一、基本流程：
產生一個驗證碼頁面（很小）→嵌入到表單中→點擊可以刷新頁面→表單提交時驗證。
二、方法：
1、定義TestAction，實現畫圖方法
package com.zhuguang.action; import java.awt.Color; import java.awt.Font; import java.awt.Graphics; import java.awt.image.BufferedImage; import java.util.Map; import javax.servlet.http.HttpServletResponse; import org.apache.struts2.interceptor.ServletResponseAware; import org.apache.struts2.interceptor.SessionAware; import com.opensymphony.xwork2.ActionSupport; import com.sun.image.codec.jpeg.JPEGCodec; import com.sun.image.codec.jpeg.JPEGImageEncoder; public class TestAction extends ActionSupport implements SessionAware,ServletResponseAware { private Map<String, Object> session; private HttpServletResponse response; private static final long serialVersionUID = 1L; private String chknumber; @Override public String execute() throws Exception { response.setHeader("Cache-Control", "no-cache"); int width=50; //圖片寬度int height=20; //圖片高度BufferedImage image=new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB); Graphics graphics=image.createGraphics(); graphics.setColor(this.getColor()); //背景顏色graphics.fillRect(0, 0, width, height); graphics.setFont(new Font("Arial",Font.BOLD,18)); graphics.setColor(this.getColor()); //字的顏色String number=String.valueOf(System.currentTimeMillis()%9000+1000); //生成四位隨機數session.put("randomCode", number); //寫入session中graphics.drawString(number, (int)(width*0.1), (int)(height*0.8)); graphics.dispose(); JPEGImageEncoder encoder=JPEGCodec.createJPEGEncoder(response.getOutputStream()); encoder.encode(image); response.getOutputStream().flush(); //刷新到頁面生成圖片response.getOutputStream().close(); //關閉writer return null; } private Color getColor(){ int red=(int)(Math.random()*1000%256); int green=(int)(Math.random()*1000%256); int blue=(int)(Math.random()*1000%256); return new Color(red,green,blue); } public String getChknumber() { return chknumber; } public void setChknumber(String chknumber) { this.chknumber = chknumber; } @Override public void setSession(Map<String, Object> session) { // TODO Auto-generated method stub this.session = session; } @Override public void setServletResponse(HttpServletResponse response) { // TODO Auto-generated method stub this.response = response; } }注意用到session和response
2、在struts.xml文件中註冊：
<action name="randomCode"> </action>
其中不返回任何信息，這樣就不會跳轉頁面
3、jsp頁面編寫
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@taglib uri="/struts-tags" prefix="s" %> <% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; %> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <script type="text/javascript"> <!-- function reloadcode(obj,base){ var rand=new Date().getTime(); //這裡用當前時間作為參數加到url中，是為了使URL發生變化，這樣驗證碼才會動態加載， //只是一個乾擾作用，無確實意義，但卻又非常巧妙，呵呵obj.src=base+"randomCode.action?abc="+rand; //其實服務器端是沒有abc的字段的。 } //--> </script> <title>測試頁面</title> </head> <body> <form action="testLogin" method="post"> Username<input type="text" name="name"><br> Password<input type="text" name="password"><br> 驗證碼：<input type="text" name="chknumber" id="chknumber" maxlength="4"> <img src="<%=basePath%>randomCode.action" id="safecode" onclick="reloadcode(this,'<%=basePath%>')" /><br> <input type="submit" value="Loginin"> </form> </body> </html>4、驗證
（1）在Action中添加一個驗證方法
public String testLogin() { if(session.get("randomCode").equals(chknumber)) { return SUCCESS; } else { return ERROR; } }（２）在struts.xml中進行註冊
<action name="testLogin" method="testLogin"><result name="success">success.jsp</result><result name="error">error.jsp</result></action>
以上所述是小編給大家介紹的Struts2實現生成動態驗證碼並驗證實例代碼，希望對大家有所幫助！