Most votes on xml questions 3

Most votes on xml questions 3. #21 How to pretty print XML from Java? #22 Pretty printing XML in Python #23 How can I build XML in C#? #24 How to handle button clicks using the XML onClick within Fragments #25 What does "xmlns" in XML mean? #26 Web colors in an Android color XML resource file #27 Can you provide some examples of why it is hard to parse XML and HTML with a regex? #28 send/post XML file using cURL command line #29 How do I read and parse an XML file in C#? #30 Best XML parser for Java

Read all the top votes questions and answers in a single page.

#21: How to pretty print XML from Java? (Score: 464)

Created: 2008-09-26 Last updated: 2018-12-25

Tags: java, xml, pretty-print

I have a Java String that contains XML, with no line feeds or indentations. I would like to turn it into a String with nicely formatted XML. How do I do this?

String unformattedXml = "<tag><nested>hello</nested></tag>";
String formattedXml = new [UnknownClass]().format(unformattedXml);

Note: My input is a String. My output is a String.

(Basic) mock result:

<?xml version="1.0" encoding="UTF-8"?>

#21 Best answer 1 of How to pretty print XML from Java? (Score: 278)

Created: 2008-09-26 Last updated: 2021-04-13

Transformer transformer = TransformerFactory.newInstance().newTransformer();
transformer.setOutputProperty(OutputKeys.INDENT, "yes");
transformer.setOutputProperty("{}indent-amount", "2");
// initialize StreamResult with File object to save to file
StreamResult result = new StreamResult(new StringWriter());
DOMSource source = new DOMSource(doc);
transformer.transform(source, result);
String xmlString = result.getWriter().toString();

Note: Results may vary depending on the Java version. Search for workarounds specific to your platform.

#21 Best answer 2 of How to pretty print XML from Java?(Score: 137)

Created: 2008-09-26 Last updated: 2008-10-31

Here’s an answer to my own question. I combined the answers from the various results to write a class that pretty prints XML.

No guarantees on how it responds with invalid XML or large documents.

package ecb.sdw.pretty;

import org.apache.xml.serialize.OutputFormat;
import org.apache.xml.serialize.XMLSerializer;
import org.w3c.dom.Document;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;

 * Pretty-prints xml, supplied as a string.
 * <p/>
 * eg.
 * <code>
 * String formattedXml = new XmlFormatter().format("<tag><nested>hello</nested></tag>");
 * </code>
public class XmlFormatter {

    public XmlFormatter() {

    public String format(String unformattedXml) {
        try {
            final Document document = parseXmlFile(unformattedXml);

            OutputFormat format = new OutputFormat(document);
            Writer out = new StringWriter();
            XMLSerializer serializer = new XMLSerializer(out, format);

            return out.toString();
        } catch (IOException e) {
            throw new RuntimeException(e);

    private Document parseXmlFile(String in) {
        try {
            DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
            DocumentBuilder db = dbf.newDocumentBuilder();
            InputSource is = new InputSource(new StringReader(in));
            return db.parse(is);
        } catch (ParserConfigurationException e) {
            throw new RuntimeException(e);
        } catch (SAXException e) {
            throw new RuntimeException(e);
        } catch (IOException e) {
            throw new RuntimeException(e);

    public static void main(String[] args) {
        String unformattedXml =
                "<?xml version=\"1.0\" encoding=\"UTF-8\"?><QueryMessage\n" +
                        "        xmlns=\"\"\n" +
                        "        xmlns:query=\"\">\n" +
                        "    <Query>\n" +
                        "        <query:CategorySchemeWhere>\n" +
                        "   \t\t\t\t\t         <query:AgencyID>ECB\n\n\n\n</query:AgencyID>\n" +
                        "        </query:CategorySchemeWhere>\n" +
                        "    </Query>\n\n\n\n\n" +

        System.out.println(new XmlFormatter().format(unformattedXml));


See also original question in stackoverflow

#22: Pretty printing XML in Python (Score: 462)

Created: 2009-04-15 Last updated: 2019-06-21

Tags: python, xml, pretty-print

What is the best way (or are the various ways) to pretty print XML in Python?

