package cn.hncu.img;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Random;

import javax.imageio.ImageIO;

import org.junit.Test;

public class imgDemo {
	@Test
	// 學習如何吧一個字串寫到一個檔案
	public void ImgDemo1() throws FileNotFoundException, IOException {

		BufferedImage img = new BufferedImage(60, 30,
				BufferedImage.TYPE_INT_RGB);
		Graphics g = img.getGraphics();// 獲得畫板
		g.drawString("Hello", 0, 10);
		g.dispose();// 功能相當於flush();
		ImageIO.write(img, "JPEG", new FileOutputStream("d:/a/a.jpg"));
	}

	// 把上面的字串改成平常用的驗證碼--生成幾個隨機數字，有背景色，有干擾線
	@Test
	public void ImgDemo2() throws FileNotFoundException, IOException {
		int width = 70;
		int height = 40;
		BufferedImage img = new BufferedImage(width, height,
				BufferedImage.TYPE_INT_RGB);
		Graphics g = img.getGraphics();// 獲得畫板
		// 設定背景色
		g.setColor(Color.white);
		g.fillRect(0, 0, width, height);// 畫背景

		// 設定字型
		g.setFont(new Font("黑體", Font.BOLD, 18));

		// 設定隨機數字
		Random r = new Random();
		for (int i = 0; i < 4; i++) {
			int a = r.nextInt(10);// 10個隨機數字
			int y = r.nextInt(20) + 10; // 10~30範圍內的一個整數，作為y座標
			Color c = new Color(r.nextInt(255), r.nextInt(255), r.nextInt(255));
			g.setColor(c);
			g.drawString("" + a, 5 + i * 15, y);
		}

		// 干擾線
		for (int i = 0; i < 10; i++) {// 設定10條幹擾線
			Color c = new Color(r.nextInt(255), r.nextInt(255), r.nextInt(255));
			g.setColor(c);
			g.drawOval(0, 0, width, height);
			g.drawLine(r.nextInt(width), r.nextInt(height), r.nextInt(width),
					r.nextInt(height));
		}
		g.dispose();// 功能相當於flush();
		ImageIO.write(img, "JPEG", new FileOutputStream("d:/a/a.jpg"));
	}

	@Test
	// 可以旋轉和放縮的驗證碼
	public void ImgDemo3() throws FileNotFoundException, IOException {
		int width = 80;
		int height = 40;

		BufferedImage img = new BufferedImage(width, height,
				BufferedImage.TYPE_INT_RGB);
		Graphics g = img.getGraphics();
		Graphics2D g2d = (Graphics2D) g;

		g2d.setFont(new Font("黑體", Font.BOLD, 20));
		Random r = new Random();
		for (int i = 0; i < 4; i++) {
			String str = "" + r.nextInt(10);

			AffineTransform aff = new AffineTransform();//旋轉函式（AffineTransform）
			aff.rotate(Math.random(), i * 20, height - 5);//旋轉角度
			aff.scale(0.6 + Math.random(), 0.6 + Math.random());
			g2d.setTransform(aff);

			g2d.drawString(str, 5 + i * 15, height - 5);
		}
		g2d.dispose();// 類似於流中的close()帶動flush()---把資料刷到img物件當中
		ImageIO.write(img, "JPEG", new FileOutputStream("d:/a/a.jpg"));
	}

}