爬虫快速入门

本文节选自《Netkiller Java 手札》

11.4. 爬虫项目

11.4.1. 创建项目

创建爬虫项目

scrapy startproject project

在抓取之前,你需要新建一个Scrapy工程

neo@MacBook-Pro ~/Documents % scrapy startproject crawler 
New Scrapy project 'crawler', using template directory '/usr/local/lib/python3.6/site-packages/scrapy/templates/project', created in:
    /Users/neo/Documents/crawler

You can start your first spider with:
    cd crawler
    scrapy genspider example example.com

neo@MacBook-Pro ~/Documents % cd crawler 
neo@MacBook-Pro ~/Documents/crawler % find .
.
./crawler
./crawler/__init__.py
./crawler/__pycache__
./crawler/items.py
./crawler/middlewares.py
./crawler/pipelines.py
./crawler/settings.py
./crawler/spiders
./crawler/spiders/__init__.py
./crawler/spiders/__pycache__
./scrapy.cfg

Scrapy 工程目录主要有以下文件组成:

scrapy.cfg: 项目配置文件
middlewares.py : 项目 middlewares 文件
items.py: 项目items文件
pipelines.py: 项目管道文件
settings.py: 项目配置文件spiders: 放置spider的目录

11.4.2. Spider

创建爬虫,名字是 netkiller, 爬行的地址是 netkiller.cn

neo@MacBook-Pro ~/Documents/crawler % scrapy genspider netkiller netkiller.cn
Created spider 'netkiller' using template 'basic' in module:
  crawler.spiders.netkiller
neo@MacBook-Pro ~/Documents/crawler % find .
.
./crawler
./crawler/__init__.py
./crawler/__pycache__
./crawler/__pycache__/__init__.cpython-36.pyc
./crawler/__pycache__/settings.cpython-36.pyc
./crawler/items.py
./crawler/middlewares.py
./crawler/pipelines.py
./crawler/settings.py
./crawler/spiders
./crawler/spiders/__init__.py
./crawler/spiders/__pycache__
./crawler/spiders/__pycache__/__init__.cpython-36.pyc
./crawler/spiders/netkiller.py
./scrapy.cfg

打开 crawler/spiders/netkiller.py 文件,修改内容如下

# -*- coding: utf-8 -*-import scrapyclass NetkillerSpider(scrapy.Spider):
    name = 'netkiller'
    allowed_domains = ['netkiller.cn']
    start_urls = ['http://www.netkiller.cn/']    def parse(self, response):
        for link in response.xpath('//div[@class="blockquote"]')[1].css('a.ulink'):            # self.log('This url is %s' % link)
            yield {                'name': link.css('a::text').extract(),                'url': link.css('a.ulink::attr(href)').extract()
                }            
        pass

