I have a Maven and Spring based Java web application.
I have a config.xml file in src/main/resources.
<?xml version="1.0" encoding="UTF-8"?>
<sourceConfigs>
<areas>
<area name="Defects">
<fileHeaders>ID,Issue Key,Fields
</fileHeaders>
</area>
<area name="Organization">
<fileHeaders>ID,Org Key,Fields
</fileHeaders>
</area>
</areas>
<sourceTypes>
<source name="source1">
<adapterObject>source1Adapter</adapterObject>
<resultObject>JsonObject</resultObject>
</source>
<source name="source2">
<adapterObject>source2Adapter</adapterObject>
<resultObject>sourceObject</resultObject>
</source>
</sourceTypes>
</sourceConfigs>
I want to parse the above XML to Java object based on the attributes.
I have created two classes.
Area.java
#XmlRootElement(name="area")
public class Area {
String name;
String fileHeaders;
#XmlAttribute
//get Name
//set Name
#XmlElement
//get fileHeaders
//set FileHeaders
}
Source.java
#XmlRootElement(name="source")
public class Source {
String name;
String adapterObject;
String resultObject;
#XmlAttribute
//get Name
//set Name
#XmlElement
//get adapterObject
//set adapterObject
#XmlElement
//get resultObject
//set resultObject
}
I want to parse the XML based on the attribute value.
ie; if the attribute value of area is Defects, the parsed object should have the values based on that, else if its Organization, then the values based on that and object type to Area object. Similarly for Source type also.
How can I do that?
When it was only a simple XML file like following
<?xml version="1.0" encoding="UTF-8"?>
<sourceConfig area="Defects">
<adapterObject>jAdapter</adapterObject>
<resultObject>jsonObject</resultObject>
</sourceConfig>
My POJO was based on that and the code I used to parse is
public SourceConfig getConfigObject() throws JAXBException, IOException {
JAXBContext jaxbContext = JAXBContext.newInstance(SourceConfig.class);
Unmarshaller jaxbUnmarshaller = jaxbContext.createUnmarshaller();
Resource resource=new ClassPathResource("config.xml");
File file=resource.getFile();
SourceConfig sourceConfig = (SourceConfig) jaxbUnmarshaller.unmarshal(file);
return sourceConfig;
}
But for this complex I don't know how to parse based on attribute values, and also multiple list of data.
How to parse based on the attribute values?
I have created two POJOs for parsing different kind. If it's a single class also it's fine.
UPDATE 1
My expected output.
When I pass the value "Defects" when unmarshalling the Area object, The values should be
name= Defects
fileHeaders=ID,Issue Key,Fields
And If I pass "Organization", The area object values should be based on that. Similarly when unmarshalling source.
Now I am getting as List of Areas and List of SourceTypes, then I take the corresponding object by checking the value.
May be is there any way to parse only selected one based on attribute value instead of getting list and then checking value and returning the object?
Related
I am trying to query the value for location with the attribute tag in my xml below. How can I do so?
My current query only returns the value for the full attribute tag but I only want the value for location, which in this case is "sampleLocation"?
i.e: location="sampleLocation"
XML:
<Products>
<Product>
<name>Sample name</name>
<attribute id="sampleid" location="sampleLocation" type="sampleType"/>
</product>
</Products>
Current code:
public String getLocationByName(String name) {
final String nameToQueryFor = name;
return engine.new Query<String>(MY_COLLECTION) {
#Override
protected String query(Collection collection) throws Exception {
XQueryService service = queryService();
ResourceSet resourceSet = service.query(
format("//Products/Product[name='%s']" +
"/attribute"
, StringEscapeUtils.escapeXml(nameToQueryFor)
));
List<String> results = newArrayList();
for (String resource : new IterableStringResources(resourceSet)) {
results.add(resource);
}
return results.get(0);
}
}.execute();
}
[Edited for the 'location' + correction]
"//Products/Product/name[text()=%s]/next-sibling::attribute/attribute::location"
Translation: in the context of //Products/Product select the element <name> with a given text. Then take the next sibling element with the <attribute> type from which get the value of the location attribute (of this element)
Some examples of 'xpath location paths' straight from the horse's mouth.
My proposal is
//Product[child::name/text()={$nameToQueryFor}]/attribute/#location
This will only work when the variable is bound to a value for the element type
I was able to solve this using the following query:
"//Products/Product[name='%s']/attribute/#Location/string()"
which returns: "sampleLocation"
Note: without using the /string() at the end it was giving the error:
attribute 'Location' has no parent element
I need to create RDF/XML documents containing objects in the OSLC namespace.
e.g.
<oslc_disc:ServiceProviderCatalog
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:dc="http://purl.org/dc/terms/"
xmlns:oslc_disc="http://open-services.net/xmlns/discovery/1.0/"
rdf:about="{self}">
<dc:title>{catalog title}</dc:title>
<oslc_disc:details rdf:resource="{catalog details uri}" />
what is the simplest way to create this doc using the Jena API ?
