Extracting Excel Content as Text

The following code extracts text content in an xlsx file

package com.finra;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.PrintWriter;

import org.apache.poi.xssf.extractor.XSSFExcelExtractor;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

public class TestExcelExtractor {

	public static void main(String [] args) throws Exception {
		
        FileInputStream file = new FileInputStream(new File("c:/users/dgandikota/Test.xlsx"));

        
        //Create Workbook instance holding reference to .xlsx file
        XSSFWorkbook workbook = new XSSFWorkbook(file);
    
        XSSFExcelExtractor excelExtractor = new XSSFExcelExtractor(workbook);
        String allTxt = excelExtractor.getText();
        System.out.println(allTxt);
        allTxt = allTxt.replaceAll("\t", "|");
        allTxt = allTxt.replace("null", "");
        if (new File("c:/users/dgandikota/excelextract.txt").exists()) {
        	new File("c:/users/dgandikota/excelextract.txt").delete();
        }
        PrintWriter pw = new PrintWriter(new FileOutputStream(new File("c:/users/dgandikota/excelextract.txt")));
        pw.print(allTxt);
        pw.close();
//        System.out.println(allTxt);
        
	}
}

The sheet names are output by default

The end of sheet is found by the absence field separator (eg. line.indexOf("|") == -1)

REST Example with Headers using TomEE Plus

apache-tomee-plus-1.7.4 comes with out of the box REST

Tools to test REST services

Firefox-Poster Add-On

Chrome - postman?

Create the following class and deploy inside a war on TomEE-Plus

package com.apache.rest;

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;

 @Path("/greeting")
 public class GreetingService {
     @GET
     @Produces( { MediaType.TEXT_XML })
      @Path("{id1}/{id2}")
     public String message(@PathParam("id1") String id1, @PathParam("id2") String id2,  @Context HttpHeaders httpHeaders) {
//called as http://localhost/greeting/{id1}/{id2}
//http://localhost//greeting/3/2
       /** how to get specific header info? **/
//        String cacheControl = httpHeaders.getRequestHeader("Cache-Control").get(0);
//         System.out.println("Cache-Control: "+cacheControl);
 /** get list of all header parameters from request **/
 Set headerKeys = httpHeaders.getRequestHeaders().keySet();
 for(String header:headerKeys){
       if (httpHeaders.getRequestHeader(header)!= null && httpHeaders.getRequestHeader(header).size() > 0 )
          System.out.println(header+":"+httpHeaders.getRequestHeader(header).get(0));
 }
         return "Hi REST!" + id1 + " " + id2;
     }

     @POST
//called as http://localhost//greeting?message=test
     public String lowerCase(final String message) {
         return "Hi REST!".toLowerCase();
     }
 }

More at http://www.vogella.com/tutorials/REST/article.html

TomEE JMS

Why I wrote this up?

When I was trying to hook up JMS with TomEE-Plus, I looked for on-line resources. There are multiple tutorials on how to do this, but not all information could be found in one page. So this tutorial is the result of gleaning from various sources. Hope you find it useful. I am not big on analysis. So let's go straight into coding.

Tested this on TomEE-Plus-1.7.4; does not work with Tomee 7 or other servers

First Configure conf/tomee.xml as follows

<tomee>
  <!-- see http://tomee.apache.org/containers-and-resources.html -->

  <!-- activate next line to be able to deploy applications in apps -->

  <!-- <Deployments dir="apps" /> -->

<Resource id="MyJmsResourceAdapter" type="ActiveMQResourceAdapter">
        BrokerXmlConfig =  broker:(tcp://localhost:61616)
        ServerUrl       =  tcp://localhost:61616
    </Resource>

    <Resource id="MyJmsConnectionFactory" type="javax.jms.ConnectionFactory">
        ResourceAdapter = MyJmsResourceAdapter
    </Resource>

    <Container id="MyJmsMdbContainer" ctype="MESSAGE">
        ResourceAdapter = MyJmsResourceAdapter
    </Container>

    <Resource id="barQueue" type="javax.jms.Queue"/>
    <Resource id="fooTopic" type="javax.jms.Topic"/>
</tomee>

