Java字符串验证码生成

生成的验证码效果如下：

                        

代码如下：

package com.hh.test;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.util.Random;

import javax.imageio.ImageIO;
import javax.imageio.stream.ImageOutputStream;
import javax.servlet.http.HttpServletResponse;

import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;

public class RandomAction extends ActionSupport{
	private ByteArrayInputStream inputStream;
	public String execute() throws Exception{
//		 在内存中创建图象
		int width = 65, height = 24;
		BufferedImage image = new BufferedImage(width, height,BufferedImage.TYPE_INT_RGB);
		Graphics g = image.getGraphics();
		Random random = new Random();
		g.setColor(getRandColor(200, 250));
		g.fillRect(0, 0, width, height);
		g.setFont(new Font("Times New Roman", Font.PLAIN, 24));
		g.setColor(getRandColor(160, 200));

		for (int i = 0; i < 150; i++) {
			int x = random.nextInt(width);
			int y = random.nextInt(height);
			int xl = random.nextInt(12);
			int yl = random.nextInt(12);
			g.drawLine(x, y, x + xl, y + yl);
		}

		//画边框
		g.setColor(new Color(50,143,207));
		g.drawRect(0, 0, width-1, height-1);
//		 取随机产生的认证码(6位数字)
		String sRand="";
		char[] codeSequence = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H','K', 'M', 'N', 'P','R','S','T','W','X', 'Y','3', '4', '5', '6', '7', '8', '9'};
		for (int i = 0; i < 4; i++) {
			String rand = String.valueOf(codeSequence[random.nextInt(codeSequence.length)]);
			sRand += rand;
			g.setColor(new Color(20 + random.nextInt(110), 20 + random.nextInt(110), 20 + random.nextInt(110)));
			g.drawString(rand, 13 * i + 6, 20);
		}
		Object object = ActionContext.getContext().getSession().get("rand");
		if(null!=object){
			ActionContext.getContext().getSession().remove("rand");
		}
//		 将认证码存入SESSION
		ActionContext.getContext().getSession().put("rand",sRand);
		System.out.println("action中生成的验证码为："+sRand);
		 HttpServletResponse response = ServletActionContext.getResponse();
		 response.setHeader("Pragma", "No-cache");
		 response.setHeader("Cache-Control", "no-cache");
		 response.setDateHeader("Expires", 0);
//		 图象生效
		g.dispose();
		ByteArrayOutputStream output = new ByteArrayOutputStream();
        ImageOutputStream imageOut = ImageIO.createImageOutputStream(output);
        ImageIO.write(image, "JPEG", imageOut);
        imageOut.close();
        ByteArrayInputStream input = new ByteArrayInputStream(output.toByteArray());
        this.setInputStream(input);
		return SUCCESS;
	}
	/*
	 * 给定范围获得随机颜色
	 */
	private Color getRandColor(int fc,int bc){
        Random random = new Random();
        if(fc>255) fc=255;
        if(bc>255) bc=255;
        int r=fc+random.nextInt(bc-fc);
        int g=fc+random.nextInt(bc-fc);
        int b=fc+random.nextInt(bc-fc);
        return new Color(r,g,b);
   }
	public void setInputStream(ByteArrayInputStream inputStream) {
		this.inputStream = inputStream;
	}
	public ByteArrayInputStream getInputStream() {
		return inputStream;
	}

}

具体页面引用方式已经配置方法，见

加法验证码生成