Thread: Donation Manager "Donator Membership"

Purpose: To add a simple system of membership or "donator membership"

Difficulty: -1

Assumed Knowledge: Copy and paste

Classes Modified: Client / Command classes?


For awhile now I've seen some pretty odd looking donation management systems this one is very basic, but it's an improvement over most.

Code:

import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.util.HashMap;

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

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

/**
 * Donation Manager; supports only lifetime memberships
 * 
 * @author Nour
 * 
 */

public class DonationManager {
	
	public DonationManager() {
		donators = new HashMap<String, String>();
		try {
			importDonators();
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
	
	public HashMap<String, String> donators;
	
	public static String FILE_PATH = ""; //path to donators.xml
	public static boolean EXPORT_AFTER_ADDITION = true; //Recommended true, false if you have other ideas for saving
	
	
	public int random(int range) {
		return (int) (java.lang.Math.random() * (range + 1));
	}
	
	public boolean isDonator(String name) {
		return donators.containsValue(name);
	}
	
	public String generateKey(int length) {
		String choices = "abcdefghijklmnopqrstuvwxyz1234567890";
		StringBuilder sb = new StringBuilder();
		for(int i = 0; i < length; i++) {
			sb.append(choices.charAt(random(choices.length() - 1)));
		}
		return sb.toString();
	}
	
	
	public void exportDonators() {
		try {
			BufferedWriter bw = new BufferedWriter(new FileWriter(FILE_PATH+"donators.xml"));
			String ENCODING = "ISO-8859-1";
			bw.write("<?xml version=\"1.0\" encoding=\""+ENCODING+"\"?>");
			bw.newLine();
			bw.write("<DONATIONS>");
			bw.newLine();
			for(String s : donators.keySet()) {
				bw.write("<DONATION><KEY>"+s+"</KEY><USER>"+donators.get(s)+"</USER></DONATION>");
				bw.newLine();
			}
			bw.write("</DONATIONS>");
			bw.close();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
	
	public void addDonator(String name, int keylength) {
		String key = generateKey(keylength);
		if(donators.containsKey(key)) {
			key = generateKey(keylength + 1);
		}
		donators.put(key, name);
		if(EXPORT_AFTER_ADDITION)
			exportDonators();
	}
	
	public void addDonator(String name) {
		String key = generateKey(8);
		if(donators.containsKey(key)) {
			key = generateKey(8 + random(4));
		}
		donators.put(key, name);
		if(EXPORT_AFTER_ADDITION)
			exportDonators();
	}
	
	public void importDonators() throws ParserConfigurationException, SAXException, IOException {
		donators.clear();
		File in = new File(FILE_PATH+"donators.xml");
		DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
		DocumentBuilder db = dbf.newDocumentBuilder();
		Document doc = db.parse(in);
		doc.getDocumentElement().normalize();
		NodeList nodeLst = doc.getElementsByTagName("DONATION");
		 for (int i = 0; i < nodeLst.getLength(); i++) {
			    Node fstNode = nodeLst.item(i);
			    if (fstNode.getNodeType() == Node.ELEMENT_NODE) {
			           Element fstElmnt = (Element) fstNode;
			           NodeList fstNmElmntLst = fstElmnt.getElementsByTagName("KEY");
			           Element fstNmElmnt = (Element) fstNmElmntLst.item(0);
			           NodeList fstNm = fstNmElmnt.getChildNodes();
			           String key = ((Node) fstNm.item(0)).getNodeValue();
			           NodeList lstNmElmntLst = fstElmnt.getElementsByTagName("USER");
			           Element lstNmElmnt = (Element) lstNmElmntLst.item(0);
			           NodeList lstNm = lstNmElmnt.getChildNodes();
			           String donator = ((Node) lstNm.item(0)).getNodeValue();
			           donators.put(key, donator);
			    }
		 }
	}
	
}

Save that as DonationManager.java

The only other step besides that is to add your own way of creating a way of adding the donators into the donation list. You can use the addDonator method to do so.

I'll make a command for an example.

Code:

if(command.startsWith("ad")) {
	String name = command.substring(3);
	donationManagerObject.addDonator(name);
}