jsp常用功能模块-JSP实例学习教程

2007-09-30 09:55 乱世文章阅读(239) 评论(0) 编辑收藏举报

<!-- 显示任意年、月的日历，可选择不同的年、月。

author:wildfield -->

<%@ page language="java" import="java.util.*" %>

<%! String year;

String month;

<% month=request.getParameter("month");

year =request.getParameter("year");

<html>

<head>

<!--

function changeMonth()

{

var mm="calendar.jsp?month="+document.sm.elements[0].selectedIndex+"&year="

+<%=year%>;

window.open(mm,"_self");

}

//--></script>

</head>

<%! String days[]; %>

days=new String[42];

for(int i=0;i<42;i++)

{

days="";

}

Calendar thisMonth=Calendar.getInstance();

if(month!=null&&(!month.equals("null")))

thisMonth.set(Calendar.MONTH, Integer.parseInt(month) );

if(year!=null&&(!year.equals("null")))

thisMonth.set(Calendar.YEAR, Integer.parseInt(year) );

year=String.valueOf(thisMonth.get(Calendar.YEAR));

month=String.valueOf(thisMonth.get(Calendar.MONTH));

thisMonth.setFirstDayOfWeek(Calendar.SUNDAY);

thisMonth.set(Calendar.DAY_OF_MONTH,1);

int firstIndex=thisMonth.get(Calendar.DAY_OF_WEEK)-1;

int maxIndex=thisMonth.getActualMaximum(Calendar.DAY_OF_MONTH);

for(int i=0;i<maxIndex;i++)

{

days[firstIndex+i]=String.valueOf(i+1);

}

<body>

<%=year%>年 <%=Integer.parseInt(month)+1%>月

<tr>

</th>

<th width="25" height="16" bgcolor="#FFFF00"><font color="green">六</fon

t></th>

</tr>

<% for(int j=0;j<6;j++) { %>

<tr>

<% for(int i=j*7;i<(j+1)*7;i++) { %>

<td width="15%" height="16" bgcolor="#C0C0C0" valign="middle" align="ce

nter">

<a href="jump.jsp?year=<%=year%>&month=<%=Integer.parseInt(month)+1%>&d

ate=<%=days[i]%>" target="main"><%=days[i]%></a></td>

<% } %>

</tr>

<% } %>

</div>

</table>

<tr>

</select></td>

<td width=28%><input type=text name="year" value=<%=year%> size=4 maxlength

=4></td>

</tr>

</table>

</FORM>

<!--

document.sm.month.options.selectedIndex=<%=month%>;

//-->

</script>

</body>

</html>

　　JSP生成彩色验证码程序

　　生成有4个随机数字和杂乱背景的图片，数字和背景颜色会改变，服务器端刷新（用history.go(-1)也会变）

　　产生验证码图片的文件image.jsp

<%@ page contentType="image/jpeg" import="java.awt.*,
java.awt.image.*,java.util.*,javax.imageio.*" %>
<%!
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);
        }
%>
<%
//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="";
for (int i=0;i<4;i++){
    String 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);
}

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

// 图象生效
g.dispose();

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

使用验证码图片的文件a.jsp

<%@ page contentType="text/html;charset=gb2312" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>认证码输入页面</title>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<META HTTP-EQUIV="Pragma" CONTENT="no-cache">
<META HTTP-EQUIV="Cache-Control" CONTENT="no-cache">
<META HTTP-EQUIV="Expires" CONTENT="0">
</head>
<body>
<form method=post action="check.jsp">
<table>
<tr>
<td align=left>系统产生的认证码：</td>
<td><img border=0 src="image.jsp"></td>
</tr>
<tr>
<td align=left>输入上面的认证码：</td>
<td><input type=text name=rand maxlength=4 value=""></td>
</tr>
<tr>
<td colspan=2 align=center><input type=submit value="提交检测"></td>
</tr>
</form>
</body>
</html>

验证的页面check.jsp

<%@ page contentType="text/html; charset=gb2312" language="java" import="java.sql.*"

errorPage="" %>
<html>
<head>
<title>认证码验证页面</title>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<META HTTP-EQUIV="Pragma" CONTENT="no-cache">
<META HTTP-EQUIV="Cache-Control" CONTENT="no-cache">
<META HTTP-EQUIV="Expires" CONTENT="0">
</head>

<body>
<%
String rand = (String)session.getAttribute("rand");
String input = request.getParameter("rand");
%>
系统产生的认证码为： <%= rand %><br>
您输入的认证码为： <%= input %><br>
<br>
<%
if (rand.equals(input)) {
%>
<font color=green>输入相同，认证成功！</font>
<%
} else {
%>
<font color=red>输入不同，认证失败！</font>
<%
}
%>
</body>
</html>

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jsp常用功能模块-JSP实例学习教程

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