Learn and shine: Getting started with spring mvc controller and je...

Learn and shine: Getting started with spring mvc controller and je...: Getting started with spring mvc and jersey rest service example This topic is about how to work with sping mvc controller using annotations...

Getting started with spring mvc controller and jersey rest service example

Getting started with spring mvc and jersey rest service example
This topic is about how to work with sping mvc controller using annotations and jersey rest service
Create dynamic web project using eclipse. Name it has springweb-mvc






This is spring project, so first we need to configure the details in web.xml for spring
Edit the web.xml file and add the below code
1. Dispatcher Servlet
2. Context LoaderListener
3. SpringServlet for rest webservice

  springweb-mvc
 
           org.springframework.web.context.ContextLoaderListener
       
        
  spring
  
                org.springframework.web.servlet.DispatcherServlet
        
  1
 
 
 
  spring
  /
  
 
  
  jersey-serlvet
  
   com.sun.jersey.spi.spring.container.servlet.SpringServlet
  
  
   com.sun.jersey.config.property.packages   com.siva.rest  
 
 
 
  jersey-serlvet
  /rest/*
 

1. Now we need to create spring-servlet.xml, hope you will understand why we need to create this file,
Let me explain , in above web.xml we have configured servlet name as spring. So as part of spring DispatcherServlet we need to create xml (servletname-servlet.xml). in this case spring –servlet.xml
2. Need to provide the jersey related configuration
Here I have provided param-value as com.siva.rest , where our rest service related files resides.

Add below code in spring-servlet.xml

In the above xml, component package we have given has com.siva.controlller, where our controller classes resides.
Since we are using annotations no other configurations required.
View configuration - our views will be under WebContent/views
Now we need to create applicationContext.xml, where application will start the executing, here I am not providing any configuration details in this file, simply I am creating file to avoid runtime exceptions .

Now it’s time to create controllers , rest service and views

1. First we will create rest webservice
Create a Calculator.java under package com.siva.rest

   package com.siva.rest;


import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement(name = "Calculator")
public class Calculator {

 private int number1;
 private int number2;

 // Must have no-argument constructor
 public Calculator() {

 }

 public Calculator(int number1, int number2) {
  this.number1 = number1;
  this.number2 = number2;
 }

 
 @Override
 public String toString() {
  return new StringBuffer(" Number 1 : ").append(this.number1)
    .append("Number 2 : ").append(this.number2).toString();
 }

 public int getNumber1() {
  return number1;
 }
 @XmlElement
 public void setNumber1(int number1) {
  this.number1 = number1;
 }

 public int getNumber2() {
  return number2;
 }

 @XmlElement
 public void setNumber2(int number2) {
  this.number2 = number2;
 }

}

Now we need to write Rest service class JersyRestService under package com.siva.rest

package com.siva.rest;

import javax.ws.rs.Consumes;
import javax.ws.rs.GET;
import javax.ws.rs.POST;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.Response;


@Path("/xmlServices")
public class JerseyRestService {
 
 @GET
 @Path("/add/{number1}/{number2}")
 @Produces(MediaType.TEXT_PLAIN)
 public String add( @PathParam("number1") Integer number1,  @PathParam("number2")Integer number2 ) {
        System.out.println("Number 1["+number1+"], Number 2["+number2+"]");
  return number1+number2 +"";
 }
 
 @POST
 @Path("/substract")
 @Produces(MediaType.TEXT_PLAIN)
 public String substract(Calculator cal ) {
        System.out.println("Number 1["+cal.getNumber1()+"], Number 2["+cal.getNumber2()+"]");
  return(cal.getNumber1()- cal.getNumber2() +"");
 }
}

Create a Controller RestServiceController class under package com.siva.controller

package com.siva.controller;

import javax.ws.rs.core.MediaType;

import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.servlet.ModelAndView;

import com.siva.rest.Calculator;
import com.sun.jersey.api.client.Client;
import com.sun.jersey.api.client.ClientResponse;
import com.sun.jersey.api.client.WebResource;

@Controller
public class RestServiceController {

 @RequestMapping(value="/addRequestDetails" ,method = RequestMethod.POST)
 public ModelAndView addNumbers(@ModelAttribute("addRequestDetails") Calculator command,
   ModelMap model) {
  System.out.println("addNumbers inside RestServiceController");
  int number1 = command.getNumber1();
  int number2 = command.getNumber2();
  String resultMessage = null;
  try {
   Client client = Client.create();
   WebResource webResource = client.resource("http://localhost:8080/springweb-mvc/rest/xmlServices/add/"+number1+"/"+number2);
   ClientResponse response = webResource.accept(MediaType.TEXT_PLAIN).get(ClientResponse.class);
   resultMessage = response.getEntity(String.class);
   System.out.println("Addition of the 2 numbers result["+resultMessage+"]");
   System.out.println(" resposne status in RestServiceController ["+response.getStatus()+"]");
   
  }  
  catch (Exception e) {
   System.out.println("Exception occurred while calling rest services..."+e);
      e.printStackTrace();
     } 
  return new ModelAndView("restresult").addObject("resultMessage", "Addition of the two values result is["+resultMessage +"]");
 }
 
