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运用Jconsole监控JVM

运用Jconsole监控JVM
运用Jconsole监控JVM

运用Jconsole监控JVM

1.Jconsole工具介绍

1.1简介

从Java 5开始引入了JConsole。JConsole是一个内置Java 性能分析器,可以从命令行或在GUI shell 中运行。您可以轻松地使用JConsole来监控Java 应用程序性能和跟踪Java 中的代码。

1.2如何启动JConsole

如果是从命令行启动,使JDK 在PATH 上,运行jconsole即可。

如果从GUI shell 启动,找到JDK 安装路径,打开bin 文件夹,双击jconsole。

当分析工具弹出时(取决于正在运行的Java 版本以及正在运行的Java 程序数量),可能会出现一个对话框,要求输入一个进程的URL 来连接,也可能列出许多不同的本地Java 进程(有时包含JConsole进程本身)来连接。如图所示:

想分析那个程序就双击那个进程。

1.3如何设置JAVA程序运行时可以被JConsolse连接分析

本地程序(相对于开启JConsole的计算机),无需设置任何参数就可以被本地开启的JConsole连接(Java SE 6开始无需设置,之前还是需要设置运行时参数

-Dcom.sun.management.jmxremote)

无认证连接(下面的设置表示:连接的端口为8999、无需认证就可以被连接) Java代码

2.Jconsole远程连接TOMCAT

Windows环境中的tomcat:

在“开始”->“运行”中,输入cmd,运行命令netstat–an |find “8999”检查端口是否被占用

打开tomcat安装目录中bin目录下的catalina.bat。

设置set JAVA_OPTS=%JAVA_OPTS% -Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.ssl=false

-Dcom.sun.management.jmxremote.port=8999 -Dcom.sun.management.jmxremote

特别注意:-Dcom.sun.management.jmxremote.port=8999,这个端点是jconsole专用的,不要和你的系统的端点冲突。再启动你的应用

最后,打开的JConsole界面操作连接->新建连接->选择远程进程->输入远程主机IP和端口号->点击“连接”,如图:

linux环境中的tomcat:

在linux环境中,输入命令netstat–an |grep 8999检查端口是否被占用

打开tomcat安装目录中bin目录下的catalina.sh。

在这个文件中找到JAVA_OPTS这个设置,在里面增加如下内容:

1.-Djava.rmi.server.hostname=19

2.168.1.100

2.-Dcom.sun.management.jmxremote.port=8999

3.-Dcom.sun.management.jmxremote.ssl=false

4.-Dcom.sun.management.jmxremote.authenticate=false

重启tomcat后,运行本地环境中的jconsole,即可正常监控。

3.Jconsole远程连接WEBLOGIC

winodws环境中的weblogic:

确保weblogic使用Sun JDK。可以通过java -version来查询。

在“开始”->“运行”中,输入cmd,运行命令netstat–an |find “8999”检查端口是否被占用.

修改%DOMAIN%\bin\setDomainEnv.cmd,添加:

set MEM_ARGS=-Xms512m -Xmx768m

-Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.port="8999"

-Dcom.sun.management.jmxremote.authenticate="false"

-Dcom.sun.management.jmxremote.ssl="false"

重启weblogic后,运行本地环境中的jconsole,即可正常监控。

linux环境中的weblogic:

确保weblogic使用Sun JDK。可以通过java -version来查询。

执行命令netstat–an |grep 8999检查端口是否被占用.

修改$Domain_HOME/bin/setDomainEnv.sh,为$JAVA_OPTIONS添加:

-Dcom.sun.management.jmxremote

-Dcom.sun.management.jmxremote.port=8999

-Dcom.sun.management.jmxremote.authenticate=false

-Dcom.sun.management.jmxremote.ssl=false

重启weblogic后,运行本地环境中的jconsole,即可正常监控。

4.Jconsole工具性能分析

下面说说如何分析,如何使用这六个标签

?概述: Displays overview information about the Java VM and monitored values. ?内存:显示内存使用信息

?线程:显示线程使用信息

?类:显示类装载信息

?*VM摘要:*显示java VM信息

?MBeans:显示MBeans.