( I know about Lyo, they use a JSP for this doc :-)
Thanks, Carsten
Here's a complete example to start you off. Be aware that this will be equivalent to XML output you want, but may not be identical. The order of properties, for example, may vary, and there are other ways to write the same content.
import com.hp.hpl.jena.rdf.model.*
import com.hp.hpl.jena.vocabulary.DCTerms;
public class Jena {
// Vocab items -- could use schemagen to generate a class for this
final static String OSLC_DISC_NS = "http://open-services.net/xmlns/discovery/1.0/";
final static Resource ServiceProviderCatalog =
ResourceFactory.createResource(OSLC_DISC_NS + "ServiceProviderCatalog");
final static Property details =
ResourceFactory.createProperty(OSLC_DISC_NS, "details");
public static void main(String[] args) {
// Inputs
String selfURI = "http://example.com/self";
String catalogTitle = "Catalog title";
String catalogDetailsURI = "http://example.com/catalogDetailsURI";
// Create in memory model
Model model = ModelFactory.createDefaultModel();
// Set prefixes
model.setNsPrefix("dc", DCTerms.NS);
model.setNsPrefix("oslc_disc", OSLC_DISC_NS);
// Add item of type spcatalog
Resource self = model.createResource(selfURI, ServiceProviderCatalog);
// Add the title
self.addProperty(DCTerms.title, catalogTitle);
// Add details, which points to a resource
self.addProperty(details, model.createResource(catalogDetailsURI));
// Write pretty RDF/XML
model.write(System.out, "RDF/XML-ABBREV");
}
}
I am doing JSON parsing in Android by the following steps:
Get an XML response from a web-service using HttpPost object.
Convert this XML to JSON string then JSON object.
Now the problem is that sometimes the XML response has null string or Null tag.
For Example:
<data>
<name>Martin Clark</name>
<city>London</city>
<country>XYZ</country> or <country /> <!-- Sometimes it will blank string like this if country is not available -->
<age>27</age>
</data>
Parsing style:
jsonObject.getString("country"); // It is working perfect when xml is this : <country>XYZ<country/>
jsonObject.getString("country"); // It is giving Exception key is not found when xml is this : <country />
i don't understand why the parser is not giving me BLANK string for blank XML object.
By deep level debugging i have found that XML to JSON converter not produce object corresponding to blank xml object.
Please help me.
Use optString instead, catching the Exception is costly and unnecessary.
public String optString (String name)
Added in API level 1 Returns the value mapped by name if it exists,
coercing it if necessary. Returns the empty string if no such mapping
exists.
public String optString (String name, String fallback)
Added in API level 1 Returns the value mapped by name if it exists,
coercing it if necessary. Returns fallback if no such mapping exists.
Documentation
You can use ths logical solution for your problem.
Try this once.
public static String getStringFromJSON(JSONObject json, String key){
String value = ""; // Blank string by default.
try {
String value = json.getString(key);
return value;
}
catch(JSONException exp){
exp.getMessage();
}
return value; // this wil return BLANk string if object is not prasent.
}
You can you this method for getting String from json object,
I have a requirement to unmarshall a subset of Unknown XML content, with that unmarshalled object, I need modify some contents and re-bind the same XML content(subset) with the Original XML.
Sample Input XML:
<Message>
<x>
</x>
<y>
</y>
<z>
</z>
<!-- Need to unmarshall this content to "Content" - java Object -->
<Content>
<Name>Robin</Name>
<Role>SM</Role>
<Status>Active</Status>
</Content>
.....
</Message>
Need to unmarshall the <Content> tag alone, by keeping the other XML part as same. Need to modify the elements in <Content> tag and bind the modified XML part with the original as shown below:
Expected Output XML:
<Message>
<x>
</x>
<y>
</y>
<z>
</z>
<!-- Need to unmarshall this content to "Content" - java Object -->
<Content>
<Name>Robin_123</Name>
<Role>Senior Member</Role>
<Status>1</Status>
</Content>
.....
</Message>
My Questions:
What is the possible solution for this Requirement ? (Except DOM parsing - as XML contnet is very huge)
Is there any option to do this in JAXB2.0 ?
Please provide your suggestions on this.
Consider cutting your source document down to size using the StAX API.
For the given sample, this code creates a DOM document with a root element of the Content element:
class ContentFinder implements StreamFilter {
private boolean capture = false;
#Override public boolean accept(XMLStreamReader xml) {
if (xml.isStartElement() && "Content".equals(xml.getLocalName())) {
capture = true;
} else if (xml.isEndElement() && "Content".equals(xml.getLocalName())) {
capture = false;
return true;
}
return capture;
}
}
XMLInputFactory inFactory = XMLInputFactory.newFactory();
XMLStreamReader reader = inFactory.createXMLStreamReader(inputStream);
reader = inFactory.createFilteredReader(reader, new ContentFinder());
Source src = new StAXSource(reader);
DOMResult res = new DOMResult();
TransformerFactory.newInstance().newTransformer().transform(src, res);
Document doc = (Document) res.getNode();
This can then be passed to JAXB as a DOMSource.
Similar techniques can be used when rewriting the XML on output.
JAXB doesn't seem to accept a StreamSource directly, at least in the Oracle 1.7 implementation.
