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hsl313:
lameig 写道
bolItemChanged = f ...
c#动态设置combobox控件下拉项宽度以实现下拉项文字可以完全显示[转] -
hsl313:
原来是要登录才可以查看到啊lameig 写道
try {
...
c#动态设置combobox控件下拉项宽度以实现下拉项文字可以完全显示[转] -
lameig:
try {
int vertScrollBarWidt ...
c#动态设置combobox控件下拉项宽度以实现下拉项文字可以完全显示[转] -
lameig:
谢谢分享,在使用中,我用到了多种对象,而不仅仅是一种类型,这样 ...
c#动态设置combobox控件下拉项宽度以实现下拉项文字可以完全显示[转] -
wonderlandsh:
...
jar运行时引用其他jar包的方法[转]
从应用程序获取环境变量Read environment variables from an application
JDK up to 1.4
Start the JVM with the "-D" switch to pass properties to the application
and read them with the System.getProperty() method.
SET myvar=Hello world SET myothervar=nothing java -Dmyvar="%myvar%" -Dmyothervar="%myothervar%" myClass
then in myClass
String myvar = System.getProperty("myvar"); String myothervar = System.getProperty("myothervar");
If you don't know in advance, the name of the variable to be passed to the JVM, then there is no 100% Java way to retrieve them.
One approach (not the easiest one), is to use a JNI call to fetch the variables, see this HowTo .
A more low-tech way, is to launch the appropriate call to the operating system and capture the output. The following snippet puts all environment variables in a Properties class and display the value the TEMP variable.
import java.io.*; import java.util.*; public class ReadEnv { public static Properties getEnvVars() throws Throwable { Process p = null; Properties envVars = new Properties(); Runtime r = Runtime.getRuntime(); String OS = System.getProperty("os.name").toLowerCase(); // System.out.println(OS); if (OS.indexOf("windows 9") > -1) { p = r.exec( "command.com /c set" ); } else if ( (OS.indexOf("nt") > -1) || (OS.indexOf("windows 2000") > -1 ) || (OS.indexOf("windows xp") > -1) ) { // thanks to JuanFran for the xp fix! p = r.exec( "cmd.exe /c set" ); } else { // our last hope, we assume Unix (thanks to H. Ware for the fix) p = r.exec( "env" ); } BufferedReader br = new BufferedReader ( new InputStreamReader( p.getInputStream() ) ); String line; while( (line = br.readLine()) != null ) { int idx = line.indexOf( '=' ); String key = line.substring( 0, idx ); String value = line.substring( idx+1 ); envVars.setProperty( key, value ); // System.out.println( key + " = " + value ); } return envVars; } public static void main(String args[]) { try { Properties p = ReadEnv.getEnvVars(); System.out.println("the current value of TEMP is : " + p.getProperty("TEMP")); } catch (Throwable e) { e.printStackTrace(); } } }
thanks to w.rijnders for the w2k fix.
An update from Van Ly :
I found that, on Windows 2003 server, the property value for "os.name" is actually "windows 2003." So either that has to be added to the bunch of tests or just relax the comparison strings a bit:
else if ( (OS.indexOf("nt") > -1) || (OS.indexOf("windows 2000") > -1 ) || (OS.indexOf("windows 2003") > -1 ) // ok // but specific to 2003 || (OS.indexOf("windows xp") > -1) ) {
else if ( (OS.indexOf("nt") > -1) || (OS.indexOf("windows 20") > -1 ) // better, // since no other OS would // return "windows" || (OS.indexOf("windows xp") > -1) ) {
I started with "windows 200" but thought "what the hell" and made it "windows 20" to lengthen its longivity. You could push it further and use "windows 2," I suppose. The only thing to watch out for is to not overlap with "windows 9."
On Windows, pre-JDK 1.2 JVM has trouble reading the Output stream directly from the SET command, it never returns. Here 2 ways to bypass this behaviour.
First, instead of calling directly the SET command, we use a BAT file, after the SET command we print a known string. Then, in Java, when we read this known string, we exit from loop.
[env.bat] @set @echo **end [java] ... if (OS.indexOf("windows") > -1) { p = r.exec( "env.bat" ); } ... while( (line = br.readLine()) != null ) { if (line.indexOf("**end")>-1) break; int idx = line.indexOf( '=' ); String key = line.substring( 0, idx ); String value = line.substring( idx+1 ); hash.put( key, value ); System.out.println( key + " = " + value ); }
The other solution is to send the result of the SET command to file and then read the file from Java.
... if (OS.indexOf("windows 9") > -1) { p = r.exec( "command.com /c set > envvar.txt" ); } else if ( (OS.indexOf("nt") > -1) || (OS.indexOf("windows 2000") > -1 || (OS.indexOf("windows xp") > -1) ) { // thanks to JuanFran for the xp fix! p = r.exec( "cmd.exe /c set > envvar.txt" ); } ... // then read back the file Properties p = new Properties(); p.load(new FileInputStream("envvar.txt"));
Thanks to JP Daviau
// UNIX public Properties getEnvironment() throws java.io.IOException { Properties env = new Properties(); env.load(Runtime.getRuntime().exec("env").getInputStream()); return env; } Properties env = getEnvironment(); String myEnvVar = env.get("MYENV_VAR");
To read only one variable :
// NT version , adaptation for other OS is left as an exercise... Process p = Runtime.getRuntime().exec("cmd.exe /c echo %MYVAR%"); BufferedReader br = new BufferedReader ( new InputStreamReader( p.getInputStream() ) ); String myvar = br.readLine(); System.out.println(myvar);
Java's System properties contains some useful informations about the environment, for example, the TEMP and PATH environment variables (on Windows).
