struts2生成验证码

思路：用response的输出流向页面输入图片

（1）图片生成工具类

package com.wframe.base.utils;import java.awt.Color;import java.awt.Font;import java.awt.Graphics;import java.awt.Graphics2D;import java.awt.RenderingHints;import java.awt.geom.AffineTransform;import java.awt.image.BufferedImage;import java.io.File;import java.io.FileOutputStream;import java.io.IOException;import java.io.OutputStream;import java.util.Arrays;import java.util.Random;import javax.imageio.ImageIO;/** * <p><b>VerifyCodeUtils Description:</b> (验证码生成)</p> * <b>DATE:</b> 2016年6月2日 下午3:53:34 */public class VerifyCodeUtils{//使用到Algerian字体，系统里没有的话需要安装字体，字体只显示大写，去掉了1,0,i,o几个容易混淆的字符public static final String VERIFY_CODES = "23456789ABCDEFGHJKLMNPQRSTUVWXYZ";private static Random random = new Random();/** * 使用系统默认字符源生成验证码 * @param verifySize验证码长度 * @return */public static String generateVerifyCode(int verifySize){return generateVerifyCode(verifySize, VERIFY_CODES);}/** * 使用指定源生成验证码 * @param verifySize验证码长度 * @param sources验证码字符源 * @return */public static String generateVerifyCode(int verifySize, String sources){if(sources == null || sources.length() == 0){sources = VERIFY_CODES;}int codesLen = sources.length();Random rand = new Random(System.currentTimeMillis());StringBuilder verifyCode = new StringBuilder(verifySize);for(int i = 0; i < verifySize; i++){verifyCode.append(sources.charAt(rand.nextInt(codesLen-1)));}return verifyCode.toString();}/** * 生成随机验证码文件,并返回验证码值 * @param w * @param h * @param outputFile * @param verifySize * @return * @throws IOException */public static String outputVerifyImage(int w, int h, File outputFile, int verifySize) throws IOException{String verifyCode = generateVerifyCode(verifySize);outputImage(w, h, outputFile, verifyCode);return verifyCode;}/** * 输出随机验证码图片流,并返回验证码值 * @param w * @param h * @param os * @param verifySize * @return * @throws IOException */public static String outputVerifyImage(int w, int h, OutputStream os, int verifySize) throws IOException{String verifyCode = generateVerifyCode(verifySize);outputImage(w, h, os, verifyCode);return verifyCode;}/** * 生成指定验证码图像文件 * @param w * @param h * @param outputFile * @param code * @throws IOException */public static void outputImage(int w, int h, File outputFile, String code) throws IOException{if(outputFile == null){return;}File dir = outputFile.getParentFile();if(!dir.exists()){dir.mkdirs();}try{outputFile.createNewFile();FileOutputStream fos = new FileOutputStream(outputFile);outputImage(w, h, fos, code);fos.close();} catch(IOException e){throw e;}}/** * 输出指定验证码图片流 * @param w * @param h * @param os * @param code * @throws IOException */public static void outputImage(int w, int h, OutputStream os, String code) throws IOException{int verifySize = code.length();BufferedImage image = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);Random rand = new Random();Graphics2D g2 = image.createGraphics();g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON);Color[] colors = new Color[5];Color[] colorSpaces = new Color[] { Color.WHITE, Color.CYAN,Color.GRAY, Color.LIGHT_GRAY, Color.MAGENTA, Color.ORANGE,Color.PINK, Color.YELLOW };float[] fractions = new float[colors.length];for(int i = 0; i < colors.length; i++){colors[i] = colorSpaces[rand.nextInt(colorSpaces.length)];fractions[i] = rand.nextFloat();}Arrays.sort(fractions);g2.setColor(Color.GRAY);// 设置边框色g2.fillRect(0, 0, w, h);Color c = getRandColor(200, 250);g2.setColor(c);// 设置背景色g2.fillRect(0, 2, w, h-4);//绘制干扰线Random random = new Random();g2.setColor(getRandColor(160, 200));// 设置线条的颜色for (int i = 0; i < 20; i++) {int x = random.nextInt(w - 1);int y = random.nextInt(h - 1);int xl = random.nextInt(6) + 1;int yl = random.nextInt(12) + 1;g2.drawLine(x, y, x + xl + 40, y + yl + 20);}// 添加噪点float yawpRate = 0.05f;// 噪声率int area = (int) (yawpRate * w * h);for (int i = 0; i < area; i++) {int x = random.nextInt(w);int y = random.nextInt(h);int rgb = getRandomIntColor();image.setRGB(x, y, rgb);}shear(g2, w, h, c);// 使图片扭曲g2.setColor(getRandColor(100, 160));int fontSize = h-4;Font font = new Font("Algerian", Font.ITALIC, fontSize);g2.setFont(font);char[] chars = code.toCharArray();for(int i = 0; i < verifySize; i++){AffineTransform affine = new AffineTransform();affine.setToRotation(Math.PI / 4 * rand.nextDouble() * (rand.nextBoolean() ? 1 : -1), (w / verifySize) * i + fontSize/2, h/2);g2.setTransform(affine);g2.drawChars(chars, i, 1, ((w-10) / verifySize) * i + 5, h/2 + fontSize/2 - 10);}g2.dispose();ImageIO.write(image, "jpg", os);}private static Color getRandColor(int fc, int bc) {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);}private static int getRandomIntColor() {int[] rgb = getRandomRgb();int color = 0;for (int c : rgb) {color = color << 8;color = color | c;}return color;}private static int[] getRandomRgb() {int[] rgb = new int[3];for (int i = 0; i < 3; i++) {rgb[i] = random.nextInt(255);}return rgb;}private static void shear(Graphics g, int w1, int h1, Color color) {shearX(g, w1, h1, color);shearY(g, w1, h1, color);}private static void shearX(Graphics g, int w1, int h1, Color color) {int period = random.nextInt(2);boolean borderGap = true;int frames = 1;int phase = random.nextInt(2);for (int i = 0; i < h1; i++) {double d = (double) (period >> 1)* Math.sin((double) i / (double) period+ (6.2831853071795862D * (double) phase)/ (double) frames);g.copyArea(0, i, w1, 1, (int) d, 0);if (borderGap) {g.setColor(color);g.drawLine((int) d, i, 0, i);g.drawLine((int) d + w1, i, w1, i);}}}private static void shearY(Graphics g, int w1, int h1, Color color) {int period = random.nextInt(40) + 10; // 50;boolean borderGap = true;int frames = 20;int phase = 7;for (int i = 0; i < w1; i++) {double d = (double) (period >> 1)* Math.sin((double) i / (double) period+ (6.2831853071795862D * (double) phase)/ (double) frames);g.copyArea(i, 0, 1, h1, 0, (int) d);if (borderGap) {g.setColor(color);g.drawLine(i, (int) d, i, 0);g.drawLine(i, (int) d + h1, i, h1);}}}public static void main(String[] args) throws IOException{File dir = new File("F:/verifies");int w = 200, h = 80;for(int i = 0; i < 50; i++){String verifyCode = generateVerifyCode(4);File file = new File(dir, verifyCode + ".jpg");outputImage(w, h, file, verifyCode);}}}