#22 Best answer 1 of Pretty printing XML in Python (Score: 409)

Created: 2009-07-30 Last updated: 2019-01-21

import xml.dom.minidom

dom = xml.dom.minidom.parse(xml_fname) # or xml.dom.minidom.parseString(xml_string)
pretty_xml_as_string = dom.toprettyxml()

#22 Best answer 2 of Pretty printing XML in Python(Score: 176)

Created: 2009-04-15 Last updated: 2017-07-14

lxml is recent, updated, and includes a pretty print function

import lxml.etree as etree

x = etree.parse("filename")
print etree.tostring(x, pretty_print=True)

Check out the lxml tutorial:

See also original question in stackoverflow

#23: How can I build XML in C#? (Score: 450)

Created: 2008-11-12 Last updated: 2014-10-27

Tags: c#, xml

How can I generate valid XML in C#?

#23 Best answer 1 of How can I build XML in C#? (Score: 518)

Created: 2008-11-12 Last updated: 2016-10-06

It depends on the scenario. XmlSerializer is certainly one way and has the advantage of mapping directly to an object model. In .NET 3.5, XDocument, etc. are also very friendly. If the size is very large, then XmlWriter is your friend.

For an XDocument example:

    new XElement("Foo",
        new XAttribute("Bar", "some & value"),
        new XElement("Nested", "data")));

Or the same with XmlDocument:

XmlDocument doc = new XmlDocument();
XmlElement el = (XmlElement)doc.AppendChild(doc.CreateElement("Foo"));
el.SetAttribute("Bar", "some & value");
el.AppendChild(doc.CreateElement("Nested")).InnerText = "data";

If you are writing a large stream of data, then any of the DOM approaches (such as XmlDocument/XDocument, etc.) will quickly take a lot of memory. So if you are writing a 100 MB XML file from CSV, you might consider XmlWriter; this is more primitive (a write-once firehose), but very efficient (imagine a big loop here):

XmlWriter writer = XmlWriter.Create(Console.Out);
writer.WriteAttributeString("Bar", "Some & value");
writer.WriteElementString("Nested", "data");

Finally, via XmlSerializer:

public class Foo
    public string Bar { get; set; }
    public string Nested { get; set; }
Foo foo = new Foo
    Bar = "some & value",
    Nested = "data"
new XmlSerializer(typeof(Foo)).Serialize(Console.Out, foo);

This is a nice model for mapping to classes, etc.; however, it might be overkill if you are doing something simple (or if the desired XML doesn’t really have a direct correlation to the object model). Another issue with XmlSerializer is that it doesn’t like to serialize immutable types : everything must have a public getter and setter (unless you do it all yourself by implementing IXmlSerializable, in which case you haven’t gained much by using XmlSerializer).

#23 Best answer 2 of How can I build XML in C#?(Score: 60)

Created: 2009-09-01 Last updated: 2013-10-15

The best thing hands down that I have tried is LINQ to XSD (which is unknown to most developers). You give it an XSD Schema and it generates a perfectly mapped complete strongly-typed object model (based on LINQ to XML) for you in the background, which is really easy to work with - and it updates and validates your object model and XML in real-time. While it’s still “Preview”, I have not encountered any bugs with it.

If you have an XSD Schema that looks like this:

  <xs:element name="RootElement">
        <xs:element name="Element1" type="xs:string" />
        <xs:element name="Element2" type="xs:string" />
       <xs:attribute name="Attribute1" type="xs:integer" use="optional" />
       <xs:attribute name="Attribute2" type="xs:boolean" use="required" />

Then you can simply build XML like this:

RootElement rootElement = new RootElement;
rootElement.Element1 = "Element1";
rootElement.Element2 = "Element2";
rootElement.Attribute1 = 5;
rootElement.Attribute2 = true;

Or simply load an XML from file like this:

RootElement rootElement = RootElement.Load(filePath);

Or save it like this:


rootElement.Untyped also yields the element in form of a XElement (from LINQ to XML).

See also original question in stackoverflow

#24: How to handle button clicks using the XML onClick within Fragments (Score: 449)

Created: 2011-05-22 Last updated: 2015-04-25

Tags: android, xml, button, android-fragments

Pre-Honeycomb (Android 3), each Activity was registered to handle button clicks via the onClick tag in a Layout’s XML:


Within that method you can use view.getId() and a switch statement to do the button logic.

