今晚看到網上有關驗證碼的實現的代碼，很早就想寫一個了，感覺驗證碼挺有意思的，于是就寫了一個，然而后來一直加載不出圖片。嘗試了很多方法，后來終于解決了，原來是我項目里面的 web.xml中沒有部署servlet的映射，web.xml如下圖：
運行效果如下：
代碼如下：
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package model; import javax.imageio.ImageIO; import java.awt.*; import java.awt.image.BufferedImage; import java.io.IOException; import java.io.OutputStream; import java.util.Random; /** * Created by Petty on 2017/5/4. */public class VCode { private int w; //圖片寬 private int h;//圖片高 private Color bgColor = new Color(240,240,240);//背景色 private Random random = new Random();//隨機對象 //設置字體范圍 private String[] fontNames = {"宋體","華文楷體","黑體","華文新魏","華文隸書","微軟雅黑","楷體"}; //設置字體樣式范圍 private int[] fontstyle = {0,1,2,3}; //設置字號范圍 private int[] fontSizes = {24,25,26,27,28}; //設置所有字符串范圍 private String codes="abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"; //無參數構造函數 public VCode(){ } //帶寬和高的構造函數 public VCode(int w,int h){ this.w = w; this.h = h; } //返回一張背景圖片 private BufferedImage createImage(){ /** * 1.創建圖片 2.設置背景色 */ //創建圖片 BufferedImage img = new BufferedImage(w,h,BufferedImage.TYPE_INT_RGB); //設置背景色 Graphics g = img.getGraphics(); g.setColor(bgColor); g.fillRect(0,0,w,h); return img; } // 隨機返回字體顏色 private Color randomColor() { int r = random.nextInt(256); int g = random.nextInt(256); int b = random.nextInt(256); return new Color(r, g, b); } //隨機返回字體樣式 private Font randomFont(){ //隨機生成字體下標，隨機從給定的范圍內獲取一個字體 int index = random.nextInt(fontNames.length); String name = fontNames[index]; //隨機生成字體樣式下標，隨即從給定的范圍內獲取一個字體樣式 index = random.nextInt(fontstyle.length); int style = fontstyle[index]; //隨機生成字體大小下標，隨機從給定的范圍內獲取一個字體大小 index = random.nextInt(fontSizes.length); int size = fontSizes[index]; return new Font(name,style,size); } //隨機返回字體內容 private String randomChar(){ int index = random.nextInt(codes.length()); return codes.charAt(index)+""; } //隨機返回幾條干擾線 private void getLine(BufferedImage img){ //設置干擾線的寬度為1.5倍寬，隨機畫五條 Graphics2D g =(Graphics2D) img.getGraphics(); g.setColor(Color.BLACK); g.setStroke(new BasicStroke(1.5f)); for(int i=0;i<5;i++){ int x1 = random.nextInt(w); int y1 = random.nextInt(h); int x2 = random.nextInt(w); int y2 = random.nextInt(h); g.drawLine(x1,y1,x2,y2); } } //用戶調用該方法獲取圖片 public BufferedImage getImage(){ /** * 隨機生成字符0-9A-Za-z,設置字體，字號，是否粗體，字符顏色，都是隨機的 */ BufferedImage img = createImage(); this.getLine(img); //獲取畫筆 Graphics g = img.getGraphics(); //畫內容 for(int i=0;i<4;i++){ g.setColor(this.randomColor());//獲取隨機顏色 g.setFont(this.randomFont());//獲取隨機字體 g.drawString(this.randomChar(),w/4*i,h-5);//獲取字符串隨機內容 } return img; } //用戶調用該方法保存圖片到本地 public void saveImage(BufferedImage img, OutputStream ous){ try { ImageIO.write(img,"JPEG",ous); } catch (IOException e) { e.printStackTrace(); } } } |
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package model; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.awt.image.BufferedImage; import java.io.IOException; /** * Created by Petty on 2017/5/4. */@WebServlet(name = "BServlet") public class BServlet extends HttpServlet { public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { VCode v = new VCode(70,35); BufferedImage img = v.getImage(); v.saveImage(img,response.getOutputStream()); } public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { VCode v = new VCode(70,35 ); BufferedImage img = v.getImage(); v.saveImage(img,response.getOutputStream()); } } |
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<%-- Created by IntelliJ IDEA. User: Petty Date: 2017/5/4 Time: 22:28 To change this template use File | Settings | File Templates. --%> <%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>一次性驗證碼</title> </head> <body> <form action="" method="get"> <table align="center"> <tr> <td><img id="img" alt="" src="servlet/BServlet" onclick="changeNext()"></td> </tr> </table> </form> </body> </html> <script type="text/javascript"> function changeNext(){ var a=document.getElementById("img"); a.src="servlet/BServlet?a="+new Date().getTime(); } </script> |
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