如何从PubNub频道的历史记录中检索100多条消息？
有关PubNub History API状态的页面
history（）函数返回最多100条消息的列表，即开始 时间标记和结束时间标记。
有没有办法检索超过100条消息？
我目前不是PubNub的付费客户。
3 个答案:
答案 0 :(得分：4)
PubNub加载历史记录超过100条消息
有时您希望在线性数据流上及时切片。通常，您希望以不同的粒度级别执行此操作。这就是为什么PubNub存储和播放API提供最大程度的灵活性。但是，有时使用首选结果集加载数据会有点棘手。
在可能跨越事务集中的数百万条消息的时间轴上加载事务历史记录时，您可能会考虑几个注意事项。有一些很好的选择，我们现在将介绍其中两个。示例将使用JavaScript编码。第一个示例通过抓取过去24小时内每小时开始的快照来加载数据摘要。第二个示例向您展示如何以完整详细信息和最大粒度加载所有事务。
上找到所有参考文件
示例PubNub Mt.Gox历史JavaScript用法
<script src="https://cdn.pubnub.com/pubnub.min.js"></script>
<script src="mtgox-history.js"></script>
<script>(function(){
// LOAD HOURLY SUMMARY
MTGOX.history.hourly({
channel : 'd5f06780-30a8-4a48-a2f8-7ed181b4a13f',
data : function(response) { console.log(JSON.stringify(response)) },
error : function() { console.log("NETWORK ERROR") }
});
// LOAD ALL WITH LIMITER OPTION
MTGOX.history.full({
limit : 500, // SET LIMIT AS HIGH AS NEEDED TO LOAD MORE!
channel : 'd5f06780-30a8-4a48-a2f8-7ed181b4a13f',
data : function(messages) { console.log(messages) },
error : function(e) { console.log("NETWORK ERROR") }
});
})();</script>
注意：运行
MTGOX.history.hourly()方法将生成过去24小时内每小时的快照列表。注意：运行
MTGOX.history.full()方法将生成包含大量数据的最大分辨率详细信息。您可以根据需要获得完全转储或部分转储;并且您应该增加limit参数以获取更多数据点。
以下JavaScript文件将为您提供MTGOX界面。
PubNub Mt.Gox历史JavaScript加载器
//
// mtgox-history.js
//
(function(){
// -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
// INITIALIZE PUBNUB
// -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
var pubnub = PUBNUB.init({
subscribe_key : 'sub-c-50d56e1e-2fd9-11e3-a041-02ee2ddab7fe'
});
// -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
// MTGOX HISTORY INTERFACE
// -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
window.MTGOX = {
history : {
hourly : hourly,
full : full
}
};
// -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
// GET ALL DATA FOREVER (WITH LIMIT OF COURSE)
// -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
/*
MTGOX.history.full({
limit : 1000,
channel : 'd5f06780-30a8-4a48-a2f8-7ed181b4a13f',
data : function(messages) { console.log(messages) },
error : function(e) { console.log("NETWORK ERROR") }
});
*/
function full(args) {
var chan = args['channel'] ||'d5f06780-30a8-4a48-a2f8-7ed181b4a13f'
, callback = args['data'] || function(){}
, error = args['error'] || function(){}
, limit = +args['limit'] || 5000
, start = 0
, count = 100
, history = []
, params = {
channel : chan,
count : count,
callback : function(messages) {
var msgs = messages[0];
start = messages[1];
params.start = start;
PUBNUB.each( msgs.reverse(), function(m) {history.push(m)} );
if (history.length >= limit) return callback(history);
if (msgs.length < count) return callback(history);
count = 100;
add_messages();
},
error : function(e) {
callback(history);
error(history);
}
};
add_messages();
function add_messages() { pubnub.history(params) }
}
// -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
// GET 24 HOURS IN HOURLY INCREMENTS
// -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
/*
MTGOX.history.hourly({
channel : 'd5f06780-30a8-4a48-a2f8-7ed181b4a13f',
data : function(response) { console.log(response) },
error : function() { console.log('ERROR') }
});
*/
function hourly(setup) {
var limit = 24;
var count = 0;
var chan = setup['channel'] ||'d5f06780-30a8-4a48-a2f8-7ed181b4a13f';
var cb = setup['data'] || function(){};
var eb = setup['error'] || function(){};
var now = new Date();
now.setUTCHours(0);
now.setUTCMinutes(0);
now.setUTCSeconds(0);
now.setUTCMilliseconds(0);
var utc_now = now.getTime();
var vectors = [];
PUBNUB.each( (new Array(limit)).join(',').split(','), function( _, d ) {
var day = utc_now - 3600000 * d;
pubnub.history({
limit : 1,
channel : chan,
start : day * 10000,
error : function() { count++; eb(); },
callback : function(messages) {
// DONE?