运行爬虫

neo@MacBook-Pro ~/Documents/crawler % scrapy crawl netkiller -o output.json2017-09-08 11:42:30 [scrapy.utils.log] INFO: Scrapy 1.4.0 started (bot: crawler)2017-09-08 11:42:30 [scrapy.utils.log] INFO: Overridden settings: {'BOT_NAME': 'crawler', 'FEED_FORMAT': 'json', 'FEED_URI': 'output.json', 'NEWSPIDER_MODULE': 'crawler.spiders', 'ROBOTSTXT_OBEY': True, 'SPIDER_MODULES': ['crawler.spiders']}2017-09-08 11:42:30 [scrapy.middleware] INFO: Enabled extensions:['scrapy.extensions.corestats.CoreStats', 'scrapy.extensions.telnet.TelnetConsole', 'scrapy.extensions.memusage.MemoryUsage', 'scrapy.extensions.feedexport.FeedExporter', 'scrapy.extensions.logstats.LogStats']2017-09-08 11:42:30 [scrapy.middleware] INFO: Enabled downloader middlewares:['scrapy.downloadermiddlewares.robotstxt.RobotsTxtMiddleware', 'scrapy.downloadermiddlewares.httpauth.HttpAuthMiddleware', 'scrapy.downloadermiddlewares.downloadtimeout.DownloadTimeoutMiddleware', 'scrapy.downloadermiddlewares.defaultheaders.DefaultHeadersMiddleware', 'scrapy.downloadermiddlewares.useragent.UserAgentMiddleware', 'scrapy.downloadermiddlewares.retry.RetryMiddleware', 'scrapy.downloadermiddlewares.redirect.MetaRefreshMiddleware', 'scrapy.downloadermiddlewares.httpcompression.HttpCompressionMiddleware', 'scrapy.downloadermiddlewares.redirect.RedirectMiddleware', 'scrapy.downloadermiddlewares.cookies.CookiesMiddleware', 'scrapy.downloadermiddlewares.httpproxy.HttpProxyMiddleware', 'scrapy.downloadermiddlewares.stats.DownloaderStats']2017-09-08 11:42:30 [scrapy.middleware] INFO: Enabled spider middlewares:['scrapy.spidermiddlewares.httperror.HttpErrorMiddleware', 'scrapy.spidermiddlewares.offsite.OffsiteMiddleware', 'scrapy.spidermiddlewares.referer.RefererMiddleware', 'scrapy.spidermiddlewares.urllength.UrlLengthMiddleware', 'scrapy.spidermiddlewares.depth.DepthMiddleware']2017-09-08 11:42:30 [scrapy.middleware] INFO: Enabled item pipelines:[]2017-09-08 11:42:30 [scrapy.core.engine] INFO: Spider opened2017-09-08 11:42:30 [scrapy.extensions.logstats] INFO: Crawled 0 pages (at 0 pages/min), scraped 0 items (at 0 items/min)2017-09-08 11:42:30 [scrapy.extensions.telnet] DEBUG: Telnet console listening on 127.0.0.1:60232017-09-08 11:42:30 [scrapy.core.engine] DEBUG: Crawled (200) <GET http://www.netkiller.cn/robots.txt> (referer: None)2017-09-08 11:42:31 [scrapy.core.engine] DEBUG: Crawled (200) <GET http://www.netkiller.cn/> (referer: None)2017-09-08 11:42:31 [scrapy.core.scraper] DEBUG: Scraped from <200 http://www.netkiller.cn/>{'name': ['Netkiller Architect 手札'], 'url': ['../architect/index.html']}2017-09-08 11:42:31 [scrapy.core.scraper] DEBUG: Scraped from <200 http://www.netkiller.cn/>{'name': ['Netkiller Developer 手札'], 'url': ['../developer/index.html']}2017-09-08 11:42:31 [scrapy.core.scraper] DEBUG: Scraped from <200 http://www.netkiller.cn/>{'name': ['Netkiller PHP 手札'], 'url': ['../php/index.html']}2017-09-08 11:42:31 [scrapy.core.scraper] DEBUG: Scraped from <200 http://www.netkiller.cn/>{'name': ['Netkiller Python 手札'], 'url': ['../python/index.html']}2017-09-08 11:42:31 [scrapy.core.scraper] DEBUG: Scraped from <200 http://www.netkiller.cn/>{'name': ['Netkiller Testing 手札'], 'url': ['../testing/index.html']}2017-09-08 11:42:31 [scrapy.core.scraper] DEBUG: Scraped from <200 http://www.netkiller.cn/>{'name': ['Netkiller Java 手札'], 'url': ['../java/index.html']}2017-09-08 11:42:31 [scrapy.core.scraper] DEBUG: Scraped from <200 http://www.netkiller.cn/>{'name': ['Netkiller Cryptography 手札'], 'url': ['../cryptography/index.html']}2017-09-08 11:42:31 [scrapy.core.scraper] DEBUG: Scraped from <200 http://www.netkiller.cn/>{'name': ['Netkiller Linux 手札'], 'url': ['../linux/index.html']}2017-09-08 11:42:31 [scrapy.core.scraper] DEBUG: Scraped from <200 http://www.netkiller.cn/>{'name': ['Netkiller FreeBSD 手札'], 'url': ['../freebsd/index.html']}2017-09-08 11:42:31 [scrapy.core.scraper] DEBUG: Scraped