4.1概述

概述很简单没啥说的,自己看看吧,不过值得一提的是对着图点击右键可以保存数据到CSV文件,以后可以使用其他工具来分析这些数据。

4.2内存

这个比较有价值,参看堆内存,非堆内存,内存池的状况总体内存的分配和使用情况以及不同的GC进行垃圾回收的次数和时间。可以手动进行GC查看内存变化。

在分析JAVA内存问题进行调优时候非常有用,你要学习JVM内存模型,之后会发现这里的每个值都具有意义。

GC的算法和参数对性能有显著的影响,注意垃圾回收次数、时间、以及partial GC和full GC,调整你所使用的不同GC和以及各个GC下的参数,然后在这个视图下观察,以得到好的性能。

这里贴一下Java HotSpot VM garbage collector 下generational GC 的各代的划分图:

关于GC,可以参考:https://www.sodocs.net/doc/2213150112.html,/technetwork/java/gc-tuning-5-138395.html

左下角显示所有的活动线程(如果线程过多,可以在下面的过滤栏中输入字符串过滤出你想要观察的线程)。点击某个显示会显示这个线程的名称、状态、阻塞和等待的次数、堆栈的信息。

统计图显示的是线程数目的峰值(红色)和当前活动的线程(蓝色)。

另外下面有个按钮“检测到死锁”,有时候会有用处。

没啥要说的。

4.5VM摘要

也没啥要说的,看看吧,内存状况,操作系统...

4.6MBean

这里可以有一些额外的操作。

4.7插件

Java代码

一看便知,是个什么东西。

however的用法

With the possible exception of the Beatles, no other band has become so successful so quickly. 可能除了披头士乐队这个例外,还没有哪个乐队如此转瞬走红的。 并列句中连接词语的功能 2006-03-01 18:54:21 ??英语中,包含两个或两个以上互不依从的主谓结构的句子称为并列句,各个相互独立的主谓结构叫作分句,多数情况下并列句中的分句由并列连接词来连接。并列句的分句之间关系密切,而并列连接词是分句之间关系的纽带,它们起着承上启下的作用,显示了分句之间逻辑关系,指示了说话人思维的走向。因此,正确理解和掌握连接词语是我们能否正确理解话语篇章意义的关键。表示并列关系的词语除了并列连词(如:and,but,or,so,for等),还有并列词组(如:in addition,as a result 等)和连接性副词(如:however,moreover,otherwise等),这里统称为连接词语。根据连接词语的语义功能,可将其分类如下: 1.表示补充、添加关系的连接词 这类连接词表示后面分句的句意是对前面分句句意的补充,说的是同类事情。常用的有:and,in addition,besides,moreover,furthermore,likewise,in the same way,what’s more 等。例如: Irene did not answer,and James,too,ceased speaking. 艾琳没有回答,詹姆斯也不再说话。(说的都是"保持沉默") Bicycling is good exercise,moreover,it doesn’t pollute the air. 骑自行车是项很好的运动,而且又不污染空气。(说的都是骑自行车的优点) A flood will break a dam;likewise, the oppressed people everywhere will overthrow their oppressors in the end. 洪水会冲毁大坝,同样,任何地方的被压迫人民也会推翻他们的压迫者。(说的是同一道理) 2.表示转折关系的连接词 这类连接词表示后面分句在意义上与前面的分句发生了转折,说的是不同情况或不同的观点。常见的有:but,however,nevertheless,instead,on the contrary,on the otherhand,yet,by contrast,whereas等。例如: The situation looked desperate,but they didn’t give up hope. 形势看来非常危急,但他们没有放弃希望。 It’s too wet to go for a walk;let’s go swimming instead. 天气潮湿,不宜去散步,我们改去游泳吧。 There was no news;nevertheless,she went on hoping. 尽管没有消息,她仍抱着希望。 3.表示因果关系的连接词