if (++count == limit) return cb(vectors);
// ADD TIME SLICES
var res = +(((messages[0][0]||{}).ticker||{}).avg||{}).value;
res && vectors.push([ new Date(day).getUTCHours(), res ]);
// KEEP IT SORTED
vectors.sort(function(a,b){ return a[0] > b[0] && -1 || 1 });
}
})
} );
}
})();
Mt.Gox PubNub代码，深度和交易的频道列表
以下是您可以在历史记录channel参数字段中使用的Mt.Gox数据Feed选项提供的频道列表。
{
"TICKER.ltcgbp": "0102A446-E4D4-4082-8E83-CC02822F9172",
"TICKER.ltccny": "0290378C-E3D7-4836-8CB1-2BFAE20CC492",
"DEPTH.btchkd": "049F65DC-3AF3-4FFD-85A5-AAC102B2A579",
"DEPTH.btceur": "057BDC6B-9F9C-44E4-BC1A-363E4443CE87",
"TICKER.nmcaud": "08C65460-CBD9-492E-8473-8507DFA66AE6",
"TICKER.btceur": "0BB6DA8B-F6C6-4ECF-8F0D-A544AD948C15",
"DEPTH.btckrw": "0C84BDA7-E613-4B19-AE2A-6D26412C9F70",
"DEPTH.btccny": "0D1ECAD8-E20F-459E-8BED-0BDCF927820F",
"TICKER.btccad": "10720792-084D-45BA-92E3-CF44D9477775",
"DEPTH.btcchf": "113FEC5F-294D-4929-86EB-8CA4C3FD1BED",
"TICKER.ltcnok": "13616AE8-9268-4A43-BDF7-6B8D1AC814A2",
"TICKER.ltcusd": "1366A9F3-92EB-4C6C-9CCC-492A959ECA94",
"TICKER.btcbtc": "13EDFF67-CFA0-4D99-AA76-52BD15D6A058",
"TICKER.ltccad": "18B55737-3F5C-4583-AF63-6EB3951EAD72",
"TICKER.nmccny": "249FDEFD-C6EB-4802-9F54-064BC83908AA",
"DEPTH.btcusd": "24E67E0D-1CAD-4CC0-9E7A-F8523EF460FE",
"TICKER.btcchf": "2644C164-3DB7-4475-8B45-C7042EFE3413",
"DEPTH.btcaud": "296EE352-DD5D-46F3-9BEA-5E39DEDE2005",
"TICKER.btcczk": "2A968B7F-6638-40BA-95E7-7284B3196D52",
"TICKER.btcsgd": "2CB73ED1-07F4-45E0-8918-BCBFDA658912",
"TICKER.nmcjpy": "314E2B7A-A9FA-4249-BC46-B7F662ECBC3A",
"TICKER.btcnmc": "36189B8C-CFFA-40D2-B205-FB71420387AE",
"DEPTH.btcinr": "414FDB18-8F70-471C-A9DF-B3C2740727EA",
"DEPTH.btcsgd": "41E5C243-3D44-4FAD-B690-F39E1DBB86A8",
"TICKER.btcltc": "48B6886F-49C0-4614-B647-BA5369B449A9",
"TICKER.ltceur": "491BC9BB-7CD8-4719-A9E8-16DAD802FFAC",
"TICKER.btcinr": "55E5FEB8-FEA5-416B-88FA-40211541DECA",
"TICKER.ltcjpy": "5AD8E40F-6DF3-489F-9CF1-AF28426A50CF",
"DEPTH.btccad": "5B234CC3-A7C1-47CE-854F-27AEE4CDBDA5",
"TICKER.btcnzd": "5DDD27CA-2466-4D1A-8961-615DEDB68BF1",
"DEPTH.btcgbp": "60C3AF1B-5D40-4D0E-B9FC-CCAB433D2E9C",
"DEPTH.btcnok": "66DA7FB4-6B0C-4A10-9CB7-E2944E046EB5",
"DEPTH.btcthb": "67879668-532F-41F9-8EB0-55E7593A5AB8",
"TICKER.btcsek": "6CAF1244-655B-460F-BEAF-5C56D1F4BEA7",
"TICKER.btcnok": "7532E866-3A03-4514-A4B1-6F86E3A8DC11",
"TICKER.btcgbp": "7B842B7D-D1F9-46FA-A49C-C12F1AD5A533",
"TRADE.LAG": "85174711-BE64-4DE1-B783-0628995D7914",
"DEPTH.btcsek": "8F1FEFAA-7C55-4420-ADA0-4DE15C1C38F3",
"DEPTH.btcdkk": "9219ABB0-B50C-4007-B4D2-51D1711AB19C",
"DEPTH.btcjpy": "94483E07-D797-4DD4-BC72-DC98F1FD39E3",
"TICKER.nmcusd": "9AAEFD15-D101-49F3-A2FD-6B63B85B6BED",
"TICKER.ltcaud": "A046600A-A06C-4EBF-9FFB-BDC8157227E8",
"TICKER.btcjpy": "A39AE532-6A3C-4835-AF8C-DDA54CB4874E",