 @RequestMapping(value="/substractRequestDetails" ,method = RequestMethod.POST)
 public ModelAndView substractNumbers(@ModelAttribute("substractRequestDetails") Calculator command,
   ModelMap model) {
  System.out.println("addNumbers inside RestServiceController");
  int number1 = command.getNumber1();
  int number2 = command.getNumber2();
  Calculator cal = new Calculator(number1, number2);
  String resultMessage = null;
  try {
   Client client = Client.create();
   WebResource webResource = client.resource("http://localhost:8080/springweb-mvc/rest/xmlServices/substract");
   ClientResponse response = webResource.accept(MediaType.TEXT_PLAIN).post(ClientResponse.class,cal);
   resultMessage = response.getEntity(String.class);
   System.out.println("Substraction of the 2 numbers result["+resultMessage+"]");
   System.out.println(" resposne status in RestServiceController ["+response.getStatus()+"]");
   
  }  
  catch (Exception e) {
   System.out.println("Exception occurred while calling rest services..."+e);
      e.printStackTrace();
     } 
  return new ModelAndView("restresult").addObject("resultMessage", "Substraction of the two values result is["+resultMessage +"]");
 }
}

Create addition.jsp page under WebContent/views/

<%@taglib uri="http://www.springframework.org/tags/form" prefix="form"%>
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>







  
    

      
Number1
      

    
     

      
Number2
      

     
     

             

      
  
    

Create substraction.jsp page under WebContent/views/

<%@taglib uri="http://www.springframework.org/tags/form" prefix="form"%>
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>







  
    

      
Number1
      

    
     

      
Number2
      

     
     

             

      
  

Now after adding/substracting the numbers we need to show the results
Create a restresult.jsp under WebContent/views/

<%@taglib uri="http://www.springframework.org/tags/form" prefix="form"%>
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>







     ${resultMessage}

Now we have completed coding now we need to run this project. I have executed this project using tomcat7 server
Required jars to executing this project, please make sure your tomcat or jboss lib having these ja rs

common jars

commons-beanutils-1.8.0.jar
commons-codec-1.3.jar
commons-collections.jar
commons-digester-2.1.jar
commons-logging-1.0.jar
commons-net-1.4.0.jar


Jersey related jars

jersey-client.jar
jersey-core-1.8.jar
jersey-server-1.8.jar
jersey-spring-1.8


spring related jars


spring-aop-4.1.5.RELEASE.jar
spring-beans-4.1.5.RELEASE.jar
spring-context-4.1.5.RELEASE.jar
spring-core-4.1.5.RELEASE.jar
spring-expression-4.1.5.RELEASE.jar
spring-web-4.1.5.RELEASE.jar
spring-webmvc-4.1.5.RELEASE.jar
asm-3.1.jar

After executing project Now it’s time to see the output.
If project deployed successfully then click the below link
http://localhost:8080/springweb-mvc/views/addition.jsp



After entering the values click on Add button



Substract the numbers using following URL
http://localhost:8080/springweb-mvc/views/substraction.jsp





After entering the details ,Result page same like the addition results page.

This is how Rest service with Spring mvc will work.

If you want execute same rest service using main method use the below code.

Create a class JersyClient.java under package com.siva.rest

package com.siva.rest;


import javax.ws.rs.core.MediaType;

import com.sun.jersey.api.client.Client;
import com.sun.jersey.api.client.ClientResponse;
import com.sun.jersey.api.client.WebResource;


public class JerseyClient {
 
 public static void main(String[] args) {
  try {
   Client client = Client.create();
   //Adding 2 numbers using GET
            WebResource webResource = client.resource("http://localhost:8080/springweb-mvc/rest/xmlServices/add/"+40+"/"+50);
   ClientResponse response = webResource.accept(MediaType.TEXT_PLAIN).get(ClientResponse.class);
   String resultMessage = response.getEntity(String.class);
   System.out.println("Addition of the 2 numbers result["+resultMessage+"]");
   System.out.println(" resposne status in RestServiceController ["+response.getStatus()+"]");
   
   
   //Substract 2 numbers using POST
      Calculator cal = new Calculator(20, 10);
   WebResource webResource1 = client.resource("http://localhost:8080/springweb-mvc/rest/xmlServices/substract");
   ClientResponse response1 = webResource1.accept(MediaType.TEXT_PLAIN).post(ClientResponse.class, cal);
   System.out.println("["+response1.getStatus()+"]");
   if (response1.getStatus() != 200) {
    throw new RuntimeException("Failed : HTTP error code : "+ response1.getStatus());
   }
   String output = response1.getEntity(String.class);
   System.out.println("Substraction of 2 numbers  : \n["+output+"]");
  } catch (Exception e) {

   e.printStackTrace();

  }

 }



}

Thanks for viewing this post.

Create a blog app using Web2py

1. Start web2py
2. Usually blog will have post and view the post details
3. Validations required to validate the post
4. Database design to store title, content, image category , blog posted date etc..
First we need to create model



5. Edit the db.py file
6.End of the file add the below code, to create a table 'blog' along with columns

db.define_table('blog',
                 Field('blog_title'),
                 Field('blog_details'),
                 Filed('blog_image'),
                 Field('blog_url'),
                 Field('blog_category'),
                 Field('blog_date_posted'))

We need to use validators inside model, more validators look inside

http://web2py.com/examples/static/web2py_cheatsheet.pdf

db.define_table('blog',
                 Field('blog_title', requires=IS_NOT_EMPTY()),
                 Field('blog_details', type='text'),
                 Filed('blog_image',requires=IS_URL()),
                 Field('blog_url',requires=IS_URL()),
                 Field('blog_category',requires=IS_IN_SET(['News','Events','Technology','Business'])),
                 Field('blog_date_posted', type='date',requires=IS_DATE()))

  

7. Need to add validation for table details


8.Now we need to create a controller, to post the blog app
9.Create controller name called blog under controller section
10.Edit blog.py
11. Add two methods one is called post and one is view

def post():
       form =SQLFORM(db.blog).process()
       return locals()
      def view():
      rows = db(db.blog).select(orderby=~db.blog.id)
      return locals()

   

12.Now we need to create views as blog/post and blog/view
13.Edit the blog/post.py

{{extend 'layout.html'}}
     
post a blog as you like
{{=form}}
  

http://127.0.0.1:8000/sivaweb2py/blog/post


14.If you submit without entering any values, then it will show the validation errors






Provide the details as required and submit the same. You can see the success message.

