useful link

http://www.esnips.com    download ebook
http://www.bookgo.org    download ebook
http://rapid4me.com      download ebook

class loader
http://www.qos.ch/logging/classloader.jsp
http://www.onjava.com/pub/a/onjava/2003/11/12/classloader.html

pdf password remove
http://www.verypdf.com/pwdremover/index.htm

closure: http://www.martinfowler.com/bliki/Closure.html
closure: http://www.jibbering.com/faq/faq_notes/closures.html

面试题: http://www.izuren.com/
hibernate fetch strategy: http://ahcen001.iteye.com/blog/305547

服务器空间（免费）：http://www.ueuo.com/

struts2: http://www.iteye.com/topic/295414?page=1
struts2: http://www.blogjava.net/max/category/16130.html

double check lock issues
http://www.cs.umd.edu/~pugh/java/memoryModel/DoubleCheckedLocking.html
http://www.ibm.com/developerworks/java/library/j-dcl.html
http://www.javaworld.com/javaworld/jw-02-2001/jw-0209-double.html?page=1

贫血模型 vs 充血模型
http://www.martinfowler.com/bliki/AnemicDomainModel.html
http://www.iteye.com/topic/281289?page=1
http://www.nofluffjuststuff.com/blog_detail.jsp?rssItemId=96860

程序员推荐书籍
http://www.iteye.com/wiki/Java_Newbie/945-java-programmers-recommendation-books
http://www.ibm.com/developerworks/cn/java/j-javaresources.html?ca=drs-cn-0302

ssl
http://www.securityfocus.com/infocus/1818
http://docs.sun.com/source/816-6156-10/contents.htm
http://java.sun.com/j2se/1.5.0/docs/guide/security/jsse/JSSERefGuide.html

digital signature
http://www.youdzone.com/signature.html
http://dictionary.zdnet.com/definition/digital+signature.html
http://dictionary.zdnet.com/definition/digital+certificate.html

dns:
rfc1034   http://www.faqs.org/rfcs/rfc1034.html
http://www.zytrax.com/books/dns/
https://www.dnspod.com

usb key:
http://www.williamlong.info/?tags=USBKey

RDBMS VS LDAP
http://www.c-sharpcorner.com/UploadFile/anandnarayanswamy/DSvsRDBMS08232005071026AM/DSvsRDBMS.aspx
http://www.openldap.org/faq/data/cache/378.html


weak reference / memory leak
http://weblogs.java.net/blog/2006/05/04/understanding-weak-references