from <200 http://www.netkiller.cn/>{'name': ['Netkiller Shell 手札'], 'url': ['../shell/index.html']}2017-09-08 11:42:31 [scrapy.core.scraper] DEBUG: Scraped from <200 http://www.netkiller.cn/>{'name': ['Netkiller Security 手札'], 'url': ['../security/index.html']}2017-09-08 11:42:31 [scrapy.core.scraper] DEBUG: Scraped from <200 http://www.netkiller.cn/>{'name': ['Netkiller Web 手札'], 'url': ['../www/index.html']}2017-09-08 11:42:31 [scrapy.core.scraper] DEBUG: Scraped from <200 http://www.netkiller.cn/>{'name': ['Netkiller Monitoring 手札'], 'url': ['../monitoring/index.html']}2017-09-08 11:42:31 [scrapy.core.scraper] DEBUG: Scraped from <200 http://www.netkiller.cn/>{'name': ['Netkiller Storage 手札'], 'url': ['../storage/index.html']}2017-09-08 11:42:31 [scrapy.core.scraper] DEBUG: Scraped from <200 http://www.netkiller.cn/>{'name': ['Netkiller Mail 手札'], 'url': ['../mail/index.html']}2017-09-08 11:42:31 [scrapy.core.scraper] DEBUG: Scraped from <200 http://www.netkiller.cn/>{'name': ['Netkiller Docbook 手札'], 'url': ['../docbook/index.html']}2017-09-08 11:42:31 [scrapy.core.scraper] DEBUG: Scraped from <200 http://www.netkiller.cn/>{'name': ['Netkiller Project 手札'], 'url': ['../project/index.html']}2017-09-08 11:42:31 [scrapy.core.scraper] DEBUG: Scraped from <200 http://www.netkiller.cn/>{'name': ['Netkiller Database 手札'], 'url': ['../database/index.html']}2017-09-08 11:42:31 [scrapy.core.scraper] DEBUG: Scraped from <200 http://www.netkiller.cn/>{'name': ['Netkiller PostgreSQL 手札'], 'url': ['../postgresql/index.html']}2017-09-08 11:42:31 [scrapy.core.scraper] DEBUG: Scraped from <200 http://www.netkiller.cn/>{'name': ['Netkiller MySQL 手札'], 'url': ['../mysql/index.html']}2017-09-08 11:42:31 [scrapy.core.scraper] DEBUG: Scraped from <200 http://www.netkiller.cn/>{'name': ['Netkiller NoSQL 手札'], 'url': ['../nosql/index.html']}2017-09-08 11:42:31 [scrapy.core.scraper] DEBUG: Scraped from <200 http://www.netkiller.cn/>{'name': ['Netkiller LDAP 手札'], 'url': ['../ldap/index.html']}2017-09-08 11:42:31 [scrapy.core.scraper] DEBUG: Scraped from <200 http://www.netkiller.cn/>{'name': ['Netkiller Network 手札'], 'url': ['../network/index.html']}2017-09-08 11:42:31 [scrapy.core.scraper] DEBUG: Scraped from <200 http://www.netkiller.cn/>{'name': ['Netkiller Cisco IOS 手札'], 'url': ['../cisco/index.html']}2017-09-08 11:42:31 [scrapy.core.scraper] DEBUG: Scraped from <200 http://www.netkiller.cn/>{'name': ['Netkiller H3C 手札'], 'url': ['../h3c/index.html']}2017-09-08 11:42:31 [scrapy.core.scraper] DEBUG: Scraped from <200 http://www.netkiller.cn/>{'name': ['Netkiller Multimedia 手札'], 'url': ['../multimedia/index.html']}2017-09-08 11:42:31 [scrapy.core.scraper] DEBUG: Scraped from <200 http://www.netkiller.cn/>{'name': ['Netkiller Perl 手札'], 'url': ['../perl/index.html']}2017-09-08 11:42:31 [scrapy.core.scraper] DEBUG: Scraped from <200 http://www.netkiller.cn/>{'name': ['Netkiller Amateur Radio 手札'], 'url': ['../radio/index.html']}2017-09-08 11:42:31 [scrapy.core.engine] INFO: Closing spider (finished)2017-09-08 11:42:31 [scrapy.extensions.feedexport] INFO: Stored json feed (28 items) in: output.json2017-09-08 11:42:31 [scrapy.statscollectors] INFO: Dumping Scrapy stats:{'downloader/request_bytes': 438, 'downloader/request_count': 2, 'downloader/request_method_count/GET': 2, 'downloader/response_bytes': 6075, 'downloader/response_count': 2, 'downloader/response_status_count/200': 2, 'finish_reason': 'finished', 'finish_time': datetime.datetime(2017, 9, 8, 3, 42, 31, 157395), 'item_scraped_count': 28, 'log_count/DEBUG': 31, 'log_count/INFO': 8, 'memusage/max': 49434624, 'memusage/startup': 49434624, 'response_received_count': 2, 'scheduler/dequeued': 1, 'scheduler/dequeued/memory': 1, 'scheduler/enqueued': 1, 'scheduler/enqueued/memory': 1, 'start_time': datetime.datetime(2017, 9, 8, 3, 42, 30, 931267)}2017-09-08 11:42:31 [scrapy.core.engine] INFO: Spider closed (finished)

