Java tutorial
package org.bouncycastle.cms; import java.util.ArrayList; import java.util.Collection; import java.util.HashMap; import java.util.Iterator; import java.util.List; import java.util.Map; import org.bouncycastle.util.Iterable; public class SignerInformationStore implements Iterable<SignerInformation> { private List all = new ArrayList(); private Map table = new HashMap(); /** * Create a store containing a single SignerInformation object. * * @param signerInfo the signer information to contain. */ public SignerInformationStore(SignerInformation signerInfo) { this.all = new ArrayList(1); this.all.add(signerInfo); SignerId sid = signerInfo.getSID(); table.put(sid, all); } /** * Create a store containing a collection of SignerInformation objects. * * @param signerInfos a collection signer information objects to contain. */ public SignerInformationStore(Collection<SignerInformation> signerInfos) { Iterator it = signerInfos.iterator(); while (it.hasNext()) { SignerInformation signer = (SignerInformation) it.next(); SignerId sid = signer.getSID(); List list = (ArrayList) table.get(sid); if (list == null) { list = new ArrayList(1); table.put(sid, list); } list.add(signer); } this.all = new ArrayList(signerInfos); } /** * Return the first SignerInformation object that matches the * passed in selector. Null if there are no matches. * * @param selector to identify a signer * @return a single SignerInformation object. Null if none matches. */ public SignerInformation get(SignerId selector) { Collection list = getSigners(selector); return list.size() == 0 ? null : (SignerInformation) list.iterator().next(); } /** * Return the number of signers in the collection. * * @return number of signers identified. */ public int size() { return all.size(); } /** * Return all signers in the collection * * @return a collection of signers. */ public Collection<SignerInformation> getSigners() { return new ArrayList(all); } /** * Return possible empty collection with signers matching the passed in SignerId * * @param selector a signer id to select against. * @return a collection of SignerInformation objects. */ public Collection<SignerInformation> getSigners(SignerId selector) { if (selector.getIssuer() != null && selector.getSubjectKeyIdentifier() != null) { List results = new ArrayList(); Collection match1 = getSigners(new SignerId(selector.getIssuer(), selector.getSerialNumber())); if (match1 != null) { results.addAll(match1); } Collection match2 = getSigners(new SignerId(selector.getSubjectKeyIdentifier())); if (match2 != null) { results.addAll(match2); } return results; } else { List list = (ArrayList) table.get(selector); return list == null ? new ArrayList() : new ArrayList(list); } } /** * Support method for Iterable where available. */ public Iterator<SignerInformation> iterator() { return getSigners().iterator(); } }