（2）在Action类通过response对象输出图片,注意：action返回null

package com.wframe.base.controller.commons.verification;import java.io.ByteArrayInputStream;import java.io.IOException;import java.io.InputStream;import java.io.OutputStream;import org.springframework.context.annotation.Scope;import org.springframework.stereotype.Controller;import com.sun.imageio.spi.OutputStreamImageOutputStreamSpi;import com.wframe.base.controller.commons.BaseAction;import com.wframe.base.domain.constant.ControllerConst;import com.wframe.base.utils.VerifyCodeUtils;@Controller@Scope("prototype") public class GenVerificationCode extends BaseAction{Integer codeNum = 4;Integer w = 100;Integer h = 30;public String genVerificationCode() throws IOException{response.setHeader("Pragma", "No-cache");          response.setHeader("Cache-Control", "no-cache");          response.setDateHeader("Expires", 0);          response.setContentType("image/jpeg");                    //生成随机字串          String verifyCode = VerifyCodeUtils.generateVerifyCode(codeNum);          //存入会话session          session = request.getSession(true);          //删除以前的        session.removeAttribute(ControllerConst.VERIFY_CODE);        session.setAttribute(ControllerConst.VERIFY_CODE, verifyCode.toLowerCase());          //生成图片          try {VerifyCodeUtils.outputImage(w, h, response.getOutputStream(), verifyCode);} catch (IOException e) {e.printStackTrace();}finally {response.getOutputStream().flush();response.getOutputStream().close();}                //不跳转任何视图        return null;}}

