com.unboundid.ldap.sdk.EntrySource Maven / Gradle / Ivy
/*
* Copyright 2009-2019 Ping Identity Corporation
* All Rights Reserved.
*/
/*
* Copyright (C) 2009-2019 Ping Identity Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License (GPLv2 only)
* or the terms of the GNU Lesser General Public License (LGPLv2.1 only)
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see .
*/
package com.unboundid.ldap.sdk;
import java.io.Closeable;
import com.unboundid.util.NotExtensible;
import com.unboundid.util.ThreadSafety;
import com.unboundid.util.ThreadSafetyLevel;
/**
* This class defines an API that may be implemented by a class that provides
* access to a sequence of entries, one entry at a time (e.g., entries read from
* an LDIF file, or returned as part of an LDAP search). It provides a
* convenient way to operate on a set of entries without regard for the source
* of those entries. Implementations currently available include the
* {@link LDAPEntrySource} class, which can be used to iterate across entries
* returned from a directory server in response to a search request, and the
* {@link com.unboundid.ldif.LDIFEntrySource} class, which can be used to
* iterate across entries in an LDIF file.
*
* Note that the {@link #close} method MUST be called if the entry source is to
* be discarded before guaranteeing that all entries have been read. The
* {@code close} method may be called after all entries have been read, but it
* is not required. All entry source implementations MUST ensure that all
* resources are properly released if the caller has read through all entries,
* or if an error occurs that prevents the caller from continuing to read
* through the entries (i.e., if {@link #nextEntry} throws an
* {@link EntrySourceException} and the
* {@link EntrySourceException#mayContinueReading()} method returns
* {@code false}).
*
* Example
* The following example demonstrates the process that may be used for iterating
* across the entries provided by an entry source:
*
* LDIFReader ldifReader = new LDIFReader(ldifFilePath);
* EntrySource entrySource = new LDIFEntrySource(ldifReader);
*
* int entriesRead = 0;
* int exceptionsCaught = 0;
* try
* {
* while (true)
* {
* try
* {
* Entry entry = entrySource.nextEntry();
* if (entry == null)
* {
* // There are no more entries to be read.
* break;
* }
* else
* {
* // Do something with the entry here.
* entriesRead++;
* }
* }
* catch (EntrySourceException e)
* {
* // Some kind of problem was encountered (e.g., a malformed entry
* // found in an LDIF file, or a referral returned from a directory).
* // See if we can continue reading entries.
* exceptionsCaught++;
* if (! e.mayContinueReading())
* {
* break;
* }
* }
* }
* }
* finally
* {
* entrySource.close();
* }
*
*/
@NotExtensible()
@ThreadSafety(level=ThreadSafetyLevel.INTERFACE_NOT_THREADSAFE)
public abstract class EntrySource
implements Closeable
{
/**
* Retrieves the next entry from the entry source, if there is at least one
* remaining entry. This method may block if no entries are immediately
* available.
*
* @return The next entry from the entry source, or {@code null} if there are
* no more entries to retrieve..
*
* @throws EntrySourceException If a problem occurs while attempting to read
* the next entry from the entry source.
*/
public abstract Entry nextEntry()
throws EntrySourceException;
/**
* Indicates that this entry source will no longer be needed and any resources
* associated with it may be closed. This method MUST be called if the entry
* source is no longer needed before all entries have been read. It MAY be
* called after all entries have been read with no ill effects, but this is
* not necessary as the entry source will have already been closed after all
* entries have been read.
*/
@Override()
public abstract void close();
}