image_jsp.java

JAVA实验图形 =各种 的 JAVA简单代码 出初学者必备！！！！！！！！！

package org.apache.jsp;

import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.jsp.*;
import java.awt.*;
import java.awt.image.*;
import java.util.*;
import javax.imageio.*;

public final class image_jsp extends org.apache.jasper.runtime.HttpJspBase
    implements org.apache.jasper.runtime.JspSourceDependent {


Color getRandColor(int fc,int bc){//给定范围获得随机颜色
          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);
          }

  private static java.util.Vector _jspx_dependants;

  public java.util.List getDependants() {
    return _jspx_dependants;
  }

  public void _jspService(HttpServletRequest request, HttpServletResponse response)
        throws java.io.IOException, ServletException {

    JspFactory _jspxFactory = null;
    PageContext pageContext = null;
    HttpSession session = null;
    ServletContext application = null;
    ServletConfig config = null;
    JspWriter out = null;
    Object page = this;
    JspWriter _jspx_out = null;
    PageContext _jspx_page_context = null;


    try {
      _jspxFactory = JspFactory.getDefaultFactory();
      response.setContentType("image/jpeg;charset=gb2312");
      pageContext = _jspxFactory.getPageContext(this, request, response,
      			null, true, 8192, true);
      _jspx_page_context = pageContext;
      application = pageContext.getServletContext();
      config = pageContext.getServletConfig();
      session = pageContext.getSession();
      out = pageContext.getOut();
      _jspx_out = out;

      out.write('\n');
      out.write('\n');
      out.write('\n');
      out.write('\n');

//设置页面不缓存
response.setHeader("Pragma","No-cache");
response.setHeader("Cache-Control","no-cache");
response.setDateHeader("Expires", 0);

// 在内存中创建图象
int width=60, height=20;
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);

// 获取图形上下文
Graphics g = image.getGraphics();

//生成随机类
Random random = new Random();

// 设定背景色
g.setColor(getRandColor(200,250));
g.fillRect(0, 0, width, height);

//设定字体
g.setFont(new Font("Times New Roman",Font.PLAIN,18));

//画边框
//g.setColor(new Color());
//g.drawRect(0,0,width-1,height-1);

// 随机产生155条干扰线，使图象中的认证码不易被其它程序探测到
g.setColor(getRandColor(160,200));
for (int i=0;i<155;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);
}

// 取随机产生的认证码(4位数字)
String sRand="";
String rand="";
for (int i=0;i<4;i++){
      rand=String.valueOf(random.nextInt(10));
      sRand+=rand;
      // 将认证码显示到图象中
      g.setColor(new Color(20+random.nextInt(110),20+random.nextInt(110),20+random.nextInt(110)));
//调用函数出来的颜色相同，可能是因为种子太接近，所以只能直接生成
      g.drawString(rand,13*i+6,16);
}

// 图象生效
g.dispose();

// 将认证码存入SESSION
session.setAttribute("random",sRand);

// 输出图象到页面
ImageIO.write(image, "JPEG", response.getOutputStream());

      out.write('\n');
    } catch (Throwable t) {
      if (!(t instanceof SkipPageException)){
        out = _jspx_out;
        if (out != null && out.getBufferSize() != 0)
          out.clearBuffer();
        if (_jspx_page_context != null) _jspx_page_context.handlePageException(t);
      }
    } finally {
      if (_jspxFactory != null) _jspxFactory.releasePageContext(_jspx_page_context);
    }
  }
}