Need to know more about SQLFORMS and validators
http://web2py.com/books/default/chapter/29/07/forms-and-validators
Now we need to update the blog

Edit the blog.py and add the below code for update method

def update():
    record = db.blog(request.args(0)) or redirect (URL(post))
    form = SQLFORM(db.blog,record)
    if form.process().accepted:
        response.flash = T('Record Updated')
    else:
        response.flash=T('Please complete the form')
    return locals()

Create update view under views section

{{extend 'layout.html'}}
            
Update the form
{{=form}}
      
       

Click on the below link to update the record or provide number after update method which ever record want to update
http://127.0.0.1:8000/sivaweb2py/blog/update/1



Now we need to create the view page

{{extend 'layout.html'}}
      
View the blog
{{ for x in rows:}}
     

       
{{=x.blog_title}}
        
 categrory:{{=x.blog_category}}
     
 blog Details:{{=x.blog_details}}  
 blog posted:{{=x.blog_date_posted}} 
{{ pass }}

 

After adding the above code in view.py, if we check the result using below url
http://127.0.0.1:8000/sivaweb2py/blog/view




This is how we can create a blog app using web2py.

Getting started with web2py framework

    Full Stack web development with Python (Web2Py)
    How to download and install web2py
1.  Go  to http://web2py.com/

2.   Down load latest version http://web2py.com/init/default/download

     Unzip the downloaded file

     CliCk on the Web2py.exe file to it will open the window like below

           Provide the password(any password) and start the server

           Server has been started. Now we need to create a application using web2py framework.

           http://localhost:8000

                                                

         Click on the Admin,  which is there on the right side in the page. And provide the password which      we have given while starting the server

                After Successful Login,  page will be open like below.

               Create a new application using this framework- > New simple application –

       Application Name - ex: sivaweb2py

              Click on the create button. Now we have created application successfully.

               Need to run the application

               http://localhost:8000/sivaweb2py

               

              Now we need to write sample code in this application. So we need to understand basics of  the
       framework

               Need to edit the application

      This framework will follow MVC architecture

          Model- Contains db details

         Controller – Method and logic details

         Views – Html input/output to the user

Now we need to create one controller and respective views

Click on the Create button under Controller Section

I have given controller name as basics – basics.py will be created under controller

       Now edit the controller – Click on the basics.py

     def helloworld():
     msg= "Hello welcome to basics controller!"
     return locals()

 In the above code helloworld is method name . Copy the code and paste the same in your file.

  Save the file and go to back – by click on the back buton

  Now we need to create a  view- under Views section

  View name should be as method name  ex: basics/helloworld

   {{extend 'layout.html'}}

    This is our first web page
   {{ =msg}}

   Writing first web2py is very easy

                          

   http://localhost:8000/sivaweb2py/basics/helloworld

        

                               

Getting started with Oracle Stored Procedure and parse clob xml data and cursor

This Post will having the details to create stored procedure in oracle and parsing the clob data through stored procedure.

employee.xml
-------------


  siva
  32
  M

Above xml will be stored as clob data in Person table

Person table Schema -

Id NUMBER,
Name Varchar2(50),
employee_details clob

Above xml will be stored as clob data in Person table

create table PERSON (Id NUMBER, Name varchar2(50), employee_details clob);
  create table EMPLOYEE (Name varchar2(50), age NUMBER ,sex varchar2(10));

We need to parse the clob data using oracle procedure

create or replace PROCEDURE SP_PARSE_CLOB (person_id NUMBER) AS
  PERSION_ID Person.id%type;
  PERSON_NAME Person.name%type;
  EMPLOYEE_DETAILS Person.employee_details%type;
  name varchar2(50);
  age varchar2(50);
  sex varchar2(50);
  EMPLOYEE_exc EXCEPTION;
  -- Create a cursor
 cursor personDataCursor IS SELECT id, Name,employee_details from PERSON;
 BEGIN
   OPEN personDataCursor;
 LOOP
 FETCH personDataCursor into PERSION_ID,PERSON_NAME,EMPLOYEE_DETAILS;
 EXIT WHEN personDataCursor%notfound;
 IF XMLTYPE(EMPLOYEE_DETAILS).existSNode('/Employee/name/text()') > 0 THEN
   name := XMLTYPE(EMPLOYEE_DETAILS).extract('/Employee/name/text()').getStringVal();
 END IF;
 IF XMLTYPE(EMPLOYEE_DETAILS).existSNode('/Employee/age/text()') > 0 THEN
  age := XMLTYPE(EMPLOYEE_DETAILS).extract('/Employee/age/text()').getStringVal();
 END IF;
 IF XMLTYPE(EMPLOYEE_DETAILS).existSNode('/Employee/sex/text()') > 0 THEN
  sex := XMLTYPE(EMPLOYEE_DETAILS).extract('/Employee/sex/text()').getStringVal();
 END IF;
 dbms_output.put_line('Name:'|| name|| ' ' || 'Age:' || ' ' ||age || ' ' || 'Sex:' || ' ' || sex);
 -- Inset into another table
BEGIN
  insert into EMPLOYEE(name,age,sex) values(name,age,sex);
 EXCEPTION
    WHEN OTHERS
   THEN
    RAISE EMPLOYEE_exc;
  END;
  commit;
  END LOOP;