You can annotate an Object property on your class with #XmlAnyElement and by default the unmapped content will be captured as a DOM nodes. If you specify a DomHandler on the #XmlAnyElement then you can control the format. Here is a link to an example where the content is kept as a String.
JAXB use String as it is
i have some user defined tag. for example data here , jssj .I have a file(not xml) which contains some data embeded in tags.I need a parser for this which will identify my tags and will extract the data in proper format.
Eg
<newpage> thix text </newpage>
<tagD>
<tagA> kk</tagA>
</tagD>
tags can also have some attributes as simlar to html tags. Eg
<mytag height="f" width ="d" > bla bla bla </mytag>
<mytag attribute="val"> bla bla bla</mytag>
You could look at a parser generator like antlr.
Unless your tag syntax can be represented with a (simple) regular grammar (in which case you could try to scan the file with regexes), you will need a proper parser. It is actually not very hard to do at all - just the first time tastes like biting bullets...
You can use JAXB, already included in Java. It's quite simple.
First you need to create a binding to your XML code. The binding provides a map between Java objects and the XML code.
An example would be:
#XmlRootElement(name = "YourRootElement", namespace ="http://someurl.org")
#XmlAccessorType(XmlAccessType.FIELD)
#XmlType(name = "", propOrder = {
"intValue",
"stringArray",
"stringValue"}
)
public class YourBindingClass {
protected int intValue;
#XmlElement(nillable = false)
protected List<String> stringArray;
#XmlElement(name = "stringValue", required = true)
protected String stringValue;
public int getIntValue() {
return intValue;
}
public void setIntValue(int value) {
this.intValue = value;
}
public List<String> getStringArray() {
if (stringArray == null) {
stringArray = new ArrayList<String>();
}
return this.stringArray;
}
public String getStringValue() {
return stringValue;
}
public void setStringValue(String value) {
this.stringValue = value;
}
}
Then, to encode your Java objects into XML, you can use:
YourBindingClass yourBindingClass = ...;
JAXBContext jaxbContext = JAXBContext.newInstance(YourBindingClass.class);
Marshaller marshaller = jaxbContext.createMarshaller();
marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
marshaller.setProperty(Marshaller.JAXB_FRAGMENT, false);
/** If you need to specify a schema */
SchemaFactory sf = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
Schema schema = sf.newSchema(new URL("http:\\www.someurl.org"));
marshaller.setSchema(schema);
marshaller.setProperty(Marshaller.JAXB_SCHEMA_LOCATION, true);
ByteArrayOutputStream stream = new ByteArrayOutputStream();
marshaller.marshal(yourBindingClass, stream);
System.out.println(stream);
To parse your XML back to objects:
InputStream resourceAsStream = ... // Your XML, File, etc.
JAXBContext jaxbContext = JAXBContext.newInstance(YourBindingClass.class);
Unmarshaller unmarshaller = jaxbContext.createUnmarshaller();
Object r = unmarshaller.unmarshal(resourceAsStream);
if (r instanceof YourBindingClass) ...
Example starting from a Java object:
YourBindingClass s = new YourBindingClass();
s.setIntValue(1);
s.setStringValue("a");
s.getStringArray().add("b1");
s.getStringArray().add("b2");
// marshal ...
Result:
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ns2:YourRootElement xmlns:ns2="http://someurl.org">
<intValue>1</intValue>
<stringArray>b1</stringArray>
<stringArray>b2</stringArray>
<stringValue>a</stringValue>
</ns2:YourRootElement>
If you don't know the input format, that means you probably don't have a XML schema. If you don't have a schema you don't have some it's benefits such as:
It is easier to describe allowable document content
It is easier to validate the correctness of data
It is easier to define data facets (restrictions on data)
It is easier to define data patterns (data formats)
It is easier to convert data between different data types
Anyway, the previous code also works with XML code that contains 'unknown' tags. However your XML code still have to present the required fields and follow the declared patterns.
So the following XML code is also valid. The only restriction is: the tag 'stringValue' should be there. Note that 'stringArrayQ' was not previously declared.
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ns2:YourRootElement xmlns:ns2="http://someurl.org">
<stringValue>a</stringValue>
<stringArrayQ>b1</stringArrayQ>
</ns2:YourRootElement>
Are these XML tags? If so, look into one of the many Java XML libraries already available. If they're some kind of custom tagging format, then you're just going to have to write it yourself.
For xml tags - use DOM parser or SAX parser.
You example is XML with this modification:
<root>
<newpage> thix text </newpage>
<tagD>
<tagA> kk</tagA>
</tagD>
</root>
You can use any XML parser you want to parse it.
Edit:
Attributes are a normal part of XML.
<root>
<newpage> thix text </newpage>
<tagD>
<tagA> kk</tagA>
</tagD>
<mytag height="f" width ="d" > bla bla bla </mytag>
<mytag attribute="val"> bla bla bla</mytag>
</root>
Every XML parser can deal with them.
Edit:
If you were able to use Python, you could do something like this:
import lxml.etree
doc = lxml.etree.parse("foo.xml")
print doc.xpath("//mytag[1]/#width")
# => ['d']
That's what i call simple.