With the introduction of Honeycomb I’m breaking these Activities into Fragments which can be reused inside many different Activities. Most of the behavior of the buttons is Activity independent, and I would like the code to reside inside the Fragments file without using the old (pre 1.6) method of registering the OnClickListener for each button.

final Button button = (Button) findViewById(;
button.setOnClickListener(new View.OnClickListener() {
    public void onClick(View v) {
        // Perform action on click

The problem is that when my layout’s are inflated it is still the hosting Activity that is receiving the button clicks, not the individual Fragments. Is there a good approach to either

  • Register the fragment to receive the button clicks?
  • Pass the click events from the Activity to the fragment they belong to?

#24 Best answer 1 of How to handle button clicks using the XML onClick within Fragments (Score: 609)

Created: 2013-01-28 Last updated: 2015-05-19

I prefer using the following solution for handling onClick events. This works for Activity and Fragments as well.

public class StartFragment extends Fragment implements OnClickListener{
	public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View v = inflater.inflate(R.layout.fragment_start, container, false);
        Button b = (Button) v.findViewById(;
        return v;
	public void onClick(View v) {
        switch (v.getId()) {


#24 Best answer 2 of How to handle button clicks using the XML onClick within Fragments(Score: 176)

Created: 2011-06-07 Last updated: 2017-09-19

You could just do this:


Fragment someFragment;    

//...onCreate etc instantiating your fragments

public void myClickMethod(View v) {


public void myClickMethod(View v) {
    switch(v.getId()) {
        // Just like you were doing

In response to @Ameen who wanted less coupling so Fragments are reuseable


public interface XmlClickable {
    void myClickMethod(View v);


XmlClickable someFragment;    

//...onCreate, etc. instantiating your fragments casting to your interface.
public void myClickMethod(View v) {


public class SomeFragment implements XmlClickable {

//...onCreateView, etc.

public void myClickMethod(View v) {
        // Just like you were doing

See also original question in stackoverflow

#25: What does "xmlns" in XML mean? (Score: 438)

Created: 2009-07-25 Last updated: 2017-03-07

Tags: xml, xml-namespaces

I saw the following line in an XML file:


I have also seen xmlns in many other XML files that I’ve come across.

What is it?

#25 Best answer 1 of What does "xmlns" in XML mean? (Score: 699)

Created: 2009-07-25 Last updated: 2017-07-11

It means XML namespace.

Basically, every element (or attribute) in XML belongs to a namespace, a way of “qualifying” the name of the element.

Imagine you and I both invent our own XML. You invent XML to describe people, I invent mine to describe cities. Both of us include an element called name. Yours refers to the person’s name, and mine to the city name—OK, it’s a little bit contrived.


If our two XMLs were combined into a single document, how would we tell the two names apart? As you can see above, there are two name elements, but they both have different meanings.

The answer is that you and I would both assign a namespace to our XML, which we would make unique:

<personxml:person xmlns:personxml=""

Now we’ve fully qualified our XML, there is no ambiguity as to what each name element means. All of the tags that start with personxml: are tags belonging to your XML, all the ones that start with cityxml: are mine.

There are a few points to note:

  • If you exclude any namespace declarations, things are considered to be in the default namespace.

  • If you declare a namespace without the identifier, that is, xmlns="http://somenamespace", rather than xmlns:rob="somenamespace", it specifies the default namespace for the document.

  • The actual namespace itself, often a IRI, is of no real consequence. It should be unique, so people tend to choose a IRI/URI that they own, but it has no greater meaning than that. Sometimes people will place the schema (definition) for the XML at the specified IRI, but that is a convention of some people only.

  • The prefix is of no consequence either. The only thing that matters is what namespace the prefix is defined as. Several tags beginning with different prefixes, all of which map to the same namespace are considered to be the same.

    For instance, if the prefixes personxml and mycityxml both mapped to the same namespace (as in the snippet below), then it wouldn’t matter if you prefixed a given element with personxml or mycityxml, they’d both be treated as the same thing by an XML parser. The point is that an XML parser doesn’t care what you’ve chosen as the prefix, only the namespace it maps too. The prefix is just an indirection pointing to the namespace.

          xmlns:mycityxml="" />
  • Attributes can be qualified but are generally not. They also do not inherit their namespace from the element they are on, as opposed to elements (see below).