EXCEPTION
    WHEN EMPLOYEE_exc
      THEN
        rollback;
     -- Do what ever you want like insert log details in any another table
    commit;
    DBMS_OUTPUT.PUT_LINE ('Insertion failed in EMPLOYEE : '|| '' || name);
    END;

ArithmeticOperations Example using Python

Arithmetic operation using python in windows.
In my previous post , I have written how to install python in windows and add plugin into eclipse.


In this post I am going to explain simple arithmetic operations.

Step 1: Open eclipse - File - New - PyDev Project - arithmeticoperation_test
Step 2: Right click on the - src - New- PyDevModule- ArithmeticOperation
Step 3:Paste below code into ArithmeticOperation.py file.

'''
Created on 07-Dec-2015


@author: rajusiva

'''
a = input("Enter a value:")
b = input("Enter b value:")
print("Addition of 2 values is[",int(a)+int(b),"]")
print("subtract of 2 values is[",int(a)-int(b),"]")
print("Multiply of 2 values is[",int(a)*int(b),"]")
print("Division of 2 values is[",int(a)/int(b),"]")
print("Exponent of 2 values is[",int(a)**int(b),"]")
print("Modules of 2 values is[",int(a)%int(b),"]")
print("Floor Division of 2 values is[",int(a)//int(b),"]")

Step 4: Right click on the program-Run As- Python Run
Step 5: output as follows

Enter a value:25
Enter b value:10
Addition of 2 values is[ 35 ]
subtract of 2 values is[ 15 ]
Multiply of 2 values is[ 250 ]
Division of 2 values is[ 2.5 ]
Exponent of 2 values is[ 95367431640625 ]
Modules of 2 values is[ 5 ]
Floor Division of 2 values is[ 2 ]

Getting started with python using eclipse

Getting started with Python using eclipse

Step1: Download latest Python from the python site.

                 https://www.python.org/downloads/

Step2:  Click on the downloaded exe file. Then it will open like below screen

           

Step 3: While installing , you need to  check the both check box.

Step 4: Click the Customize installation, .

Step 5: Click on the Next button,

Step 6: Change the Customize install location(C:\Python32), you can give any location where ever

                  you need python to be install. Then click finish

Step 7:  Python installed successfully on your machine.

Step 8: Now we need to download eclipse latest version for windows from this link.

                    http://www.eclipse.org/downloads/

Step 9 : unzip the downloaded eclipse.

Step 10:  open eclipse and select workspace

Step 11:   Click on help – Install New Software

Step 12: Provide   http://pydev.org/updates as mentioned below screenshot select all checkboxes, then click finish.

Step 13 :Select the checkboxes to install the python plugin in eclipse

Step 14: Need to configure python in eclipse.

  Go to eclipse – Windows- preferences-

Step 15: Check for PyDev or python – Python Interpreter – Click on the new button

Add the Interpreter Name and Interpreter Executable – where ever your python installed location

Python plugin has been configured in your eclipse successfully.

Step 16 : create PyDev project- Give any project name (helloworld_python)

    In eclipse- File- New - PyDev project

Provide name as  - helloworld_python then click finish, But make sure – Create src folder and add it to the PYTHONPATH- radio button selected

Step 17: Now python project created. Need to create Python Module in order to start the coding.

              Right click on the src folder of the python project- >new -> pyDevModule

Step 18: Click finish

Copy below code into your program

def hello(userInput):
    return "Hello World:"+userInput
userInput= input("Please type your name:")
print(hello(userInput))

Step 19: How to run the python program – Right click on the program

  Run As – Python Run

Input - Please type your name: siva

Output- Hello World: siva

Hadoop Oozie Framework

Oozie  -  Framework

Oozie is a workflow/coordination system that you can use to manage Apache Hadoop jobs.

Oozie server a web application that runs in java servlet container(the standard Oozie distribution is using Tomcat).

This server supports reading and executing Workflows. Coordinators and Bundles definitions.

Oozie is a framework which is used to handle to run the Hadoop jobs.
It is same like Autosys,Cron jobs, ContolM  Scheduling tools

HPDF – Hadoop process definition language – defining the job details, start node , stop node ,input directory ,output directory etc.. details.
Main features:
 Execute and Monitor workflows in Hadoop
 Periodic scheduling of workflows
 Trigger execution of data availability
 HTTP and command line interface and webconsole
Oozie work flow start
Go to installation directory of oozie

Ex: cd /usr/lib/oozie-4.0.0/
:  ./bin/oozie-start.sh

Once it’s started then click the below URL to check whether Oozie started or not.

localhost:11000/oozie

In Oozie webconsole, you can see the job information (logs,configuration,etc..)

Oozie Workflow:

PREP: when a workflow job is first created it will be PREP state. Job is defined but not running.

RUNNING: When a CREATED workflow job is started.it goes into RUNNING state, it will remain in RUNNING state while it does not reach it’s end state, ends in error or it is suspended.

