Java Callback pro

Spring bean destruction callback

package com.java2novice.beans;

import java.io.IOException;

import java.net.HttpURLConnection;

import java.net.MalformedURLException;

import java.net.URL;

import org.springframework.beans.factory.DisposableBean;

import org.springframework.beans.factory.InitializingBean;

public class NetworkManager implements InitializingBean, DisposableBean

{

 private HttpURLConnection connection;

 private String urlStr;

 public void setUrlStr(String urlStr)

{

        this.urlStr = urlStr;

 }

 public void afterPropertiesSet()

{

         

 System.out.println("Inside init() method...");

        URL obj;

 try

    {

            obj = new URL(this.urlStr);

            this.connection = (HttpURLConnection) obj.openConnection();

     }

 catch (MalformedURLException e)

 {

             e.printStackTrace();

  }

 catch (IOException e)

 {

             e.printStackTrace();

        }

    }

  public void destroy()

  {

   try

       {

            System.out.println("Inside destroy() method...");

            if(this.connection != null)

           {

                connection.disconnect();

            }

        }

         catch(Exception ex){}

    }

    public void readData()

   {

        try

        {

            int responseCode = this.connection.getResponseCode();

            System.out.println("Response code: "+responseCode);

          } catch (IOException e)

          {

                      e.printStackTrace();

        }

    }

}

Configure default initialization and destroy methods in all spring beans

package com.java2novice.beans;

import java.io.IOException;

import java.net.HttpURLConnection;

import java.net.MalformedURLException;

import java.net.URL;

public class NetworkManager

{

 private HttpURLConnection connection;

 private String urlStr;

     

    public void setUrlStr(String urlStr)

   {

        this.urlStr = urlStr;

    }

    public void init()

   {

        System.out.println("Inside init() method...");

        URL obj;

        try

        {

            obj = new URL(this.urlStr);

            this.connection = (HttpURLConnection) obj.openConnection();

        }

        catch (MalformedURLException e)

        {

                    e.printStackTrace();

        }

        catch (IOException e)

        {

                    e.printStackTrace();

        }

    }

    public void destroy()

    {

        try

         {

            System.out.println("Inside destroy() method...");

            if(this.connection != null)

            {

                connection.disconnect();

            }

        }

         catch(Exception ex){}

    }

     public void readData()

     {

        try

          {

            int responseCode = this.connection.getResponseCode();

            System.out.println("Response code: "+responseCode);

        }

         catch (IOException e)

          {

                      e.printStackTrace();

        }

    }

}

Spring bean init and destroy methods using annotations Post Construct and PreDestroy

package com.java2novice.beans;

import java.io.IOException;

import java.net.HttpURLConnection;

import java.net.MalformedURLException;

import java.net.URL;

import javax.annotation.PostConstruct;

import javax.annotation.PreDestroy;

public class NetworkManager

{

    private HttpURLConnection connection;

    private String urlStr;

 public void setUrlStr(String urlStr)

 {

        this.urlStr = urlStr;

  }

    PostConstruct

    public void init()

    {

         

        System.out.println("Inside init() method...");

        URL obj;

        try

        {

            obj = new URL(this.urlStr);

            this.connection = (HttpURLConnection) obj.openConnection();

        }

             catch (MalformedURLException e)

        {

            e.printStackTrace();

        }

        catch (IOException e)

        {

                    e.printStackTrace();

        }

    }

    public void destroy()

   {

        try

        {

            System.out.println("Inside destroy() method...");

            if(this.connection != null)

            {

                connection.disconnect();

            }

        }

        catch(Exception ex){}

    }

    public void readData()

   {

        try

          {

            int responseCode = this.connection.getResponseCode();

            System.out.println("Response code: "+responseCode);

        }

         catch (IOException e)

         {

                     e.printStackTrace();

        }

    }

}