svltcheckcode.java

最简单的生成验证码图片的程序

package com.sparrow.test;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;

import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class SvltCheckCode extends HttpServlet{

	public SvltCheckCode(){
		super();
	}

	public void doGet(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException{
		doPost(request,response);
	}

	public void doPost(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException{
		response.setHeader("pragma","no-cache");
		response.setHeader("cache-control","no-cache");
		response.setDateHeader("expires",0);

		int width=70;
		int height=20;
		BufferedImage image=new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);
		Graphics g=image.getGraphics();
		g.setColor(new Color(0,0,0));//设置前景颜色
		g.fillRect(0,0,width,height);//填充图片区域
		g.setFont(new Font("Times New Roman",Font.ITALIC,height));//设置字体
		g.setColor(new Color(255,255,255));//设置前景颜色
		g.drawLine(0,0,70,20);//画线

		StringBuilder s=new StringBuilder();
		s.append("EDFG");
		g.drawString(s.toString(),0,height-4);//写字符串

		g.dispose();

		try{
			Thread.sleep(100);
		}catch(Exception ex){
		}

		OutputStream os=response.getOutputStream();
		ImageIO.write(image,"JPEG",os);
		os.flush();
		os.close();
	}

}