a different object with the same identifier value was already associated with the session
I have found two solution to this issue. Here it is, there are two.
1. Use cascase = none.
2. Use merge instead of saveandupdate.
The problem here is that you pass in a detached object which gets reattached to the Session. You also fetch the same object with the find. This causes the exception.
- You could change the query to do all the validation you require and therefore don't return it into the Session.
- Otherwise you'd have to evict the entity returned from the query.
给Mysql增加用户帐号-Adding New User Accounts to MySQL
mysql>GRANT ALL PRIVILEGES ON *.* TO 'monty'@'localhost'->IDENTIFIED BY 'some_pass' WITH GRANT OPTION;mysql>GRANT ALL PRIVILEGES ON *.* TO 'monty'@'%'->IDENTIFIED BY 'some_pass' WITH GRANT OPTION;mysql>GRANT RELOAD,PROCESS ON *.* TO 'admin'@'localhost';mysql>GRANT USAGE ON *.* TO 'dummy'@'localhost';
用UTF-8开发面向国际化Java/J2EE应用并解决中文问题
我的前一篇Mysql Hibernate Struts Tomcat中文问题解决方法讲了用GBK编码来开发中文Java/J2EE Web应用解决中文问题，这一篇将用UTF-8编码的方式开发面向国际化的Java/J2EE Web应用解决包括中文的各种语言问题。思想是在涉及到字符/文件编码的地方全部都使用UTF-8编码。
Linux启动过程综述
本文以Redhat 6.0 Linux 2.2.19 for Alpha/AXP为平台，描述了从开机到登录的 Linux 启动全过程。该文对i386平台同样适用。
理解Linux的启动过程非常有用，从而可以帮助理解Linux的工作原理，对解决系统安全和系统问题有很大作用。
例如：设置Tomcat随Linux系统启动而自动启动，你可以在catalina.sh中设置$JAVA_HOME系统环境变量，并把startup.sh加入/etc/rc.d/rc.local中；你也可以在rc.local中加入$JAVA_HOME环境变量，并把startup.sh加入/etc/rc.d/rc.local中。但是如果只在/etc/profile或者/etc/.bash_profile加入$JAVA_HOME系统环境变量，这并不会使加在/etc/rc.d/rc.local中startup.sh脚本使用到这些环境变量。
Java读取UTF-8/UNICODE等字符编码格式的文本文件
Java要读取数据流的时候一定要指定数据流的编码方式，至少读取String流的时候要这么做。
Java读取UTF-8/UNICODE等特定字符编码格式文件时，应该要指定相应的编码读取，如UTF-8,UTF-16,UNICODE,GBK,GB2312,
ISO-8859-1,Big5等。
如下示例代码：InputStreamReader read = new InputStreamReader (new FileInputStream(f),"UTF-8");//或者UNICODE,UTF-16BufferedReader reader=new BufferedReader(read);String line;while ((line = reader.readLine()) != null) {System.out.println(line);}
reader.close();
read.close();
Bookmarks links 2(我收藏的链接2)
在appfuse应用架构下用Eclipse进行DAO单元测试
在appfuse应用架构下用Eclipse进行DAO单元测试：
假设工程根目录为%PROJECT_ROOT%
1、把%PROJECT_ROOT%下build\dao\gen等目录加入工程的“Java构建路径”——“库”中的“构建路径上的jar和类文件夹”列表中，完整的须加入的路径：
<classpathentry kind="lib" path="build/dao/gen"/>
<classpathentry kind="lib" path="build/web/classes"/>
<classpathentry kind="lib" path="build/[webappName]"/>
3、为了支持ant test-dao，修改properties.xml的dao.test.classpath，增加
<fileset dir="${commons.dir}" includes="*.jar"/>
<fileset dir="${osworkflow.dir}" includes="*.jar"/>
测试DAO依赖 mail.properties、database.properties等文件和下列xml文件：
%PROJECT_ROOT%\build\dao\gen\*.hbm.xml
%PROJECT_ROOT%\dao\applicationContext-resources.xml
%PROJECT_ROOT%\build\dao\gen\META-INF\applicationContext-hibernate.xml
下面的代码就可以满足测试DAO的依赖
protected String[] getConfigLocations() {
setAutowireMode(AUTOWIRE_BY_NAME);
return new String [] {"classpath*:/**/dao/applicationContext-*.xml",
"classpath*:META-INF/applicationContext-*.xml","/WEB-INF/applicationContext-resources.xml"};
}