Create a servlet thus

package com.apache.jms;


import java.io.IOException;

import javax.annotation.Resource;
import javax.jms.Connection;
import javax.jms.ConnectionFactory;
import javax.jms.DeliveryMode;
import javax.jms.MessageProducer;
import javax.jms.Queue;
import javax.jms.Session;
import javax.jms.TextMessage;
import javax.jms.Topic;
import javax.naming.InitialContext;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
@WebServlet(name="mytest", urlPatterns={"/myurl"}) 
 public class MyJmsServlet extends HttpServlet {
  
     //@Resource(name = "fooTopic")
     static private Topic fooTopic;
  
     //@Resource(name = "barQueue")
     static private Queue barQueue;
  
     //@Resource (name="MyJmsConnectionFactory" , type = ConnectionFactory.class)
     static private ConnectionFactory connectionFactory;
  
     @Override
     protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
         //...
  try {
    InitialContext ctx = new InitialContext();
    connectionFactory = (ConnectionFactory) ctx.lookup("java:openejb/Resource/MyJmsConnectionFactory");
    barQueue = (Queue) ctx.lookup("java:openejb/Resource/barQueue");
    fooTopic = (Topic) ctx.lookup("java:openejb/Resource/fooTopic");
         Connection connection = connectionFactory.createConnection();
         connection.start();
  
         // Create a Session
         Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
  
         // Create a MessageProducer from the Session to the Topic or Queue
         MessageProducer producer = session.createProducer(barQueue);
         producer.setDeliveryMode(DeliveryMode.PERSISTENT);
  
         // Create a message
         TextMessage message = session.createTextMessage("Hello World!");
  
         // Tell the producer to send the message
         producer.send(message);
  
         //...
     } catch (Exception e) {
      e.printStackTrace();
     }
     }
     
     public static void main(String [] args) {
       try {
           Connection connection = connectionFactory.createConnection();
           connection.start();
    
           // Create a Session
           Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
    
           // Create a MessageProducer from the Session to the Topic or Queue
           MessageProducer producer = session.createProducer(fooTopic);
           producer.setDeliveryMode(DeliveryMode.NON_PERSISTENT);
    
           // Create a message
           TextMessage message = session.createTextMessage("Hello World!");
    
           // Tell the producer to send the message
           producer.send(message);
    
           //...
       } catch (Exception e) {
        e.printStackTrace();
       }
     }
}

Create a client thus

package com.apache.jms;

import java.util.Properties;

import javax.jms.Connection;
import javax.jms.ConnectionFactory;
import javax.jms.Message;
import javax.jms.MessageConsumer;
import javax.jms.Queue;
import javax.jms.Session;
import javax.jms.TextMessage;
import javax.jms.Topic;
import javax.naming.InitialContext;

public class MyJmsClient {
   //@Resource(name = "fooTopic")
    static private Topic fooTopic;
 
    //@Resource(name = "barQueue")
    static private Queue barQueue;
 
    //@Resource (name="MyJmsConnectionFactory" , type = ConnectionFactory.class)
    static private ConnectionFactory connectionFactory;
    private static MessageConsumer consumer=null;
 public static void main(String [] args) {
     try {
      Properties props = new Properties();
//      props.put("java.naming.factory.initial", "org.apache.openejb.client.LocalInitialContextFactory");
      props.put("java.naming.factory.initial", "org.apache.openejb.client.RemoteInitialContextFactory");
       
           props.put("java.naming.provider.url", "http://127.0.0.1:8080/tomee/ejb");
        props.put("java.naming.security.principal", "tomee");
        props.put("java.naming.security.credentials","tomee");
      InitialContext ctx = new InitialContext(props);
    connectionFactory = (ConnectionFactory) ctx.lookup("MyJmsConnectionFactory");
    barQueue = (Queue) ctx.lookup("barQueue");
    fooTopic = (Topic) ctx.lookup("fooTopic");
         Connection connection = connectionFactory.createConnection();
  
        Session session = connection.createSession(
              false, 
              Session.AUTO_ACKNOWLEDGE);
   consumer = session.createConsumer(barQueue);
   connection.start();
   while (true) {
       Message m = consumer.receive(1); 
       if (m != null) { 
           if (m instanceof TextMessage) { 
               TextMessage message = (TextMessage) m; 
               System.out.println("Reading message: " + message.getText()); 
           } else { 
               break; 
           } 
       }
   }
     } catch (Exception e) {
      e.printStackTrace();
     }
   }
}

