codeimg.java

本程序是作者开发的一个宽带娱乐系统的一个模块.

package com.singnet.util;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Random;

import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGImageDecoder;
import com.sun.image.codec.jpeg.JPEGImageEncoder;

public class Codeimg extends HttpServlet {

	private static final String CONTENT_TYPE = "image/jpeg;charset=GBK";
	  private String imageFile =""; //被嵌的图片的路径D:/Tomcat 5.5/webapps/personal/code/codebg
	  private int x = 2; //显示坐标X
	  private int y = 18; //显示坐标Y
	  private String fontColor = "ffffff"; //字体颜色
	  private int fontSize = 16; //字体大小
	  private String fontName = ""; //字体名称
	  private int fontnum = 6; //验证码的长度

	  public void init() throws ServletException {
	  }

	  private StringBuffer getCode() {
	    String str =
	        "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
	    StringBuffer sb = new StringBuffer(fontnum);
	    String strreturn;
	    Random random = new Random();
	    for (int i = 0; i < fontnum; i++) {
	      int tmpint = Math.abs(random.nextInt()) % 36;
	      sb.append(str.charAt(tmpint));
	    }
	    return sb;
	  } //end getCode

	  public void doGet(HttpServletRequest request, HttpServletResponse response) throws
	      ServletException, IOException {
	    //PrintWriter out = response.getWriter();
	    HttpSession session = request.getSession(true);
	    session.setMaxInactiveInterval(90); //设定90秒后session失效
	    String text = getCode().toString(); //获得要嵌的文字
	    session.setAttribute("code", text);

	    ServletOutputStream output = response.getOutputStream();
	    imageFile=request.getRealPath("/")+"Codeimg.jpg";
	    //System.out.print(imageFile);
	    File bgfile = new File(imageFile);
	    InputStream imageIn = new FileInputStream(bgfile);
	    JPEGImageDecoder decoder = JPEGCodec.createJPEGDecoder(imageIn);
	    BufferedImage image = decoder.decodeAsBufferedImage();
	    Graphics grap = image.getGraphics();
	    //设置颜色
	    Color fontcolor = new Color(Integer.parseInt(fontColor, 16));
	    grap.setColor(fontcolor);

	    //设置字体
	    Font mFont = new Font(fontName, Font.PLAIN, fontSize); //默认字体
	    grap.setFont(mFont);

	    //输出文字
	    grap.drawString(text, x, y);

	    //输出数据流
	    JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(output);
	    encoder.encode(image);

	    imageIn.close();
	    output.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() {
	  }
}