Posted on 2009-05-25 23:19
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J2SE
這里介紹一個簡單struts2的驗證碼程序：
package com.yan;
import java.io.ByteArrayInputStream;
import com.opensymphony.xwork2.Action;
import com.opensymphony.xwork2.ActionContext;
/**
* 輸出驗證碼的Action
* @author Billy
*/
public class RandomAction{
private static final long serialVersionUID = -540011645418859040L;
private ByteArrayInputStream inputStream;
public ByteArrayInputStream getInputStream() {
return inputStream;
}
public void setInputStream(ByteArrayInputStream inputStream) {
this.inputStream = inputStream;
}
public String execute() {
RandomNumUtil rdnu=RandomNumUtil.Instance();
this.setInputStream(rdnu.getImage());//取得帶有隨機字符串的圖片
ActionContext.getContext().getSession().put("VerificationCode", rdnu.getString());//取得隨機字符串放入HttpSession
return Action.SUCCESS;
}
}
package com.yan;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.util.Random;
import javax.imageio.ImageIO;
import javax.imageio.stream.ImageOutputStream;
public class RandomNumUtil {
private ByteArrayInputStream image;// 圖像
private String str;// 驗證碼
private static int width = 60;// 驗證碼圖片的長度
private static int height = 20; // 驗證碼圖片的高度
private static int number = 4;// 驗證碼的位數
private RandomNumUtil() {
init();// 初始化屬性
}
/*
* 取得RandomNumUtil實例
*/
public static RandomNumUtil Instance() {
return new RandomNumUtil();
}
/*
* 取得驗證碼圖片
*/
public ByteArrayInputStream getImage() {
return this.image;
}
/*
* 取得圖片的驗證碼
*/
public String getString() {
return this.str;
}
private void init() {
// 在內存中創建圖象
BufferedImage image = new BufferedImage(width, height,
BufferedImage.TYPE_INT_RGB);
// 獲取圖形上下文
Graphics g = image.getGraphics();
// 生成隨機類
Random random = new Random();
// 設定背景色
g.setColor(getRandColor(200, 250));
g.fillRect(0, 0, width, height);
// 設定字體
g.setFont(new Font("Times New Roman", Font.PLAIN, 18));
// 隨機產生155條干擾線，使圖象中的認證碼不易被其它程序探測到
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);
}
// 取隨機產生的認證碼(6位數字)
String sRand = "";
for (int i = 0; i < number; i++) {
String rand = String.valueOf(random.nextInt(10));
sRand += rand;
// 將認證碼顯示到圖象中
g.setColor(new Color(20 + random.nextInt(110), 20 + random
.nextInt(110), 20 + random.nextInt(110)));
// 調用函數出來的顏色相同，可能是因為種子太接近，所以只能直接生成
g.drawString(rand, 13 * i + 6, 16);
}
// 賦值驗證碼
this.str = sRand;
// 圖象生效
g.dispose();
ByteArrayInputStream input = null;
ByteArrayOutputStream output = new ByteArrayOutputStream();
try {
ImageOutputStream imageOut = ImageIO
.createImageOutputStream(output);
ImageIO.write(image, "JPEG", imageOut);
imageOut.close();
input = new ByteArrayInputStream(output.toByteArray());
} catch (Exception e) {
System.out.println("驗證碼圖片產生出現錯誤：" + e.toString());
}
this.image = input;/* 賦值圖像 */
}
/*
* 給定范圍獲得隨機顏色
*/
private Color getRandColor(int fc, int bc) {
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);
}
}
struts.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
"http://struts.apache.org/dtds/struts-2.0.dtd">
<struts>
<include file="struts-default.xml"/>
<package name="ryan" extends="struts-default">
<action name="random" class="com.yan.RandomAction">
<result type="stream">
<param name="contentType">image/jpeg</param>
<param name="inputName">inputStream</param>
</result>
</action>
<action name="phoenix" class="com.yan.PhoenixAction">
<result name="input">/identifying.jsp</result>
<result name="success">/success.jsp</result>
</action>
</package>
</struts>
頁面
<%@ page language="java" pageEncoding="utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<%@ taglib prefix="s" uri="/struts-tags"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<script type="text/javascript">
function changeValidateCode(obj) {
//獲取當前的時間作為參數，無具體意義
var timenow = new Date().getTime();
//每次請求需要一個不同的參數，否則可能會返回同樣的驗證碼
//這和瀏覽器的緩存機制有關系，也可以把頁面設置為不緩存，這樣就不用這個參數了。
obj.src="random.action?d="+timenow;
}
</script>
</head>
<body>
<s:fielderror></s:fielderror>
<s:form action="phoenix">
<s:textfield name="inputCode" id="inputCode" cssStyle="width:81px"/><img src="random.action" onclick="changeValidateCode(this)" title="點擊圖片刷新驗證碼"/><br>
<s:submit value="submit"></s:submit>
</s:form>
</body>
</html>
-- 
學海無涯