"DEPTH.btcczk": "A7A970CF-4F6C-4D85-A74E-AC0979049B87",
"TICKER.ltcdkk": "B10A706E-E8C7-4EA8-9148-669F86930B36",
"TICKER.btcpln": "B4A02CB3-2E2D-4A88-AEEA-3C66CB604D01",
"TEST": "BAD99F24-FA8B-4938-BFDF-0C1831FC6665",
"TICKER.btcrub": "BD04F720-3C70-4DCE-AE71-2422AB862C65",
"TICKER.nmcgbp": "BF5126BA-5187-456F-8AE6-963678D0607F",
"TICKER.btckrw": "BF85048D-4DB9-4DBE-9CA3-5B83A1A4186E",
"TICKER.btccny": "C251EC35-56F9-40AB-A4F6-13325C349DE4",
"DEPTH.btcnzd": "CEDF8730-BCE6-4278-B6FE-9BEE42930E95",
"TICKER.btchkd": "D3AE78DD-01DD-4074-88A7-B8AA03CD28DD",
"TICKER.btcthb": "D58E3B69-9560-4B9E-8C58-B5C0F3FDA5E1",
"TICKER.btcusd": "D5F06780-30A8-4A48-A2F8-7ED181B4A13F",
"DEPTH.btcrub": "D6412CA0-B686-464C-891A-D1BA3943F3C6",
"TICKER.nmceur": "D8512D04-F262-4A14-82F2-8E5C96C15E68",
"TRADE.btc": "DBF1DEE9-4F2E-4A08-8CB7-748919A71B21",
"TICKER.nmccad": "DC28033E-7506-484C-905D-1C811A613323",
"DEPTH.btcpln": "E4FF055A-F8BF-407E-AF76-676CAD319A21",
"TICKER.btcdkk": "E5CE0604-574A-4059-9493-80AF46C776B3",
"TICKER.btcaud": "EB6AAA11-99D0-4F64-9E8C-1140872A423D"
}
答案 1 :(得分：1)
参见https://help.pubnub.com/entries/24113341-How-do-I-Page-Through-Stored-Messages- 如果需要进一步的帮助，请联系PubNub支持（help @ ...）
答案 2 :(得分：0)
以下Java类可用于在此格式的高级for循环中轻松检索和处理长时间范围的历史消息：
PubnubHistoryExcerpt history = new PubnubHistoryExcerpt(pubnub, channel, start, end);
for (Object message : history) {
// do something with the message object
}
即时检索消息，因此不会出现内存问题。
以下是完整的代码。您可以在类的main()方法中找到完全可运行的用法示例。
我还没有广泛测试过这门课程。欢迎增强。
/*
* PubnubHistoryExcerpt.java
*
* This file is distributed under the FreeBSD License:
*
* Copyright (c) 2014, Daniel S. (http://stackoverflow.com/users/1838726/daniel-s)
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* The views and conclusions contained in the software and documentation are those
* of the authors and should not be interpreted as representing official policies,
* either expressed or implied, of the FreeBSD Project.
*/
import java.math.BigDecimal;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.NoSuchElementException;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import com.pubnub.api.Callback;
import com.pubnub.api.Pubnub;
import com.pubnub.api.PubnubError;
/**
* You can use this class to iterate over historical PubNub messages. The messages are retrieved transparently while you
* iterate over the history excerpt. This class and the returned iterators are thread-safe.
*
* See {@link #main(String[])} for a usage example.
*/
public class PubnubHistoryExcerpt implements Iterable<Object> {
/**
* This main method contains a usage example for this class. It downloads last 3 hour's messages of the MtGox BTC/USD ticker
* channel from PubNub and outputs the timestamp and USD value which are found in the messages.