it 做形式主语和however 用法

不管however以何种形式出现,它都不外乎以下两种用法。 1. 用作副词 (1) 表示让步:意为“无论如何”“不管怎样”,用来修饰形容词或副词, 其词序为:however+形容词或副词+主语+谓语。这样用的however其实具有连词的功能,用以引导让步状语从句。如: however much he eats, he never gets fat. 不管他吃多少,他永远吃不胖。 用于此用法时,请注意以下几点: ①此用法属however所有用法中最重要的考点,同学们务请引起高度重视。 ②这样用的 however 与 no matter how 大致同义。如: People always want more, however [no matter how] rich they are. 人总是富了还想再富。 however [No matter how] hard I worked, she was never satisfied. 无论我多么努力地工作,她从来没满意过。 ③有时从句谓语可用情态动词。如: Don’t laugh, however funny it may be. 无论多么有趣也不要笑。 I’ll try to finish it in time, however hard it may be. 无论多么难,我也要按时完成。 ④“however+形容词或副词+主语+谓语”有时可以有所省略。如: I refuse, however favorable the conditions. 不管条件如何有利,我都不干。(conditions 后省去了are) I’d rather have a room of my own, however small (it is), than share a room. 无论房间多么小,我宁愿一个人住一间,而不愿意与别人合住一个房间。 A grammar rule, however true (it is), is useless unless it can be understood. 一条语法规则,不管如何正确,除非能懂,否则毫无用处。 (2) 表示转折:尤其用于谈及一个既成事实时,表示转折,其意为“可是”“仍然”等。可放在句首、句中或句末,通常用逗号与句子其他成分隔开。如: My father, however, did not agree. 但是,我父亲不同意。 My room is small; however, it’s comfortable. 我的房间很小,但却很舒服。 He said that it was so; he was mistaken, however. 他说情况如此,可是他错了。注:however不能像 but(但是)那样直接连接两个句子(注意正句中的标点符号)。如: 我们都已尽了最大的努力,不过我们还是输了。. 正:We all tried our best, but we lost the game. 正:We all tried our best; however, we lost the game. 正:We all tried our best. however, we lost the game. (3) 表示惊奇或强调:相当于how ever的用法,其意为“究竟怎样,到底以什么方式”。如:however did you get here without a car? 没有汽车你究竟是怎样来的呢? No matter +疑问词或者疑问词-ever 含义为“无论……都, 不管……都”。他们引导让步状语从句,并且可以互换。

but,however,while,although和though用法小结

but, however, while, although和though用法小结 【观察】阅读下列句子,注意各句中黑体单词的用法。 1. We have made some achievements, but we should be modest. 2. He promised to help me. However, he is busy and hasn’t come. 3. She felt ill. She went to work, however, and tried to concentrate. 4. He said that it was so; he was mistaken, however. 5. You like sports, while I’d rather read. 6. While I understand what you say, I can’t agree with you. 7. Although / Though it was late, she went on working. 8. Tired though he was, he went on working. 9. Although he’s got a good job now, he still complains. 10. She promised to phone. I heard nothing, though. 【归纳总结】 ★but与however均可表示转折,意为“但是,然而”,都可以引出表转折意义的句子(句1-句4),但二者用法也有区别: 1. 从语义上看,but所表示的是非常明显的对比,转折的意味较however要强。 2. 从语法上看,but是个并列连词,而however却是个连接副词(句2-句4)。 3. 从语序上看,but总是位于它所引出的分句之首,而however可位于句首、句中或句尾。

英语中however的用法

英语中however的用法 1. 表示“在……期间”,是介词,不要将其误用作连词。如: 他在巴黎期间,与他的朋友住在一起。 误:During he was in Paris, he lived with his friends. 正:While he was in Paris, he lived with his friends. 正:During his stay in Paris, he lived with his friends. 2. during 和for 均可表示一段时间,但两者有差别。 (1) during 通常表示事件发生在何时(when),而for则表示事件持续了多长时间(how long)。如: He was in hospital for six weeks during the summer. 他在夏天住了6 个星期的医院。 (2) 两者之后均可接由the whole 引起的时间短语,但通常不能接由all 引起的时间短语。如: 他整个夏天都住在那儿。 正:He stayed there for [during] the whole summer.

