??xml version="1.0" encoding="utf-8" standalone="yes"?>青青草国产一区二区三区,亚洲人精品午夜,亚洲精品视频中文字幕 http://www.aygfsteel.com/dong/Share Our Experience of Java zh-cn Wed, 07 May 2025 21:08:41 GMT Wed, 07 May 2025 21:08:41 GMT 60 C-JDBC 数据库集中间g资料 http://www.aygfsteel.com/dong/archive/2010/03/25/316577.htmlDong Dong Thu, 25 Mar 2010 12:23:00 GMT http://www.aygfsteel.com/dong/archive/2010/03/25/316577.html http://www.aygfsteel.com/dong/comments/316577.html http://www.aygfsteel.com/dong/archive/2010/03/25/316577.html#Feedback 0 http://www.aygfsteel.com/dong/comments/commentRss/316577.html http://www.aygfsteel.com/dong/services/trackbacks/316577.html CJDBC官网 http://c-jdbc.ow2.org/
cjdbc与hibernate的整?/strong>
Configuring C-JDBC with Hibernate
C-JDBC just has to be defined as any JDBC driver in Hibernate, leaving the syntax set to the proper database. Here is a configuration example to use Hibernate with a C-JDBC cluster made of Sybase backends:
## C-JDBC
hibernate.dialect net.sf.hibernate.dialect.SybaseDialect
hibernate.connection.driver_class org.objectweb.cjdbc.driver.Driver
hibernate.connection.username user
hibernate.connection.password pass
hibernate.connection.url jdbc:cjdbc://localhost:25322/test
转自Q?/font>http://lzj0470.javaeye.com/blog/445348
一、前a
cjdbc ( http://c-jdbc.objectweb.org/ ) 是一个open source的数据库集群中间ӞMZjdbc的应用都可以通过它透明地访问数据库集群Q它可以q行各个节点之间的数据复Ӟq且可以实现各个节点的查询负载均衡。通过q样的YӞ偶们可以方便的实现RAIDb - Redundant Array of Inexpensive Database 廉h数据库冗余阵列?br />
大型应用随着用户量访问越来越大,增加数据库存储和做好数据库冗余可以增加系l的可靠性和性能?br />
下面利用cjdbcQ把两台对等?Mysql ?RAIDbQ?strong>本文假定你已l搭建好两台对等?Mysql环境q徏好一个需要做集群冗余的数据库 clusterdb?/strong>
二、配|环?/span>
Mysql: 5.0.19, q?InnoDB 作ؓ Mysql 引擎
C-jdbc: 2.0.2
Jdk: 1.5
三、选择合适的 C-JDBC RAIDb 机制
cjdbc有几URAIDb的机制可以选择Q如RAIDb-0QRAIDb-1{等Q可以根据不同的情况选择不同的RAIDb的机制。各U?RAIDb的机制详情请查看 cjdbc 的文档和 Demo?br />
RAIDb-1有如下功能:
完全镜像处理机制Q每个节点上都有完整的数据库l构Q这U方式提供了最好的定w处理Qƈ且通过讄合理的Loading Balance{略Q可以带来查询性能相当好的提高。但是由于对于Q何的写操作(create/update/delete)Q需要在各个节点上进行传播复Ӟ写操作就会比原来慢一些了Q如下图Q?/span>
q里选择 RAIDb-1 做ؓ cjdbc RAIDb 机制?/span>
四、给两台对等?Mysql Q假设两?Mysql 的IP分别?192.168.0.2?92.168.0.3
bash> mysql -h192.168.0.2 -uroot
bash> use clusterdb
bash> create table user (id int(3) not null auto_increment primary key, name char(50) not null) engine innodb ;
bash> exit;
bash> mysql -h192.168.0.3 -uroot
bash> use clusterdb
bash> create table user (id int(3) not null auto_increment primary key, name char(50) not null) engine innodb ;
bash> exit;
五、在 Linux 下安?C-JDBC Controller
bash> mkdir -p /usr/local/c-jdbc
bash> cd /usr/local/c-jdbc
bash> tar xvfz c-jdbc-2.0.2-bin.tar.gz
bash> export CJDBC_HOME=/usr/local/c-jdbc
六、把 Mysql JDBC Driver 攑ֈ C-JDBC Controller 中来
q里我们使用 mysql-connector-java-3.1.12-bin.jar 驱动E序Q把它放?br />
