Java生成图片验证码
手动实现图片验证码生成
import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Arrays;
import java.util.Random;
public class VerificationCode {
private static Random random = new Random(7);
/**
* 指定色系范围随机生成颜色 ，随机公式 RGB = fc + random.nextInt(Math.abs(bc - fc))
* @param fc
* @param bc
* @return
*/
private static Color getRandColor(int fc, int bc) {
if (fc > 255)
fc = 255;
if (bc > 255)
bc = 255;
int temp = Math.abs(bc - fc);
int r = fc + random.nextInt(temp);
int g = fc + random.nextInt(temp);
int b = fc + random.nextInt(temp);
return new Color(r, g, b);
}
/**
* 随机生成一个颜色数值
* @return
*/
private static int getRandomIntColor() {
int[] rgb = getRandomRgb();
int color = 0;
for (int c : rgb) {
color = color << 8;
color = color | c;
}
return color;
}
/**
* 随机生成三原色并返回
* @return
*/
private static int[] getRandomRgb() {
int[] rgb = new int[3];
for (int i = 0; i < 3; i++) {
rgb[i] = random.nextInt(255);
}
return rgb;
}
/**
* 将图片内容扭曲
* @param g
* @param w1
* @param h1
* @param color
*/
private static void shear(Graphics g, int w1, int h1, Color color) {
shearX(g, w1, h1, color);
shearY(g, w1, h1, color);
}
private static void shearX(Graphics g, int w1, int h1, Color color) {
int period = random.nextInt(2);
boolean borderGap = true;
int frames = 1;
int phase = random.nextInt(2);
for (int i = 0; i < h1; i++) {
double d = (double) (period >> 1)
* Math.sin((double) i / (double) period
+ (6.2831853071795862D * (double) phase)
/ (double) frames);
g.copyArea(0, i, w1, 1, (int) d, 0);
if (borderGap) {
g.setColor(color);
g.drawLine((int) d, i, 0, i);
g.drawLine((int) d + w1, i, w1, i);
}
}
}
private static void shearY(Graphics g, int w1, int h1, Color color) {
int period = random.nextInt(40) + 10; // 50;
boolean borderGap = true;
int frames = 20;
int phase = 7;
for (int i = 0; i < w1; i++) {
double d = (double) (period >> 1)
* Math.sin((double) i / (double) period
+ (6.2831853071795862D * (double) phase)
/ (double) frames);
g.copyArea(i, 0, 1, h1, 0, (int) d);
if (borderGap) {
g.setColor(color);
g.drawLine(i, (int) d, i, 0);
g.drawLine(i, (int) d + h1, i, h1);
}
}
}
/**
* 获取验证码图片
* @param w 图片宽度
* @param h 图片高度
* @param os 图片保存的流
* @param code 验证码
* @throws IOException
*/
public static void getCodeImage(int w, int h, OutputStream os, String code) throws IOException {
BufferedImage bufferedImage = new BufferedImage(w,h,BufferedImage.TYPE_INT_RGB);
Graphics2D graphics2D = bufferedImage.createGraphics();
graphics2D.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON);
Color[] colors = new Color[5];
Color[] colorSpaces = new Color[] { Color.WHITE, Color.CYAN,
Color.GRAY, Color.LIGHT_GRAY, Color.MAGENTA, Color.ORANGE,
Color.PINK, Color.YELLOW };
float[] fractions = new float[colors.length];
for(int i = 0; i < colors.length; i++){
colors[i] = colorSpaces[random.nextInt(colorSpaces.length)];
fractions[i] = random.nextFloat();
}
Arrays.sort(fractions);
graphics2D.setColor(Color.GRAY);// 设置边框色
graphics2D.fillRect(0, 0, w, h);
// 随机颜色并设置背景色
Color randColor = getRandColor(200, 250);
graphics2D.setColor(randColor);// 设置背景色
graphics2D.fillRect(0, 2, w, h-4);
//绘制干扰线
graphics2D.setColor(getRandColor(0, 255));// 设置线条的颜色
for (int i = 0; i < 15; i++) {
int x = 0;
int y = random.nextInt(h - 1);
int xl = w - 1;
int yl = random.nextInt(w - 1);
graphics2D.drawLine(x, y, xl, yl);
}
// 添加噪点
float yawpRate = 0.05f;// 噪声率
int area = (int) (yawpRate * w * h);
for (int i = 0; i < area; i++) {
int x = random.nextInt(w);
int y = random.nextInt(h);
int rgb = getRandomIntColor();
bufferedImage.setRGB(x, y, rgb);
}
shear(graphics2D, w, h, randColor);// 使图片扭曲
int verifySize = 4;
graphics2D.setColor(getRandColor(100, 160));
int fontSize = h-4;
// 设置字体
Font font = new Font("Algerian", Font.ITALIC, fontSize);
graphics2D.setFont(font);
char[] chars = code.toCharArray();
for(int i = 0; i < verifySize; i++){
AffineTransform affine = new AffineTransform();
affine.setToRotation(Math.PI / 4 * random.nextDouble() * (random.nextBoolean() ? 1 : -1), (w / verifySize) * i + fontSize/2, h/2);
graphics2D.setTransform(affine);
graphics2D.drawChars(chars, i, 1, ((w-10) / verifySize) * i + 5, h/2 + fontSize/2 - 10);
}
graphics2D.dispose();
ImageIO.write(bufferedImage, "jpg", os);
}
}
调用演示
OutputStream os = new FileOutputStream("/home/test.jpg");
VerificationCode.getCodeImage(90, 30, os, "anca");