Using the API Version 2.0 Beta with Java and the API's XML interface

Author: Roopali Kaujalgi, Program Manager II, Bing API

This is the first of a series of posts that show how you can use the API with Java. This post shows how you can use Java to create a console application that sends a request to the API's XML interface and displays the results. The last post in the series will include a pointer to a site from which you can download all instructions and code associated with each post in the series.

Coming next: Using the API with Java and the SOAP interface

Requirements

• Java Development Kit (JDK) 1.6
• Live Search API Version 2.0 AppId (available at http://search.live.com/developers)

Demonstrates

These code samples demonstrates how to:

• Send a request to the Live Search XML interface and the Web SourceType
• Display the Live Search response as results

To run the sample

1. Create files named WebSample.java and APINameSpaceContext.java.
2. Copy "File 1 Content: WebSample.java" from the section of that name in this post to WebSample.java.
3. Copy "File 2 Content: APINameSpaceContext.java" from the section of that name in this post to APINameSpaceContext.java.
4. In WebSample.java, substitute your AppId for Insert your AppId here.
5. Edit your computer's PATH environment variable to include the bin directory of the JAVA installation.
6. Compile the 2 files.
7. Run the sample (for example, typing java WebSample from the command line in the directory containing WebSample.java).

File Content

The remainder of this post consists of the content (in the form of code) that you will copy in Steps 2 and 3 of "To Run the Sample."

File 1 Content: WebSample.java

import java.io.IOException;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathExpression;
import javax.xml.xpath.XPathExpressionException;
import javax.xml.xpath.XPathFactory;

import org.w3c.dom.Document;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;

//Live Search API 2.0 code sample demonstrating the use of the
//Web SourceType over the XML Protocol.
class WebSample 
{
	static XPathFactory factory = null;
	static XPath xpath = null;
	static XPathExpression expr = null;

	public static void main(String[] args) throws ParserConfigurationException, SAXException, IOException, 
XPathExpressionException
	{
		// Build the request.
		String requestURL = BuildRequest();

		// Send the request to the Live Search Service and get the response.
		Document doc = GetResponse(requestURL);

		if(doc != null)
		{
			// Display the response obtained from the Live Search Service.
			DisplayResponse(doc);
		}

	}
	private static String BuildRequest()
	{
		// Replace the following string with the AppId you received from the
		// Live Search Developer Center.
		String AppId = "Insert your AppId here.";
		String requestString = "http://api.search.live.net/xml.aspx?"

			// Common request fields (required)
			+ "AppId=" + AppId
			+ "&Query=msdn blogs"
			+ "&Sources=Web"

			// Common request fields (optional)
			+ "&Version=2.0"
			+ "&Market=en-us"
			+ "&Adult=Moderate"

			// Web-specific request fields (optional)
			+ "&Web.Count=10"
			+ "&Web.Offset=0"
			+ "&Web.FileType=DOC"
			+ "&Web.Options=DisableHostCollapsing+DisableQueryAlterations";

		return requestString;
	}

	private static Document GetResponse(String requestURL) throws ParserConfigurationException, SAXException, 

IOException 
	{
		DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
		dbf.setNamespaceAware(true);
		Document doc = null;
		DocumentBuilder db = dbf.newDocumentBuilder();

		if (db != null)
		{              
			doc = db.parse(requestURL);
		}

		return doc;
	}

	private static void DisplayResponse(Document doc) throws XPathExpressionException
	{
		factory = XPathFactory.newInstance();
		xpath = factory.newXPath();
		xpath.setNamespaceContext(new APINameSpaceContext());
		NodeList errors = (NodeList) xpath.evaluate("//api:Error",doc,XPathConstants.NODESET);

		if(errors != null && errors.getLength() > 0 )
		{
			// There are errors in the response. Display error details.
			DisplayErrors(errors);
		}
		else
		{
			DisplayResults(doc);
		}
	}

	private static void DisplayResults(Document doc) throws XPathExpressionException 
	{
		String version = (String)xpath.evaluate("//@Version",doc,XPathConstants.STRING);
		String searchTerms = (String)xpath.evaluate("//api:SearchTerms",doc,XPathConstants.STRING);
		int total = Integer.parseInt((String)xpath.evaluate("//web:Web/web:Total",doc,XPathConstants.STRING));
		int offset = Integer.parseInt((String)xpath.evaluate("//web:Web/web:Offset",doc,