Also, element namespaces are inherited from the parent element. In other words I could equally have written the above XML as

<person xmlns="">
    <homecity xmlns="">

#25 Best answer 2 of What does "xmlns" in XML mean?(Score: 311)

Created: 2009-07-25 Last updated: 2013-02-27

It defines an XML Namespace.

In your example, the Namespace Prefix is “android” and the Namespace URI is “

In the document, you see elements like: <android:foo />

Think of the namespace prefix as a variable with a short name alias for the full namespace URI. It is the equivalent of writing < /> with regards to what it “means” when an XML parser reads the document.

NOTE: You cannot actually use the full namespace URI in place of the namespace prefix in an XML instance document.

Check out this tutorial on namespaces:

See also original question in stackoverflow

#26: Web colors in an Android color XML resource file (Score: 427)

Created: 2010-09-22 Last updated: 2021-04-01

Tags: android, xml

What do all of the X11/w3c color codes look like in the format of an Android XML resource file?

I know this looks a tad ridiculous as a question, but given the votes apparently it’s useful and since it clearly does not require an off-site resource I’m reformatting it to keep it around. –Editor.

#26 Best answer 1 of Web colors in an Android color XML resource file (Score: 1019)

Created: 2011-09-06 Last updated: 2016-02-01

You have surely made your own by now, but for the benefit of others, please find w3c and x11 below.

<?xml version="1.0" encoding="utf-8"?>
 <color name="white">#FFFFFF</color>
 <color name="yellow">#FFFF00</color>
 <color name="fuchsia">#FF00FF</color>
 <color name="red">#FF0000</color>
 <color name="silver">#C0C0C0</color>
 <color name="gray">#808080</color>
 <color name="olive">#808000</color>
 <color name="purple">#800080</color>
 <color name="maroon">#800000</color>
 <color name="aqua">#00FFFF</color>
 <color name="lime">#00FF00</color>
 <color name="teal">#008080</color>
 <color name="green">#008000</color>
 <color name="blue">#0000FF</color>
 <color name="navy">#000080</color>
 <color name="black">#000000</color>