SUSPENDED: A RUNNING workflow job can be suspended, it will remain in SUSPENDED state until the workflow job is resumed or it’s killed.

                   

                                   




Scheduling with Oozie

Coordinator to Map Reduce  ->   Launch MR jobs at Regular intervals

Map Reduce to HDFS -> Write Files
         


Oozie – workflow.xml

The workflow definition language is  XML based and it is called HPDL- Hadoop Process Definiton language).

Workflow.xml minimum details we need to mention like name, starting point and ending point.

Ex:
                                   Name=”WorkFlowRunnerTest”>
        
        

Flow control nodes: Provides a way to control the workflow execution path
Start node start : This specifies a starting point of an Oozie Workflow
End node end: This specifies an end point for an Oozie Workflow.
To this we need to add action , and within that we will specify the map-reduce parameters.

   
      localhost:8032
      hdfs://localhost:9000 
    
   
       
           mapred.input.dir
           {inputDir}
      
       
           mapred.output.dir
           (outputDir)
        

action requires and tags to direct the next action on success or failure.

Job.properties file needs to mention details like input dir, output dir.
Job.properties file no need to move to HDFS.


Running a Oozie Application

1. Create a directory for Oozie Job(WordCountTest)
2. Write a application and create a jar (ex:Mapreduce jar). Move this jar to lib folder in WordCountTest directory.
3. Job.properties and workflow.xml inside WordCountTest directory
4. Move this directory to HDFS
5. Running the application
oozie job  -oozie http://localhost:11000/oozie  - config  job.properties –run
    (job.properties should be from local path)

Workflow Job Status command
oozie job –info job_123
Workflow Job Log
oozie job  –log  job_123
 Workflow Job definition
  oozie job  –definition job_123
   Oozie version
   oozie admin –oozie http://localhost:11000/oozie -version

Oozie Coordinator

The Oozie Coordinator supports the automated starting of Oozie workflow process.

It is typically used for the design and execution of recurring invocations of Workflow processed triggered by time and/or data availability.

  
      
         hdfs://bar:9000/app/logs/${YEAR}/${MONTH}/${DAY}/${HOUR}
        
      
       
            
                       ${current(0)}
            
            
            
              
                      
                              hdfs://localhost:9000/WordCountTest_TimeBased
                              
              inputData
              ${data(‘inputLogs’)}
                    
                  
              
          

Oozie commands

Checking the multiple workflow jobs

oozie jobs –oozie http://localhost:11000/oozie -localtime -len -filter status=RUNNING

Checking the status of the multiple coordinator jobs

oozie  jobs –oozie  http://localhost:11000/oozie -jobtype coordinator

Killing a workflow , Coordinator or Bundle Job

oozie  job –oozie  http://localhost:11000/oozie -kill

Checking the Status of a workflow , Coordinator or Bundle Job or a Coordinator Action

oozie job –oozie  http://localhost:11000/oozie –info


Hope this will guide you how to work with Oozie framework.

struts multibox example

Struts multibox [multiple check boxes] example

1. create a memeber variables and respective setters and getters in any form class like below

import org.apache.struts.action.ActionForm;
   
   public class LanguageForm extends ActionForm
    private String[] selectedLanguages = {}; 
 private String[] languages = {"Java","J2EE","JSP","STRUTS","Spring"}; 
 
 public String[] getSelectedLanguages() {
  return selectedLanguages;
 }

 public void setSelectedLanguages(String[] selectedLanguages) {
  this.selectedLanguages = selectedLanguages;
 }

 public String[] getLanguages() {
  return languages;
 }

 public void setLanguages(String[] languages) {
  this.languages = languages;
 }
 

2. Add below code inside action class to display languages in JSP

public class LanguageAction extends Action {
 private static final String SUCCESS = "success";

 /**
  * 
  */
 public ActionForward execute(ActionMapping mapping, ActionForm form,
   HttpServletRequest request, HttpServletResponse response)
   throws Exception {
          String selectedLanguageValues="";
    LanguageForm languageForm = (LanguageForm)form;
   for (String selectedLanguage : languageForm.getSelectedLanguages()) {
    selectedLanguageValues = selectedLanguageValues.concat(selectedLanguage+",");
   }
   if(selectedLanguageValues != null && !selectedLanguageValues.isEmpty()){
    selectedLanguageValues = selectedLanguageValues.substring(0,selectedLanguageValues.length()-1);
   }
   System.out.println("selectedLanguageValues["+selectedLanguageValues+"]");
   return SUCCESS;
   
 }
}

3. JSP code as mentioned below

<%@taglib uri="http://jakarta.apache.org/struts/tags-html" prefix="html"%>
         <%@taglib uri="http://jakarta.apache.org/struts/tags-bean" prefix="bean"%>
         <%@taglib uri="http://struts.apache.org/tags-logic" prefix="logic"%>


        
            
              
              
             
         

     

4. Need to do respective configuratio in struts-config.xml like action class, form class etc...
Refer Struts Step By Step example in this blog for configuration related details.

Create WordCount example using mapreduce framework in hadoop using eclipse run on windows

Create WordCount example using mapreduce framework in hadoop using eclipse run on windows
1. Open Eclipse
2. Create new java project and named it as - mapreduce_demo
3. Create Java class with name WordCount.java

How map reduce will work in hadoop
Approach:1
input.txt file having the following data..

