Java, Web Development and Tools – That's all !!!
I would thank the visitors of my blog. Currently, this blog has over more 300 unique visitors by day without advertising.
I know that I didn’t post new article from several weeks, but, currently, I don’t have really any time because of my second and third jobs 
… Project Manager and Project Owner for the building of my home.
Hurray! I have one of the top 10% most viewed @LinkedIn profiles for 2012:
http://lu.linkedin.com/in/huseyinozveren
…I wonder if this is right or it is may be a marketing ploy..;)
Huseyin
Hi,
In this article, I will try to present briefly:
1) the management of SSL certificates with keytool;
2) a complete example of certificate’s generation;
3) installation on web server and tests;
1. Presentation of keytool
Java uses its own tools to generate and use certificates, based on a proprietary storage in a keystore file, comprised of certificates / keys accessible by alias. A keystore file is protected by password, the default keystore is that of current user(~/.keystore). It’s possible to import and export certificates/keys to be used in Java applications.
C:\Users\huseyin>keytool -list
keytool -list -keystore C:\MyFiles\Development\Java\tools\.sslcertificates
keytool -genkey -keystore C:\MyFiles\Development\Java\tools\.sslcertificates -alias myhuocert -keyalg RSA
keytool -delete -keystore C:\MyFiles\Development\Java\tools\.sslcertificates -alias myhuocert
keytool -list -keystore C:\MyFiles\Development\Java\tools\.sslcertificates -export -alias myhuocert -rfc
keytool -import -keystore C:\MyFiles\Development\Java\tools\.sslcertificates -alias myhuocertimport -storepass myhuopass -file C:\MyFiles\Development\Java\tools\.sslcertificatestoimport
The official documentation of keytool : http://java.sun.com/javase/6/docs/technotes/tools/windows/keytool.html
2. Generate a SSL certificate
First, our JRE is installed in: C:\Program Files (x86)\Java\jre6\bin
..so, the following commands allow the generation of a certificate named in the keystore file “C:\MyFiles\Development\Java\tools\sslcertificates” protected by the password “javablog.fr” for a tomcat server:
Note: These commands are checked with a french system.
C:\Program Files (x86)\Java\jre6\bin>keytool -genkey -alias tomcat -keyalg RSA -keystore C:\MyFiles\Development\Java\tools\sslcertificates
Answer the password for example “javablog.fr”:
Tapez le mot de passe du Keystore :
Answer again the same password “javablog.fr”:
Ressaisissez le nouveau mot de passe :
Answer your name, for example in my case “HUSEYIN OZVEREN”:
Quels sont vos prénom et nom ? [Unknown] : HUSEYIN OZVEREN
Answer the name of unit, here “JAVABLOG.FR”:
Quel est le nom de votre unité organisationnelle ? [Unknown] : JAVABLOG.FR
Answer the name for your organization, here “JAVA”:
Quelle est le nom de votre organisation ? [Unknown] : JAVA
Answer the name of your city:
Quel est le nom de votre ville de résidence ? [Unknown] : Lux
Answer the name of your state:
Quel est le nom de votre état ou province ? [Unknown] : Lux
Answer the code of your country on 2 characters, here “LU”:
Quel est le code de pays à deux lettres pour cette unité ? [Unknown] : LU
Confirm the generation of certificate:
Est-ce CN=HUSEYIN OZVEREN, OU=JAVABLOG.FR, O=JAVA, L=Lux, ST=Lux, C=LU ? [non] : oui
Press the “[RETURN]” key on keyboard:
Spécifiez le mot de passe de la clé pour <tomcat>
(appuyez sur EntrÚe s'il s'agit du mot de passe du Keystore) :
A file named “sslcertificates” could be created in “C:\MyFiles\Development\Java\tools”.
3. Configuration of SSL on tomcat and tests
Activate the following connector in the file “server.xml” of “conf” folder, to use the https protocol targeting the “C:\MyFiles\Development\Java\tools\sslcertificats” keystore with the password filled above “javablog.fr”: (keystore=”C:\MyFiles\Development\Java\tools\sslcertificats” keystorePass=”javablog.fr”):
<!-- Define a SSL HTTP/1.1 Connector on port 8443
This connector uses the JSSE configuration, when using APR, the
connector should be using the OpenSSL style configuration
described in the APR documentation -->
<Connector port="8443" protocol="HTTP/1.1" SSLEnabled="true"
maxThreads="150" scheme="https" secure="true"
keystore="C:\MyFiles\Development\Java\tools\sslcertificates" keystorePass="javablog.fr"
clientAuth="false" sslProtocol="TLS" />
…don’t modify the connector because, per default, the 8080 port is redirected to the 8443 port:
<Connector connectionTimeout="20000" port="8080" protocol="HTTP/1.1" redirectPort="8443"/>
…and when the tomcat server is started:
4 févr. 2013 00:56:35 org.apache.coyote.http11.Http11Protocol init INFO: Initialisation de Coyote HTTP/1.1 sur http-8080 4 févr. 2013 00:56:36 org.apache.coyote.http11.Http11Protocol init INFO: Initialisation de Coyote HTTP/1.1 sur http-8443
If we check our configuration by access to application deployed on tomcat server (for example: https://localhost:8443/test_extJs_1/index2.html):
According to our browser, our certificate seems invalid…to be investigate 
Kind regards,
Huseyin OZVEREN
Hi,
After my post Java: Log4j Concepts and Explanations about Log4j concepts, I would introduce Log4j in practice through several concrets examples and their results.