误:He stayed there for [during] all the summer. (3) 在“数词+时间名词”之前以及在some time, a long time之类表示泛指一段时间的词组之前,可用介词for,但不用during。如: He lived here for ten years (for some time). 他在这儿住过10 年(一段时间)。 3. during与in均可表示“时间点”,有时可互换。如: I'll be on holiday in [during] August. 我将在8月度假。 He woke up three times in [during] the night. 夜里他醒了3 次。 但在使用时还有以下几点要注意: (1) 比较而言,during 更强调时间的延续,in 只是指一般性的某一时间。因此若表示状态或习惯性动作,多用during,否则以用in为常见。如: Many people suffered hardship during the war. 许多人在战争期间受苦遭难。 He was injured in the war. 他在战争期间受了伤。 (2) 在stay, visit, meal等表示行为要持续一段时间的名词之前,只能用during 而不能用in。如:

一道高考题引发对however用法的思考

一道高考题引发对however用法的思考 however用法详解 一、考点描述however是高考英语中一个十分重要的考点,近几年来每年的各省考题均有所涉及。请看两道典型高考真题: 1. You should try to get a good night?s sleep _____ much work you have to do. A. however B. no matter C. although D. whatever 【分析】答案选A。however作连接副词时,与no matter how相当,后接形容词或副词,意为“无论……”“不管……”。句意是:不管你有多少工作要做,你都应该好好休息一个晚上。 2. He tried his best to solve the problem, _____ difficult it was. A. however B. no matter C. whatever D. although 【分析】答案选A。因difficult是形容词,修饰形容词要用连接副词however(无论如何,不管多么),引导一个让步状语从句。 二、用法详解 不管however以何种形式出现在高考题中,它都不外乎以下两种用法。1. 用作副词(1) 表示让步:意为(1) “无论如何”“不管怎样”,用来修饰形容词或副词,其词序为:however+形容词或副词+主语+谓语。这样用的however其实具有连词的功能,用以引导让步状语从句。如:Phone me when you arrive, however late it is. 你到达之后就给我打电话,不论多么晚也要打。However much he eats, he never gets fat. 不管他吃多少,他永远吃不胖。However cold it is, he always goes swimming. 不管天有多冷,他都去游泳。You won’t move the stone, however strong you are. 不管你力气有多大,也休想搬动那块石头。However far it is, l intend to drive there tonight 不管有多远,我今晚也要开车到那儿去。用于此用法时,请注意以下几点:①此用法属however所有用法中最重要的考点,同学们务请引起高度重视。②这样用的howeverfont-family: 'Times New Roman'">②与no matter how 大致同义。如:People always want more, however [no matter how] rich they are. 人总是富了还想再富。However [No matter how] hard I worked, she was never satisfied. 无论我多么努力地工作,她从来没满意过。③有时从句谓语可用情态动词。如:Don’t laugh, however funny it may be. 无论多么有趣也不要笑。I’ll try to finish it in time, however hard it may be. 无论多么难,我也要按时完成。④“however+形容词或副词+主语+谓语”有时可以有所省略。如:I refuse, however favorable the conditions. 不管条件如何有利,我都不干。(conditions后省去了are) I’d rather have a room of my own, however small (it is), than share a room. 无论房间多么小,我宁愿一个人住一间,而不愿意与别人合住一个房间。 A grammar rule, however true (it is), is useless unless it can be understood. 一条语法规则,不管如何正确,除非能懂,否则毫无用处。 一条语法规则,不管如何正确,除非能懂,否则毫无用处。 (2) 表示转折:尤其用于谈及一个既成事实时,表示转折,其意为“可是”“仍然”等。可放在句首、句中或句末,通常用逗号与句子其他成分隔开。如:My father, however, did not agree. 但是,我父亲不同意。My room is small; however, it’s comfortable. 我的房间很小,但却很舒服。My room is small; however, it’s comfortable. He said that it was so; he was mistaken, however. 他说情况如此,可是他错了。注:however不能像but(但是)那样直接连