/usr/local/c-jdbc/drivers ?/span>
七、配|?C-JDBC Controller
1、在 /usr/local/c-jdbc/config/virtualdatabase 目录中创?虚拟数据库配|文Ӟq把它命名ؓ mysql-raidb1-distribution.xmlQ内容如下:
<?xml version="1.0" encoding="UTF8"?>
<!DOCTYPE C-JDBC PUBLIC "-//ObjectWeb//DTD C-JDBC 2.0.2//EN" "http://c-jdbc.objectweb.org/dtds/c-jdbc-2.0.2.dtd">
<C-JDBC>
<VirtualDatabase name="myDB">
<Distribution>
</Distribution>
<AuthenticationManager>
<Admin>
<User username="admin" password="c-jdbc"/>
</Admin>
<VirtualUsers>
<VirtualLogin vLogin="boss" vPassword="boss"/>
</VirtualUsers>
</AuthenticationManager>
<DatabaseBackend name="mysqlNode211" driver="org.gjt.mm.mysql.Driver" url="jdbc:mysql://192.168.0.2/clusterdb" connectionTestStatement="select 1">
<ConnectionManager vLogin="boss" rLogin="boss_user" rPassword="123456">
<VariablePoolConnectionManager initPoolSize="10" minPoolSize="10" maxPoolSize="50" idleTimeout="30" waitTimeout="10"/>
</ConnectionManager>
</DatabaseBackend>
<DatabaseBackend name="mysqlNode213" driver="org.gjt.mm.mysql.Driver" url="jdbc:mysql://192.168.0.3/clusterdb" connectionTestStatement="select 1">
<ConnectionManager vLogin="boss" rLogin="boss_user" rPassword="123456">
<VariablePoolConnectionManager initPoolSize="10" minPoolSize="10" maxPoolSize="50" idleTimeout="30" waitTimeout="10"/>
</ConnectionManager>
</DatabaseBackend>
<RequestManager>
<RequestScheduler>
<RAIDb-1Scheduler level="passThrough"/>
</RequestScheduler>
<LoadBalancer>
<RAIDb-1>
<WaitForCompletion policy="first"/>
<RAIDb-1-LeastPendingRequestsFirst/>
</RAIDb-1>
</LoadBalancer>
</RequestManager>
</VirtualDatabase>
</C-JDBC>
2、在 /usr/local/c-jdbc/config/controller 目录中创?C-JDBC controller 配置文gQƈ把它命名?uud-controller-distributed.xmlQ内容如下:
<?xml version="1.0" encoding="UTF8" ?>
<!DOCTYPE C-JDBC-CONTROLLER PUBLIC "-//ObjectWeb//DTD C-JDBC-CONTROLLER 2.0.2//EN" "http://c-jdbc.objectweb.org/dtds/c-jdbc-controller-2.0.2.dtd">
<C-JDBC-CONTROLLER>
<Controller port="25323">
<JmxSettings>
<RmiJmxAdaptor port="1091"/>
</JmxSettings>
<VirtualDatabase configFile="mysql-raidb1-distribution.xml" virtualDatabaseName="myDB" autoEnableBackends="true"/>
</Controller>
</C-JDBC-CONTROLLER>
3、在 /usr/local/c-jdbc/config/demo 目录中创建启?C-JDBC controller shQƈ把它命名?uud-distributed-raidb1-controller.shQ内容如下:
#!/bin/sh
export CJDBC_HOME=/usr/local/c-jdbc
export JAVA_HOME=/opt/jdk1.5
cd $CJDBC_HOME/bin
echo "Waiting for mysql servers to finish start up"
echo "Starting Controller"
./controller.sh -f ../config/controller/uud-controller-distributed.xml &
八、启?C-JDBC Controller
bash> cd /usr/local/c-jdbc/demo
bash> chmod u+rwx uud-distributed-raidb1-controller.sh
bash> ./uud-distributed-raidb1-controller.sh &
如果启动正常Q显C的信息如下Q?
