java-design-patterns/model-view-presenter/src/main/java/com/iluwatar/FileLoader.java

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;

/**
 * Every instance of this class represents the Model component
 * in the Model-View-Presenter architectural pattern.
 * 
 * It is responsible for reading and loading the contents of a given file.
 */
public class FileLoader {
	
	/**
	 * Indicates if the file is loaded or not.
	 */
	private boolean loaded = false;
	
	/**
	 * The name of the file that we want to load.
	 */
	private String fileName;
	
	/**
	 * Loads the data of the file specified.
	 */
	public String loadData() {
		try {
			BufferedReader br = new BufferedReader(new FileReader(new File(this.fileName)));
			String text = "";
			String line = "";
			
			while( (line = br.readLine()) != null ) {
				text += line + "\n";
			}
			
			this.loaded = true;
			br.close();
			
			return text;
		}
		
		catch(Exception e) {
			e.printStackTrace();
		}
		
		return null;
	}
	
	/**
	 * Sets the path of the file to be loaded, to the given value.
	 * 
	 * @param fileName The path of the file to be loaded.
	 */
	public void setFileName(String fileName) {
		this.fileName = fileName;
	}
	
	/**
	 * @return fileName The path of the file to be loaded.
	 */
	public String getFileName() {
		return this.fileName;
	}
	
	/**
	 * @return True, if the file given exists, false otherwise.
	 */
	public boolean fileExists() {
		return new File(this.fileName).exists();
	}
	
	/**
	 * @return True, if the file is loaded, false otherwise.
	 */
	public boolean isLoaded() {
		return this.loaded;
	}
}