(map)
--------------------------------------------------------------------------------------
abc def ghi jkl mno pqr stu vwx    P1- abc 1 def 1 ghi 1 jkl 1 mno-1 pqr 1  stu 1 vwx 1
abc def ghi jkl mno pqr stu vwx    P2- abc 1 def 1 ghi 1 jkl 1 mno-1 pqr 1  stu 1 vwx 1
abc def ghi jkl mno pqr stu vwx    P3- abc 1 def 1 ghi 1 jkl 1 mno-1 pqr 1  stu 1 vwx 1
abc def ghi jkl mno pqr stu vwx    P4- abc 1 def 1 ghi 1 jkl 1 mno-1 pqr 1  stu 1 vwx 1
abc def ghi jkl mno pqr stu vwx    P5- abc 1 def 1 ghi 1 jkl 1 mno-1 pqr 1  stu 1 vwx 1
abc def ghi jkl mno pqr stu vwx    P6- abc 1 def 1 ghi 1 jkl 1 mno-1 pqr 1  stu 1 vwx 1
abc def ghi jkl mno pqr stu vwx    P7- abc 1 def 1 ghi 1 jkl 1 mno-1 pqr 1  stu 1 vwx 1
abc def ghi jkl mno pqr stu vwx    P8- abc 1 def 1 ghi 1 jkl 1 mno-1 pqr 1  stu 1 vwx 1
abc def ghi jkl mno pqr stu vwx    P9- abc 1 def 1 ghi 1 jkl 1 mno-1 pqr 1  stu 1 vwx 1
abc def ghi jkl mno pqr stu vwx    P10- abc 1 def 1 ghi 1 jkl 1 mno-1 pqr 1  stu 1 vwx 1
---------------------------------------------------------------------------------------
map
-----
  processes one line at a time, as provided by the specified TextInputFormat
  emits a key-value pair of < , 1>.


Reducer
----------
The Reducer implementation, via the reduce method just sums up the values, which are the occurence counts for each key  
    emit(eachWord, sum)

4. Paste the below code in the WordCount.java file

import java.io.IOException;
import java.util.StringTokenizer;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.Reducer;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.input.TextInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.mapreduce.lib.output.TextOutputFormat;

public class WordCount {

  public static class Map extends Mapper{

    public void map(LongWritable key, Text value, Context context
                    ) throws IOException, InterruptedException {
      StringTokenizer itr = new StringTokenizer(value.toString());
      while (itr.hasMoreTokens()) {
        value.set(itr.nextToken());
        context.write(value, new IntWritable(1));
      }
    }
  }

  public static class Reduce extends Reducer {
   
   
    public void reduce(Text key, Iterable values,
                       Context context) throws IOException, InterruptedException {
     
      int sum = 0;
      for (IntWritable val : values) {
        sum += val.get();
      }
       context.write(key, new IntWritable(sum));
    }
  }

  public static void main(String[] args) throws Exception {
    Configuration conf = new Configuration();
    Job job = new Job(conf,"mywordcount");
    
    job.setJarByClass(WordCount.class);
    job.setMapperClass(Map.class);
    job.setReducerClass(Reduce.class);
    
    job.setOutputKeyClass(Text.class);
    job.setOutputValueClass(IntWritable.class);
    
    job.setInputFormatClass(TextInputFormat.class);
    job.setOutputFormatClass(TextOutputFormat.class);
    
    Path outputPath = new Path(args[1]);
    
    FileInputFormat.addInputPath(job, new Path(args[0]));
    FileOutputFormat.setOutputPath(job, new Path(args[1]));
    
    outputPath.getFileSystem(conf).delete(outputPath);
    
    System.exit(job.waitForCompletion(true) ? 0 : 1);
  }
}

5. Set up the build path to avoid errors.
Right Click on the project(mapreduce_demo)->Properties->Java Build Path-> Libraries ->Add External Jars
select jar's from

c:\hadoop\hadoop-2.4.1\share\hadoop\common
 c:\hadoop\hadoop-2.4.1\share\hadoop\common\lib
 c:\hadoop\hadoop-2.4.1\share\hadoop\mapreduce
 c:\hadoop\hadoop-2.4.1\share\hadoop\mapreduce\lib
 

6. Once you completed the above steps, now we need to create jar to run the WordCount.java in hadoop.
7. Create Jar:

Right click on the project(mapreduce_demo)->Export->Jar(Under java)->Click Next->Next->Main Class->
Select WordCount->Click Finish
8. Now we have created jar successfully.
9. Before Executing the jar, need to start the (namenode,datanode,resourcemanager and nodemanager)
10. c:\hadoop\hadoop-2.4.1\sbin>start-dfs.cmd
11. c:\hadoop\hadoop-2.4.1\sbin>start-yarn.cmd
12. Check whether any inut files available in the hdfs system already if not create the same.

Hadoop basic commands:

c:\hadoop\hadoop-2.4.1\bin>hdfs dfs -ls input (If it is not created) then use below command to create directory
c:\hadoop\hadoop-2.4.1\bin>hdfs dfs -mkdir input
Copy any text file into input directory of hdfs
c:\hadoop\hadoop-2.4.1\bin>hdfs dfs -copyFromLocal input_file.txt input
Verify file has been copied to hdfs or not using below command
c:\hadoop\hadoop-2.4.1\bin>hdfs dfs -ls input
Verift the data of the file which you copied into hdfs
c:\hadoop\hadoop-2.4.1\bin>hdfs dfs -cat input.
 