代词的用法one however 与instead的区别的练习题

专题专练 2013-10-19 韩晓威Multiply choice A. that B. one C. it D. what 1.I need a pen. Do you have________? 2.I want a box for my book, _______ that isn’t too big. 3.Mr. Green asked me to borrow a book for him, _______ about how to be a good volunteer. 4.The number 5.12 is a special number, _______ I think, that will be remembered by the Chinese people. 5.---Good morning. May I help you? ---Yes, I’m looking for a flat. I’d like _____ with two bedrooms 6.---Why don’t we take a little break? ---Didn’t we just have ________? 7.Meeting my uncle after all these years was an unforgettable moment, ______ I will always treasure. Fill in the blankets with however or instead 8. The composition is all right; there’s room for improvement,__________. 9. I’d like to go shopping with you; __________, my two hands are full. 10. The medicine had been applied. ___________, it did not seem to have much effect. 11. Mark is busy writing the report at the moment. Let me go _________. 12 It’ll take days by car, so let’s fly _________. 13. He didn’t answer my question. __________, he asked me a strange question. 14. Last Summer I went to France. This year I’m going to Italy __________. 15. If Harry is not well enough to go with you, take me _________. 16. Mr. Black seldom teaches his students boring historical facts in class. ______, he allots(分配) most of the time to free discussions. A. Instead B. Therefore C. However D. Nevertheless 17. Furniture and flooring usually come to mind when we think of ways to use bamboo. Not many of us, ________, think of bamboo clothing. A. thus B. therefore C. however D. meanwhile

whatever,whoever,whichever,whenever,wherever, however用法归纳

whatever,whoever,whichever,whenever,wherever, however用法归纳 一、引导状语从句 它们都可用来引导状语从句(让步状语从句),其大意为“无论什么(是谁、哪一个、什么时候、什么地方、如何)”等,相当于英语中的no matter what (who, which, when, where, how)。如:Whatever [No matter what] you say, I believe you. 无论你说什么,我都相信你。 Whoever [No matter who] telephones, tell them I’m out. 不管是谁打电话,都说我出去了。Whichever [No matter which] day you come, I’ll be pleasedto see you. 无论你哪天来,我都欢迎。 Whenever [No matter when] you come, you are welcome. 你什么时候来,我们都欢迎。 We found the people friendly wherever [no matter where] we went. 无论我们走到哪里,我们都发现人们很友好。 However [No matter how] much he eats, he never gets fat. 无论他吃多少,他都不发胖。 注:有时从句谓语可用情态动词: 无论他在哪里,我都要找到他。 正:I’ll find him, wherever he is. 正:I’ll find him, wherever he may be. 无论发生什么事都要保持冷静。 正:Keep calm, whatever happens. 正:Keep calm, whatever may happen另外,whoever 的宾格也是whoever, 而不是whomever, 后者在现代英语已基本不用,有的词典已不收录此词。如: Whoever you marry, make sure he can cook. 不管你跟谁结婚,他一定要会做饭才行。 二、引导名词性从句 除引导状语从句外,whatever, whoever, whichever等还可引导名词性从句(主语从句或宾语从句)。如: He does whatever she asks him to do. 她要他做什么,他就做什么。 I will just say whatever comes into my mind. 我想到什么就说什么。 Whoever breaks the rules will be punished. 谁违反这些规则都将受到处罚。 I’ll give the ticket to whoever wants it. 请想要这票,我就把它给谁。 Whichever team gains the most points wins. 哪个队得分最多,哪个队就赢。 Whichever of us gets home first starts cooking. 我们当中无论哪个先到家,哪个就先开始做饭。

however让步状语从句倒装省略

however让步状语从句倒装省略 however让步状语从句倒装省略引导的让步状语从句不完全倒装,形容词提前,后面继续陈述。 如however cheap it is,i don't want to buy it. 让步从句也不一定倒装,如, i like to buy this house,however i do not have the money. 引导让步状语从句的连词主要有以下这些: though,although,while,as; even if,even though; whether...or...; no matter+疑问词,疑问词-ever,regardless of+名词/名词短语/名词从句,despite,in spite of。 切记although,though 不可与but连用,但可以与still 和yet连用。 however的造句 1. the mechanics of the job, however, have changed little since then. 不过,工作流程从那以后就几乎没有任何变化。 2. the deal with chelsea may not, however, be dead. 不过,与切尔西的交易或许还有戏。 3. what is missing, however, is an internal, artistic cohesion. 不过,缺乏的是一种内在的艺术凝聚力。 4. however, many customers found the smell of this

