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Asked: 2026-05-28T07:58:44+00:00

I am writing an application which needs to add nodes to an existing XML

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I am writing an application which needs to add nodes to an existing XML file repeatedly, throughout the day. Here is a sample of the list of nodes that I am trying to append:

    <gx:Track>
        <when>2012-01-21T14:37:18Z</when>
        <gx:coord>-0.12345 52.12345 274.700</gx:coord>
        <when>2012-01-21T14:38:18Z</when>
        <gx:coord>-0.12346 52.12346 274.700</gx:coord>
        <when>2012-01-21T14:39:18Z</when>
        <gx:coord>-0.12347 52.12347 274.700</gx:coord>
        ....

This can happen up to several times a second over a long time and I would like to know what the best or most efficient way of doing this is.

Here is what I am doing right now: Use a DocumentBuilderFactory to parse the XML file, look for the container node, append the child nodes and then use the TransformerFactory to write it back to the SD card. However, I have noticed that as the file grows larger, this is taking more and more time.

I have tried to think of a better way and this is the only thing I can think of: Use RandomAccessFile to load the file and use .seek() to a specific position in the file. I would calculate the position based on the file length and subtract what I ‘know’ is the length of the file after what I’m appending.

I’m pretty sure this method will work but it feels a bit blind as opposed to the ease of using a DocumentBuilderFactory.

Is there a better way of doing this?

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1 Answer

  1. Editorial Team

    You should try using JAXB. It’s a Java XML Binding library that comes in most of the Java 1.6 JDKs. JAXB lets you specify an XML Schema Definition file (and has some experimental support for DTD). The library will then compile Java classes for you to use in your code that translate back into an XML Document.

    It’s very quick and useful with optional support for validation. This would be a good starting point. This would be another good one to look at. Eclipse also has some great tools for generating the Java classes for you, and providing a nice GUI tool for XSD creation. The Eclipse plugins are called Davi I believe.

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