Resource loader : Spring ResourceLoader interface is used to load external data(i.e text file, media file, image file) in Spring application using the method getResource(). We can use three ways for loading resources :
URL Path :

Resource resource = appContext.getResource("file:c:\\testing.txt");

File System :

Resource resource = appContext.getResource("url:http://www.yourdomain.com/testing.txt");

Class Path :

Resource resource = appContext.getResource("classpath:com/bhagwan/common/testing.txt");

Here, I explain example with getResource() method :

package com.bhagwan.common;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.core.io.Resource;
public class ResourceApplication 
{
    public static void main( String[] args )
    {
        ApplicationContext appContext = 
           new ClassPathXmlApplicationContext(new String[] {"If-you-have-any.xml"});

        Resource resource = 
           appContext.getResource("classpath:com/bhagwan/common/testing.txt");

    try{
           InputStream is = resource.getInputStream();
          BufferedReader br = new BufferedReader(new InputStreamReader(is));

          String line;
          while ((line = br.readLine()) != null) {
             System.out.println(line);
             } 
          br.close();

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

    }
}