Ctrl+N | Opens a new window. |
Ctrl+T | Opens a new tab. |
Ctrl+Shift+N | Opens a new window in incognito mode. |
Ctrl+B | Toggles the bookmarks bar on and off. |
Press Ctrl+O, then select file. | Opens a file from your computer in Google Chrome. |
Press Ctrl and click a link. Or click a link with your middle mouse button (or mousewheel). | Opens the link in a new tab in the background . |
Press Ctrl+Shift and click a link. Or pressShift and click a link with your middle mouse button (or mousewheel). | Opens the link in a new tab and switches to the newly opened tab. |
Press Shift and click a link. | Opens the link in a new window. |
Ctrl+Shift+T | Reopens the last tab you've closed. Google Chrome remembers the last 10 tabs you've closed. |
Drag a link to a tab. | Opens the link in the tab. |
Drag a link to a blank area on the tab strip. | Opens the link in a new tab. |
Drag a tab out of the tab strip. | Opens the tab in a new window. |
Drag a tab out of the tab strip and into an existing window. | Opens the tab in the existing window. |
Press Esc while dragging a tab. | Returns the tab to its original position. |
Ctrl+1 through Ctrl+8 | Switches to the tab at the specified position number on the tab strip. |
Ctrl+9 | Switches to the last tab. |
Ctrl+Tab orCtrl+PgDown | Switches to the next tab. |
Ctrl+Shift+Tab orCtrl+PgUp | Switches to the previous tab. |
Ctrl+Shift+Q | Closes Google Chrome. |
Ctrl+W or Ctrl+F4 | Closes the current tab or pop-up. |
Click a tab with your middle mouse button (or mousewheel). | Closes the tab you clicked. |
Right-click, or click and hold either the Back or Forward arrow in the browser toolbar. | Displays your browsing history in the tab. |
Press Backspace | Goes to the previous page in your browsing history for the tab. |
PressShift+Backspace | Goes to the next page in your browsing history for the tab. |
Click either the Back arrow, Forward arrow, or Go button in the toolbar with your middle mouse button (or mousewheel). | Opens the button destination in a new tab in the background. |
Double-click the blank area on the tab strip. | Maximizes or minimizes the window. |
Use the following shortcuts in the address bar:
Type a search term, then press Enter. | Performs a search using your default search engine. |
Type a search engine keyword, press Space, type a search term, and press Enter. | Performs a search using the search engine associated with the keyword. |
Begin typing a search engine URL, pressTab when prompted, type a search term, and press Enter. | Performs a search using the search engine associated with the URL. |
Ctrl+L | Highlights the URL. |
Ctrl+E | Places a '?' in the address bar. Type a search term after the question mark to perform a search using your default search engine. |
Press Ctrl+Shift and the left arrow together. | Moves your cursor to the preceding key term in the address bar |
Press Ctrl+Shift and the right arrow together. | Moves your cursor to the next key term in the address bar |
Ctrl+Backspace | Deletes the key term that precedes your cursor in the address bar |
Select an entry in the address bar drop-down menu with your keyboard arrows, then press Shift+Delete. | Deletes the entry from your browsing history, if possible. |
Click an entry in the address bar drop-down menu with your middle mouse button (or mousewheel). | Opens the entry in a new tab in the background. |
Press Page Up orPage Down when the address bar drop-down menu is visible. | Selects the first or last entry in the drop-down menu. |
Ctrl+P | Prints your current page. |
Ctrl+S | Saves your current page. |
Ctrl+R | Reloads your current page. |
Esc | Stops the loading of your current page. |
Ctrl+F | Opens the find bar. |
Ctrl+G or Enter | Finds the next match for your input in the find bar. |
Ctrl+Shift+G orShift+Enter | Finds the previous match for your input in the find bar. |
Press Alt and click a link. | Downloads the target of the link. |
Drag a link to bookmarks bar | Bookmarks the link. |
Ctrl+D | Bookmarks your current webpage. |
Space bar | Scrolls down the web page. |
Home | Goes to the top of the page. |
End | Goes to the bottom of the page. |
Ctrl+C | Copies highlighted content to the clipboard. |
Ctrl+V or Shift+Insert | Pastes content from the clipboard. |
Ctrl+Shift+V | Paste content from the clipboard without formatting. |
Ctrl+X or Shift+Delete | Deletes the highlighted content and copies it to the clipboard. |
Hi,
I'm trying to change font size for my package explorer and it's not working. Is it right or not (I tried to find such a bug but I didn't).
Dani
-Xms
|
初始Heap大小
|
-Xmx
|
java heap最大?