Run the main method of the client; make sure it is listening for messages; and pass this to the JVM -DResource/javax.jms.ConnectionFactory=connectionfactory:org.apache.activemq.ActiveMQConnectionFactory:tcp://localhost:61616

For example:

java -cp ./activemq-all-5.14.3.jar:openejb-client-7.0.2.jar:concurrent-1.3.3.jar:javax.ejb.jar:. -DResource/javax.jms.ConnectionFactory=connectionfactory:org.apache.activemq.ActiveMQConnectionFactory:tcp://172.20.0.218:61616 MyJmsClient topic

Deploy the servlet on TomEE and invoke it as http://localhost:8080/myurl

You should see the following message

Reading message: Hello World!

Required Jars:

activemq-all-5.14.3.jar

openejb-client-7.0.2.jar

concurrent-1.3.3.jar

Active MQ Stand Alone

Download apache-activemq-5.14.3.zip

Unzip it

set JAVA_HOME and go to the bin directory and type "activemq start"

Create a Sender Thus

import javax.jms.Connection;
import javax.jms.ConnectionFactory;
import javax.jms.Destination;
import javax.jms.JMSException;
import javax.jms.MessageProducer;
import javax.jms.Session;
import javax.jms.TextMessage;
import org.apache.activemq.ActiveMQConnection;
import org.apache.activemq.ActiveMQConnectionFactory;

public class Sender {

private ConnectionFactory factory = null;
private Connection connection = null;
private Session session = null;
private Destination destination = null;
private MessageProducer producer = null;

public Sender() {

}

public void sendMessage() {

try {
factory = new ActiveMQConnectionFactory(
ActiveMQConnection.DEFAULT_BROKER_URL);
connection = factory.createConnection();
connection.start();
session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
destination = session.createQueue("SAMPLEQUEUE");
producer = session.createProducer(destination);
TextMessage message = session.createTextMessage();
message.setText("Hello ...This is a sample message..sending from FirstClient");
producer.send(message);
System.out.println("Sent: " + message.getText());

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

public static void main(String[] args) {
Sender sender = new Sender();
sender.sendMessage();
}

}

Create a receiver thus

import javax.jms.Connection;
import javax.jms.ConnectionFactory;
import javax.jms.Destination;
import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.MessageConsumer;
import javax.jms.Session;
import javax.jms.TextMessage;
import org.apache.activemq.ActiveMQConnection;
import org.apache.activemq.ActiveMQConnectionFactory;

public class Receiver {
private ConnectionFactory factory = null;
private Connection connection = null;
private Session session = null;
private Destination destination = null;
private MessageConsumer consumer = null;

public Receiver() {

}

public void receiveMessage() {
try {
factory = new ActiveMQConnectionFactory(
ActiveMQConnection.DEFAULT_BROKER_URL);
connection = factory.createConnection();
connection = factory.createConnection();
connection.start();
session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
destination = session.createQueue("SAMPLEQUEUE");
consumer = session.createConsumer(destination);
Message message = consumer.receive();

if (message instanceof TextMessage) {
TextMessage text = (TextMessage) message;
System.out.println("Message is : " + text.getText());
}
} catch (JMSException e) {
e.printStackTrace();
}
}

public static void main(String[] args) {
Receiver receiver = new Receiver();
receiver.receiveMessage();
}
}

when compiling the files use the following class path

C:\jms>"c:\Program Files\java\jdk1.8.0_101\bin\javac.exe" -cp apache-activemq-5.1
4.3\activemq-all-5.14.3.jar;. Sender.java

When running use the same class path

Windows invokation of Client

C:\jms>"c:\Program Files\Java\jdk1.8.0_101\bin\java.exe" 
-cp apache-activemq-5.14.3\activemq-all-5.14.3.jar;.;bak\openejb-client.jar;bak\javax.ejb.jar -DResource/javax.jms.ConnectionFactory=connectionfactory:org.apache.activemq.ActiveMQConnectionFactory:tcp://localhost:61616 MyJmsClient