/*
 * Created on 2004-3-22 By Liudong
 */
package jdlog.util.image;

import java.awt.*;
import java.awt.image.*;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;

import javax.imageio.ImageIO;

import org.apache.commons.lang.RandomStringUtils;
/**
 * 隨即圖片生成器
 * 該類用于用戶注冊時候需要用戶根據圖片內容進行填寫正確后方可注冊
 * @author Liudong
 */
public class RandomImageGenerator {
    
    public static String random() {
        return RandomStringUtils.randomNumeric(4);
    }
    /**
     * 根據要求的數字生成圖片,背景為白色,字體大小16,字體顏色黑色粗體
     * @param num	要生成的數字
     * @param out	輸出流
     * @throws IOException
     */
    public static void render(String num, OutputStream out) throws IOException{
        if(num.getBytes().length>4)
            throw new IllegalArgumentException("The length of param num cannot exceed 4.");
        int width = 40;
        int height = 15;
        BufferedImage bi = new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);        
        Graphics2D g = (Graphics2D)bi.getGraphics();
        g.setColor(Color.WHITE);
        g.fillRect(0,0,width,height);
        Font mFont = new Font("Arial", Font.BOLD, 14);
        g.setFont(mFont);
        g.setColor(Color.RED);
        g.drawString(num,2,13);
        ImageIO.write(bi,"jpg",out);
    }
    
    public static void main(String[] args) throws IOException{
        String num = random();
        System.out.println(num);
        render(num,new FileOutputStream("D:\\test.jpg"));
        System.out.println("Image generated.");
    }
}