<?xml version="1.0" encoding="utf-8"?>
 <color name="White">#FFFFFF</color>
 <color name="Ivory">#FFFFF0</color>
 <color name="LightYellow">#FFFFE0</color>
 <color name="Yellow">#FFFF00</color>
 <color name="Snow">#FFFAFA</color>
 <color name="FloralWhite">#FFFAF0</color>
 <color name="LemonChiffon">#FFFACD</color>
 <color name="Cornsilk">#FFF8DC</color>
 <color name="Seashell">#FFF5EE</color>
 <color name="LavenderBlush">#FFF0F5</color>
 <color name="PapayaWhip">#FFEFD5</color>
 <color name="BlanchedAlmond">#FFEBCD</color>
 <color name="MistyRose">#FFE4E1</color>
 <color name="Bisque">#FFE4C4</color>
 <color name="Moccasin">#FFE4B5</color>
 <color name="NavajoWhite">#FFDEAD</color>
 <color name="PeachPuff">#FFDAB9</color>
 <color name="Gold">#FFD700</color>
 <color name="Pink">#FFC0CB</color>
 <color name="LightPink">#FFB6C1</color>
 <color name="Orange">#FFA500</color>
 <color name="LightSalmon">#FFA07A</color>
 <color name="DarkOrange">#FF8C00</color>
 <color name="Coral">#FF7F50</color>
 <color name="HotPink">#FF69B4</color>
 <color name="Tomato">#FF6347</color>
 <color name="OrangeRed">#FF4500</color>
 <color name="DeepPink">#FF1493</color>
 <color name="Fuchsia">#FF00FF</color>
 <color name="Magenta">#FF00FF</color>
 <color name="Red">#FF0000</color>
 <color name="OldLace">#FDF5E6</color>
 <color name="LightGoldenrodYellow">#FAFAD2</color>
 <color name="Linen">#FAF0E6</color>
 <color name="AntiqueWhite">#FAEBD7</color>
 <color name="Salmon">#FA8072</color>
 <color name="GhostWhite">#F8F8FF</color>
 <color name="MintCream">#F5FFFA</color>
 <color name="WhiteSmoke">#F5F5F5</color>
 <color name="Beige">#F5F5DC</color>
 <color name="Wheat">#F5DEB3</color>
 <color name="SandyBrown">#F4A460</color>
 <color name="Azure">#F0FFFF</color>
 <color name="Honeydew">#F0FFF0</color>
 <color name="AliceBlue">#F0F8FF</color>
 <color name="Khaki">#F0E68C</color>
 <color name="LightCoral">#F08080</color>
 <color name="PaleGoldenrod">#EEE8AA</color>
 <color name="Violet">#EE82EE</color>
 <color name="DarkSalmon">#E9967A</color>
 <color name="Lavender">#E6E6FA</color>
 <color name="LightCyan">#E0FFFF</color>
 <color name="BurlyWood">#DEB887</color>
 <color name="Plum">#DDA0DD</color>
 <color name="Gainsboro">#DCDCDC</color>
 <color name="Crimson">#DC143C</color>
 <color name="PaleVioletRed">#DB7093</color>
 <color name="Goldenrod">#DAA520</color>
 <color name="Orchid">#DA70D6</color>
 <color name="Thistle">#D8BFD8</color>
 <color name="LightGrey">#D3D3D3</color>
 <color name="Tan">#D2B48C</color>
 <color name="Chocolate">#D2691E</color>
 <color name="Peru">#CD853F</color>
 <color name="IndianRed">#CD5C5C</color>
 <color name="MediumVioletRed">#C71585</color>
 <color name="Silver">#C0C0C0</color>
 <color name="DarkKhaki">#BDB76B</color>
 <color name="RosyBrown">#BC8F8F</color>
 <color name="MediumOrchid">#BA55D3</color>
 <color name="DarkGoldenrod">#B8860B</color>
 <color name="FireBrick">#B22222</color>
 <color name="PowderBlue">#B0E0E6</color>
 <color name="LightSteelBlue">#B0C4DE</color>
 <color name="PaleTurquoise">#AFEEEE</color>
 <color name="GreenYellow">#ADFF2F</color>
 <color name="LightBlue">#ADD8E6</color>
 <color name="DarkGray">#A9A9A9</color>
 <color name="Brown">#A52A2A</color>
 <color name="Sienna">#A0522D</color>
 <color name="YellowGreen">#9ACD32</color>
 <color name="DarkOrchid">#9932CC</color>
 <color name="PaleGreen">#98FB98</color>
 <color name="DarkViolet">#9400D3</color>
 <color name="MediumPurple">#9370DB</color>
 <color name="LightGreen">#90EE90</color>
 <color name="DarkSeaGreen">#8FBC8F</color>
 <color name="SaddleBrown">#8B4513</color>
 <color name="DarkMagenta">#8B008B</color>
 <color name="DarkRed">#8B0000</color>
 <color name="BlueViolet">#8A2BE2</color>
 <color name="LightSkyBlue">#87CEFA</color>
 <color name="SkyBlue">#87CEEB</color>
 <color name="Gray">#808080</color>
 <color name="Olive">#808000</color>
 <color name="Purple">#800080</color>
 <color name="Maroon">#800000</color>
 <color name="Aquamarine">#7FFFD4</color>
 <color name="Chartreuse">#7FFF00</color>
 <color name="LawnGreen">#7CFC00</color>
 <color name="MediumSlateBlue">#7B68EE</color>
 <color name="LightSlateGray">#778899</color>
 <color name="SlateGray">#708090</color>
 <color name="OliveDrab">#6B8E23</color>
 <color name="SlateBlue">#6A5ACD</color>
 <color name="DimGray">#696969</color>
 <color name="MediumAquamarine">#66CDAA</color>
 <color name="CornflowerBlue">#6495ED</color>
 <color name="CadetBlue">#5F9EA0</color>
 <color name="DarkOliveGreen">#556B2F</color>
 <color name="Indigo">#4B0082</color>
 <color name="MediumTurquoise">#48D1CC</color>
 <color name="DarkSlateBlue">#483D8B</color>
 <color name="SteelBlue">#4682B4</color>
 <color name="RoyalBlue">#4169E1</color>
 <color name="Turquoise">#40E0D0</color>
 <color name="MediumSeaGreen">#3CB371</color>
 <color name="LimeGreen">#32CD32</color>
 <color name="DarkSlateGray">#2F4F4F</color>
 <color name="SeaGreen">#2E8B57</color>
 <color name="ForestGreen">#228B22</color>
 <color name="LightSeaGreen">#20B2AA</color>
 <color name="DodgerBlue">#1E90FF</color>
 <color name="MidnightBlue">#191970</color>
 <color name="Aqua">#00FFFF</color>
 <color name="Cyan">#00FFFF</color>
 <color name="SpringGreen">#00FF7F</color>
 <color name="Lime">#00FF00</color>
 <color name="MediumSpringGreen">#00FA9A</color>
 <color name="DarkTurquoise">#00CED1</color>
 <color name="DeepSkyBlue">#00BFFF</color>
 <color name="DarkCyan">#008B8B</color>
 <color name="Teal">#008080</color>
 <color name="Green">#008000</color>
 <color name="DarkGreen">#006400</color>
 <color name="Blue">#0000FF</color>
 <color name="MediumBlue">#0000CD</color>
 <color name="DarkBlue">#00008B</color>
 <color name="Navy">#000080</color>
 <color name="Black">#000000</color>