public class ShowSome { public static void main(String args[]){ System.out.println("TEMP : " + System.getProperty("java.io.tmpdir")); System.out.println("PATH : " + System.getProperty("java.library.path")); System.out.println("CLASSPATH : " + System.getProperty("java.class.path")); System.out.println("SYSTEM DIR : " + System.getProperty("user.home")); // ex. c:\windows on Win9x System.out.println("CURRENT DIR: " + System.getProperty("user.dir")); } }
Here some tips from H. Ware about the PATH on different OS.
PATH is not quite the same as library path. In unixes, they are completely different---the libraries typically have their own directories.
System.out.println("the current value of PATH is: {" + p.getProperty("PATH")+"}"); System.out.println("LIBPATH: {" + System.getProperty("java.library.path")+"}");
gives
the current value of PATH is: {/home/hware/bin:/usr/local/bin:/usr/xpg4/bin:/opt/SUNWspro/bin: /usr/ucb:/bin:/usr/bin:/home/hware/linux-bin:/usr/openwin/bin/: /usr/local/games:/usr/ccs/lib/:/usr/new:/usr/sbin/:/sbin/: /usr/openwin/lib:/usr/X11/bin:/usr/bin/X11/:/usr/local/bin/X11: /usr/bin/pbmplus:/usr/etc/:/usr/dt/bin/:/usr/lib: /usr/lib/nis:/usr/share/bin:/usr/share/bin/X11: /home/hware/work/cdk/main/cdk/../bin:.} LIBPATH: {/usr/lib/j2re1.3/lib/i386:/usr/lib/j2re1.3/lib/i386/native_threads: /usr/lib/j2re1.3/lib/i386/client:/usr/lib/j2sdk1.3/lib/i386:/usr/lib:/lib}
on my linux workstation. (java added all those except /lib and /usr/lib). But these two lines aren't the same on window either:
This system is windows nt
the current value of PATH is: {d:\OrbixWeb3.2\bin;D:\jdk1.3\bin;c:\depot\cdk\main\cdk\bin;c:\depot\ cdk\main\cdk\..\bin;d:\OrbixWeb3.2\bin;D:\Program Files\IBM\GSK\lib;H:\pvcs65\VM\win32\bin;c:\cygnus \cygwin-b20\H-i586-cygwin32\bin;d:\cfn\bin;D:\orant\bin; C:\WINNT\system32;C:\WINNT; d:\Program Files\Symantec\pcAnywhere; C:\Program Files\Executive Software\DiskeeperServer\;} LIBPATH: {D:\jdk1.3\bin;.;C:\WINNT\System32;C:\WINNT;D:\jdk1.3\bin; c:\depot\cdk\main\cdk\bin;c:\depot\cdk\main\cdk\..\bin; d:\OrbixWeb3.2\bin;D:\Program Files\IBM\GSK\lib; H:\pvcs65\VM\win32\bin;c:\cygnus\cygwin-b20\H-i586-cygwin32\bin;d:\cfn\bin; D:\orant\bin;C:\WINNT\system32; C:\WINNT;C:\Program Files\Dell\OpenManage\ResolutionAssistant\Common\bin; d:\Program Files\Symantec\pcAnywhere; C:\Program Files\Executive Software\DiskeeperServer\;}
Java is prepending itself! That confused me--- and broke my exec from ant.
发表评论
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类的加载方法:Class.forName与ClassLoader.loadClass
2012-05-04 16:52 2756Class.forName和ClassLoader.load ... -
Rod Johnson谈Spring、Spring、Spring及企业级Java的未来[转]
2009-06-07 22:22 1169转自http://www.kuqin.com/java/200 ... -
Java中四种XML解析技术
2009-06-07 21:53 663转自 http://www.kuqin.com/jav ... -
Java编程极限考验:ClassLoader类装载策略[转]
2009-06-07 20:19 822Java编程极限考验:ClassLoader类装载策略 ... -
==, .equals(), compareTo(), and compare()[转]
2009-04-29 09:59 1717转自[Java Notes]http://leepoint.n ... -
Java对象的序列化和反序列化实践[转]
2009-03-24 16:32 951Java对象的序列化和反序列化实践 2007-09-19 ... -
java获取当前路径[转]
2009-03-24 12:06 1492java 获取当前路径 http://hi.bai ... -
System.getProperty()参数大全
2009-03-24 12:03 853System.getProperty()参数大全 htt ... -
Common XP environment variables[转 ]
2009-03-24 11:58 847Common XP environment variables ... -
Retrieve environment variable (JNI)[转]
2009-03-24 11:57 844Retrieve environment variable ( ... -
Retrieve environment variables (JDK1.5)
2009-03-24 11:55 749Retrieve environment variables ... -
Java读取环境变量
2009-03-24 11:45 9370读取环境变量时可以使用 System.getProperty ... -
jar运行时引用其他jar包的方法[转]
2009-03-10 22:17 2630转自http://www.iteye.com/topi ... -
JDK 6.0 API 中文版已正式发布[转]
2009-03-09 15:31 1190转自 http://www.iteye.com/topic/6 ...
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