The section of this article will be:
1) Use of Log4j directly
2) Specifying granularity for external library or for custom package
3) Use of Log4j with a wrapper
4) Extended example with DailyRollingFileAppender
5) Use of environment variables in Log4J
6) Configure Log4J with Spring in web application
Reminder:
Log4j API defines five levels of logging exposed below by decreasing severity:
logger.fatal(msg);
logger.error(msg);
logger.warn(msg);
logger.info(msg);
logger.debug(msg);
logger.trace(msg);
1) Use of Log4j directly
In this section, I will expose a direct use of Log4j i.e. without wrapper.
First, we need to add the Log4j framework library log4j-1.2.15.jar (in our case), in the classpath of our project.
Second, we create a simple test class in order to prove that Log4j “works”:
//...
public static void main(String[] args) {
/** The logger */
Logger logger = Logger.getLogger(UseLog4DirectlyDEFAULT.class);
String msg = "message to log from "+ UseLog4DirectlyDEFAULT.class.getName();
logger.fatal(msg);
logger.error(msg);
logger.warn(msg);
logger.info(msg);
logger.debug(msg);
logger.trace(msg);
}
//...
Then, in executing the above main method, we will obtain the following messages in console:
log4j:WARN No appenders could be found for logger (com.ho.log4j.directly.UseLog4Directly). log4j:WARN Please initialize the log4j system properly.
….because Log4j needs the configuration parameters in the classpath of the class. These parameters are sought by default in a file log4j.properties.
So, we will create this file log4j.properties:
log4j.rootCategory=DEBUG,CONSOLE,LOGFILE
#ONLY FATAL MESSAGES
log4j.logger.com.ho.log4j.directly.UseLog4DirectlyOnlyFATAL=FATAL
#ONLY ERROR MESSAGES
log4j.logger.com.ho.log4j.directly.UseLog4DirectlyOnlyERROR=ERROR
#ONLY WARN MESSAGES
log4j.logger.com.ho.log4j.directly.UseLog4DirectlyOnlyWARN=WARN
#ONLY INFO MESSAGES
log4j.logger.com.ho.log4j.directly.UseLog4DirectlyOnlyINFO=INFO
#ONLY DEBUG MESSAGES
log4j.logger.com.ho.log4j.directly.UseLog4DirectlyOnlyDEBUG=DEBUG
#ONLY TRACE MESSAGES
log4j.logger.com.ho.log4j.directly.UseLog4DirectlyOnlyTRACE=TRACE
###################################################
##################### DEFINITION OF APPENDERS #####
###################################################
# CONSOLE is set to be a ConsoleAppender using a PatternLayout.
log4j.appender.CONSOLE=org.apache.log4j.ConsoleAppender
log4j.appender.CONSOLE.layout=org.apache.log4j.PatternLayout
log4j.appender.CONSOLE.layout.ConversionPattern=%-d{HH:mm:ss} %-5p %60.60c %-25.25M %m%n
# LOGFILE is set to be a File appender using a PatternLayout.
log4j.appender.LOGFILE=org.apache.log4j.RollingFileAppender
log4j.appender.LOGFILE.File=./mylogfile.log
log4j.appender.LOGFILE.MaxFileSize=500KB
log4j.appender.LOGFILE.MaxBackupIndex=10
log4j.appender.LOGFILE.layout=org.apache.log4j.PatternLayout
log4j.appender.LOGFILE.layout.ConversionPattern=%-d{MMMM dd HH:mm:ss} %-5p %30.30c %-25.25M %m%n
Some explanations:
Then, we create several classes:
…these classes contain the same code:
//...
/** The logger */
private Logger logger = Logger.getLogger(this.getClass());
public static void main(String[] args) {
UseLog4DirectlyDEFAULT me = new UseLog4DirectlyDEFAULT();
String msg = "message to log from "+ me.getClass().getName();
me.logger.fatal(msg);
me.logger.error(msg);
me.logger.warn(msg);
me.logger.info(msg);
me.logger.debug(msg);
me.logger.trace(msg);
}
//...