product distinctly off-putting. 然而,很多顾客觉得该产品有一股异味,非常难闻。 5. when angry or excited, however, he could be wild, profane, and terrifying. 但愤怒或激动的时候,他也会发狂、会骂人、令人生畏。 6. his testimony, however, was only one in a salvo of new attacks. 然而他的证词只是新一轮唇枪舌剑中的一股火力。 7. they were not finished, however, not by any means. 不过,他们并没有结束,绝对没有。 8. some of the food crops failed. however, the cotton did quite well. 有些粮食作物歉收。但棉花的收成仍相当不错。 9. such cars, however, do grip the road well, even in the dry. 不过,这种车即使在干燥路面上也表现出了良好的抓地性能。 10. however, the rationale for such in-itiatives is not, of course, solely economic. 然而,这种提议的根据当然并不仅仅是经济方面的。 让步状语从句的用法让步状语从句表示:虽然,尽管,即使等概念,由although, though(尽管,即使),however(无论怎样),whatever(无论什么),whoever(无论谁),whomever(无论谁),whichever(无论哪个),whenever(无论何时),wherever(无论哪里),whether(是否),no matter (who,what,where,when,

however的用法

however的用法 一般情况however都是和but区别使用的。 辨析however和but 二者都意为“可是,但是”; but是并列名词,连接两个并列分句,上下二句在总的意义上构成了对比。 I really don't like cheese, but I will try just a little this time.我实在是不喜欢吃奶酪,但是这次我要尝一点。 however不能直接连接两个分句,必须另起新句,并用逗号隔开。 It was raining hard. However, we went out to look for the boy. 雨下得很大,不过我们还是出去寻找那个孩子 1.however比but用的场合更正式,so however用于书面语,而but 常用于口语. 2.however后有"," 而but 没有 3.另外,however的意思还不只局限于"但是;然而" 肯定式为as...as,否定式为not so...as...,用于书面语和正式文体;not as...as...,用于口语和非正式文体。对于一般学习者可以不加区分。第一个是:不是像什么一样的。做个比较第二个是:不是像什么那样的。描述一个事物物。 表示三者或三者以上的比较用最高级,意为“最……”,句型中经常带有表示比较范围介词短语in…或of…结构:主语+V.+the+adj.最高级+比较的范围 because of后加东西,比如说 I am late because of the broken car。 because后不能直接加东西,要加句子,比如说I am late because the car is broken。because后面接句子;because of后面接非句子,即短语或者非谓语。 如:1.I did not answer the telephone at that time,because I was washing my clothes then.(去掉because,后半部分仍然是个句子) 2.I did not see you because of his arrival.(去掉because of,后半部分不是句子) 1. 用作形容词 (1)表示与职务、身份、场合是否相称,用词组be fit for The book is fit for children. She is not fit for the job. (2)“恰当的,得体的,健康的”的意思。如: The room is a fit place for study. He keeps himself fit by running 5 miles every day. 2. 用作动词 (1)表示衣服鞋袜等是否合身要用动词。如: His coat fits beautifully. This suit doesn’t fit me well. Have you got a larger size? (2)还可作“配合,安装,安置”讲。如: The key doesn’t fit the lock. A man came and fitted the telephone for her.

英语中but与however的用法区别

英语中but与however的用法区别 两者均可表示转折或对比,意为“但是”、“可是”、“然而”等,但有区别: 1. 表示转折时,but 是连词。如: He is young but very experienced. 他虽年轻,但经验很丰富。 He has three daughters but no sons. 他有3 个女儿,但没有儿子。 He likes sports, but his wife likes music. 他喜欢运动,而他妻子则喜欢音乐。 2. however 表示“然而”、“可是”时,有的词书认为它是连词,有的词书认为它是副词。之所以将其视为副词,也许是因为像许多副词一样不仅能位于句首,而且能位于句中(注意前后使用逗号),甚至句末(注意其前也用逗号)。如: Later, however, he changed his mind. 可是他后来改变了主意。 He hasn’t arrived. He may, however, come later. 他还没有到,不过他等会儿可能会来。 He said that it was so; he was mistaken, however. 他说情况如此,可是他错了。 注:以上各例中的however 不能换成but,但可用but 来改写。如:

He said that it was so, but he was mistaken. 他说情况如此,可他错了。 3. 当连接两个句子时,其前通常应用分号,或另起新句。如: It’s raining hard; however, I think we should go out. / It’s raining hard. However, I think we should go out. 雨下得很大,但我想我们还得出去。 注:上例中的however 不能换成but,但可用but 来改写(注意所用标点的变化)。如: It’s raining hard, but I think we should go out.

however与no-matter-how的区别

“疑问词+ ever ”可分为两类,“疑问代词+ ever ”:whatever / whichever / whoever (宾格whomever )和“疑问副词+ ever ”:wherever / whenever / however. 不论是“疑问代词+ ever ”还是“疑问副词+ ever ”,其意义都是“不管/ 无论+ 该疑问词的本义”。 1. “疑问代词+ ever”可引导两种类型的从句,即让步状语从句和名词性从句(主语从句、宾语从句)。 (1)引导让步状语从句。此时whatever / whoever / whichever 分别等于“ no matte r + what / who / which”。例如: Whatever happened / No matter what happened,he wouldn't say a word.. Whoever says so / No matter who says so, it is wrong. Whichever / No matter which dictionary you (may)take,you will have to pay at least 20 dollars. 注意:这类从句中应用一般现在时表将来,从句中也常用情态动词may / might . (2)引导名词性从句。例如: Whoever smokes here will be punished. (主语从句) Beggars will eat whatever they are given. (宾语从句) Whichever he likes will be given to him. (主语从句) You may invite whoever / whomever you like. (常用whoever 代替whomever)此时它们都不能换成“ no matter + 疑问词”的形式,但whoever 等于anyone who,whatever 等于anything that. 2. “疑问副词+ever ”:wherever / whenever / however 一般只能引导一种类型的从句,即让步状语从句,此时它们分别等于“ no matter + where / when / how ”。例如: Wherever / No matter where he goes (may go). I'll follow him. Whenever / I visited him , he was always busy workings . However late he is / No matter how late he is,his mother will wait for him to have 注意:当however 用作连接副词时也可引导名词性从句,而whenever/ wherever 则不能引导名词性从句。例如: I'll give you however much money you need. (宾语从句,此时however 不能改成no matter how )。 3. 另外,whatever / whichever / whoever 与whenever / wherever / however 分别可相当于what / which / who 与when / where / how 的强调式,引起的特殊疑问句往往是简单句,与原疑问词的意思、用法完全相同,只是表达的语气更为强烈,翻译时可加上“到底;究竟”等。例如: What(ever)are you doing ?你(到底)在干什么? Which(ever)do you want to buy ?你(究竟)要买哪一个? Who(ever)told you such a foolish story?(究竟)是谁讲给你这么蠢的事?When(ever)can I enjoy a long vacation?(究竟)什么时候才能给我放个长假呢? Where(ever)did you leave your dictionary?你(究竟)把词典放哪儿了?How(ever)did you collect so much money?你(到底)是怎样筹到这么多钱的?

however的详细用法

however的详细用法 今天给大家带来however的用法,我们一起来学习吧,下面就和大家分享,来欣赏一下吧。 however的用法 1.用作副词 (1)表示让步:意为“无论如何”“不管怎样”,用来修饰形容词或副词, 其词序为:however+形容词或副词+主语+谓语。这样用的however 其实具有连词的功能,用以引导让步状语从句.如:However much he eats,he never gets fat.不管他吃多少,他永远吃不胖。 用于此用法时,请注意:这样用的however 与no matter how 大致同义,如:however [No matter how] hard I worked,she was never satisfied.无论我多么努力地工作,她从来没满意过. 2、表示转折:尤其用于谈及一个既成事实时,表示转折,其意为“可是”“仍然”等.可放在句首、句中或句末,通常用逗号与句子其