*/
public static void main(String[] args) throws JSONException {
String PUBNUB_SUBSCRIBE_KEY_MTGOX = "sub-c-50d56e1e-2fd9-11e3-a041-02ee2ddab7fe";
String PUBNUB_CHANNEL_MTGOX_TICKER_BTCUSD = "d5f06780-30a8-4a48-a2f8-7ed181b4a13f";
Pubnub pubnub = new Pubnub(null, PUBNUB_SUBSCRIBE_KEY_MTGOX);
long ONE_HOUR_IN_MILLIS = 60 * 60 * 1000;
long end = System.currentTimeMillis();
long start = end - 3 * ONE_HOUR_IN_MILLIS;
// convert from milliseconds as time unit (10^-3 seconds) to
// pubnub's better-than-microsecond precision time units (10^-7 seconds)
start *= 10000;
end *= 10000;
PubnubHistoryExcerpt history = new PubnubHistoryExcerpt(pubnub, PUBNUB_CHANNEL_MTGOX_TICKER_BTCUSD, start, end);
DefaultDateFormat dateFormat = DefaultDateFormat.create();
for (Object message : history) {
JSONObject messageJson = (JSONObject) message;
JSONObject ticker = messageJson.getJSONObject("ticker");
long instant = ticker.getLong("now");
BigDecimal value = new BigDecimal(ticker.getJSONObject("last_local").getString("value"));
instant /= 1000; // convert from microseconds to milliseconds
System.out.println(dateFormat.format(instant) + ": " + value);
}
System.exit(0);
}
/**
* This is the maximum number of messages to fetch in one batch. If you fetch many messages, higher numbers improve
* performance. Setting this to a value higher than 100 doesn't have an effect, because Pubnub currently doesn't
* support fetching more than this many messages at once.
*/
private static final int BATCH_SIZE = 100;
private final Pubnub pubnub;
private final String channel;
private final long start;
private final long end;
/**
* Constructs a new excerpt over which you can iterate. Insances represent an excerpt. No retrieval operations are
* started unless you call iterator().next() for the first time.
*
* @param pubnub
* The Pubnub connection to use for retrieving messages.
* @param channel
* The channel for which to retrieve historical messages.
* @param start
* The beginning of the time interval for which to retrieve messages, in pubnub's time units (10^-7
* seconds, so milliseconds * 10000) since 1970-01-01 00:00:00).
* @param end
* The end of the time interval for which to retrieve messages, in pubnub's time units (10^-7 seconds, so
* milliseconds * 10000) since 1970-01-01 00:00:00).
*/
private PubnubHistoryExcerpt(Pubnub pubnub, String channel, long start, long end) {
this.pubnub = pubnub;
this.channel = channel;
this.start = start;
this.end = end;
}
public Iterator<Object> iterator() {
return new Iter();
}
private class Iter implements Iterator<Object> {
/**
* This list is used as a fifo buffer for messages retrieves through this iterator. It also acts as the main
* synchronization lock for synchronizing access between threads accessing this class as an iterator and threads
* calling back from the Pubnub API.
*/
private LinkedList<Object> buffer = new LinkedList<Object>();
/**
* This field stores the end of the time range of the previous batch retrieval, in Pubnub time units (10th of a
* microsecond, so milliseconds*10000). For the following batch retrieval, this is used as the start time for
* retrieving the following messages.
*/
private long prevBatchTimeRangeEnd = PubnubHistoryExcerpt.this.start;
/**
* Retrieval of messages is handled asynchronously. That means that exceptions which are thrown during retrieval
* can't automatically be propagated through to the code which invokes <code>next()</code> or
* <code>hasNext()</code> . Therefor, such an exception is stored temporarily in this field and then re-thrown
* from within <code>next()</code> or <code>hasNext()</code>.
*/
private Exception caughtDuringRetrieval = null;
/**
* This object is used to wait on and to notify about updates of the buffer.
*/
private Object notifier = new Object();
/**
* Because of spurious wakeups that can happen during wait(), this field is necessary to tell the waiting thread
* if retrieval is still running.
*/
private boolean retrieving = false;
/**
* The callback object to use for retrieving messages. This is stored in a field here for re-use. This is a
* compromise between performance and low memory footprint, slightly in favor of performance.
