Create new user in unix with root permissions

1. Add new user

root@0d9d9ddf04bb:~# useradd anil

2. set password

root@0d9d9ddf04bb:~# passwd anil
Enter new UNIX password:
Retype new UNIX password:
passwd: password updated successfully

3. Tye sudo visudo, add below entry at the end

anil ALL=(ALL) NOPASSWD:ALL

Imagination vs Knowledge

Knowledge is limited
Imagination is unlimited

Knowledge takes you from A to B
Imagination takes you everywhere

I’m enough of an artist to draw freely on my imagination, which I think is more important than knowledge. Knowledge is limited. Imagination encircles the world. –Albert Einstein

 

Mac Tricks: Opening hidden directory in Finder

I had this requirement all the time to navigate through ~/.m2 directory from Finder – I found below step is very easy to open hidden directory from finder – 

1) Go to Terminal

2) open ~/.m2

That’s it.

Nice website on making cron expressions

http://www.cronmaker.com/

I liked this website. It allows you to build the cron expressions based on timeline setup and also provides schedule runs for cron expression provided.

Growl kind of message notifications in ZK Framework

In this post, I am trying to share an implementation to get Growl kind of message notifications in ZK based application.

In summary, Idea is to have JQuery for notifications and make javascript calls from java code in ZK.

I chose jquery plug-in developed by Eric from his blog here

Steps:
1)  Download jquery and plugin available here

2) Include plugin in .zul file. I kept this in my template file header area of application

<style src="/resources/css/ui.notify.css"/>
<script type="text/javascript" src="/resources/js/jquery-1.7.1.js"></script>
<script type="text/javascript" src="/resources/js/jquery.ui.widget.js"></script>
<script type="text/javascript" src="/resources/js/jquery.notify.js"></script>

3) Create two div tags, one for regular notifications and one for error messages in zul file.
Note: I added only two containers here. One for success messages and another one for both warning and error message. You can create as many as you want to display messages in different styles.

<h:div id="<strong>container</strong>" style="height: 0px;">
...
</h:div>
<h:div id="<strong>errorContainer</strong>" style="height: 0px;">
..
</h:div>

4) Added code to call notify() method on page load (as explained for jquery)

<script type="text/javascript" <strong>defer="true"</strong>>
jQuery("#container").notify();
jQuery("#errorContainer").notify();
</script>

5) Added below javascript code to one of js files

/* Growl message display methods */
function displayNotificationMessage(messageTitle, message) {
jQuery("#container").notify();
jQuery("#container").notify("create", 0, {
title: messageTitle,
text: message
});
}

function displayErrorMessage(messageTitle, message) {
jQuery("#errorContainer").notify();
jQuery("#errorContainer").notify("create", "error-msg-template", {
title: messageTitle,
text: message
});
}

6) Created below java class to call above javascript methods –

This class’s interface exposes below methods –

public void displayNotificationMessage(String summary, String detail); //Displays notification message
public void displayWarningMessage(String summary, String detail); //Displays warning message
public void displayErrorMessage(String summary, String detail); //Displays error message
public void addNotificationMessage(String summary, String detail); //Adds a notification message to session
public void addWarningMessage(String summary, String detail); //Adds a warning message to session
public void addErrorMessage(String summary, String detail); //Adds a error message to session
public void displayPendingMessages(); //Displays all messages stored in session and clean them up.

Implementaiton

import org.zkoss.zk.ui.Executions;

import org.zkoss.zk.ui.util.Clients;

import java.util.ArrayList;
import java.util.List;

/**
* JQuery based grawl message display handler.
*
* @author Anil
*/
public class GrowlJQMessageHandler implements MessageHandler {

@Override
public void displayNotificationMessage(String summary, String detail) {
Clients.evalJavaScript("displayNotificationMessage('" + summary + "', '" + detail + "')");
}

@Override
public void displayWarningMessage(String summary, String detail) {
Clients.evalJavaScript("displayErrorMessage('" + summary + "', '" + detail + "')");
}

@Override
public void displayErrorMessage(String summary, String detail) {
Clients.evalJavaScript("displayErrorMessage('" + summary + "', '" + detail + "')");
}