13. Once above steps's done. Now run the mapreduce program using the following command
c:\hadoop\hadoop-2.4.1\bin>
yarn jar c:\hadoop\hadoop-2.4.1\wordcount.jar input/ output/

14. verify the result.

c:\hadoop\hadoop-2.4.1\bin>hdfs dfs -cat output
verify the status of the job details and output through web url

http://localhost:50075
http://localhost:8088/cluster

RPC (Remote Procedure Call)

RPC- Remote Procedure Call
 The term itself defines calling remote methods through client program.
In this post added both server and client in the same package.
Normally we have to write server classes which having business functionality
and client will only will access that methods.

Step 1: Start Eclipse
Step 2: Create new dynamic project(name it as you like Ex: rpc-test
Step 3: Create a server class(Ex:Calculator)under src folder
Step 4: Write methods as of your requirement

Ex:

package com.siva;

public class Calculator 
{
public int add(int i1, int i2) {
return i1 + i2;
}
public int substract(int i1, int i2) {
return i1 - i2;
}
public int multiply(int i1, int i2) {
return i1 * i2;
}
}

Step 5: We have to write configuration of xmlrpcservlet in web.xml
Step 6: Open web.xml, which is under WEB-INF/

XmlRpcServlet
org.apache.xmlrpc.webserver.XmlRpcServlet

enabledForExtensionstrue
Sets, whether the servlet supports vendor extensions for XML-RPC.




XmlRpcServlet
xmlrpc

Step 7: Need to declare server class location in the properties file name called-
XmlRpcServlet.properties under package - org.apache.xmlrpc.webserver
Step 8: XmlRpcServlet.properties file details as mentioned below

Calculator=com.siva.Calculator

The bold Calculator is being used in clent class to access the Calculator methods.

Step 9: Write the Client class

package com.siva;

import java.net.URL;
import org.apache.xmlrpc.client.XmlRpcClient;
import org.apache.xmlrpc.client.XmlRpcClientConfigImpl;

public class SimpleClient {

public SimpleClient() {

try {
System.out.println("Try to call calculator methods via XML-RPC...");
XmlRpcClientConfigImpl config = new XmlRpcClientConfigImpl();

//server ip addess or machine name/project name/servlet url pattern
config.setServerURL(new URL("http://127.0.0.1:8080/rpc-test/xmlrpc"));

XmlRpcClient client = new XmlRpcClient();
client.setConfig(config);

Object[] params = new Object[] { new Integer(2), new Integer(3) };
Integer result = (Integer) client.execute("Calculator.substract", params);

System.out.println("The returned values is: " + result);

} catch (Exception e) {
e.printStackTrace();
}
}

public static void main(String[] args) {
new SimpleClient();
}

}

in the above client class to call the RPC methods, first we have to provide the server ip addrss, url pattern name
While calling the method name which being used for to access the business logic.

Step 10: required jars

commons-logging-1.1.jar
ws-commons-util-1.0.2.jar
xmlrpc-client-3.1.3.jar
xmlrpc-common-3.1.3.jar
xmlrpc-server-3.1.3.jar
Step 11 : Required Tomcat server or any webserver to run the application

Step 12 : Start the server after adding project to the server and run the client application,
Run As Java Application, you will see the result.
If you want to call another methods , change the method name from Clicent class and stop start the
server.

I hope this post will help to get basic knowledge about RPC.

struts example

Struts example

Below post shows how to build simple application with struts.

open eclipse -> project -> create dynamic Webproject->

provide name as - struts_sample [As you like]

select Dynamic web module version as 2.5

Then click on Finish button.

-> open the web.xml , which available inside WEB-INF folder

copy the below code and paste in side web.xml .

      
             action 
              org.apache.struts.action.ActionServlet     
               
                   config                   /WEB-INF/struts-config.xml              
              1
  
     
		       action   
		       *.do
    

-> Create xml and name it as struts-config.xml inside WEB-INF.
->open the struts-config.xml and paste the below code inside the struts-config.xml

-> Now it's time to start our work like creating jsp files, form classes, action classes and need to add required jars.

-> first we will write jsp page. Here i am writting 4 jsp pages
1. login.jsp
2. welcome.jsp
3. adduser.jsp
4. success.jsp

-> create one folder inside WebContent with name jsp [WebContent/jsp/login.jsp] -- this is for login details which will have user name and password along with validation.
paste the below code inside login.jsp

	<%@taglib uri="http://jakarta.apache.org/struts/tags-html" prefix="html"%><%@taglib
	uri="http://jakarta.apache.org/struts/tags-bean" prefix="bean"%>







	
Login
	
		
	
	

-> create welcome.jsp [WebContent/jsp/welcome.jsp] -- this is for after successful login details .
paste the below code inside welcome.jsp

	
	<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
	pageEncoding="ISO-8859-1"%>






	<%        String message = (String)request.getAttribute("message");    %>
	
		Welcome User :
		<%= message %>
You have successfully logged in.

-> create adduser.jsp [WebContent/jsp/adduser.jsp] -- this contains user details along with required validation.
paste the below code inside adduser.jsp

	<%@taglib uri="http://jakarta.apache.org/struts/tags-html" prefix="html"%><%@taglib
	uri="http://jakarta.apache.org/struts/tags-bean" prefix="bean"%>







	
	
		
	

-> create success.jsp [WebContent/jsp/success.jsp] -- this page will display after successful user details.
paste the below code inside success.jsp

	<%@taglib uri="http://jakarta.apache.org/struts/tags-html" prefix="html"%><%@taglib
	uri="http://jakarta.apache.org/struts/tags-bean" prefix="bean"%>






	
success
	successfully Added.

