本文共 3634 字，大约阅读时间需要 12 分钟。

VerifyCode.java:

package com.xjs.image;import java.awt.BasicStroke;import java.awt.Color;import java.awt.Font;import java.awt.Graphics2D;import java.awt.image.BufferedImage;import java.io.IOException;import java.io.OutputStream;import java.util.Random;import javax.imageio.ImageIO;public class VerifyCode {    private int w = 70;    private int h = 35;     private Random r = new Random();     // {"宋体", "华文楷体", "黑体", "华文新魏", "华文隶书", "微软雅黑", "楷体_GB2312"}    private String[] fontNames  = {"宋体", "华文楷体", "黑体", "微软雅黑", "楷体_GB2312"};    // 可选字符    private String codes  = "23456789abcdefghjkmnopqrstuvwxyzABCDEFGHJKMNPQRSTUVWXYZ";    // 背景色    private Color bgColor  = new Color(255, 255, 255);    // 验证码上的文本    private String text ;    // 生成随机的颜色    private Color randomColor () {        int red = r.nextInt(150);        int green = r.nextInt(150);        int blue = r.nextInt(150);        return new Color(red, green, blue);    }    // 生成随机的字体    private Font randomFont () {        int index = r.nextInt(fontNames.length);        String fontName = fontNames[index];//生成随机的字体名称        int style = r.nextInt(4);//生成随机的样式, 0(无样式), 1(粗体), 2(斜体), 3(粗体+斜体)        int size = r.nextInt(5) + 24; //生成随机字号, 24 ~ 28        return new Font(fontName, style, size);    }    // 画干扰线    private void drawLine (BufferedImage image) {        int num  = 3;//一共画3条        Graphics2D g2 = (Graphics2D)image.getGraphics();        for(int i = 0; i < num; i++) {//生成两个点的坐标，即4个值            int x1 = r.nextInt(w);            int y1 = r.nextInt(h);            int x2 = r.nextInt(w);            int y2 = r.nextInt(h);            g2.setStroke(new BasicStroke(1.5F));            g2.setColor(Color.BLUE); //干扰线是蓝色            g2.drawLine(x1, y1, x2, y2);//画线        }    }    // 随机生成一个字符    private char randomChar () {        int index = r.nextInt(codes.length());        return codes.charAt(index);    }    // 创建BufferedImage    private BufferedImage createImage () {        BufferedImage image = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);        Graphics2D g2 = (Graphics2D)image.getGraphics();        g2.setColor(this.bgColor);        g2.fillRect(0, 0, w, h);         return image;    }    // 调用这个方法得到验证码    public BufferedImage getImage () {        BufferedImage image = createImage();//创建图片缓冲区        Graphics2D g2 = (Graphics2D)image.getGraphics();//得到绘制环境        StringBuilder sb = new StringBuilder();//用来装载生成的验证码文本        // 向图片中画4个字符        for(int i = 0; i < 4; i++)  {//循环四次，每次生成一个字符            String s = randomChar() + "";//随机生成一个字母            sb.append(s); //把字母添加到sb中            float x = i * 1.0F * w / 4; //设置当前字符的x轴坐标            g2.setFont(randomFont()); //设置随机字体            g2.setColor(randomColor()); //设置随机颜色            g2.drawString(s, x, h-5); //画图        }        this.text = sb.toString(); //把生成的字符串赋给了this.text        drawLine(image); //添加干扰线        return image;    }    // 返回验证码图片上的文本    public String getText () {        return text;    }    // 保存图片到指定的输出流    public static void output (BufferedImage image, OutputStream out)                throws IOException {        ImageIO.write(image, "JPEG", out);    }}

测试：

import java.awt.image.BufferedImage;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.IOException;import org.junit.Test;public class Demo {    @Test    public void fun1() throws FileNotFoundException, IOException{        VerifyCode vc=new VerifyCode();        BufferedImage bi=vc.getImage();//得到验证码图片，是一个BufferedImage类型的        VerifyCode.output(bi, new FileOutputStream("F://VerifyCode.jpg"));        System.out.println(vc.getText());    }}

运行后会在指定文件路径下生成一张图片，以及在控制台打印图片上的文本。

转载地址：http://pwloi.baihongyu.com/