Ubuntu 安裝 RPM 檔案

Alien 是一個將 rpm, dpkg, stampede slp 及 slackware tgz 檔案格式間轉換的工具，在 Ubuntu 上安裝 Alien 也只需用 apt 即可，相當方便，以下是安裝方法:

$sudo apt-get install alien

例如:

sudo alien -k xxxx.rpm #會將rpm轉換為deb，完成後會生成一個同名的xxxx.deb。

sudo dpkg -i xxxx.deb #安裝deb檔。

VirtualBox 分享資料夾

裝置->分享資料夾

名稱: share

路徑: C:\share

在客端(Linux)底下新增要分享的目錄(如/mnt/share)

mount -t vboxsf share /mnt/share

如果要開機就掛載的話請將上面那行加在/etc/rc.local裡面

參考網址：
http://lunafox.wordpress.com/2008/02/12/%E5%9C%A8virtualbox-154-%E4%B8%8A%E5%AE%89%E8%A3%9Dubuntu-710/#_


成為Ubuntu Root管理者

1. 在終端機中輸入：
   sudo su
   (記得輸入密碼)
   再輸入：
   passwd
   輸入新的密碼(不會顯示)
   再次確認(不會顯示)
   到系統 > 管理 > 登入畫面
   按標籤"安全性",把"允許本地端系統管理員登入"框框打勾
2. 在終端機下指令：sudo nautilus
3. 用Lazybuntu安裝nautilus的外掛指令，就可以在滑鼠右鍵裏面選以root身份開檔案管理員

參考的網址：
http://www.ubuntu.org.tw/modules/newbb/viewtopic.php?topic_id=9454&forum=7&post_id=46529#forumpost46529

eclipse Deployment failure

前幾天發現Deployment failure 的問題，出現以下錯誤訊息

Deployment failure on Tomcat 5.x. Could not copy all resources to E:\javatool\Java\Tomcat 5.5\webapps\web. If a file is locked, you can wait until the lock times out to redeploy, or stop the server and redeploy, or manually remove the deployment at E:\javatool\Java\Tomcat 5.5\webapps\web

原因有可能是eclipse 包了不存在的JAR 檔，解決方法：確認jar files並重新reference jar files 設定

Ubuntu 8.04 LTS 出爐了

Ubuntu 8.04 LTS 終於出爐了，這禮拜打算重新安裝看看，順便把一些專案會用到的工具也一起安裝起來。

Ubuntu 8.04 LTS 是屬於長期維護的版本，桌面版部份保證維護 3 年，而伺服器部份則是 5 年。有興趣的人可以安裝看看。


安裝後再提供，安裝後心得與感想。

JavaWeb中URL上的jsessionid

FYI :
http://www.blogjava.net/steady/archive/2007/09/08/143664.html
http://randomcoder.com/articles/jsessionid-considered-harmful

上列網頁中提到，透過加入 Filter 的方式過滤掉 URL 中包含的 jsessionid，再重新包装 Response 返回给瀏覽器。
以解決jsessionid在URL出現的問題。

import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpServletResponseWrapper;
import javax.servlet.http.HttpSession;
import java.io.IOException;
/**
* Servlet filter which disables URL-encoded session identifiers.
** Copyright (c) 2006, Craig Condit. All rights reserved.

*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
*  Redistributions of source code must retain the above copyright notice,
*     this list of conditions and the following disclaimer.
*   * Redistributions in binary form must reproduce the above copyright notice,
*     this list of conditions and the following disclaimer in the documentation
*     and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
* 

*/
@SuppressWarnings("deprecation")
public class DisableUrlSessionFilter implements Filter {

/**
* Filters requests to disable URL-based session identifiers.
*/
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
// skip non-http requests
if (!(request instanceof HttpServletRequest)) {
chain.doFilter(request, response);
return;
}

HttpServletRequest httpRequest = (HttpServletRequest) request;
HttpServletResponse httpResponse = (HttpServletResponse) response;

// clear session if session id in URL
if (httpRequest.isRequestedSessionIdFromURL()) {
HttpSession session = httpRequest.getSession();
if (session != null) session.invalidate();
}

// wrap response to remove URL encoding
HttpServletResponseWrapper wrappedResponse = new HttpServletResponseWrapper(httpResponse) {
@Override
public String encodeRedirectUrl(String url) {
return url;
}

@Override
public String encodeRedirectURL(String url) {
return url;
}

@Override
public String encodeUrl(String url) {
return url;
}

@Override
public String encodeURL(String url) {
return url;
}
};

// process next request in chain
chain.doFilter(request, wrappedResponse);
}

/**
* Unused.
*/
public void init(FilterConfig config) throws ServletException {
}

/**
* Unused.
*/
public void destroy() {
}

Error Message: Illegal memory access for BEA

currently system

----------------------------------------------------------
Error Message: Illegal memory access. [54] ----I couldn't find any thing release notes of 27.4 update
Version BEA JRockit(R) R27.4.0
C Heap : Good; no memory allocations have failed
StackOverFlow: 0 StackOverFlowErrors have occured
OutOfMemory : 0 OutOfMemoryErrors have occured
-----------------------------------------------------------

I couldn't find jcaptcha problem for jrockit.10158.dump.

For BEA

The paper describes some possible solutions to stack overflow errors.
at http://edocs.bea.com/jrockit/geninfo/diagnos/crash.html#wp998430


But I find some body have same problem,too.
Maybe we can try it to solve the problem.


1) Try the latest version of JRockit (Version BEA JRockit(R) R27.5.0 )

2)
I first tried disabling JIT optimizations but that didn't help
I then changed GC to single generational (-Xgc:singlecon) and that seems to have fixed the problem


References
http://forums.bea.com/thread.jspa?threadID=300004611



For JCaptcha Framework

In JCaptcha Site have some Issue Navigator.

3) May be we could try to give more than 4M to JVM!!
-Xmx4M !!


References
http://forge.octo.com/jcaptcha/jira/browse/FWK-64