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Exception while parsing string to document object

I try to bild document object from string and append it into element but I get exception java.io.FileNotFoundException: project folder path\org.xml.sax.InputSource in this line: Document constantDocument = docBuilder.parse(
String.valueOf(new InputSource( new StringReader( xmlAsString ) )));.
My code looks like this:
Element infoElement = document.createElement("information");
String xmlAsString = "..."; //xml in string format
Document constantDocument = docBuilder.parse(
String.valueOf(new InputSource( new StringReader( xmlAsString ) ))); //java.io.FileNotFoundException
infoElement.appendChild(constantDocument);
What am I missing?

Reason is given here in the Documentation :
public Document parse(String uri)
throws SAXException,
IOException
Parse the content of the given URI as an XML document and return a new
DOM Document object. An IllegalArgumentException is thrown if the URI
is null null.
You are providing a String, and Java is looking to fetch the file at the given String / URI and hence the Exception ...
Based on your attempt, the closest you could use is :
parse(InputSource is)
Parse the content of the given input source as
an XML document and return a new DOM Document object.
So changing the .parse to below should solve your problem :
Document constantDocument = docBuilder.parse(new InputSource(new StringReader(xmlAsString)));

Found what I was looking for:
DocumentBuilder db = DocumentBuilderFactory.newInstance().newDocumentBuilder();
InputSource is = new InputSource();
is.setCharacterStream(new StringReader("<root><nod1></node1></root>"));
Document doc = db.parse(is);

From URL to Document object

I would like to transform a feed to a Document object.
I tried the following code but it seems it's not working with a real feed (uri = null), but it works with an XML file which is already in my computer.
The transform function :
public static Document obtainDocument(String feedurl) {
Document doc = null;
DocumentBuilder builder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
URL url = new URL(feedurl);
doc = builder.parse(url.openStream());
...Exceptions...
return doc;
}
EDIT
I'm pretty sure that the URL is right, I use:
String feedurl = "http://feeds2.feedburner.com/Pressecitron";
I tried to use the following code too:
public static Document obtainDocument(String feedurl) {
Document doc = null;
try {
DocumentBuilder builder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
URL url = new URL(feedurl);
URLConnection conn = url.openConnection();
doc = builder.parse(conn.getInputStream());
...
return doc;
}
which seems to not works better
And my first version of parser used a String too, but my mate wants me to use a Document (if the connection doesn't work). It worked with the String if I remember well.

Have you tried all the possible ways of using the parse() method ?
Are you sure the URI / URL is correct ?
From the method that you have, you get the feedURL as a String. You can directly pass it to the parse() method and see if that works.

How to create a XML object from String in Java?

I am trying to write a code that helps me to create a XML object. For example, I will give a string as input to a function and it will return me a XMLObject.
XMLObject convertToXML(String s) {}
When I was searching on the net, generally I saw examples about creating XML documents. So all the things I saw about creating an XML and write on to a file and create the file. But I have done something like that:
Document document = new Document();
Element child = new Element("snmp");
child.addContent(new Element("snmpType").setText("snmpget"));
child.addContent(new Element("IpAdress").setText("127.0.0.1"));
child.addContent(new Element("OID").setText("1.3.6.1.2.1.1.3.0"));
document.setContent(child);
Do you think it is enough to create an XML object? and also can you please help me how to get data from XML? For example, how can I get the IpAdressfrom that XML?
Thank you all a lot
EDIT 1: Actually now I thought that maybe it would be much easier for me to have a file like base.xml, I will write all basic things into that for example:
<snmp>
<snmpType><snmpType>
<OID></OID>
</snmp>
and then use this file to create a XML object. What do you think about that?

If you can create a string xml you can easily transform it to the xml document object e.g. -
String xmlString = "<?xml version=\"1.0\" encoding=\"utf-8\"?><a><b></b><c></c></a>";
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
DocumentBuilder builder;
try {
builder = factory.newDocumentBuilder();
Document document = builder.parse(new InputSource(new StringReader(xmlString)));
} catch (Exception e) {
e.printStackTrace();
}
You can use the document object and xml parsing libraries or xpath to get back the ip address.

try something like
public static Document loadXML(String xml) throws Exception
{
DocumentBuilderFactory fctr = DocumentBuilderFactory.newInstance();
DocumentBuilder bldr = fctr.newDocumentBuilder();
InputSource insrc = new InputSource(new StringReader(xml));
return bldr.parse(insrc);
}

Using a string inside the DocumentBuilder parse method (need it for parsing XML using XPath) [duplicate]