@Override
public void addNotificationMessage(String summary, String detail) {
ZKMessage message = new ZKMessage(ZKMessage.INFO_MSG, summary, detail);
addMessage(message);
}

@Override
public void addWarningMessage(String summary, String detail) {
ZKMessage message = new ZKMessage(ZKMessage.WARNING_MSG, summary, detail);
addMessage(message);
}

@Override
public void addErrorMessage(String summary, String detail) {
ZKMessage message = new ZKMessage(ZKMessage.ERROR_MSG, summary, detail);
addMessage(message);
}

@Override
public void displayPendingMessages() {
List zkMessages = (List) Executions.getCurrent().getSession().getAttribute(SkillSessionScopeKey.PENDING_MESSAGE_LIST.getValue());
if(zkMessages != null) {
for (ZKMessage message : zkMessages) {
if (message.getSeverity() == ZKMessage.INFO_MSG) {
displayNotificationMessage(message.getSummary(), message.getDetails());
} else if (message.getSeverity() == ZKMessage.WARNING_MSG) {
displayWarningMessage(message.getSummary(), message.getDetails());
} else if (message.getSeverity() == ZKMessage.ERROR_MSG) {
displayErrorMessage(message.getSummary(), message.getDetails());
}
}
zkMessages.clear();
Executions.getCurrent().getSession().setAttribute(SkillSessionScopeKey.PENDING_MESSAGE_LIST.getValue(), zkMessages);
}
}

private void addMessage(ZKMessage message) {
List zkMessages = null;
if (Executions.getCurrent().getSession().getAttribute(SkillSessionScopeKey.PENDING_MESSAGE_LIST.getValue()) != null) {
zkMessages = (List) Executions.getCurrent().getSession().getAttribute(SkillSessionScopeKey.PENDING_MESSAGE_LIST.getValue());
zkMessages.add(message);
} else {
zkMessages = new ArrayList();
zkMessages.add(message);
}
Executions.getCurrent().getSession().setAttribute(SkillSessionScopeKey.PENDING_MESSAGE_LIST.getValue(), zkMessages);
}
}

Usage:

Below code can be called from one of the composite right after particular action

1) To display success message immediately after the action (On same page) –

messageHandler.displayNotificationMessage("Success", "Session cancelled successfully!!!");

2) To display warning message immediately after the action (On same page) –

messageHandler.displayWarningMessage("Invalid Session ID", "Session ID entry is invalid, Please try again");

3) To display success message in redirected page after the action (On redirected page) –

messageHandler.addNotificationMessage("Success", "Session cancelled successfully!!!");

Below are screen shots of success and warning messages

Hope this post helps!!!

Command to change apache user password for SVN repo access

It took a while for me to figure out this command. I thought of sharing this one here –

Syntax:

sudo htpasswd -b <.passwd file> <username> <pass>

Ex:

sudo htpasswd -b svn.passwd  anil <pass>

Documentation link here – http://httpd.apache.org/docs/2.0/programs/htpasswd.html

Posted in apache, svn. Tags: , . 1 Comment »

Spring OXM with XStream example

Here is a simple example to marshalling/unmarshalling xml content to/from java object using Spring XOM.

Here I am generating xml content from java object, writing the content to file system, reading that back to java object.

Spring configuration – applicationContext.xml

<beans xmlns=”http://www.springframework.org/schema/beans&#8221;

xmlns:xsi=”http://www.w3.org/2001/XMLSchema-instance&#8221;

xsi:schemaLocation=”http://www.springframework.org/schema/beans

http://www.springframework.org/schema/beans/spring-beans-3.0.xsd”&gt;

<bean id=”xstreamExample”>

<property name=”marshaller” ref=”xstreamMarshaller” />

</bean>

<bean id=”xstreamMarshaller”>

<property name=”aliases”>

<props>

<prop key=”bean”>com.example.ConfigurationBean</prop>

</props>

</property>

</bean>

</beans>

Simple java bean – ConfigurationBean.java

package com.example;

 

public class ConfigurationBean {

 

private String name;
private Integer age;
private String jobDescription;
private boolean executive;