Waiting for mysql servers to finish start up
Starting Controller
2006-04-20 10:32:21,126 INFO controller.core.Controller C-JDBC controller (2.0.2)
2006-04-20 10:32:21,189 INFO controller.core.Controller Loading configuration file: ../config/controller/uud-controller-distributed.xml
2006-04-20 10:32:21,278 INFO controller.core.Controller JMX is enabled
2006-04-20 10:32:21,308 INFO controller.core.Controller Starting JMX server on host: 127.0.0.1
2006-04-20 10:32:21,674 INFO backend.DatabaseBackend.mysqlNode211 Adding connection manager for virtual user "boss"
2006-04-20 10:32:21,749 INFO backend.DatabaseBackend.mysqlNode213 Adding connection manager for virtual user "boss"
2006-04-20 10:32:21,809 INFO controller.RequestManager.myDB Request manager will parse requests with the following granularity: NO_PARSING
2006-04-20 10:32:21,814 INFO controller.virtualdatabase.myDB Configuring jgroups using: file:/usr/local/c-jdbc/config/jgroups.xml
-------------------------------------------------------
GMS: address is 127.0.0.1:32773
-------------------------------------------------------
2006-04-20 10:32:26,476 INFO controller.virtualdatabase.myDB Group myDB connected to /127.0.0.1:32773[/127.0.0.1:32773]
2006-04-20 10:32:26,476 INFO controller.virtualdatabase.myDB First controller in group myDB
2006-04-20 10:32:26,477 WARN controller.virtualdatabase.myDB No recovery log has been configured, enabling backend without checkpoint.
[1]+ Done ./uud-distributed-raidb1-controller.sh
八、编?C-JDBC 客户端程?/span>
1、把 C-JDBC Drivers(/usr/local/c-jdbc/drivers/c-jdbc-driver.jar) 攄?CLASSPATH ?br />
2、编写插?10 条数据到 Mysql 中,E序如下Q?
/**
* @author 胡荣?br />
* @Company 世纪?21cn
*/
package com.cjdbc.test;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.DriverManager;
/**
*
*/
public class GenerateSampleData {
public void generate() {
Connection conn = null;
PreparedStatement pstmt = null;
try {
// q是 c-jdbc drivers ?Drivers classQ注意不?mysql ?Drivers class
Class.forName("org.objectweb.cjdbc.driver.Driver").newInstance();
// 192.168.0.1 ?cjdbc controller 所在的 ip
// myDB 是在 文g mysql-raidb1-distribution.xml 里定义的 <VirtualDatabase name="myDB">
// user=boss&password=boss 是在 文g mysql-raidb1-distribution.xml 里定义的
// <VirtualUsers>
// <VirtualLogin vLogin="boss" vPassword="boss"/>
// </VirtualUsers>
String url = "jdbc:cjdbc://192.168.0.1:25323/myDB?user=boss&password=boss";