#26 Best answer 2 of Web colors in an Android color XML resource file(Score: 112)

Created: 2010-09-22 Last updated: 2015-05-08

You have to create the colors.xml file in the res/values folder of your project. The code of colors.xml is

<?xml version="1.0" encoding="utf-8"?>
 <color name="orange">#ff5500</color>
 <color name="white">#ffffff</color>
 <color name="transparent">#00000000</color>
 <color name="date_color">#999999</color>
 <color name="black">#000000</color>
 <color name="gray">#999999</color>
 <color name="blue">#0066cc</color>
 <color name="gold">#e6b121</color>
 <color name="blueback">#99FFFF</color>
 <color name="articlecolor">#3399FF</color> 
 <color name="article_title">#3399FF</color> 
 <color name="cachecolor">#8ad0e8</color>

Or, you can use Colors in your application by following way;


See also original question in stackoverflow

#27: Can you provide some examples of why it is hard to parse XML and HTML with a regex? (Score: 405)

Created: 2009-03-31 Last updated: 2017-05-23

Tags: html, xml, regex

One mistake I see people making over and over again is trying to parse XML or HTML with a regex. Here are a few of the reasons parsing XML and HTML is hard:

People want to treat a file as a sequence of lines, but this is valid:


People want to treat < or <tag as the start of a tag, but stuff like this exists in the wild:

<img src="imgtag.gif" alt="<img>" />

People often want to match starting tags to ending tags, but XML and HTML allow tags to contain themselves (which traditional regexes cannot handle at all):

<span id="outer"><span id="inner">foo</span></span> 

People often want to match against the content of a document (such as the famous “find all phone numbers on a given page” problem), but the data may be marked up (even if it appears to be normal when viewed):

<span class="phonenum">(<span class="area code">703</span>)
<span class="prefix">348</span>-<span class="linenum">3020</span></span>

Comments may contain poorly formatted or incomplete tags:

<a href="foo">foo</a>
<!-- FIXME:
    <a href="
<a href="bar">bar</a>

What other gotchas are you aware of?

#27 Best answer 1 of Can you provide some examples of why it is hard to parse XML and HTML with a regex? (Score: 266)

Created: 2009-03-31 Last updated: 2009-03-31

Here’s some fun valid XML for you:

<!DOCTYPE x [ <!ENTITY y "a]>b"> ]>
    <a b="&y;>" />
    <![CDATA[[a>b <a>b <a]]>
    <?x <a> <!-- <b> ?> c --> d

And this little bundle of joy is valid HTML:

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "" [
    <!ENTITY % e "href='hello'">
    <!ENTITY e "<a %e;>">
    <p id  =  a:b center>
    <span / hello </span>
    &amp<br left>
    <!---- >t<!---> < -->
    &e link </a>

Not to mention all the browser-specific parsing for invalid constructs.

Good luck pitting regex against that!

EDIT (Jörg W Mittag): Here is another nice piece of well-formed, valid HTML 4.01:


#27 Best answer 2 of Can you provide some examples of why it is hard to parse XML and HTML with a regex?(Score: 71)

Created: 2009-03-31 Last updated: 2009-03-31


<img src="imgtag.gif" alt="<img>" />

is not valid HTML, and is not valid XML either.

