using_flickrj.java

程序使用 Flickr 的API 提取用户名的个人资料, 是良好的 Java 和 Web 的混合使用教材

import java.util.*;
import java.io.*;
import java.net.*;

import org.w3c.dom.*;
import javax.xml.parsers.*;
import javax.xml.transform.*; 
import javax.xml.transform.dom.DOMSource; 
import javax.xml.transform.stream.StreamResult; 

import com.aetrion.flickr.*;
import com.aetrion.flickr.contacts.*;
import com.aetrion.flickr.people.*;

public class using_flickrj
{
	public int depth = 0;
	private URL url = null;
	public String id = "";
	public Flickr flickr = null;
	public User userGen;
	private ContactsInterface ci;
	private PeopleInterface people;

	// class with details for a contact
	static class PersonContact
	{
		public String userURL; // contact url
		public String relationURL; // base url, the url you start the search
		public int degree; // depth of the contacts' tree
		public String refURL; // contact parent's url
	}
	
	private ArrayList<PersonContact> listaContacte;

	// class constructor
	public using_flickrj(String apiKey, String sharedSecret)
	{
		try
		{
			this.flickr = new Flickr(apiKey, sharedSecret, new REST()); // main API class. you need an apiKey and a sharedSecret, you can obtain them from the address http://www.flickr.com/services/api/
			this.listaContacte = new ArrayList<PersonContact>(); // the contacts' list
			ci = this.flickr.getContactsInterface(); // the interface needed to work with the contacts
			people = this.flickr.getPeopleInterface(); // the interface needed to work with people informations (you need it to gain the details for a given username)
		}
		catch(Exception e)
		{
			System.out.println(e.getMessage());
		}
	}

	// read the input and set the remaining class variables
	public void ReadInput(String xmlFile)
	{
		try
		{
			// citesc xml-ul
			// Create a factory
			DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
			// Use the factory to create a builder
			DocumentBuilder builder = factory.newDocumentBuilder();
			Document doc = builder.parse(new File(xmlFile));

			Element elem = doc.getDocumentElement();
			if(elem.getTagName().compareTo("config") == 0)
			{
				NodeList children = elem.getChildNodes();
				for(int i = 0; i < children.getLength(); i++)
				{
					Node child = children.item(i);
					if(child.getNodeName().compareTo("url") == 0)
					{
						url = new URL(child.getChildNodes().item(0).getNodeValue());
					}
					if(child.getNodeName().compareTo("username") == 0)
					{
						id = child.getChildNodes().item(0).getNodeValue();
						PeopleInterface people = flickr.getPeopleInterface();
						userGen = people.findByUsername(id);
					}
					if(child.getNodeName().compareTo("depth") == 0)
					{
						depth = Integer.parseInt(child.getAttributes().getNamedItem("value").getNodeValue());
					}
				}
			}
		}
		catch(Exception e)
		{
			System.out.println(e.getMessage());
		}
	}

	// function for building the contacts list
	public void ProcessContact(String username, int degree, String parentId)
	{
		try
		{
			User userLoc = people.findByUsername(username);
			System.out.println("Username: " + username + ", id: " + userLoc.getId() + ", parent id: " + parentId);

			// build the current contact
			PersonContact person = new PersonContact();
			person.userURL = "http://www.flickr.com/people/" + userLoc.getId() + "/";
			person.relationURL = "http://www.flickr.com/people/" + userGen.getId() + "/";
			person.degree = depth - degree;
			person.refURL = "http://www.flickr.com/people/" + parentId + "/"; 
			listaContacte.add(person); // add the contact to the contacts list

			if(degree > 0)
			{
				Iterator<Contact> it = ci.getPublicList(userLoc.getId()).iterator();
				for(int i = 0; i < ci.getPublicList(userLoc.getId()).size(); i++)
				{
					Contact contact = it.next();
					// recursive function, call it for someone's contacts
					ProcessContact(contact.getUsername(), degree-1, userLoc.getId());
				}
			}
		}
		catch(Exception e)
		{
			System.out.println(e.getMessage());
		}
	}

	// output creation function, based on the function provided here: http://www.roseindia.net/xml/dom/createdomchildelement.shtml
	public void CreateOutput(String outXmlFile)
	{
		try
		{
			File f = new File(outXmlFile);

			//Create instance of DocumentBuilderFactory
			DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
			//Get the DocumentBuilder
			DocumentBuilder docBuilder = factory.newDocumentBuilder();
			//Create blank DOM Document
			Document doc = docBuilder.newDocument();

			//create the root element
			Element root = doc.createElement("socialnetwork");
			//add it to the xml tree
			doc.appendChild(root);

			for(int i = 0; i < listaContacte.size(); i++)
			{
				Element userElement = doc.createElement("user");
				//Add the atribute to the child
				userElement.setAttribute("url", listaContacte.get(i).userURL);
				Element relationElement = doc.createElement("relation");
				relationElement.setAttribute("url", listaContacte.get(i).relationURL);
				relationElement.setAttribute("degree", (new Integer(listaContacte.get(i).degree)).toString());
				relationElement.setAttribute("ref", listaContacte.get(i).refURL);
				userElement.appendChild(relationElement);
				root.appendChild(userElement);
			}

			TransformerFactory tranFactory = TransformerFactory.newInstance(); 
			Transformer aTransformer = tranFactory.newTransformer(); 

			Source src = new DOMSource(doc); 
			Result dest = new StreamResult(f); 
			aTransformer.transform(src, dest); 

		}
		catch(Exception e)
		{
			System.out.println(e.getMessage());
		}
	}

	public static void main(String[] args)
	{
		try
		{
			using_flickrj uf = new using_flickrj("your_key", "your_secret"); // replace the 2 Strings with the key and secret obtained from http://www.flickr.com/services/api/
			uf.ReadInput("config.xml");
			uf.ProcessContact(uf.id, uf.depth, "");
			uf.CreateOutput("socialnetwork.xml");
		}
		catch(Exception e)
		{
			System.out.println(e.getMessage());
		}
	}
}