 

public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
public String getJobDescription() {
return jobDescription;
}
public void setJobDescription(String jobDescription) {
this.jobDescription = jobDescription;
}
public boolean isExecutive() {
return executive;
}
public void setExecutive(boolean executive) {
this.executive = executive;
}
}

Spring bean with main main method (for testing): XStreamExample.java

package com.example;

 

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.oxm.xstream.XStreamMarshaller;

 

import javax.xml.transform.stream.StreamResult;
import javax.xml.transform.stream.StreamSource;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

 

/**
* Example to marshal/unmarshal xml to/from java object using Spring 3.0 OXM feature.
*
* @author Anil Sadineni
*/
public class XStreamExample {
private static final String F_NAME = "example.xml";
private List configurationBeans;

 

private XStreamMarshaller marshaller;

 

public void setMarshaller(XStreamMarshaller marshaller) {
this.marshaller = marshaller;
Map alias = new HashMap();
alias.put("configurations", List.class);
alias.put("configuration", ConfigurationBean.class);
try {
this.marshaller.setAliases(alias);
} catch (Exception e) {
e.printStackTrace();
}
}

 

public void loadConfigurationBeans() throws IOException {
FileInputStream is = null;
try {
is = new FileInputStream(F_NAME);
this.configurationBeans = (List) this.marshaller.unmarshal(new StreamSource(is));
} finally {
if (is != null) {
is.close();
}
}
}

 

public void saveConfigurationBeans() throws IOException {
FileOutputStream os = null;
try {
os = new FileOutputStream(F_NAME);
this.marshaller.marshal(configurationBeans, new StreamResult(os));
} finally {
if (os != null) {
os.close();
}
}
}

 

public static void main(String[] args) throws IOException {
ApplicationContext appContext = new ClassPathXmlApplicationContext("applicationContext.xml");
XStreamExample ex = (XStreamExample) appContext.getBean("xstreamExample");
ex.execute();
}

private void execute() throws IOException {
configurationBeans = getConfigurationBeans();

saveConfigurationBeans();
loadConfigurationBeans();

for (ConfigurationBean configurationBean : configurationBeans) {
System.out.println(“name: ” + configurationBean.getName());
System.out.println(“desc : ” + configurationBean.getJobDescription());
System.out.println(“age: ” + configurationBean.getAge());
System.out.println(“Exec : ” + configurationBean.isExecutive());
}
}

private List getConfigurationBeans() {
List beans = new ArrayList();

for (int i = 1; i <= 5; i++) {
ConfigurationBean configurationBean = new ConfigurationBean();
configurationBean.setAge(26);
configurationBean.setExecutive(false);
configurationBean.setJobDescription(“Jab Desc – ” + i);
configurationBean.setName(“Anil S – ” + i);
beans.add(configurationBean);
}

return beans;
}
}

 

Output on console:
name: Anil S – 1
desc : Jab Desc – 1
age: 26
Exec : false
name: Anil S – 2
desc : Jab Desc – 2
age: 26
Exec : false
name: Anil S – 3
desc : Jab Desc – 3
age: 26
Exec : false
name: Anil S – 4
desc : Jab Desc – 4
age: 26
Exec : false
name: Anil S – 5
desc : Jab Desc – 5
age: 26
Exec : false

Generated XML content (example.xml) –

<configurations>

<configuration>

<name>Anil S – 1</name>

<age>26</age>

<jobDescription>Jab Desc – 1</jobDescription>

<executive>false</executive>

</configuration>

<configuration>

<name>Anil S – 2</name>

<age>26</age>

<jobDescription>Jab Desc – 2</jobDescription>

<executive>false</executive>

</configuration>

<configuration>

<name>Anil S – 3</name>

<age>26</age>

<jobDescription>Jab Desc – 3</jobDescription>

<executive>false</executive>

</configuration>

<configuration>

<name>Anil S – 4</name>

<age>26</age>

<jobDescription>Jab Desc – 4</jobDescription>

<executive>false</executive>

</configuration>

<configuration>

<name>Anil S – 5</name>

<age>26</age>

<jobDescription>Jab Desc – 5</jobDescription>

<executive>false</executive>

</configuration>