LinkedinBolt.java

/*
    The MIT License (MIT)

    Copyright (c) 2016 sinfonier-project

    Permission is hereby granted, free of charge, to any person obtaining a copy
    of this software and associated documentation files (the "Software"), to deal
    in the Software without restriction, including without limitation the rights
    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
    copies of the Software, and to permit persons to whom the Software is
    furnished to do so, subject to the following conditions:

    The above copyright notice and this permission notice shall be included in
    all copies or substantial portions of the Software.

    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
    THE SOFTWARE.
*/

package com.sinfonier.bolts;

import java.io.IOException;

import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.jsoup.select.Elements;

public class LinkedinBolt extends BaseSinfonierBolt {

    // Class variables
    String ESTUDIOS;
    String LOCALIDAD;
    // Must implement constructor. Do not touch
    public LinkedinBolt(String path) {
        super(path);
    }

    @Override
    public void userprepare() {
        // Initialize your DB Connections or non-serializable classes.
        // This method will be executed once.
        this.ESTUDIOS =  this.getParam("educacion");
        this.LOCALIDAD = this.getParam("localidad");
    }

    @Override
    public void userexecute() {
    	String url="";
                
        if ( this.getField(this.ESTUDIOS) != "0" && this.getField(this.LOCALIDAD) != "0")
            url = "https://www.linkedin.com/jobs/search?keywords="+ this.getField(this.ESTUDIOS)+"&location="+this.getField(this.LOCALIDAD)+"&trk=jobs_jserp_search_button_execute&locationId=";
        else if ( this.getField(this.ESTUDIOS) == "0" && this.getField(this.LOCALIDAD) != "0")
            url = "https://www.linkedin.com/jobs/search?location="+this.getField(this.LOCALIDAD)+"&trk=jobs_jserp_search_button_execute&locationId=";
        else if ( this.getField(this.ESTUDIOS) != "0" && this.getField(this.LOCALIDAD) == "0")
            url = "https://www.linkedin.com/jobs/search?keywords="+ this.getField(this.ESTUDIOS)+"&trk=jobs_jserp_search_button_execute&locationId=";
        else if ( this.getField(this.ESTUDIOS) == "0" && this.getField(this.LOCALIDAD) == "0")
        	System.out.println("No existe el usuario ni la localización");
        
        Document doc;
          try {

              // need http protocol
              doc = Jsoup.connect(url).get();

              // get page title
              String title = doc.title();
          //    System.out.println("title : " + title);

              // get all links
              Elements loginform = doc.getElementsByClass("job-title-link");
             
              int i = 1;
              for (Element link : loginform) {
                 

                  // get the value from href attribute
                  if(!link.attr("href").equals("null"))
                	  this.addField("oferta"+i,link.attr("href"));
                  else
                	  this.addField("oferta"+i,0);

                  if(!link.text().equals("null"))
                	  this.addField("enlace"+i,link.text());
                  else
                	  this.addField("enlace"+i,0);


                  i++;
              }

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


        this.emit();  // Call emit() always at the end of this method.
    }

    @Override
    public void usercleanup() {
        // Close connections, clean resources
    }

}

Es mejor realizar la inicialización de parámetros en la función userprepare(), ya que mantienen el valor durante toda la ejecución de la topología. Las urls también se podrían inicializar en esta función para un mayor rendimiento.

public void userprepare() {
estudios = this.getParam("educacion");
localidad = this.getParam("localidad");
}