J2EE之驗證碼實現

package cn.itcast.response;import java.awt.Color;import java.awt.Font;import java.awt.Graphics;import java.awt.image.BufferedImage;import java.io.IOException;import java.io.PrintWriter;import java.util.Random;import javax.imageio.ImageIO;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;public class ResponseDemo5 extends HttpServlet {private int WIDTH = 120;private int HEIGHT = 25;public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {BufferedImage image = new BufferedImage(WIDTH , HEIGHT , BufferedImage.TYPE_INT_RGB);Graphics graphics = image.getGraphics();//設定背景色setBackgroundColor(graphics);//設定邊框setBorder(graphics);//繪製隨機線drawRandomLine(graphics);//繪製隨機數字drawRandomNum(graphics);response.setContentType("image/jpeg");ImageIO.write(image, "jpg", response.getOutputStream());}private void drawRandomNum(Graphics graphics) {// TODO Auto-generated method stubgraphics.setColor(Color.RED);graphics.setFont(new Font("楷體", Font.BOLD, 20));String base="\u96d5\u864e\u7684\u4e00\u4e86\u662f\u6211\u4e0d\u5728\u4eba\u4eec\u6709\u6765\u4ed6\u8fd9\u4e0a\u7740\u4e2a\u5730\u5230\u5927\u91cc\u8bf4\u5c31\u53bb\u5b50" +"\u5f97\u4e5f\u548c\u90a3\u8981\u4e0b\u770b\u5929\u65f6\u8fc7\u51fa\u5c0f\u4e48\u8d77\u4f60\u90fd\u628a\u597d\u8fd8\u591a\u6ca1\u4e3a\u53c8\u53ef\u5bb6\u5b66\u53ea" +"\u4ee5\u4e3b\u4f1a\u6837\u5e74\u60f3\u751f\u540c\u8001\u4e2d\u5341\u4ece\u81ea\u9762\u524d\u5934\u9053\u5b83\u540e\u7136\u8d70\u5f88\u50cf\u89c1\u4e24\u7528\u5979" +"\u56fd\u52a8\u8fdb\u6210\u56de\u4ec0\u8fb9\u4f5c\u5bf9\u5f00\u800c\u5df1\u4e9b\u73b0\u5c71\u6c11\u5019\u7ecf\u53d1\u5de5\u5411\u4e8b\u547d\u7ed9\u957f\u6c34\u51e0" +"\u4e49\u4e09\u58f0\u4e8e\u9ad8\u624b\u77e5\u7406\u773c\u5fd7\u70b9\u5fc3\u6218\u4e8c\u95ee\u4f46\u8eab\u65b9\u5b9e\u5403\u505a\u53eb";int x = 10;for(int i = 0; i < 4; i++){String str = base.charAt(new Random().nextInt(base.length())) + "";graphics.drawString(str, x, 21);x += 28;}}private void drawRandomLine(Graphics graphics) {// TODO Auto-generated method stubgraphics.setColor(Color.GREEN);for(int i = 0; i < 5; i++){int x1 = new Random().nextInt(WIDTH);int y1 = new Random().nextInt(HEIGHT);int x2 = new Random().nextInt(WIDTH);int y2 = new Random().nextInt(HEIGHT);graphics.setColor(Color.GREEN);graphics.drawLine(x1, y1, x2, y2);}}private void setBorder(Graphics graphics) {// TODO Auto-generated method stubgraphics.setColor(Color.BLACK);graphics.drawRect(0, 0, WIDTH, HEIGHT);}private void setBackgroundColor(Graphics graphics) {// TODO Auto-generated method stubgraphics.setColor(Color.WHITE);graphics.fillRect(0, 0, WIDTH - 1, HEIGHT - 1);}}