CacheableImage

CacheableImage

Computers -> Developing -> Java

Images are often needed to be cached to save RAM. This small class offers a method to save Images in temporary files. more >>

Contents

Class CacheableImage

Create a class named CacheableImage.

This is the source code of the class:

import java.awt.image.BufferedImage;
import java.io.*;
import java.util.Random;
import javax.imageio.ImageIO;

public class CacheableImage{
        private File tempFile;
        
        public boolean cache(BufferedImage content) throws IOException{
        	 if(null==content) return false;
        	 if(null==tempFile){
         	       Random random = new Random();
                  int v = random.nextInt(1000000);
                  String pref="temp_"+Integer.toString(v)+"_"+System.currentTimeMillis();
                  tempFile = File.createTempFile(pref, ".png");
                  System.out.println("temporary file created: " +tempFile.getPath());
 	              tempFile.deleteOnExit();
            }
        
   	        ImageIO.write(content, "png", tempFile);
            System.out.println("temporary file written: " +tempFile.getPath());
            return true;
        }
        
        public BufferedImage getImage() throws IOException{
        	  if(null!=tempFile)
        		    return ImageIO.read(tempFile);
              return null; 		    
        }
        
        public File getTempFile(){
        	  return tempFile;
        }
}

Test the class

This Class is for testing only.

import javax.swing.*;
import java.awt.image.*;
import java.awt.*;
import javax.imageio.ImageIO;

public class TestFrame extends JFrame {
        public static void main(String[] args){
        	 TestFrame f=new TestFrame();
        	 
        	 BufferedImage buf=new BufferedImage(400,300, BufferedImage.TYPE_INT_RGB);
        	 Graphics g=buf.getGraphics();
        	 g.setColor(Color.RED);
        	 g.fillRect(20,20,50,50);
        	 
        	 CachableImage c=new CachableImage();
        	 try{ 
        		 c.cache(buf);
        		 BufferedImage b= ImageIO.read(c.getTempFile());
        		 f.getContentPane().add(new JLabel(new ImageIcon(b)));
        	 }
        	 catch(Exception ex){
        		 
        	 }
        	 f.pack();
        	 f.setVisible(true);
        }
}