|
-Xmn
|
young generation的heap大小
|
PermGen spaceQ全U是Permanent Generation space.是说是怹保存的区?用于存放Class和Meta信息,Class在被Load的时候被攑օ该区域Heap spaceQ存放Instance?/p>
GC(Garbage Collection)应该不会对PermGen spaceq行清理,所以如果你的APP会LOAD很多CLASS的话,很可能出现PermGen space错误
Java Heap分ؓ3个区
1.Young
2.Old
3.Permanent
Young保存刚实例化的对象。当该区被填满时QGC会将对象UdOld区。Permanent区则负责保存反射对象Q本文不讨论该区?/p>
JVM的Heap分配可以使用-X参数讑֮Q?/p>
-Xms
初始Heap大小
-Xmx
java heap最大?nbsp;
-Xmn
young generation的heap大小
JVM?个GCU程
W一个线E负责回收Heap的Young?br />
W二个线E在Heap不Ӟ
遍历HeapQ将Young 区升UؓOlder?br />
Older区的大小{于-Xmx减去-XmnQ不能将-Xms的D的过大,因ؓW二
个线E被q运行会降低JVM的性能?br />
Z么一些程序频J发生GCQ?/p>
有如下原因:
1.E序内调用了System.gc()或Runtime.gc()?br />
2.一些中间g软g调用自己的GCҎQ此旉
要设|参数禁止这些GC?br />
3.Java的Heap太小Q一般默认的Heap值都很小?br />
4.频繁实例化对象,Release对象
此时量保存q用对象,例如使用StringBuffer()和String()?/p>
如果你发现每ơGC后,Heap的剩余空间会是ȝ间的50%Q这表示你的Heap处于健康状?许多Server端的JavaE序每次GC后最? 能有65%的剩余空?/p>
l验之谈Q?/strong>
1QServer端JVM最好将-Xms?Xmx设ؓ相同倹{ؓ了优化GCQ最好让-Xmn值约{于-Xmx?/3?br /> 2Q一个GUIE? 序最好是?0?0U间q行一ơGCQ每ơ在半秒之内完成?/p>
注意Q?/strong>
1Q增加Heap的大虽然会降低GC的频率,但也增加了每ơGC的时间。ƈ且GCq行Ӟ所有的用户U程暂停,也就是GC期间QJava应用E? 序不做Q何工作?br /> 2QHeap大小q不军_q程的内存用量。进E的内存使用量要大于-Xmx定义的|因ؓJava为其他Q务分配内存,例如? 个线E的Stack{?/p>
Stack的设?br /> 每个U程都有他自qStack?/p>
-Xss
每个U程的Stack大小
Stack的大限制着U程的数量。如果Stackq大好D内存溢漏?Xss参数军_Stack大小Q例?Xss1024K。如? Stack太小Q也会导致Stack溢漏?/p>
g环境
g环境也媄响GC的效率,例如机器的种c,内存QswapI间Q和CPU的数量?br /> 如果你的E序需要频J创建很多transient对象Q? 会导致JVM频繁GC。这U情况你可以增加机器的内存,来减SwapI间的用?/p>
4UGC
1、第一Uؓ单线EGCQ也是默认的GCQ该GC适用于单CPU机器?br /> 2、第二种为Throughput GCQ是多线E的GCQ适用于多CPUQ用大量线E的E序。第二种GC与第一UGC怼Q不同在于GC在收集Young区是多线E的Q但在Old区和W? 一U一P仍然采用单线E?XX:+UseParallelGC参数启动该GC?br /> 3、第三种为Concurrent Low Pause GCQ类gW一U,适用于多CPUQƈ要求~短因GC造成E序停滞的时间。这UGC可以在Old区的回收同时Q运行应用程序? -XX:+UseConcMarkSweepGC参数启动该GC?br /> 4、第四种为Incremental Low Pause GCQ适用于要求羃短因GC造成E序停滞的时间。这UGC可以在Young区回收的同时Q回收一部分Old区对象?Xincgc参数启动该GC?/p>
单文件的JVM内存q行讄
默认的java虚拟机的大小比较,在对大数据进行处理时java׃报错Qjava.lang.OutOfMemoryError?br />
讄
jvm内存的方法,对于单独?classQ可以用下面的方法对Testq行时的jvm内存q行讄?br />
java -Xms64m
-Xmx256m Test
-Xms是设|内存初始化的大?br />
-Xmx是设|最大能够用内存的大小Q最好不要超q物理内存大)
tomcat启动jvm内存讄
LinuxQ?/strong>
?usr/local/apache-tomcat-5.5.23/bin目录下的catalina.shdQJAVA_OPTS='-
Xms512m -Xmx1024m'要加“m”说明是MBQ否则就是KB了,在启动tomcat时会报内存不?br />
-XmsQ初始?br />
-XmxQ?
最大?br />
-XmnQ最值Windows
在catalina.bat最前面加入
set JAVA_OPTS=-Xms128m
-Xmx350m
如果用startup.bat启动tomcat,OK讄生效.够成功的分配200M内存.但是如果不是执行startup.bat启动tomcat而是
利用windows的系l服务启动tomcat服务,上面的设|就不生效了,是说set JAVA_OPTS=-Xms128m -Xmx350m
没v作用.上面分配200M内存OOM?.windows服务执行的是bin"tomcat.exe.他读取注册表中的?而不?
catalina.bat的设|?解决办法:
修改注册表HKEY_LOCAL_MACHINE"SOFTWARE"Apache Software Foundation"Tomcat Service Manager"Tomcat5"Parameters"JavaOptions
原gؓ
-Dcatalina.home="C:"ApacheGroup"Tomcat 5.0"
-Djava.endorsed.dirs="C:"ApacheGroup"Tomcat
5.0"common"endorsed"
-Xrs加入 -Xms300m -Xmx350m
重vtomcat服务,讄生效
weblogic启动jvm内存讄
在weblogic中,可以在startweblogic.cmd中对每个domain虚拟内存的大进行设|,默认的设|是? commEnv.cmd里面?/p>
JBoss
默认可以使用的内存ؓ64MB
$JBOSSDIR$/bin/run.config
JAVA_OPTS = "-server
-Xms128 -Xmx512"
Eclipse
在所在目录下Q键?
eclipse.exe -vmargs -Xms256m -Xmx512m
256m表示JVM堆内存最
?
512m表示JVM堆内存最?/p>
Websphere
q入控制台去讄Q应用程序服务器 > server1 > q程定义 > Java 虚拟?/p>