标签：
Servlet部分：
package servlet;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;
import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class LoginServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
// 产生随即的字体
private Font getFont() {
Random random = new Random();
Font font[] = new Font[5];
font[0] = new Font( "Ravie", Font. PLAIN, 24);
font[1] = new Font( "Antique Olive Compact", Font.PLAIN, 24);
font[2] = new Font( "Forte", Font. PLAIN, 24);
font[3] = new Font( "Wide Latin", Font. PLAIN, 24);
font[4] = new Font( "Gill Sans Ultra Bold", Font.PLAIN, 24);
return font[ random.nextInt(5)];
}
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost( request, response);
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
// 设置响应头 Content-type类型
response.setContentType( "image/jpeg");
// 以下三句是用于设置页面不缓存
response.setHeader( "Pragma", "No-cache");
response.setHeader( "Cache-Control", "No-cache");
response.setDateHeader( "Expires", 0);
OutputStream os = response.getOutputStream();
int width = 83, height = 30;
// 建立指定宽、高和BufferedImage对象
BufferedImage image = new BufferedImage( width, height, BufferedImage. TYPE_INT_RGB);
Graphics g = image.getGraphics(); // 该画笔画在image上
Color c = g.getColor(); // 保存当前画笔的颜色，用完画笔后要回复现场
g.fillRect(0, 0, width, height);
char[] ch = "abcdefghjkmnpqrstuvwxyz23456789" .toCharArray(); // 随即产生的字符串
// 不包括 i
// l(小写L)
// o（小写O）
// 1（数字1）0(数字0)
int length = ch. length; // 随即字符串的长度
String sRand = ""; // 保存随即产生的字符串
Random random = new Random();
for ( int i = 0; i < 4; i++) {
// 设置字体
g.setFont(getFont());
// 随即生成0-9的数字
String rand = new Character(ch[ random.nextInt( length)]).toString();
sRand += rand;
// 设置随机颜色
g.setColor( new Color( random.nextInt(255), random.nextInt(255), random.nextInt(255)));
g.drawString( rand, 20 * i + 6, 25);
}
// 产生随即干扰点
for ( int i = 0; i < 20; i++) {
int x1 = random.nextInt( width);
int y1 = random.nextInt( height);
g.drawOval( x1, y1, 2, 2);
}
g.setColor( c); // 将画笔的颜色再设置回去
g.dispose();
// 将验证码记录到session
request.getSession().setAttribute( "safecode", sRand);
// 输出图像到页面
ImageIO. write(image, "JPEG", os);
}
}
前端Jsp:
<%
String action = request.getParameter( "action");
String safecodeText = request.getParameter( "safecodeTest");
if("action".equals(action)){
String safecode = (String)session.getAttribute("safecode" );
if(safecode.equals(safecodeText)){
out.print( "验证码正确！" );
}else{
out.print( "验证码错误！请重新输入！" );
}
}
%>
< head>
<title >验证码测试 </title >
</ head>
< body>
<form action ="index.jsp" method="post">
<input type ="hidden" name="action" value= "action"/>
<img alt ="验证码" src= "login">
<input type ="text" name="safecodeTest">
<input type ="submit" value="go">
</form >
</ body>
</html>
Servlet部分：
package servlet;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;
import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class LoginServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
// 产生随即的字体
private Font getFont() {
Random random = new Random();
Font font[] = new Font[5];
font[0] = new Font( "Ravie", Font. PLAIN, 24);
font[1] = new Font( "Antique Olive Compact", Font.PLAIN, 24);
font[2] = new Font( "Forte", Font. PLAIN, 24);
font[3] = new Font( "Wide Latin", Font. PLAIN, 24);
font[4] = new Font( "Gill Sans Ultra Bold", Font.PLAIN, 24);
return font[ random.nextInt(5)];
}
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost( request, response);
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
// 设置响应头 Content-type类型
response.setContentType( "image/jpeg");
// 以下三句是用于设置页面不缓存
response.setHeader( "Pragma", "No-cache");
response.setHeader( "Cache-Control", "No-cache");
response.setDateHeader( "Expires", 0);
OutputStream os = response.getOutputStream();
int width = 83, height = 30;
// 建立指定宽、高和BufferedImage对象
BufferedImage image = new BufferedImage( width, height, BufferedImage. TYPE_INT_RGB);
Graphics g = image.getGraphics(); // 该画笔画在image上
Color c = g.getColor(); // 保存当前画笔的颜色，用完画笔后要回复现场
g.fillRect(0, 0, width, height);
char[] ch = "abcdefghjkmnpqrstuvwxyz23456789" .toCharArray(); // 随即产生的字符串
// 不包括 i
// l(小写L)
// o（小写O）
// 1（数字1）0(数字0)
int length = ch. length; // 随即字符串的长度
String sRand = ""; // 保存随即产生的字符串
Random random = new Random();
for ( int i = 0; i < 4; i++) {
// 设置字体
g.setFont(getFont());
// 随即生成0-9的数字
String rand = new Character(ch[ random.nextInt( length)]).toString();
sRand += rand;
// 设置随机颜色
g.setColor( new Color( random.nextInt(255), random.nextInt(255), random.nextInt(255)));
g.drawString( rand, 20 * i + 6, 25);
}
// 产生随即干扰点
for ( int i = 0; i < 20; i++) {
int x1 = random.nextInt( width);
int y1 = random.nextInt( height);
g.drawOval( x1, y1, 2, 2);
}
g.setColor( c); // 将画笔的颜色再设置回去
g.dispose();
// 将验证码记录到session
request.getSession().setAttribute( "safecode", sRand);
// 输出图像到页面
ImageIO. write(image, "JPEG", os);
}
}
前端Jsp:
<%
String action = request.getParameter( "action");
String safecodeText = request.getParameter( "safecodeTest");
if("action".equals(action)){
String safecode = (String)session.getAttribute("safecode" );
if(safecode.equals(safecodeText)){
out.print( "验证码正确！" );
}else{
out.print( "验证码错误！请重新输入！" );
}
}
%>
< head>
<title >验证码测试 </title >
</ head>
< body>
<form action ="index.jsp" method="post">
<input type ="hidden" name="action" value= "action"/>
<img alt ="验证码" src= "login">
<input type ="text" name="safecodeTest">
<input type ="submit" value="go">
</form >
</ body>
</html>
Jsp验证码
标签：
原文地址：http://www.cnblogs.com/phantomfjh/p/4959496.html