conn = DriverManager.getConnection(url);
try{
conn.setAutoCommit(false);
pstmt = conn.prepareStatement("insert into user values ('', ?)");
int numOfTestRecords = 10;
System.out.println("Update Record Start.");
for (int i=0;i<numOfTestRecords;i++) {
String newkey = i + "-" + i;
pstmt.setString(1, "hua_" + newkey);
pstmt.executeUpdate();
}
conn.commit();
System.out.println("Update Record Success.");
}
catch(Exception ex){
conn.rollback();
ex.printStackTrace();
}
finally{
try {
if( pstmt != null )
pstmt.close();
if( conn != null)
conn.close();
}
catch(Exception e) {
e.printStackTrace();
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
GenerateSampleData g = new GenerateSampleData();
g.generate();
}
}
3、程序执行完毕后Q分别到 Mysql Node 192.168.0.2 ?192.168.0.3 查询Q看看是否已同步了数据,如果两个 Mysql Node 都有相同的数据,说明 C-JDBC 环境搭徏成功?/span>
]]> 颠覆JAVAQ用WEB的方式开发桌面程?一) http://www.aygfsteel.com/dong/archive/2009/03/19/260789.htmlDong Dong Thu, 19 Mar 2009 07:16:00 GMT http://www.aygfsteel.com/dong/archive/2009/03/19/260789.html http://www.aygfsteel.com/dong/comments/260789.html http://www.aygfsteel.com/dong/archive/2009/03/19/260789.html#Feedback 23 http://www.aygfsteel.com/dong/comments/commentRss/260789.html http://www.aygfsteel.com/dong/services/trackbacks/260789.html 最q做了一个日志管理系l?br />
个h觉得采用了一套非帔R常创新或者变态的开发方式,像题目说的那样Q用web的方法开发桌面应用程序,当然所有的技术都是基于java的?br />
ȝ一下在整个目中用到的技?/strong>
1、底层服务器的开发socket通信、http报文解析、反机Ӟq些技术其实就是开发了一Ƒְ型的服务器,让我们的web代码能够在本地运行v来,之所以选择自己开发服务器的原因是Qtomcat对于我们q个桌面程序来说还是太大了点,如果作ؓ桌面启动Q用户不可能{待E序启动q么长的旉Q我l这个服务器起了个名字叫?span style="color: #ff0000">jnetQ?br />
2、SWTQ包括的览器控件和H口{?br />
3、用installanywhere来打包程序,方便发布
4、前台展现数据用了ext2.2
5、扩展自己开发的服务?span style="color: #ff0000">jnetQ开发出自己?#8220;action”Q应该来说还是符合MVC?br />
数据库用的是accessQ采用jdbc的方式访问,你知道,如果在桌面Y件上使用hibernate...
好了Q不说废?br />
先脓出成品的效果?br />
1、桌面图?br />
2、登录界?br />
3、登录效果图
4、主界面
是不是觉得还不错呢?JAVA也可以扬眉吐气开发出q样的桌面系l,可惜的是因ؓ使用CSWTQ所以整个项目ƈ不能跨^収ͼ攑ֈlinuxpȝ下去q行?br />
好了先理一理,发一张项目的原理?/strong>
看图说话Q我们整个项目的构架Q就是这个样子的Q采用SWT装了IE作ؓ前台展现Q后C用自己开发的服务器作为后台来处理数据Q中间数据通信方式当然只能是http?br />
所以中心思想是Q我开发了个服务器Q这个服务器能够让用h展自qc,自己的方法,然后用户可以根据自q需要来书写自己的系l,最最最重要的就是,让我们这些写惯了J2EE的h能够使用已经形成的思维来编写桌面系l,我们可以不需要再dswing和swtQ可以用html的方式来做前台的布局Q因实说我每次写桌面程序的时候,M把代码弄得一团糟Q在webpȝ上容易规规矩矩的写出分层的代码,桌面pȝ...布局p我头大(我的意思是当你跑出LU活q的时候,不用再学一套东西,呵呵Q?br />
好了Q这个帖子只是一个简单的介绍Q整个系l具体的实现方式Q会在后l的帖子中一步步解析Q大家有什么意见或者徏议可以给我留aQ谢谢!