XPathConstants.STRING));
		NodeList results = (NodeList)xpath.evaluate"//web:Web/web:Results/web:WebResult",doc,

XPathConstants.NODESET); 

		// Display the results header.
		System.out.println("Live Search API Version " + version);
		System.out.println("Web results for " + searchTerms);
		System.out.println("Displaying " + (offset+1) + " to " + (offset + 

results.getLength()) + " of " + total + " results ");
		System.out.println();

		// Display the Web results.
		StringBuilder builder = new StringBuilder();

		for(int i = 0 ; i < results.getLength(); i++)
		{
			NodeList childNodes = results.item(i).getChildNodes();

			for (int j = 0; j < childNodes.getLength(); j++) 
			{
				if(!childNodes.item(j).getLocalName().equalsIgnoreCase("DisplayUrl"))
				{
					String fieldName = childNodes.item(j).getLocalName();

					if(fieldName.equalsIgnoreCase("DateTime"))
					{
						fieldName = "Last Crawled";
					}

					builder.append(fieldName + ":" + childNodes.item(j).getTextContent());
					builder.append("\n");
				}
			}

			builder.append("\n");
		}

		System.out.println(builder.toString());
	}

	private static void DisplayErrors(NodeList errors) 
	{
		System.out.println("Live Search API Errors:");
		System.out.println();

		for (int i = 0; i < errors.getLength(); i++) 
		{
			NodeList childNodes = errors.item(i).getChildNodes();

			for (int j = 0; j < childNodes.getLength(); j++) 
			{
				System.out.println(childNodes.item(j).getLocalName() + ":" + childNodes.item(j).getTextContent());
			}

			System.out.println();
		}
	}
}

File 2 Content: APINameSpaceContext.java

import java.util.Iterator;

import javax.xml.XMLConstants;
import javax.xml.namespace.NamespaceContext;

// Map prefixes to Namespace URIs
public class APINameSpaceContext implements NamespaceContext 
{
	static final String WEB_NAMESPACE =  "http://schemas.microsoft.com/LiveSearch/2008/04/XML/web";
	static final String API_NAMESPACE = "http://schemas.microsoft.com/LiveSearch/2008/04/XML/element";
	static final String SPELL_NAMESPACE = "http://schemas.microsoft.com/LiveSearch/2008/04/XML/spell";
	static final String RS_NAMESPACE = "http://schemas.microsoft.com/LiveSearch/2008/04/XML/relatedsearch";
	static final String PB_NAMESPACE = "http://schemas.microsoft.com/LiveSearch/2008/04/XML/phonebook";
	static final String MM_NAMESPACE = "http://schemas.microsoft.com/LiveSearch/2008/04/XML/multimedia";
	static final String AD_NAMESPACE = "http://schemas.microsoft.com/LiveSearch/2008/04/XML/ads";
	static final String IA_NAMESPACE = "http://schemas.microsoft.com/LiveSearch/2008/04/XML/instantanswer";
	static final String NEWS_NAMESPACE = "http://schemas.microsoft.com/LiveSearch/2008/04/XML/news";
	static final String ENCARTA_NAMESPACE = "http://schemas.microsoft.com/LiveSearch/2008/04/XML/encarta";

	public String getNamespaceURI(String prefix) 
	{
		if (prefix == null) throw new NullPointerException("Null prefix");
		else if ("api".equals(prefix)) return API_NAMESPACE;
		else if ("web".equals(prefix)) return WEB_NAMESPACE;
		return XMLConstants.NULL_NS_URI;
	}
	
	// This method isn't necessary for XPath processing.
	public String getPrefix(String uri) 
	{
		throw new UnsupportedOperationException();
	}
	
	public Iterator getPrefixes(String arg0) 
	{
		throw new UnsupportedOperationException();
	}
}