你会看到返回结果

{'name': ['Netkiller Architect 手札'], 'url': ['../architect/index.html']}

11.4.2.1. 翻页操作

下面我们演示爬虫翻页,例如我们需要遍历这部电子书《Netkiller Linux 手札》 https://netkiller.cn/linux/index.html,首先创建一个爬虫任务

neo@MacBook-Pro ~/Documents/crawler % scrapy genspider book netkiller.cn
Created spider 'book' using template 'basic' in module:
  crawler.spiders.book

编辑爬虫任务

# -*- coding: utf-8 -*-import scrapyclass BookSpider(scrapy.Spider):
    name = 'book'
    allowed_domains = ['netkiller.cn']
    start_urls = ['https://netkiller.cn/linux/index.html']    def parse(self, response):
        yield {'title': response.css('title::text').extract()}        # 这里取出下一页连接地址
        next_page = response.xpath('//a[@accesskey="n"]/@href').extract_first() 
        self.log('Next page: %s' % next_page)        # 如果页面不为空交给 response.follow 来爬取这个页面
        if next_page is not None:            yield response.follow(next_page, callback=self.parse)    

        pass

11.4.2.2. 采集内容保存到文件

下面的例子是将 response.body 返回采集内容保存到文件中

# -*- coding: utf-8 -*-import scrapyclass BookSpider(scrapy.Spider):
    name = 'book'
    allowed_domains = ['netkiller.cn']
    start_urls = ['https://netkiller.cn/linux/index.html']    def parse(self, response):
        yield {'title': response.css('title::text').extract()}

        filename = '/tmp/%s' % response.url.split("/")[-1]        with open(filename, 'wb') as f:
            f.write(response.body)
        self.log('Saved file %s' % filename)

        next_page = response.xpath('//a[@accesskey="n"]/@href').extract_first()
        self.log('Next page: %s' % next_page)        if next_page is not None:            yield response.follow(next_page, callback=self.parse)    

        pass

任务运维结束后查看采集出来的文件

neo@MacBook-Pro ~/Documents/crawler % ls /tmp/*.html/tmp/apt-get.html            /tmp/disc.html               /tmp/infomation.html         /tmp/lspci.html              /tmp/svgatextmode.html/tmp/aptitude.html           /tmp/dmidecode.html          /tmp/install.html            /tmp/lsscsi.html             /tmp/swap.html/tmp/author.html             /tmp/do-release-upgrade.html /tmp/install.partition.html  /tmp/lsusb.html              /tmp/sys.html/tmp/avlinux.html            /tmp/dpkg.html               /tmp/introduction.html       /tmp/package.html            /tmp/sysctl.html/tmp/centos.html             /tmp/du.max-depth.html       /tmp/kernel.html             /tmp/pr01s02.html            /tmp/system.infomation.html/tmp/cfdisk.html             /tmp/ethtool.html            /tmp/kernel.modules.html     /tmp/pr01s03.html            /tmp/system.profile.html/tmp/console.html            /tmp/framebuffer.html        /tmp/kudzu.html              /tmp/pr01s05.html            /tmp/system.shutdown.html/tmp/console.timeout.html    /tmp/gpt.html                /tmp/linux.html              /tmp/preface.html            /tmp/tune2fs.html/tmp/dd.clone.html           /tmp/hdd.label.html          /tmp/locale.html             /tmp/proc.html               /tmp/udev.html/tmp/deb.html                /tmp/hdd.partition.html      /tmp/loop.html               /tmp/rpm.html                /tmp/upgrades.html/tmp/device.cpu.html         /tmp/hwinfo.html             /tmp/lsblk.html              /tmp/rpmbuild.html           /tmp/yum.html/tmp/device.hba.html         /tmp/index.html              /tmp/lshw.html               /tmp/smartctl.html