-> We need to create java classes.
-> create a package -> com.siva.form
-> com.siva.action

->create LoginForm.java inside com.siva.form package and paste the below code.

package com.siva.form;

import javax.servlet.http.HttpServletRequest;

import org.apache.struts.action.ActionErrors;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.action.ActionMessage;

/**
 * 
 * @author sivaraju
 *
 */
public class LoginForm extends ActionForm {
	/**
	 * 
	 */
	private static final long serialVersionUID = -1743531020254647308L;
	private String userName;
	private String password;

	public ActionErrors validate(ActionMapping mapping,
			HttpServletRequest request) {
		ActionErrors actionErrors = new ActionErrors();
		if (userName == null || userName.trim().equals("")) {
			actionErrors.add("userName", new ActionMessage("error.username"));
		}
		try {
			if (password == null || password.trim().equals("")) {
				actionErrors.add("password",
						new ActionMessage("error.password"));
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
		return actionErrors;
	}

	public String getUserName() {
		return userName;
	}

	public void setUserName(String userName) {
		this.userName = userName;
	}

	public String getPassword() {
		return password;
	}

	public void setPassword(String password) {
		this.password = password;
	}
}

->create UserForm.java inside com.siva.form and paste below code

  package com.siva.form;

import javax.servlet.http.HttpServletRequest;

import org.apache.struts.action.ActionErrors;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.action.ActionMessage;

/**
 * 
 * @author sivaraju
 *
 */
public class UserForm extends ActionForm {
	/**
	 * 
	 */
	private static final long serialVersionUID = -2087861874662967982L;
	private String userName;
	private String sex;
	private int age;

	public ActionErrors validate(ActionMapping mapping,
			HttpServletRequest request) {
		ActionErrors actionErrors = new ActionErrors();
		try {
				if (userName == null || userName.trim().equals("")) {
					actionErrors.add("userName", new ActionMessage("error.username"));
				}
				if (sex == null || sex.trim().equals("")) {
					actionErrors.add("sex",new ActionMessage("error.sex"));
				}
				if (age <=0 ) {
					actionErrors.add("age",new ActionMessage("error.age"));
				}
			
		} catch (Exception e) {
			e.printStackTrace();
		}
		return actionErrors;
	}

	public String getUserName() {
		return userName;
	}

	public void setUserName(String userName) {
		this.userName = userName;
	}
	public String getSex() {
		return sex;
	}

	public void setSex(String sex) {
		this.sex = sex;
	}

	public int getAge() {
		return age;
	}

	public void setAge(int age) {
		this.age = age;
	}

	
}

-> create LoginAction.java inside com.siva.action pakage and paste the below code

  package com.siva.action;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;

import com.siva.form.LoginForm;

public class LoginAction extends Action {
	private static final String FAILURE = "failure";
	private static final String SUCCESS = "success";

	public ActionForward execute(ActionMapping mapping, ActionForm form,
			HttpServletRequest request, HttpServletResponse response)
			throws Exception {
		String target = null;
		LoginForm loginForm = (LoginForm) form;
		if (loginForm.getUserName().equals("admin")
				&& loginForm.getPassword().equals("admin123")) {
			target = SUCCESS;
			request.setAttribute("message", loginForm.getUserName());
		} else {
			target = FAILURE;
		}
		return mapping.findForward(target);
	}
}

-> create AddUserAction.java inside com.siva.action package and paste below code.

package com.siva.action;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;

import com.siva.form.UserForm;
/**
 * 
 * @author sivaraju
 *
 */
public class AddUserAction extends Action {
	private static final String SUCCESS = "success";

	/**
	 * 
	 */
	public ActionForward execute(ActionMapping mapping, ActionForm form,
			HttpServletRequest request, HttpServletResponse response)
			throws Exception {
		UserForm userForm = (UserForm) form;
		System.out.println("username["+userForm.getUserName()+"]");
		System.out.println("Age["+userForm.getAge()+"]");
		System.out.println("Sex["+userForm.getSex()+"]");
		//If this details need to store in db. Then need to get the db details from data source object. Store as per requirement.
		return mapping.findForward(SUCCESS);
	}
	
	
}

->create MessageResource.properties file inside src/resource [src/resource/MessageResource.properties] and paste the below code

label.username = User Name
label.password = Password
label.welcome = Welcome 
error.username =Username is required.
error.password = Password is required.


label.age = Age
label.sex = Sex

label.adduser = Add User


error.age = Age is required field
error.sex=Sex is required field 

-> Add the below jars inside lib folder.(Among below jar's few of the jar's may not be required]

    bcprov-jdk14-121.jar
    commons-digester-2.1.jar
    commons-fileupload-1.1.1.jar
    commons-io-1.2.jar
    commons-lang-2.4.jar
    org-apache-commons-logging.jar
    org.apache.commons.beanutils.jar
    servlet-api.jar
    struts.jar
	
	

-> Right click on the project-> Run As-> Run On Server-> [select the server which ever server you want to run the application]. Tomcat is prefered. -> http://localhost:8080/struts_sample/login.jsp [ after submitting it will redirect to welcome.jsp]- username - admin / password - admin123 -> http://localhost:8080/struts_sample/jsp/adduser.jsp [after submitting it will redirec tto success.jsp]. In this way stuts application will work.