他成分隔开.如:My father,however,did not agree.但是,我父亲不同意. 3、表示惊奇或强调:相当于how ever的用法,其意为“究竟怎样,到底以什么方式”.如: However did you get here without a car?没有汽车你究竟是怎样来的呢? but与however的用法区别 两者均可表示转折或对比,意为“但是”、“可是”、“然而”等,但有区别: 1. 表示转折时,but 是连词。如: He is young but very experienced. 他虽年轻,但经验很丰富。 He has three daughters but no sons. 他有3 个女儿,但没有儿子。 He likes sports, but his wife likes music. 他喜欢运动,而他妻子则喜欢音乐。 2. however 表示“然而”、“可是”时,有的词书认为它是连词,有的词书认为它是副词。之所以将其视为副词,也许是因为像许多副词一样不仅能位于句首,而且能位于句中(注意前后使用逗号),甚至句末(注意其前也用逗号)。如:

HOWEVER,OTHERWISE等连词用法

1.however: ●可是,仍然,然而,不过; He said that is was so,he was mistaken,however.(他说情况既是如何,不过,他错了) My father,however,did not agree.(但是,我父亲不同意) My room is small,however,it is comfortable.(我房间很小,但是很舒服) ●无论如何,不管怎样; However much he eats,he never gets fat .(不管他吃多少,他都不胖。) People always want more,however (no matter how) rich they are.(人总是富了还想富) ●究竟怎样,到底以什么样的方式; However did you get here without a car?(没有汽车你到底是怎么到这来的。) 2. otherwise: ●否则,不然(or,if not) I was ill that day,otherwise I would have taken part in the sports meet. ●用别的方法,不同地,在其他方面,除此之外; He is rich,but otherwise an unhappy man.(他很有钱,但是在其他方面不幸福) He is naughty,but otherwise a nice boy(他很调皮,但是除此之外他是个不错的男孩) ●And otherwise:等等;及其他; In the kindergarten, the children learn singing, dancing,drawing and otherwise. 孩子们在幼儿园里学唱歌、跳舞、画画等等。 ●or otherwise 或相反;或其他情况。 Fine or otherwise, we shall have to go. 不管天气好不好,我们非去不可。 3.Moreover:此外,而且。 "The price is too high, and moreover, the house isn't in a suitable position." ”房价太高,而且房屋的地点也不太合适。”

however用法详解

however用法详解 however用法详解 一、考点描述however是高考英语中一个十分重要的考点,近几年来每年的各省考题均有所涉及。请看两道典型高考真题: 1. You should try to get a good night’s sleep _____ much work you have to do. A. however B. no matter C. although D. whatever 【分析】答案选A。however作连接副词时,与no matter how相当,后接形容词或副词,意为“无论……”“不管……”。句意是:不管你有多少工作要做,你都应该好好休息一个晚上。 2. He tried his best to solve the problem, _____ difficult it was. A. however B. no matter C. whatever D. although 【分析】答案选A。因difficult是形容词,修饰形容词要用连接副词however(无论如何,不管多么),引导一个让步状语从句。 二、用法详解 不管however以何种形式出现在高考题中,它都不外乎以下两种用法。1. 用作副词(1) 表示让步:意为(1) “无论如何”“不管怎样”,用来修饰形容词或副词,其词序为:however+形容词或副词+主语+谓语。这样用的however其实具有连词的功能,用以引导让步状语从句。如:Phone me when you arrive, however late it is. 你到达之后就给我打电话,不论多么晚也要打。However much he eats, he never gets fat. 不管他吃多少,他永远吃不胖。However cold it is, he always goes swimming. 不管天有多冷,他都去游泳。You won’t move the stone, however strong you are. 不管你力气有多大,也休想搬动那块石头。However far it is, l intend to drive there tonight 不管有多远,我今晚也要开车到那儿去。用于此用法时,请注意以下几点:①此用法属however所有用法中最重要的考点,同学们务请引起高度重视。②这样用的howeverfont-family: 'Times New Roman'">②与no matter how 大致同义。如:People always want more, however [no matter how] rich they are. 人总是富了还想再富。However [No matter how] hard I worked, she was never satisfied. 无论我多么努力地工作,她从来没满意过。③有时从句谓语可用情态动词。如:Don’t laugh, however funny it may be. 无

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