It is not valid XML because the ‘<’ and ‘>’ are not valid characters inside attribute strings. They need to be escaped using the corresponding XML entities &lt; and &gt;

It is not valid HTML either because the short closing form is not allowed in HTML (but is correct in XML and XHTML). The ‘img’ tag is also an implicitly closed tag as per the HTML 4.01 specification. This means that manually closing it is actually wrong, and is equivalent to closing any other tag twice.

The correct version in HTML is

<img src="imgtag.gif" alt="&lt;img&gt;">

and the correct version in XHTML and XML is

<img src="imgtag.gif" alt="&lt;img&gt;"/>

The following example you gave is also invalid


This is not valid HTML or XML either. The name of the tag must be right behind the ‘<’, although the attributes and the closing ‘>’ may be wherever they want. So the valid XML is actually


And here’s another funkier one: you can actually choose to use either " or ' as your attribute quoting character

<img src="image.gif" alt='This is single quoted AND valid!'>

All the other reasons that were posted are correct, but the biggest problem with parsing HTML is that people usually don’t understand all the syntax rules correctly. The fact that your browser interprets your tagsoup as HTML doesn’t means that you have actually written valid HTML.

Edit: And even agrees with me regarding the definition of valid and invalid. Your invalid XML/HTML is not highlighted, while my corrected version is.

Basically, XML is not made to be parsed with regexps. But there is also no reason to do so. There are many, many XML parsers for each and every language. You have the choice between SAX parsers, DOM parsers and Pull parsers. All of these are guaranteed to be much faster than parsing with a regexp and you may then use cool technologies like XPath or XSLT on the resulting DOM tree.

My reply is therefore: not only is parsing XML with regexps hard, but it is also a bad idea. Just use one of the millions of existing XML parsers, and take advantage of all the advanced features of XML.

HTML is just too hard to even try parsing on your own. First the legal syntax has many little subtleties that you may not be aware of, and second, HTML in the wild is just a huge stinking pile of (you get my drift). There are a variety of lax parser libraries that do a good job at handling HTML like tag soup, just use these.

See also original question in stackoverflow

#28: send/post XML file using cURL command line (Score: 404)

Created: 2010-06-09 Last updated: 2021-04-01

Tags: xml, command-line, curl

How can I send/post an XML file to a local server http://localhost:8080 using cURL from the command line?

What command should I use?

#28 Best answer 1 of send/post XML file using cURL command line (Score: 521)

Created: 2010-06-09 Last updated: 2019-04-04

If that question is connected to your other Hudson questions use the command they provide. This way with XML from the command line:

$ curl -X POST -d '<run>...</run>' \
http://user:[email protected]:myport/path/of/url

You need to change it a little bit to read from a file:

 $ curl -X POST -d @myfilename http://user:[email protected]:myport/path/of/url

Read the manpage. following an abstract for -d Parameter.


(HTTP) Sends the specified data in a POST request to the HTTP server, in the same way that a browser does when a user has filled in an HTML form and presses the submit button. This will cause curl to pass the data to the server using the content-type application/x-www-form-urlencoded. Compare to -F/–form.

-d/–data is the same as –data-ascii. To post data purely binary, you should instead use the –data-binary option. To URL-encode the value of a form field you may use –data-urlencode.

If any of these options is used more than once on the same command line, the data pieces specified will be merged together with a separating &-symbol. Thus, using ‘-d name=daniel -d skill=lousy’ would generate a post chunk that looks like ‘name=daniel&skill=lousy’.

If you start the data with the letter @, the rest should be a file name to read the data from, or - if you want curl to read the data from stdin. The contents of the file must already be URL-encoded. Multiple files can also be specified. Posting data from a file named ‘foobar’ would thus be done with –data @foobar.

#28 Best answer 2 of send/post XML file using cURL command line(Score: 194)

Created: 2010-06-09

From the manpage, I believe these are the droids you are looking for:

-F/--form <name=content>

(HTTP) This lets curl emulate a filled-in form in which a user has pressed the submit button. This causes curl to POST data using the Content-Type multipart/form-data according to RFC2388. This enables uploading of binary files etc. To force the ‘content’ part to be a file, prefix the file name with an @ sign.

