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Given an enumeration of candidates, check whether each item in enumeration satifies the given filter. Each item is a Binding and the following is used to get its attributes for used by the filter: ((DirContext)item.getObject()).getAttributes(""). If item.getObject() is not an DirContext, the item is skipped The items in the enumeration are obtained one at a time as items from the search enumeration are requested.
Author:Rosanna Lee
/** * Given an enumeration of candidates, check whether each * item in enumeration satifies the given filter. * Each item is a Binding and the following is used to get its * attributes for used by the filter: * * ((DirContext)item.getObject()).getAttributes(""). * If item.getObject() is not an DirContext, the item is skipped * * The items in the enumeration are obtained one at a time as * items from the search enumeration are requested. * * @author Rosanna Lee */
package com.sun.jndi.toolkit.dir; import javax.naming.*; import javax.naming.directory.*; import javax.naming.spi.DirectoryManager; import java.util.NoSuchElementException; import java.util.Hashtable; final public class LazySearchEnumerationImpl implements NamingEnumeration<SearchResult> { private NamingEnumeration<Binding> candidates; private SearchResult nextMatch = null; private SearchControls cons; private AttrFilter filter; private Context context; private Hashtable<String, Object> env; private boolean useFactory = true; public LazySearchEnumerationImpl(NamingEnumeration<Binding> candidates, AttrFilter filter, SearchControls cons) throws NamingException { this.candidates = candidates; this.filter = filter; if(cons == null) { this.cons = new SearchControls(); } else { this.cons = cons; } } @SuppressWarnings("unchecked") // For Hashtable clone: env.clone() public LazySearchEnumerationImpl(NamingEnumeration<Binding> candidates, AttrFilter filter, SearchControls cons, Context ctx, Hashtable<String, Object> env, boolean useFactory) throws NamingException { this.candidates = candidates; this.filter = filter; this.env = (Hashtable<String, Object>) ((env == null) ? null : env.clone()); this.context = ctx; this.useFactory = useFactory; if(cons == null) { this.cons = new SearchControls(); } else { this.cons = cons; } } public LazySearchEnumerationImpl(NamingEnumeration<Binding> candidates, AttrFilter filter, SearchControls cons, Context ctx, Hashtable<String, Object> env) throws NamingException { this(candidates, filter, cons, ctx, env, true); } public boolean hasMore() throws NamingException { // find and do not remove from list return findNextMatch(false) != null; } public boolean hasMoreElements() { try { return hasMore(); } catch (NamingException e) { return false; } } public SearchResult nextElement() { try { return findNextMatch(true); } catch (NamingException e) { throw new NoSuchElementException(e.toString()); } } public SearchResult next() throws NamingException { // find and remove from list return (findNextMatch(true)); } public void close() throws NamingException { if (candidates != null) { candidates.close(); } } private SearchResult findNextMatch(boolean remove) throws NamingException { SearchResult answer; if (nextMatch != null) { answer = nextMatch; if (remove) { nextMatch = null; } return answer; } else { // need to find next match Binding next; Object obj; Attributes targetAttrs; while (candidates.hasMore()) { next = candidates.next(); obj = next.getObject(); if (obj instanceof DirContext) { targetAttrs = ((DirContext)(obj)).getAttributes(""); if (filter.check(targetAttrs)) { if (!cons.getReturningObjFlag()) { obj = null; } else if (useFactory) { try { // Give name only if context non-null, // otherwise, name will be interpreted relative // to initial context (not what we want) Name nm = (context != null ? new CompositeName(next.getName()) : null); obj = DirectoryManager.getObjectInstance(obj, nm, context, env, targetAttrs); } catch (NamingException e) { throw e; } catch (Exception e) { NamingException e2 = new NamingException( "problem generating object using object factory"); e2.setRootCause(e); throw e2; } } answer = new SearchResult(next.getName(), next.getClassName(), obj, SearchFilter.selectAttributes(targetAttrs, cons.getReturningAttributes()), true); if (!remove) nextMatch = answer; return answer; } } } return null; } } }