import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;

import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;

public class MehrereBilderDarstellenClass {

    public static void main(String[] args) throws IOException {
        BufferedImage[] bia = liesBildDateien();
        JFrame jf = new JFrame();
        jf.getContentPane().setLayout(new GridLayout(bia.length / 2, 3));
        
        for (int i = 0; i < bia.length; i++) {
            JLabel label = new JLabel();
            ImageIcon icon = new ImageIcon(bia[i]);
            label.setIcon(icon);
            jf.getContentPane().add(label);
        }
        
        jf.setSize(new Dimension(300, 300));
        jf.setVisible(true);
        jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }

    private static BufferedImage[] liesBildDateien() throws IOException {
        File inputFile = new File("/pfad");
        File[] dateienFileArray = inputFile.listFiles();
        BufferedImage[] bufferedImageArray = new BufferedImage[dateienFileArray.length];
        for (int i = 0; i < bufferedImageArray.length; i++) {
            if (dateienFileArray[i].isFile()) {
                bufferedImageArray[i] = ImageIO.read(dateienFileArray[i]);
            }
        }
        return bufferedImageArray;
    }
}