package com.wframe.base.controller.commons;import javax.servlet.ServletContext;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import javax.servlet.http.HttpSession;import org.apache.struts2.ServletActionContext;import com.opensymphony.xwork2.ActionSupport;public class BaseAction extends ActionSupport{protected HttpServletRequest request = ServletActionContext.getRequest();protected HttpServletResponse response = ServletActionContext.getResponse();protected HttpSession session = request.getSession();protected ServletContext application = ServletActionContext.getServletContext();}

（3）struts.xml配置，注意：不配置任何结果集

<package name="base" extends="struts-default" namespace="/pc/server/base"> <span style="white-space:pre"></span><action name="verification-img" class="genVerificationCode" method="genVerificationCode">        </action> </package>

错误示例：

如果GenVerificationCode这个Action类返回SUCCESS，而且struts2.xml配置了结果集

<action name="verification-img" class="genVerificationCode" method="genVerificationCode">
            <result name="success" type="stream"></result>
 </action>

会出现以下错误：

ERROR StreamResult Can not find a java.io.InputStream with the name [inputStream] in the invocation stack. Check the <param name="inputName"> tag specified for this action.ERROR DefaultDispatcherErrorHandler Exception occurred during processing request: [java.lang.IllegalArgumentException: Can not find a java.io.InputStream with the name [inputStream] in the invocation stack. Check the <param name="inputName"> tag specified for this action., Can not find a java.io.InputStream with the name [inputStream] in the invocation stack. Check the <param name="inputName"> tag specified for this action.]十月 23, 2016 5:45:07 下午 org.apache.catalina.core.StandardWrapperValve invoke严重: Servlet.service() for servlet [default] in context with path [/ss2h] threw exception [Filtered request failed.] with root causejava.lang.IllegalStateException: Cannot call sendError() after the response has been committedat org.apache.catalina.connector.ResponseFacade.sendError(ResponseFacade.java:450)at org.apache.struts2.dispatcher.DefaultDispatcherErrorHandler.sendErrorResponse(DefaultDispatcherErrorHandler.java:79)at org.apache.struts2.dispatcher.DefaultDispatcherErrorHandler.handleError(DefaultDispatcherErrorHandler.java:60)at org.apache.struts2.dispatcher.Dispatcher.sendError(Dispatcher.java:850)at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:568)at org.apache.struts2.dispatcher.ExecuteOperations.executeAction(ExecuteOperations.java:81)at org.apache.struts2.dispatcher.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:113)at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197)at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)at org.apache.shiro.web.servlet.AbstractShiroFilter.executeChain(AbstractShiroFilter.java:449)at org.apache.shiro.web.servlet.AbstractShiroFilter$1.call(AbstractShiroFilter.java:365)at org.apache.shiro.subject.support.SubjectCallable.doCall(SubjectCallable.java:90)at org.apache.shiro.subject.support.SubjectCallable.call(SubjectCallable.java:83)at org.apache.shiro.subject.support.DelegatingSubject.execute(DelegatingSubject.java:383)at org.apache.shiro.web.servlet.AbstractShiroFilter.doFilterInternal(AbstractShiroFilter.java:362)at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125)at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:346)at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:262)at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505)at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169)at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:956)at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:436)at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1078)at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:625)at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2517)at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2506)at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)at java.lang.Thread.run(Thread.java:745)