这里只是做演示,生产环境请不要在 parse(self, response) 中处理,后面会讲到 Pipeline。

11.4.3. settings.py 爬虫配置文件

11.4.3.1. 忽略 robots.txt 规则

# Obey robots.txt rulesROBOTSTXT_OBEY = False

11.4.4. Item

Item 在 scrapy 中的类似“实体”或者“POJO”的概念,是一个数据结构类。爬虫通过ItemLoader将数据放到Item中

下面是 items.py 文件

# -*- coding: utf-8 -*-# Define here the models for your scraped items## See documentation in:# http://doc.scrapy.org/en/latest/topics/items.htmlimport scrapyclass CrawlerItem(scrapy.Item):
    # define the fields for your item here like:
    title = scrapy.Field()
    author = scrapy.Field()
    content = scrapy.Field()
    ctime = scrapy.Field()    
    pass

下面是爬虫文件

# -*- coding: utf-8 -*-import scrapyfrom scrapy.loader import ItemLoaderfrom crawler.items import CrawlerItem 
import timeclass ExampleSpider(scrapy.Spider):
    name = 'example'
    allowed_domains = ['netkiller.cn']
    start_urls = ['https://netkiller.cn/java/index.html']    def parse(self, response):

        item_selector = response.xpath('//a/@href')        for url in item_selector.extract():            if 'html' in url.split('.'):
                url = response.urljoin(url)                yield response.follow( url, callback=self.parse_item)

        next_page = response.xpath('//a[@accesskey="n"]/@href').extract_first()
        self.log('Next page: %s' % next_page)        if next_page is not None:            yield response.follow(next_page, callback=self.parse)   
        
    def parse_item(self, response):
        l = ItemLoader(item=CrawlerItem(), response=response)
        l.add_css('title', 'title::text')
        l.add_value('ctime', time.strftime( '%Y-%m-%d %X', time.localtime() ))
        l.add_value('content', response.body)        return l.load_item()

yield response.follow( url, callback=self.parse_item) 会回调 parse_item(self, response) 将爬到的数据放置到 Item 中

11.4.5. Pipeline

Pipeline 管道线,主要的功能是对 Item 的数据处理,例如计算、合并等等。通常我们在这里做数据保存。下面的例子是将爬到的数据保存到 json 文件中。

默认情况 Pipeline 是禁用的,首先我们需要开启 Pipeline 支持,修改 settings.py 文件,找到下面配置项,去掉注释。

# Configure item pipelines# See http://scrapy.readthedocs.org/en/latest/topics/item-pipeline.htmlITEM_PIPELINES = {    'crawler.pipelines.CrawlerPipeline': 300,
}

修改 pipelines.py 文件。

# -*- coding: utf-8 -*-# Define your item pipelines here## Don't forget to add your pipeline to the ITEM_PIPELINES setting# See: http://doc.scrapy.org/en/latest/topics/item-pipeline.htmlimport jsonclass CrawlerPipeline(object):
    def open_spider(self, spider):
        self.file = open('items.json', 'w')    def close_spider(self, spider):
        self.file.close()    def process_item(self, item, spider):
        # self.log("PIPE: %s" % item)
        line = json.dumps(dict(item)) + "\n"
        self.file.write(line)   
        return item

下面是 items.py 文件

# -*- coding: utf-8 -*-# Define here the models for your scraped items## See documentation in:# http://doc.scrapy.org/en/latest/topics/items.htmlimport scrapyclass CrawlerItem(scrapy.Item):
    # define the fields for your item here like:
    title = scrapy.Field()
    author = scrapy.Field()
    content = scrapy.Field()
    ctime = scrapy.Field()    
    pass

下面是爬虫文件

# -*- coding: utf-8 -*-import scrapyfrom scrapy.loader import ItemLoaderfrom crawler.items import CrawlerItem 
import timeclass ExampleSpider(scrapy.Spider):
    name = 'example'
    allowed_domains = ['netkiller.cn']
    start_urls = ['https://netkiller.cn/java/index.html']    def parse(self, response):

        item_selector = response.xpath('//a/@href')        for url in item_selector.extract():            if 'html' in url.split('.'):
                url = response.urljoin(url)                yield response.follow( url, callback=self.parse_item)

        next_page = response.xpath('//a[@accesskey="n"]/@href').extract_first()
        self.log('Next page: %s' % next_page)        if next_page is not None:            yield response.follow(next_page, callback=self.parse)   
        