*/
private InternalCallback internalCallback = new InternalCallback();
private void retrieveNextBatch() {
synchronized (notifier) {
this.retrieving = true;
// String startStr = DefaultDateFormat.create().format(prevBatchTimeRangeEnd / 10000);
// String endStr = DefaultDateFormat.create().format(end / 10000);
// System.out.println("fetching from " + startStr + " till " + endStr);
if (Iter.this.prevBatchTimeRangeEnd < PubnubHistoryExcerpt.this.end) {
PubnubHistoryExcerpt.this.pubnub.history( //
PubnubHistoryExcerpt.this.channel, //
Iter.this.prevBatchTimeRangeEnd, //
PubnubHistoryExcerpt.this.end, //
BATCH_SIZE, //
false, //
Iter.this.internalCallback //
);
waitUntilNextBatchRetrievalFinished();
}
}
}
private void waitUntilNextBatchRetrievalFinished() {
while (this.retrieving) {
try {
this.notifier.wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
private class InternalCallback extends Callback {
@Override
public void successCallback(String channel, Object message) {
synchronized (Iter.this.notifier) {
try {
processSuccessCallback(channel, message);
} catch (Exception e) {
Iter.this.caughtDuringRetrieval = e;
} finally {
Iter.this.retrieving = false;
Iter.this.notifier.notifyAll();
}
}
}
@Override
public void errorCallback(String channel, PubnubError error) {
Iter.this.caughtDuringRetrieval = new Exception("" + //
error.getClass().getName() + ": " + //
error.getErrorString() + //
" (code=" + error.errorCode + "; extendedCode=" + error.errorCodeExtended + ")");
Iter.this.caughtDuringRetrieval.fillInStackTrace();
}
}
private void processSuccessCallback(String channel, Object message) throws JSONException {
if (message == null)
throw new NullPointerException("retrieved message is null");
if (!(message instanceof JSONArray))
throw new RuntimeException("retrieved message is not a " + JSONArray.class.getName());
JSONArray historyMessage = (JSONArray) message;
// System.out.println(historyMessage.toString(2));
JSONArray messageList = extractMessageList(historyMessage);
long batchTimeRangeEnd = extractBatchTimeRangeEnd(historyMessage);
if (batchTimeRangeEnd > 0)
Iter.this.prevBatchTimeRangeEnd = batchTimeRangeEnd;
else
Iter.this.prevBatchTimeRangeEnd = end;
processMessageList(messageList);
}
private void processMessageList(JSONArray messageList) {
int i = 0;
for (; i < messageList.length(); i++) {
JSONObject message;
try {
message = messageList.getJSONObject(i);
} catch (JSONException e) {
String str;
try {
str = messageList.toString(2);
} catch (JSONException secondaryE) {
str = "(couldn't convert messageList to String because of " + secondaryE.toString() + ")";
}
throw new RuntimeException("couldn't extract message at index " + i + " from messageList (messageList:\n" + str
+ "\n(end of messageList)\n)", e);
}
Iter.this.buffer.add(message);
}
}
private long extractBatchTimeRangeEnd(JSONArray historyMessage) {
long batchTimeRangeEnd;
try {
batchTimeRangeEnd = historyMessage.getLong(2);
} catch (JSONException e) {
String str = safeConvertHistoryMessageToString(historyMessage);
throw new RuntimeException("could not extract element 2 (batchTimeRangeEnd) of retrieved historyMessage (historyMessage:\n" + str
+ "\n(end of historyMessage)\n)", e);
}
return batchTimeRangeEnd;
}
private String safeConvertHistoryMessageToString(JSONArray historyMessage) {
String str;
try {
str = historyMessage.toString(2);
} catch (JSONException secondaryE) {
str = "(couldn't convert historyMessage to String because of " + secondaryE.toString() + ")";
}
return str;
}
private JSONArray extractMessageList(JSONArray historyMessage) {
JSONArray messageArJson;
try {
messageArJson = historyMessage.getJSONArray(0);
} catch (JSONException e) {
String str = safeConvertHistoryMessageToString(historyMessage);
throw new RuntimeException("could not extract element 0 (messageList) of retrieved historyMessage (historyMessage:\n" + str
+ "\n(end of historyMessage)\n)", e);
}
return messageArJson;
}
public boolean hasNext() {
synchronized (Iter.this.buffer) {
ensureNotInExceptionState();
if (Iter.this.buffer.isEmpty())
retrieveNextBatch();
return !Iter.this.buffer.isEmpty();
}
}
public Object next() {
synchronized (Iter.this.buffer) {
if (!hasNext()) {
throw new NoSuchElementException("there are no more elements in this iterator");
}
Object result = Iter.this.buffer.removeFirst();
return result;
}
}
private void ensureNotInExceptionState() {
if (caughtDuringRetrieval != null) {
throw new RuntimeException("an exception was caught already by a previous attempt to access this iterator", caughtDuringRetrieval);
}
}
public void remove() {
throw new UnsupportedOperationException(getClass().getName() + " doesn't support remove()");
}
}
}
相关问题
最新问题
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