authimg.java

五种不同功能的jsp验证码提供下载

package web;

import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;
import com.sun.image.codec.jpeg.*;
import java.awt.*;
import java.awt.image.*;

/**
 * <p>Title: bbsOnline</p>
 * <p>Description: davidchowStudio BBS System</p>
 * <p>Copyright: Copyright (c) 2007</p>
 * <p>Company: davidchowstudio.com</p>
 * @author davidchow
 * @version 6.0
 */


public class AuthImg extends HttpServlet {

  private static final String CONTENT_TYPE = "text/html; charset=UTF-8";

  private Font mFont = new Font("Times New Roman", Font.PLAIN, 16);

  //Initialize global variables
  public void init() throws ServletException {
  }

  //Process the HTTP Get request
  public void doGet(HttpServletRequest request, HttpServletResponse response) throws
      ServletException, IOException {

//    UserCheck uc = new UserCheck(request, response);
//
//    uc.addAuthCode();
//    String s = uc.getAuthCode();
	
	String s = "7g3N";	//此处应随机生成
	
	// 设置图片的长宽
   int width = 60, height = 22;
   
    response.setContentType("image/jpeg");
    ServletOutputStream out = response.getOutputStream();
    BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
    Graphics gra = image.getGraphics();
    
    gra.setColor(Color.yellow);
    gra.fillRect(1, 1, width, height);
    gra.setColor(Color.black);
    gra.setFont(mFont);

    char c;
    for (int i = 0; i < 4; i++) {
      c = s.charAt(i);
      gra.drawString(String.valueOf(c), i * 13 + 4, 16);
    }

    JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
    encoder.encode(image);
    out.close();
  }

  //Process the HTTP Post request
  public void doPost(HttpServletRequest request, HttpServletResponse response) throws
      ServletException, IOException {
    doGet(request, response);
  }

  //Clean up resources
  public void destroy() {
  }
}