BlogJava-我爱JAVA-随笔分类-J2EEhttp://www.blogjava.net/flustar/category/18560.htmlzh-cnFri, 02 Mar 2007 06:33:52 GMTFri, 02 Mar 2007 06:33:52 GMT60用java实现彩色验证码http://www.blogjava.net/flustar/archive/2006/12/20/89043.htmlflustarflustarWed, 20 Dec 2006 07:06:00 GMThttp://www.blogjava.net/flustar/archive/2006/12/20/89043.htmlhttp://www.blogjava.net/flustar/comments/89043.htmlhttp://www.blogjava.net/flustar/archive/2006/12/20/89043.html#Feedback0http://www.blogjava.net/flustar/comments/commentRss/89043.htmlhttp://www.blogjava.net/flustar/services/trackbacks/89043.html <%@ page language="java" contentType="image/jpeg"
    pageEncoding="gb2312"%>
<%@ page import="java.awt.*,java.awt.image.*,java.util.*,javax.imageio.*"%>

<%!
   Color getRandColor(int fc,int bc){
 Random rand=new Random();
 if(fc>255) fc=255;
 if(bc>255) bc=255;
 int r=fc+rand.nextInt(bc-fc);
 int g=fc+rand.nextInt(bc-fc);
 int b=fc+rand.nextInt(bc-fc);
 return new Color(r,g,b);
}
%>
<%
  //设置页面不缓存
  response.setHeader("Pragma","No-cache");
  response.setHeader("Cache-Control","no-cache");
  response.setDateHeader("Expires",0);
 
  //在内存中创建图像
  int width=60,height=20;
  BufferedImage image=new BufferedImage(width,height,BufferedImage.TYPE_INT_BGR);
 
  //获取图像
  Graphics g=image.getGraphics();
  //生成随机类
  Random rand=new Random();
  //设定背景颜色
  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));
//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=rand.nextInt(width);
  int y=rand.nextInt(height);
  int x1=rand.nextInt(12);
  int y1=rand.nextInt(12);
  g.drawLine(x,y,x+x1,y+y1);
 
 }
 //取随机产生的4位验证码
 String sRand="";
 for(int i=0;i<4;i++){
  String strRand=String.valueOf(rand.nextInt(10));
  sRand+=strRand;
  //将验证码显示到图像中
  g.setColor(new Color(20+rand.nextInt(110),20+rand.nextInt(110),20+rand.nextInt(110)));
  g.drawString(strRand,13*i+6,16);

 }
 //将验证码放入session
  session.setAttribute("rand",sRand);
 
 g.dispose();
//输出图象到页面
 ImageIO.write(image, "JPEG", response.getOutputStream());

 

%>



flustar 2006-12-20 15:06 发表评论
]]>用JSP实现下拉列表框三级联动效果http://www.blogjava.net/flustar/archive/2006/12/20/89041.htmlflustarflustarWed, 20 Dec 2006 07:03:00 GMThttp://www.blogjava.net/flustar/archive/2006/12/20/89041.htmlhttp://www.blogjava.net/flustar/comments/89041.htmlhttp://www.blogjava.net/flustar/archive/2006/12/20/89041.html#Feedback0http://www.blogjava.net/flustar/comments/commentRss/89041.htmlhttp://www.blogjava.net/flustar/services/trackbacks/89041.html一、在数据库数据库中建立三个表
1.city
字段：
districtname，locationid，districtid
2.province
字段：
locationid，locationname
3.village
字段：
villageid,villagename,districtid
二、代码如下：
<%@ page language="java" contentType="text/html; charset=gb2312"
    pageEncoding="gb2312"%>
<%@ page import="java.sql.* "%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>jsp实现三级联动的下拉列表框效果</title>
<%
   Connection conn=null;
   Statement stmt=null;
   ResultSet rs=null,rs1=null,rs2=null;
   String sql;
   int count;
   int count2;
   String drivername="com.microsoft.jdbc.sqlserver.SQLServerDriver";
   String url="jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=SJLD";
   try{
    Class.forName(drivername);
    conn=DriverManager.getConnection(url,"sa","");
    stmt=conn.createStatement（）;
    sql="select * from city order by locationid asc";
    rs=stmt.executeQuery(sql);
   }catch(SQLException e){
    System.out.println(e.getMessage());
   }
  
%>
<script language="javascript">
var onecount;
onecount=0;
subcat=new Array();
<%
count=0;
while(rs.next()){
 %>
 subcat[<%=count%>]=new Array("<%=rs.getString("districtname")%>","<%=rs.getInt("locationid")%>","<%=rs.getInt("districtid")%>");
 <%
 count = count + 1 ;

}
rs.close();
rs=null;
%>
onecount=<%=count%>;
function changelocation(locationid){
document.myform.smalllocation.length=0;
var locationid=locationid;
var i;
document.myform.smalllocation.options[0]=new Option('==所选城市的地区==','');
for(i=0;i<onecount;i++){
if (subcat[i][1] == locationid)
{
document.myform.smalllocation.options[document.myform.smalllocation.length] = new Option(subcat[i][0], subcat[i][2]);
}
}

  
}
</script>
<%
 sql="select * from village order by districtid asc";
 rs2=stmt.executeQuery(sql);
%>
<script language="javascript">
var onecount2;
onecount2=0;
subcat2=new Array();
<%
count2=0;
while(rs2.next()){
 %>
 subcat2[<%=count2%>]=new Array("<%=rs2.getString("villagename")%>","<%=rs2.getInt("districtid")%>","<%=rs2.getInt("villageid")%>");
 <%
 count2 = count2 + 1 ;

}
rs2.close();
rs2=null;
%>
onecount2=<%=count2%>;
function changelocation2(districtid)
{
document.myform.village.length = 0;

var districtid=districtid;
var j;
document.myform.village.options[0] = new Option('==所选地区的县区==','');
for (j=0;j < onecount2; j++)
{
  if (subcat2[j][1] == districtid)
 {
  document.myform.village.options[document.myform.village.length] = new Option(subcat2[j][0], subcat2[j][2]);
  }
}

}
</script>

</head>
<body>
<form name="myform" method="post">
分类：<select name="biglocation" onChange="changelocation(document.myform.biglocation.options[document.myform.biglocation.selectedIndex].value)" size="1">
<option selected>请选择你所在的省份</option>
<%
  sql ="select * from province order by locationname asc";
 rs1 = stmt.executeQuery(sql);
 while(rs1.next()){
 %>
 <option value="<%=rs1.getInt("locationid")%>"><%=rs1.getString("locationname")%></option>

 <% }
 
 
 rs1.close();
 rs1 = null;
 conn.close();
 conn =null;


%>
</select><select name="smalllocation" onChange="changelocation2(document.myform.smalllocation.options[document.myform.smalllocation.selectedIndex].value)">
<option selected value="">==所有地区==</option>
</select><select name="village" size="1">
<option selected>==所有县区==</option>
</select>
</form>

</body>
</html>



flustar 2006-12-20 15:03 发表评论
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