private Account account;老师,这里我不太懂为什么可以直接用Account类型的啊?还有,那个讲super(name)的时候说把name存到super里面是什么意思啊?
老师,报这个错误怎么解决啊
老师,这个bug什么意思,看半天不知道怎么解决
为什么报错删不掉
老师您好,我用的是swiper-8.0.7,我这个一从网页中打开控制塔台就弹出无法加载是什么原因,应该怎么解决
老师,我这边到最后删除元素是返回来的值是空的,检查了一边没看出来什么原因
老师,
C c = new CImp01();
这段代码是否可以换成
CImp01 c = new CImp01();
以下是完整代码
public class TestMultiplelnheritance { public static void main(String[] args) { C c = new CImp01(); //接口 变量名=new 实现接口(); c.testA(); //调用重写后的方法 c.testB(); //调用重写后的方法 c.testC(); //调用重写后的方法 } } interface A{ //接口A void testA(); } interface B{ //接口B void testB(); } interface C extends A,B{ //接口C,继承了接口A和B,所以拥有接口A和B的方法 void testC(); } class CImp01 implements C{ //子类实现接口 @Override public void testA() { //重写方法 System.out.println("我是A"); } @Override public void testB() { //重写方法 System.out.println("我是B"); } @Override public void testC() { //重写方法 System.out.println("我是C"); } }
用scrapy框架爬取网易云音乐,返回的response是id=${x.id},而不是<a href="/song?id=1813864802"> 这种样式的,用requests模块是可以获取id的数字的 scrapy settings文件如下: # Scrapy settings for wangyiyun project # # For simplicity, this file contains only settings considered important or # commonly used. You can find more settings consulting the documentation: # # https://docs.scrapy.org/en/latest/topics/settings.html # https://docs.scrapy.org/en/latest/topics/downloader-middleware.html # https://docs.scrapy.org/en/latest/topics/spider-middleware.html BOT_NAME = 'wangyiyun' SPIDER_MODULES = ['wangyiyun.spiders'] NEWSPIDER_MODULE = 'wangyiyun.spiders' # Crawl responsibly by identifying yourself (and your website) on the user-agent #USER_AGENT = 'wangyiyun (+http://www.yourdomain.com)' # Obey robots.txt rules ROBOTSTXT_OBEY = False LOG_LEVEL = 'ERROR' # Configure maximum concurrent requests performed by Scrapy (default: 16) #CONCURRENT_REQUESTS = 32 # Configure a delay for requests for the same website (default: 0) # See https://docs.scrapy.org/en/latest/topics/settings.html#download-delay # See also autothrottle settings and docs #DOWNLOAD_DELAY = 3 # The download delay setting will honor only one of: #CONCURRENT_REQUESTS_PER_DOMAIN = 16 #CONCURRENT_REQUESTS_PER_IP = 16 # Disable cookies (enabled by default) #COOKIES_ENABLED = False # Disable Telnet Console (enabled by default) #TELNETCONSOLE_ENABLED = False # Override the default request headers: DEFAULT_REQUEST_HEADERS = { 'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8', # 'Accept-Language': 'en', } USER_AGENT = 'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/96.0.4664.93 Safari/537.36' DOWNLOAD_DELAY = 2 # Enable or disable spider middlewares # See https://docs.scrapy.org/en/latest/topics/spider-middleware.html #SPIDER_MIDDLEWARES = { # 'wangyiyun.middlewares.WangyiyunSpiderMiddleware': 543, #} # Enable or disable downloader middlewares # See https://docs.scrapy.org/en/latest/topics/downloader-middleware.html DOWNLOADER_MIDDLEWARES = { 'wangyiyun.middlewares.WangyiyunDownloaderMiddleware': 543, } # Enable or disable extensions # See https://docs.scrapy.org/en/latest/topics/extensions.html #EXTENSIONS = { # 'scrapy.extensions.telnet.TelnetConsole': None, #} # Configure item pipelines # See https://docs.scrapy.org/en/latest/topics/item-pipeline.html #ITEM_PIPELINES = { # 'wangyiyun.pipelines.WangyiyunPipeline': 300, #} # Enable and configure the AutoThrottle extension (disabled by default) # See https://docs.scrapy.org/en/latest/topics/autothrottle.html #AUTOTHROTTLE_ENABLED = True # The initial download delay #AUTOTHROTTLE_START_DELAY = 5 # The maximum download delay to be set in case of high latencies #AUTOTHROTTLE_MAX_DELAY = 60 # The average number of requests Scrapy should be sending in parallel to # each remote server #AUTOTHROTTLE_TARGET_CONCURRENCY = 1.0 # Enable showing throttling stats for every response received: #AUTOTHROTTLE_DEBUG = False # Enable and configure HTTP caching (disabled by default) # See https://docs.scrapy.org/en/latest/topics/downloader-middleware.html#httpcache-middleware-settings #HTTPCACHE_ENABLED = True #HTTPCACHE_EXPIRATION_SECS = 0 #HTTPCACHE_DIR = 'httpcache' #HTTPCACHE_IGNORE_HTTP_CODES = [] #HTTPCACHE_STORAGE = 'scrapy.extensions.httpcache.FilesystemCacheStorage'
请问老师这块的代码资料和excel资料怎么没有???
老师我的为什么会会这样
老师这里第一个问题:where userid= 这里等于后面不用指定条件吗 第二个问题:最后为什么+userid写在了引号外面
这节课是为了演示转换流才用字节流吧,一般什么情况需要用字节流读文本文件?
用super关键字时候的格式是什么呢?
复制出来的图片文件是空的可能是什么问题呢?前面几个实验复制都成功了
下面文件路径我有小小遮下
package com.bjsxt; import java.io.BufferedInputStream; import java.io.BufferedOutputStream; import java.io.FileInputStream; import java.io.FileOutputStream; public class FileStreamBuffer3Demo { public static void main(String[] args) { FileInputStream fis = null; FileOutputStream fos = null; BufferedInputStream bis = null; BufferedOutputStream bos = null; try { fis = new FileInputStream("/Users/.../Documents/...jpg"); bis = new BufferedInputStream(fis); fos = new FileOutputStream("/Users/.../Documents/...jpg"); bos = new BufferedOutputStream(fos); int temp = 0; while((temp = bis.read()) != -1){ bos.write(temp); } bos.flush(); }catch (Exception e ){ e.printStackTrace(); }finally { try { }catch (Exception e){ e.printStackTrace(); } } } }
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