1. 生成图片和验证码
package com.jmu.code; 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.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; import org.apache.struts2.ServletActionContext; import com.opensymphony.xwork2.ActionSupport; /** * 生成图片和验证码类 * * @author Sky * @date 2017年3月4日 上午10:18:08 * */ public class CreateImageAction extends ActionSupport { private static final long serialVersionUID = 1L; private ByteArrayInputStream inputStream; private static int WIDTH = 60; private static int HEIGHT = 20; public ByteArrayInputStream getInputStream() { return inputStream; } public void setInputStream(ByteArrayInputStream inputStream) { this.inputStream = inputStream; } /** * 产生随机数 * @return */ private static String createRandom() { String str = "0123456789qwertyuiopasdfghjklzxcvbnm"; char[] rands = new char[4]; Random random = new Random(); for (int i = 0; i < 4; i++) { rands[i] = str.charAt(random.nextInt(36)); } return new String(rands); } private void drawBackground(Graphics g) { // 画背景 g.setColor(new Color(0xDCDCDC)); g.fillRect(0, 0, WIDTH, HEIGHT); // 随机产生 120 个干扰点 for (int i = 0; i < 120; i++) { int x = (int) (Math.random() * WIDTH); int y = (int) (Math.random() * HEIGHT); int red = (int) (Math.random() * 255); int green = (int) (Math.random() * 255); int blue = (int) (Math.random() * 255); g.setColor(new Color(red, green, blue)); g.drawOval(x, y, 1, 0); } } private void drawRands(Graphics g, String rands) { g.setColor(Color.BLACK); g.setFont(new Font(null, Font.ITALIC | Font.BOLD, 18)); // 在不同的高度上输出验证码的每个字符 g.drawString("" + rands.charAt(0), 1, 17); g.drawString("" + rands.charAt(1), 16, 15); g.drawString("" + rands.charAt(2), 31, 18); g.drawString("" + rands.charAt(3), 46, 16); //System.out.println(rands); } @Override public String execute() throws Exception { HttpServletResponse response = ServletActionContext.getResponse(); // 设置浏览器不要缓存此图片 response.setHeader("Pragma", "no-cache"); response.setHeader("Cache-Control", "no-cache"); response.setDateHeader("Expires", 0); String rands = createRandom(); BufferedImage image = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_RGB); Graphics g = image.getGraphics(); // 产生图像 drawBackground(g); drawRands(g, rands); // 结束图像的绘制过程， 完成图像 g.dispose(); ByteArrayOutputStream outputStream = new ByteArrayOutputStream(); ImageIO.write(image, "jpeg", outputStream); ByteArrayInputStream input = new ByteArrayInputStream(outputStream .toByteArray()); this.setInputStream(input); HttpSession session = ServletActionContext.getRequest().getSession(); session.setAttribute("checkCode", rands); input.close(); outputStream.close(); return SUCCESS; } }
2. 前台jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!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"> <title>Insert title here</title> <script type="text/javascript"> function refreshImage(obj){ /** * 每次请求需要一个不同的参数，否则可能会返回同样的验证码 * 这和浏览器的缓存机制有关系，也可以把页面设置为不缓存，这样就不用这个参数了。 */ var timeNow = new Date().getTime(); obj.src="createImageAction.action?" + timeNow; } </script> </head> <body> <form action="loginValidateAction" method="post"> <!--若要点击图片刷新，重新得到一个验证码，要在后面加上个随机数，这样保证每次提交过去的都是不一样的path，防止因为缓存而使图片不刷新--> 验证码：<input type="text" name="checkCode" /> <img src="createImageAction.action" onclick="refreshImage(this)" title="点击图片刷新验证码" /> <br> <button>提交</button> </form> </body> </html>
3. strut2.xml
<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE struts PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 2.3//EN" "http://struts.apache.org/dtds/struts-2.3.dtd"> <struts> <package name="default" namespace="/" extends="struts-default"> <action name="createImageAction" class="com.jmu.code.CreateImageAction" method="execute"> <result name="success" type="stream"> <param name="contentType">image/jpeg</param> <param name="inputName">inputStream</param> </result> </action> <action name="loginValidateAction" class="com.jmu.code.LoginValidateAction"> <result name="success">/success.jsp</result> <result name="input">/login.jsp</result> </action> </package> </struts>
4. web.xml 要加上strut2的过滤
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0"> <display-name>code</display-name> <filter> <filter-name>struts2</filter-name> <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class> </filter> <filter-mapping> <filter-name>struts2</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> </web-app>
5. 后台检查输入验证码是否正确
package com.jmu.code; import javax.servlet.http.HttpSession; import org.apache.struts2.ServletActionContext; import com.opensymphony.xwork2.ActionSupport; public class LoginValidateAction extends ActionSupport { private static final long serialVersionUID = 1L; private String checkCode; @Override public String execute() throws Exception { if(checkCode()){ System.out.println("check success"); }else { System.out.println("check false"); } return SUCCESS; } /** * 验证验证码是否正确 * @return true or false */ public boolean checkCode() { HttpSession session = ServletActionContext.getRequest().getSession(); String checkCode2 = (String)session.getAttribute("checkCode"); if(!checkCode.equals(checkCode2)) { this.addActionError("输入的验证码不正确，请重新输入！"); return false; } return true; } public String getCheckCode() { return checkCode; } public void setCheckCode(String checkCode) { this.checkCode = checkCode; } }
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