByTagName("subject").item(0).getFirstChild().getNodeValue();
      subjectLabel.setText(subject);
      
      // get the message body by explicitly casting to a text node
      Text bodyNode = (Text)messageDom.getElementsByTagName("body").item(0).getFirstChild();
      String body = bodyNode.getData();
      bodyLabel.setText(body);
    } catch (DOMException e) {
      Window.alert("Could not parse XML document. ");
    }
  }
}

What I need to know is which package I put the xml file?
Is this code correct?

Laurence Turpin

Greenhorn

Posts: 19

posted 12 years ago

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Hi,

I resolved my problem.
I found that I had imported the wrong namespace.
I changed the imports for both Text and Element and my program worked.