    def parse_item(self, response):
        l = ItemLoader(item=CrawlerItem(), response=response)
        l.add_css('title', 'title::text')
        l.add_value('ctime', time.strftime( '%Y-%m-%d %X', time.localtime() ))
        l.add_value('content', response.body)        return l.load_item()

items.json 文件如下

{"title": ["5.31.\u00a0Spring boot with Data restful"], "ctime": ["2017-09-11 11:57:53"]}
{"title": ["5.30.\u00a0Spring boot with Phoenix"], "ctime": ["2017-09-11 11:57:53"]}
{"title": ["5.29.\u00a0Spring boot with Apache Hive"], "ctime": ["2017-09-11 11:57:53"]}
{"title": ["5.28.\u00a0Spring boot with Elasticsearch 5.5.x"], "ctime": ["2017-09-11 11:57:53"]}
{"title": ["5.27.\u00a0Spring boot with Elasticsearch 2.x"], "ctime": ["2017-09-11 11:57:53"]}
{"title": ["5.23.\u00a0Spring boot with Hessian"], "ctime": ["2017-09-11 11:57:53"]}
{"title": ["5.22.\u00a0Spring boot with Cache"], "ctime": ["2017-09-11 11:57:53"]}
{"title": ["5.26.\u00a0Spring boot with HTTPS SSL"], "ctime": ["2017-09-11 11:57:53"]}
{"title": ["5.25.\u00a0Spring boot with Git version"], "ctime": ["2017-09-11 11:57:53"]}
{"title": ["5.24.\u00a0Spring boot with Apache Kafka"], "ctime": ["2017-09-11 11:57:53"]}
{"title": ["5.21.\u00a0Spring boot with Scheduling"], "ctime": ["2017-09-11 11:57:53"]}
{"title": ["5.20.\u00a0Spring boot with Oauth2"], "ctime": ["2017-09-11 11:57:53"]}
{"title": ["5.19.\u00a0Spring boot with Spring security"], "ctime": ["2017-09-11 11:57:53"]}
{"title": ["5.16.\u00a0Spring boot with PostgreSQL"], "ctime": ["2017-09-11 11:57:53"]}
{"title": ["5.18.\u00a0Spring boot with Velocity template"], "ctime": ["2017-09-11 11:57:53"]}
{"title": ["5.13.\u00a0Spring boot with MongoDB"], "ctime": ["2017-09-11 11:57:53"]}
{"title": ["5.11.\u00a0Spring boot with Session share"], "ctime": ["2017-09-11 11:57:53"]}
{"title": ["5.17.\u00a0Spring boot with Email"], "ctime": ["2017-09-11 11:57:53"]}
{"title": ["5.15.\u00a0Spring boot with Oracle"], "ctime": ["2017-09-11 11:57:53"]}
{"title": ["5.14.\u00a0Spring boot with MySQL"], "ctime": ["2017-09-11 11:57:53"]}
{"title": ["5.10.\u00a0Spring boot with Logging"], "ctime": ["2017-09-11 11:57:53"]}
{"title": ["5.9.\u00a0String boot with RestTemplate"], "ctime": ["2017-09-11 11:57:53"]}

原文发布于微信公众号 - Netkiller(netkiller-ebook)

原文发表时间:2017-09-12

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小伙伴们一定很熟悉kill -9 来杀某个进程了,其实这样做在生产系统中是存在安全隐患的。 我们知道线程分为守护线程和用户线程。如果是系统中存在的均是守护线程,...

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来自专栏大内老A

通过WCF扩展实现消息压缩

对于需要进行大规模数据传输的WCF应用来说,对于请求消息和回复消息进行传输前的压缩,不但可以降低网络流量,也可以提高网络传输的性能。由于WCF的扩展性,我们可以...

16410
来自专栏码匠的流水账

Deque的使用实例

双向队列(Deque),是Queue的一个子接口,双向队列是指该队列两端的元素既能入队(offer)也能出队(poll)。使用场景比如工作窃取,比如限流。

591
来自专栏杨建荣的学习笔记

一个oracle查询引起的bug (r4笔记第59天)

任何软件都不是完美的,oracle也是如此,隔一段时间就会收到oracle的邮件说建议打哪些安全补丁什么的。新发布的产品都是release 1,比如10gR1...

3686
来自专栏JavaNew

Spring Boot实战:数据库操作

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