Example, to send your password file to the server, where ‘password’ is the name of the form-field to which /etc/passwd will be the input:

curl -F [email protected]/etc/passwd

So in your case, this would be something like
curl -F [email protected]/some/file/on/your/local/disk http://localhost:8080

See also original question in stackoverflow

#29: How do I read and parse an XML file in C#? (Score: 398)

Created: 2009-03-13 Last updated: 2009-03-19

Tags: c#, xml

How do I read and parse an XML file in C#?

#29 Best answer 1 of How do I read and parse an XML file in C#? (Score: 518)

Created: 2009-03-13 Last updated: 2015-12-07

XmlDocument to read an XML from string or from file.

XmlDocument doc = new XmlDocument();



then find a node below it ie like this

XmlNode node = doc.DocumentElement.SelectSingleNode("/book/title");


foreach(XmlNode node in doc.DocumentElement.ChildNodes){
   string text = node.InnerText; //or loop through its children as well

then read the text inside that node like this

string text = node.InnerText;

or read an attribute

string attr = node.Attributes["theattributename"]?.InnerText

Always check for null on Attributes[“something”] since it will be null if the attribute does not exist.

#29 Best answer 2 of How do I read and parse an XML file in C#?(Score: 234)

Created: 2009-03-26 Last updated: 2019-02-06

LINQ to XML Example:

// Loading from a file, you can also load from a stream
var xml = XDocument.Load(@"C:\contacts.xml");

// Query the data and write out a subset of contacts
var query = from c in xml.Root.Descendants("contact")
            where (int)c.Attribute("id") < 4
            select c.Element("firstName").Value + " " +

foreach (string name in query)
    Console.WriteLine("Contact's Full Name: {0}", name);

Reference: LINQ to XML at MSDN

See also original question in stackoverflow

#30: Best XML parser for Java (Score: 393)

Created: 2008-12-17 Last updated: 2015-10-26

Tags: java, xml, parsing

I need to read smallish (few MB at the most, UTF-8 encoded) XML files, rummage around looking at various elements and attributes, perhaps modify a few and write the XML back out again to disk (preferably with nice, indented formatting).

What would be the best XML parser for my needs? There are lots to choose from. Some I’m aware of are:

And of course the one in the JDK (I’m using Java 6). I’m familiar with Xerces but find it clunky.


#30 Best answer 1 of Best XML parser for Java (Score: 258)

Created: 2008-12-17 Last updated: 2014-04-21

I think you should not consider any specific parser implementation. Java API for XML Processing lets you use any conforming parser implementation in a standard way. The code should be much more portable, and when you realise that a specific parser has grown too old, you can replace it with another without changing a line of your code (if you do it correctly).

Basically there are three ways of handling XML in a standard way:

  • SAX This is the simplest API. You read the XML by defining a Handler class that receives the data inside elements/attributes when the XML gets processed in a serial way. It is faster and simpler if you only plan to read some attributes/elements and/or write some values back (your case).
  • DOM This method creates an object tree which lets you modify/access it randomly so it is better for complex XML manipulation and handling.
  • StAX This is in the middle of the path between SAX and DOM. You just write code to pull the data from the parser you are interested in when it is processed.

Forget about proprietary APIs such as JDOM or Apache ones (i.e. Apache Xerces XMLSerializer) because will tie you to a specific implementation that can evolve in time or lose backwards compatibility, which will make you change your code in the future when you want to upgrade to a new version of JDOM or whatever parser you use. If you stick to Java standard API (using factories and interfaces) your code will be much more modular and maintainable.

There is no need to say that all (I haven’t checked all, but I’m almost sure) of the parsers proposed comply with a JAXP implementation so technically you can use all, no matter which.

#30 Best answer 2 of Best XML parser for Java(Score: 130)

Created: 2011-04-14

Here is a nice comparision on DOM, SAX, StAX & TrAX (Source: )

Feature                  StAX                  SAX                      DOM                  TrAX

API Type                Pull,streaming     Push,streaming    In memory tree    XSLT Rule

Ease of Use          High                    Medium                 High                    Medium

XPath Capability   No                       No                        Yes                      Yes

CPU & Memory     Good                  Good                    Varies                  Varies

Forward Only        Yes                    Yes                        No                       No

Read XML              Yes                    Yes                        Yes                     Yes

Write XML              Yes                    No                          Yes                     Yes

CRUD                      No                      No                         Yes                     No

See also original question in stackoverflow

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