可以旋转文字的验证码

直接上图，验证码可以设置字符个数，字符颜色，背景颜色，旋转角度，新的字体。

请注意加载新字体那一块代码，一定要注册一下，不然带不出文字。

自己看代码吧。。。

package com.ukWord.servlet;import com.ukWord.util.AppConst;import org.apache.commons.lang3.StringUtils;import sun.font.FontDesignMetrics;import javax.imageio.ImageIO;import javax.servlet.ServletException;import javax.servlet.ServletOutputStream;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import java.awt.*;import java.awt.image.BufferedImage;import java.io.IOException;import java.io.InputStream;import java.util.LinkedList;import java.util.List;import java.util.Properties;import java.util.Random;public class SecurityCodeServlet extends HttpServlet {private static final long serialVersionUID = 1L;private int width = 173;private int height = 24;private int fontSize = height;private int securityCodeLength = 4;    private int interferingLineCount = 20;    private Font font = new Font("Times New Romans", Font.BOLD, fontSize);private String charStr = "A0KLBMNC2PD3QRE4STF5UVG6WXH7YZ8J9秋花惨淡秋草黄耿耿秋灯秋夜长已觉秋窗秋不尽那堪风雨助凄凉";private String[] chars;private int charWidth;private int charHeight;@Overridepublic void init() throws ServletException {try{Properties config = new Properties();config.load(SecurityCodeServlet.class.getResourceAsStream("/config.properties"));String withStr = config.getProperty("security.code.width");if(StringUtils.isNotEmpty(withStr)){this.width = Integer.parseInt(withStr);}String securityCodeLengthStr = config.getProperty("security.code.length");if(StringUtils.isNotEmpty(securityCodeLengthStr)){this.securityCodeLength = Integer.parseInt(securityCodeLengthStr);}String interferingLineCountStr = config.getProperty("security.code.interfering.line.count");if(StringUtils.isNotEmpty(interferingLineCountStr)){this.interferingLineCount = Integer.parseInt(interferingLineCountStr);}String fontStr = config.getProperty("security.code.fontStyle");if(StringUtils.isNotEmpty(fontStr)){if(!StringUtils.contains(fontStr, ".ttf")){this.font = new Font(fontStr, Font.BOLD, fontSize);}else{this.font = registerFont(fontStr);}}String charsStr = config.getProperty("security.code.text");if(StringUtils.isNotEmpty(charsStr)){this.charStr = charsStr;}this.chars = new String[charsStr.length()];for(int i = 0; i < charsStr.length(); i++){this.chars[i] = String.valueOf(charsStr.charAt(i));}FontMetrics fontMetrics = FontDesignMetrics.getMetrics(this.font);this.charWidth = fontMetrics.stringWidth("M");this.charHeight = fontMetrics.getHeight();}catch(Exception e){e.printStackTrace();}}    @Overrideprotected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {this.doPost(request, response);}@Overrideprotected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {try {Random random = new Random();BufferedImage buffImg = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);Graphics2D g = buffImg.createGraphics();g.setFont(this.font);//画背景g.setColor(this.getRandomColor(random, 200, 55));g.fillRect(0, 0, width, height);//画边框g.setColor(this.getRandomColor(random, 100, 155));g.drawRect(0, 0, width-1, height-1);//画干扰线g.setColor(this.getRandomColor(random, 0, 255));g.setStroke(new BasicStroke(1f));for (int i = 0; i < this.interferingLineCount; i++) {int x = random.nextInt(this.width);int y = random.nextInt(this.height);int xl = random.nextInt(this.width);int yl = random.nextInt(this.height);g.drawLine(x, y, x + xl, y + yl);}//画旋转文字int charX = 0;List<String> chartList = this.getRandomString(random);int charsRealWidth = this.charWidth * this.securityCodeLength;if(this.width > charsRealWidth){charX = (this.width - charsRealWidth)/2;}double radianPercent = 0D;int chartY = this.height - 5;for(String chart : chartList){g.setColor(this.getRandomColor(random, 80, 120));radianPercent =  Math.PI * (random.nextInt(60)/180D);if(random.nextBoolean()) radianPercent = -radianPercent;g.rotate(radianPercent, charX + 9, chartY);g.drawString(chart, charX, chartY);g.rotate(-radianPercent, charX + 9, chartY);charX += this.charWidth;}//释放此图形的上下文以及它使用的所有系统资源g.dispose();//设置response类型response.setContentType("image/jpeg");//取消缓存response.setHeader("Pragma", "no-cache");response.setHeader("Cache-Control", "no-cache");response.setDateHeader("Expires", 0);//输出图像ServletOutputStream os = response.getOutputStream();ImageIO.write(buffImg, "jpeg", os);os.close();//设置Session，将字符串转换成小写request.getSession().setAttribute(AppConst.SECURITY_CODE_SESSION_KEY, StringUtils.join(chartList, "").toLowerCase());}catch (Exception e) {e.printStackTrace();}}private Font registerFont(String fontStr) throws Exception {InputStream fontInputStream = SecurityCodeServlet.class.getClassLoader().getResourceAsStream(fontStr);Font fontNew = Font.createFont(Font.TRUETYPE_FONT, fontInputStream);Font fontNewPt = fontNew.deriveFont(Font.BOLD, this.fontSize);fontInputStream.close();//注意这里，如果不注册文字的话，什么都画不出来GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();ge.registerFont(fontNew);return fontNewPt;}private List<String> getRandomString(Random random){List<String> chartList = new LinkedList<String>();for(int i = 0; i < this.securityCodeLength; i++){String character = this.chars[random.nextInt(this.chars.length)];character = (random.nextBoolean() == true ? character.toUpperCase() : character.toLowerCase());chartList.add(character);}return chartList;}private Color getRandomColor(Random random, int start, int max){int r = start + random.nextInt(max);int g = start + random.nextInt(max);int b = start + random.nextInt(max);return new Color(r, g, b);}}