This question already has answers here:
In Java, how do I parse XML as a String instead of a file?
(6 answers)
Closed 9 years ago.
I'm trying to create a RESTful webservice using a Java Servlet. The problem is I have to pass via POST method to a webserver a request. The content of this request is not a parameter but the body itself.
So I basically send from ruby something like this:
url = URI.parse(#host)
req = Net::HTTP::Post.new('/WebService/WebServiceServlet')
req['Content-Type'] = "text/xml"
# req.basic_auth 'account', 'password'
req.body = data
response = Net::HTTP.start(url.host, url.port){ |http| puts http.request(req).body }
Then I have to retrieve the body of this request in my servlet. I use the classic readline, so I have a string. The problem is when I have to parse it as XML:
private void useXML( final String soft, final PrintWriter out) throws ParserConfigurationException, SAXException, IOException, XPathExpressionException, FileNotFoundException {
DocumentBuilderFactory domFactory = DocumentBuilderFactory.newInstance();
domFactory.setNamespaceAware(true); // never forget this!
DocumentBuilder builder = domFactory.newDocumentBuilder();
Document doc = builder.parse(soft);
XPathFactory factory = XPathFactory.newInstance();
XPath xpath = factory.newXPath();
XPathExpression expr = xpath.compile("//software/text()");
Object result = expr.evaluate(doc, XPathConstants.NODESET);
NodeList nodes = (NodeList) result;
for (int i = 0; i < nodes.getLength(); i++) {
out.println(nodes.item(i).getNodeValue());
}
}
The problem is that builder.parse() accepts: parse(File f), parse(InputSource is), parse(InputStream is).
Is there any way I can transform my xml string in an InputSource or something like that? I know it could be a dummy question but Java is not my thing, I'm forced to use it and I'm not very skilled.

You can create an InputSource from a string by way of a StringReader:
Document doc = builder.parse(new InputSource(new StringReader(soft)));

With your string, use something like :
ByteArrayInputStream input =
new ByteArrayInputStream(yourString.getBytes(perhapsEncoding));
builder.parse(input);
ByteArrayInputStream is an InputStream.

How to deal with unknown entity references?

I'm parsing (a lot of) XML files that contain entity references which i dont know in advance (can't change that fact).
For example:
xml = "<tag>I'm content with &funny; &entity; &references;.</tag>"
when i try to parse this using the following code:
final DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
final DocumentBuilder db = dbf.newDocumentBuilder();
final InputSource is = new InputSource(new StringReader(xml));
final Document d = db.parse(is);
i get the following exception:
org.xml.sax.SAXParseException: The entity "funny" was referenced, but not declared.
but, what i do want to achieve is, that the parser replaces every entity that is not declared (unknown to the parser) with an empty String ''.
Or even better, is there a way to pass a map to the parser like:
Map<String,String> entityMapping = ...
entityMapping.put("funny","very");
entityMapping.put("entity","important");
entityMapping.put("references","stuff");
so that i could do the following:
final DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
final DocumentBuilder db = dbf.newDocumentBuilder();
final InputSource is = new InputSource(new StringReader(xml));
db.setEntityResolver(entityMapping);
final Document d = db.parse(is);
if i would obtain the text from the document using this example code i should receive:
I'm content with very important stuff.
Any suggestions? Of course, i already would be happy to just replace the unknown entity's with empty strings.
Thanks,

The StAX API has support for this. Have a look at XMLInputFactory, it has a runtime property which dictates whether or not internal entities are expanded, or left in place. If set to false, then the StAX event stream will contain instances of EntityReference to represent the unexpanded entities.
If you still want a DOM as the end result, you can chain it together like this:
XMLInputFactory inputFactory = XMLInputFactory.newInstance();
inputFactory.setProperty(XMLInputFactory.IS_REPLACING_ENTITY_REFERENCES, false);
Transformer transformer = TransformerFactory.newInstance().newTransformer();
String xml = "my xml";
StringReader xmlReader = new StringReader(xml);
XMLEventReader eventReader = inputFactory.createXMLEventReader(xmlReader);
StAXSource source = new StAXSource(eventReader);
DOMResult result = new DOMResult();
transformer.transform(source, result);
Node document = result.getNode();
In this case, the resulting DOM will contain nodes of org.w3c.dom.EntityReference mixed in with the text nodes. You can then process these as you see fit.

Since your XML input seems to be available as a String, could you not do a simple pre-processing with regular expression replacement?
xml = "...";
/* replace entities before parsing */
for (Map.Entry<String,String> entry : entityMapping.entrySet()) {
xml = xml.replaceAll("&" + entry.getKey() + ";", entry.getValue());
}
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
...
It's quite hacky, and you may want to spend some extra effort to ensure that the regexps only match where they really should (think <entity name="&don't-match-me;"/>), but at least it's something...
Of course, there are more efficient ways to achieve the same effect than calling replaceAll() a lot of times.

You could add the entities at the befinning of the file. Look here for more infos.
You could also take a look at this thread where someone seems to have implemented an EntityResolver interface (you could also implement EntityResolver2 !) where you can process the entities on the fly (e.g. with your proposed Map).
WARNING: there is a bug! in jdk6, but you could try it with jdk5