… so the results will be:
01:17:43 FATAL com.ho.log4j.directly.UseLog4DirectlyDEFAULT main message to log from com.ho.log4j.directly.UseLog4DirectlyDEFAULT 01:17:43 ERROR com.ho.log4j.directly.UseLog4DirectlyDEFAULT main message to log from com.ho.log4j.directly.UseLog4DirectlyDEFAULT 01:17:43 WARN com.ho.log4j.directly.UseLog4DirectlyDEFAULT main message to log from com.ho.log4j.directly.UseLog4DirectlyDEFAULT 01:17:43 INFO com.ho.log4j.directly.UseLog4DirectlyDEFAULT main message to log from com.ho.log4j.directly.UseLog4DirectlyDEFAULT 01:17:43 DEBUG com.ho.log4j.directly.UseLog4DirectlyDEFAULT main message to log from com.ho.log4j.directly.UseLog4DirectlyDEFAULT
01:18:07 FATAL com.ho.log4j.directly.UseLog4DirectlyOnlyFATAL main message to log from com.ho.log4j.directly.UseLog4DirectlyOnlyFATAL
01:18:19 FATAL com.ho.log4j.directly.UseLog4DirectlyOnlyERROR main message to log from com.ho.log4j.directly.UseLog4DirectlyOnlyERROR 01:18:19 ERROR com.ho.log4j.directly.UseLog4DirectlyOnlyERROR main message to log from com.ho.log4j.directly.UseLog4DirectlyOnlyERROR
01:18:37 FATAL com.ho.log4j.directly.UseLog4DirectlyOnlyWARN main message to log from com.ho.log4j.directly.UseLog4DirectlyOnlyWARN 01:18:37 ERROR com.ho.log4j.directly.UseLog4DirectlyOnlyWARN main message to log from com.ho.log4j.directly.UseLog4DirectlyOnlyWARN 01:18:37 WARN com.ho.log4j.directly.UseLog4DirectlyOnlyWARN main message to log from com.ho.log4j.directly.UseLog4DirectlyOnlyWARN
01:19:22 FATAL com.ho.log4j.directly.UseLog4DirectlyOnlyINFO main message to log from com.ho.log4j.directly.UseLog4DirectlyOnlyINFO 01:19:22 ERROR com.ho.log4j.directly.UseLog4DirectlyOnlyINFO main message to log from com.ho.log4j.directly.UseLog4DirectlyOnlyINFO 01:19:22 WARN com.ho.log4j.directly.UseLog4DirectlyOnlyINFO main message to log from com.ho.log4j.directly.UseLog4DirectlyOnlyINFO 01:19:22 INFO com.ho.log4j.directly.UseLog4DirectlyOnlyINFO main message to log from com.ho.log4j.directly.UseLog4DirectlyOnlyINFO
01:19:38 FATAL com.ho.log4j.directly.UseLog4DirectlyOnlyDEBUG main message to log from com.ho.log4j.directly.UseLog4DirectlyOnlyDEBUG 01:19:38 ERROR com.ho.log4j.directly.UseLog4DirectlyOnlyDEBUG main message to log from com.ho.log4j.directly.UseLog4DirectlyOnlyDEBUG 01:19:38 WARN com.ho.log4j.directly.UseLog4DirectlyOnlyDEBUG main message to log from com.ho.log4j.directly.UseLog4DirectlyOnlyDEBUG 01:19:38 INFO com.ho.log4j.directly.UseLog4DirectlyOnlyDEBUG main message to log from com.ho.log4j.directly.UseLog4DirectlyOnlyDEBUG 01:19:38 DEBUG com.ho.log4j.directly.UseLog4DirectlyOnlyDEBUG main message to log from com.ho.log4j.directly.UseLog4DirectlyOnlyDEBUG
01:19:58 FATAL com.ho.log4j.directly.UseLog4DirectlyOnlyTRACE main message to log from com.ho.log4j.directly.UseLog4DirectlyOnlyTRACE 01:19:58 ERROR com.ho.log4j.directly.UseLog4DirectlyOnlyTRACE main message to log from com.ho.log4j.directly.UseLog4DirectlyOnlyTRACE 01:19:58 WARN com.ho.log4j.directly.UseLog4DirectlyOnlyTRACE main message to log from com.ho.log4j.directly.UseLog4DirectlyOnlyTRACE 01:19:58 INFO com.ho.log4j.directly.UseLog4DirectlyOnlyTRACE main message to log from com.ho.log4j.directly.UseLog4DirectlyOnlyTRACE 01:19:58 DEBUG com.ho.log4j.directly.UseLog4DirectlyOnlyTRACE main message to log from com.ho.log4j.directly.UseLog4DirectlyOnlyTRACE 01:19:58 TRACE com.ho.log4j.directly.UseLog4DirectlyOnlyTRACE main message to log from com.ho.log4j.directly.UseLog4DirectlyOnlyTRACE
2) Specifying granularity for external library or for custom package
It’s possible to specify the granularity:
#Spring Framework log4j.logger.org.springframework=INFO log4j.logger.org.springframework.orm=INFO log4j.logger.org.springframework.transaction=INFO #Hibernate log4j.logger.org.hibernate.SQL=WARN log4j.logger.org.hibernate.type=INFO log4j.logger.org.hibernate.tool.hbm2ddl=INFO log4j.logger.org.hibernate.pretty=INFO log4j.logger.org.hibernate.cache=INFO log4j.logger.org.hibernate.transaction=INFO log4j.logger.org.hibernate.jdbc=INFO log4j.logger.org.hibernate.hql.ast.AST=INFO log4j.logger.org.hibernate.secure=INFO log4j.logger.org.hibernate=INFO #Documentum log4j.logger.com.documentum=INFO #Apache log4j.logger.org.apache.commons=INFO #Controller log4j.logger.com.ho.log4j.controller=INFO
3) Use of Log4j with a wrapper
In this section, I will expose a use of Log4j with wrapper.