]]>JAVA反射机制的简单应?/title> http://www.aygfsteel.com/dong/archive/2008/06/05/206083.htmlDong Dong Thu, 05 Jun 2008 08:36:00 GMT http://www.aygfsteel.com/dong/archive/2008/06/05/206083.html http://www.aygfsteel.com/dong/comments/206083.html http://www.aygfsteel.com/dong/archive/2008/06/05/206083.html#Feedback 7 http://www.aygfsteel.com/dong/comments/commentRss/206083.html http://www.aygfsteel.com/dong/services/trackbacks/206083.html 开发的时候有时候会到q样的情况,我们在写E序的时候ƈ不知道需要调用某个对象的哪个ҎQ只有程序运行后Q我们才能够知道。或许我们需要根据客L传过来的某个String参数的值来判断我们应该执行哪个Ҏ。在q种情况下JAVA的反执行就可以帮上忙了。下面是我做的一个简单的试代码Q提供给大家做个参考?br />
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
/** */ /**
* @author Dong
* 试JAVA reflect机制
*/
public class TestRef {
/** */ /**
* @param args
*/
public static void main(String[] args) {
TestBean test = new TestBean();
Method[] methods = test.getClass().getMethods();
test.setAbc( " --- " );
for ( int i = 0 ;i < methods.length;i ++ ) {
if (methods[i].getName().equalsIgnoreCase( " getabc " )) {
try {
System.out.println(methods[i].invoke(test));
} catch (IllegalArgumentException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
}
}
}
}
}
]]> JAVA中Object[]数据转String[] http://www.aygfsteel.com/dong/archive/2008/06/02/205280.htmlDong Dong Mon, 02 Jun 2008 03:25:00 GMT http://www.aygfsteel.com/dong/archive/2008/06/02/205280.html http://www.aygfsteel.com/dong/comments/205280.html http://www.aygfsteel.com/dong/archive/2008/06/02/205280.html#Feedback 0 http://www.aygfsteel.com/dong/comments/commentRss/205280.html http://www.aygfsteel.com/dong/services/trackbacks/205280.html (String[])ArrayList.toArray(new String[0]);
]]> 在XML配置文g中输?amp;W号 http://www.aygfsteel.com/dong/archive/2008/05/21/201812.htmlDong Dong Wed, 21 May 2008 01:03:00 GMT http://www.aygfsteel.com/dong/archive/2008/05/21/201812.html http://www.aygfsteel.com/dong/comments/201812.html http://www.aygfsteel.com/dong/archive/2008/05/21/201812.html#Feedback 0 http://www.aygfsteel.com/dong/comments/commentRss/201812.html http://www.aygfsteel.com/dong/services/trackbacks/201812.html XML里是无法直接正常输出&{特D字W的Q可?amp;amp;转义表示Q?/span>
]]> Fmt标签的?/title> http://www.aygfsteel.com/dong/archive/2008/05/20/201568.htmlDong Dong Tue, 20 May 2008 01:29:00 GMT http://www.aygfsteel.com/dong/archive/2008/05/20/201568.html http://www.aygfsteel.com/dong/comments/201568.html http://www.aygfsteel.com/dong/archive/2008/05/20/201568.html#Feedback 0 http://www.aygfsteel.com/dong/comments/commentRss/201568.html http://www.aygfsteel.com/dong/services/trackbacks/201568.html 1、数字格式化
<fmt:formatNumber value="33.33333" pattern="#.0"></fmt:formatNumber>-->输出33.3
pattern中符LU束规定
0 一个数?br />
# 一个数位,前导零和q尾零不昄
. 数点分割位|?br />
Q?nbsp; l分隔符的位|?br />
- 负数前缀
% ?00乘,q显C百分号
其他MW号 在输出字W串中包括指定符?/div>
2、日期格式化
<fmt:formatDate value="${vo.lateCompleteDate}" type="both" pattern="yy-MM-dd"/>
]]>
HashMap标准遍历Ҏ http://www.aygfsteel.com/dong/archive/2008/05/19/201440.htmlDong Dong Mon, 19 May 2008 09:09:00 GMT http://www.aygfsteel.com/dong/archive/2008/05/19/201440.html http://www.aygfsteel.com/dong/comments/201440.html http://www.aygfsteel.com/dong/archive/2008/05/19/201440.html#Feedback 0 http://www.aygfsteel.com/dong/comments/commentRss/201440.html http://www.aygfsteel.com/dong/services/trackbacks/201440.html HashMap<String,String> testMap = new HashMap<String,String>();
for (Map.Entry<String, String> entry : testMap .entrySet()) {
entry.getKey();
entry.getValue();
}
]]> 在java环境中访问spring中配|的对象 http://www.aygfsteel.com/dong/archive/2008/05/19/201430.htmlDong Dong Mon, 19 May 2008 08:45:00 GMT http://www.aygfsteel.com/dong/archive/2008/05/19/201430.html http://www.aygfsteel.com/dong/comments/201430.html http://www.aygfsteel.com/dong/archive/2008/05/19/201430.html#Feedback 0 http://www.aygfsteel.com/dong/comments/commentRss/201430.html http://www.aygfsteel.com/dong/services/trackbacks/201430.html ApplicationContext ctx = new ClassPathXmlApplicationContext("application-config.xml");
Map<String,String> bureauMap = ((DictionaryService)ctx.getBean("dictionaryService")).getBureauMap();
]]> 关于request.request.getRequestDispatcher().forward()Ҏ的一点看?/title> http://www.aygfsteel.com/dong/archive/2008/04/17/193658.htmlDong Dong Thu, 17 Apr 2008 02:28:00 GMT http://www.aygfsteel.com/dong/archive/2008/04/17/193658.html http://www.aygfsteel.com/dong/comments/193658.html http://www.aygfsteel.com/dong/archive/2008/04/17/193658.html#Feedback 1 http://www.aygfsteel.com/dong/comments/commentRss/193658.html http://www.aygfsteel.com/dong/services/trackbacks/193658.html 今天在调试一个ServletE序的时候,报了以下错误Q?br style="font-family: " />
java.lang.IllegalStateException: Cannot forward after response has been committed
Ҏ字面理解的话Q意识是在response已经提交后程序不能再一ơ的跌{Q?br />
研究代码以后发现Q是因ؓ前面已经执行q一?font face="Arial" size="2">request.request.getRequestDispatcher().forward()
但是后面?font face="Arial" size="2">request.request.getRequestDispatcher().forward()依然被执行到了!
那么很有理由怿request.request.getRequestDispatcher().forward() 跌{本n是不会返回什么,也不会终止程序体的执行!
E序体后面该执行的还是会执行Q?/span>
]]> Tomcat配置JNDI数据?报错解决 http://www.aygfsteel.com/dong/archive/2008/02/24/181755.htmlDong Dong Sun, 24 Feb 2008 05:47:00 GMT http://www.aygfsteel.com/dong/archive/2008/02/24/181755.html http://www.aygfsteel.com/dong/comments/181755.html http://www.aygfsteel.com/dong/archive/2008/02/24/181755.html#Feedback 1 http://www.aygfsteel.com/dong/comments/commentRss/181755.html http://www.aygfsteel.com/dong/services/trackbacks/181755.html
< Resource name ="jdbc/dong" auth ="Container" type ="javax.sql.DataSource" />
< ResourceParams name ="jdbc/dong" >
< parameter >
< name > factory </ name >
< value > org.apache.commons.dbcp.BasicDataSourceFactory </ value >
</ parameter >
< parameter >
< name > maxActive </ name >
< value > 100 </ value >
</ parameter >
< parameter >
< name > maxIdle </ name >
< value > 30 </ value >
</ parameter >
< parameter >
< name > maxWait </ name >
< value > 5000 </ value >
</ parameter >
< parameter >
< name > username </ name >
< value > root </ value >
</ parameter >
< parameter >
< name > password </ name >
< value > colorful </ value >
</ parameter >
< parameter >
< name > driverClassName </ name >
< value > org.gjt.mm.mysql.Driver </ value >
</ parameter >
< parameter >
< name > url </ name >
< value > jdbc:mysql://localhost:3306/dong </ value >
</ parameter >
</ ResourceParams >
使用如上配置的时候一直报q个
org.apache.tomcat.dbcp.dbcp.SQLNestedException: Cannot create JDBC driver of class '' for connect URL 'null'错误
在网l上寻觅后发现是因ؓTomcat版本引v的,Ҏ如下问题消׃
< Resource
name ="jdbc/dong"
type="javax.sql.DataSource"
password="colorful"
driverClassName="org.gjt.mm.mysql.Driver"
maxIdle="2"
maxWait="5000"
username="root"
url="jdbc:mysql://localhost:3306/dong"
maxActive="4" />
]]>
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