First, we need to add the Apache commons logging library commons-logging-1.1.1.jar (in our case), in the classpath of our project.
Second, we create a simple test class in order to prove that Log4j with wrapper Apache commons “works”:
package com.ho.log4j.wrapper;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
/**
* UseLog4ViaWrapper: A basic use of Log4J via Apache Commons Logging so with wrapper.
*
* @author huseyin
*
*/
public class UseLog4ViaWrapper {
/** The logger */
private Log logger = LogFactory.getLog(this.getClass());
public static void main(String[] args) {
UseLog4ViaWrapper me = new UseLog4ViaWrapper();
String msg = "message to log from "+ me.getClass().getName();
me.logger.fatal(msg);
me.logger.error(msg);
me.logger.warn(msg);
me.logger.info(msg);
me.logger.debug(msg);
me.logger.trace(msg);
}
}
… the results could be:
00:19:42 FATAL com.ho.log4j.wrapper.UseLog4ViaWrapper main message to log from com.ho.log4j.wrapper.UseLog4ViaWrapper 00:19:42 ERROR com.ho.log4j.wrapper.UseLog4ViaWrapper main message to log from com.ho.log4j.wrapper.UseLog4ViaWrapper 00:19:42 WARN com.ho.log4j.wrapper.UseLog4ViaWrapper main message to log from com.ho.log4j.wrapper.UseLog4ViaWrapper 00:19:42 INFO com.ho.log4j.wrapper.UseLog4ViaWrapper main message to log from com.ho.log4j.wrapper.UseLog4ViaWrapper 00:19:42 DEBUG com.ho.log4j.wrapper.UseLog4ViaWrapper main message to log from com.ho.log4j.wrapper.UseLog4ViaWrapper
4) Extended example with DailyRollingFileAppender
In this section, I will expose a more advanced example: we will define a logging level of INFO and a new appender named AUDITFILE. LOG4J will create a specific file for the logging events of the “AuditLogger” class of the package “com.ho.log4j.audit.util”.
First, we will modify the configuation file:
#Audit
log4j.logger.com.ho.log4j.audit.util.AuditLogger=INFO,AUDITFILE
# AUDITFILE is set to be a File appender using a PatternLayout.
log4j.appender.AUDITFILE=org.apache.log4j.DailyRollingFileAppender
log4j.appender.AUDITFILE.File=./myauditlogfile.log
log4j.appender.AUDITFILE.DatePattern='.'yyyy-MM-dd-HH
log4j.appender.AUDITFILE.append=true
log4j.appender.AUDITFILE.layout=org.apache.log4j.PatternLayout
log4j.appender.AUDITFILE.layout.ConversionPattern=%-d{MMMM dd HH:mm:ss} %-5p %60.60c %-25.25M %m%n
Some explanations:
5) Use of environment variables in Log4J
It is possible to use Log4J with the standard environment variables or personal variable defined at server startup.
Note:There are server-specific log files: for example the file named “tomcat7-stdout.yyyy-mm-dd” containing all of the outputs in the console “sysout” on TOMCAT.
6) Configure Log4J with Spring in web application
More, it is possible to configure LOG4J: the name of Log4J properties file in a web application by using Spring (the default file name must be “log4j.properties” in the classpath):
Here, a simple example of LOG4J configuration in a WEB application:
web.xml:
<context-param> <param-name>log4jConfigLocation</param-name> <param-value>classpath:myfile-log4j.properties</param-value> </context-param> <listener> <listener-class>org.springframework.web.util.Log4jConfigListener</listener-class> </listener>
That’s all!!!!!!!!
Source : test_log4j.zip
Huseyin OZVEREN
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