src鏈接到生成驗證碼圖片的servlet
應用於數據回顯
package com.huanfeng.cn;import java.awt.Color;import java.awt.Font;import java.awt.Graphics;import java.awt.Graphics2D;import java.awt.image.BufferedImage;import java.io.BufferedReader;import java.io.FileReader;import java.io.IOException;import java.util.ArrayList;import java.util.List;import java.util.Random;import javax.imageio.ImageIO;import javax.servlet.ServletException;import javax.servlet.http.Cookie;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import javax.servlet.http.HttpSession;/*** 驗證碼生成程序****/public class CheckImgServlet extends HttpServlet {// 集合中保存所有成語private Listwords = new ArrayList ();@Overridepublic void init() throws ServletException {// 初始化階段，讀取new_words.txt// web工程中讀取 文件，必須使用絕對磁盤路徑String path = getServletContext().getRealPath("/WEB-INF/new_words.txt");try {BufferedReader reader = new BufferedReader(new FileReader(path));String line;while ((line = reader.readLine()) != null) {words.add(line);}reader.close();} catch (IOException e) {e.printStackTrace();}}public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {// 禁止緩存// response.setHeader("Cache-Control", "no-cache");// response.setHeader("Pragma", "no-cache");// response.setDateHeader("Expires", -1);int width = 120;int height = 30;// 步驟一 繪製一張內存中圖片BufferedImage bufferedImage = new BufferedImage(width, height,BufferedImage.TYPE_INT_RGB);// 步驟二 圖片繪製背景顏色 ---通過繪圖對象Graphics graphics = bufferedImage.getGraphics();// 得到畫圖對象 --- 畫筆// 繪製任何圖形之前 都必須指定一個顏色graphics.setColor(getRandColor(200, 250));graphics.fillRect(0, 0, width, height);// 步驟三 繪製邊框graphics.setColor(Color.WHITE);graphics.drawRect(0, 0, width - 1, height - 1);// 步驟四 四個隨機數字Graphics2D graphics2d = (Graphics2D) graphics;// 設置輸出字體graphics2d.setFont(new Font("宋體", Font.BOLD, 18));Random random = new Random();// 生成隨機數int index = random.nextInt(words.size());String word = words.get(index);// 獲得成語// 定義x座標int x = 10;for (int i = 0; i < word.length(); i++) {// 隨機顏色graphics2d.setColor(new Color(20 + random.nextInt(110), 20 + random.nextInt(110), 20 + random.nextInt(110)));// 旋轉 -30 --- 30度int jiaodu = random.nextInt(60) - 30;// 換算弧度double theta = jiaodu * Math.PI / 180;// 獲得字母數字char c = word.charAt(i);// 將c 輸出到圖片graphics2d.rotate(theta, x, 20);graphics2d.drawString(String.valueOf(c), x, 20);graphics2d.rotate(-theta, x, 20);x += 30;}// 將驗證碼內容保存sessionrequest.getSession().setAttribute("checkcode_session", word);// 步驟五 繪製干擾線graphics.setColor(getRandColor(160, 200));int x1;int x2;int y1;int y2;for (int i = 0; i < 30; i++) {x1 = random.nextInt(width);x2 = random.nextInt(12);y1 = random.nextInt(height);y2 = random.nextInt(12);graphics.drawLine(x1, y1, x1 + x2, x2 + y2);}// 將上面圖片輸出到瀏覽器 ImageIOgraphics.dispose();// 釋放資源//將圖片寫到response.getOutputStream()中ImageIO.write(bufferedImage, "jpg", response.getOutputStream());}public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {doGet(request, response);}/*** 取其某一範圍的color** @param fc* int 範圍參數1* @param bc* int 範圍參數2* @return Color*/private Color getRandColor(int fc, int bc) {// 取其隨機顏色Random random = new Random();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);}}
保存驗證碼到session
package com.huanfeng.cn;import java.io.IOException;import java.sql.SQLException;import javax.servlet.ServletException;import javax.servlet.http.Cookie;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import javax.servlet.http.HttpSession;import org.apache.commons.dbutils.QueryRunner;import org.apache.commons.dbutils.handlers.BeanHandler;public class login extends HttpServlet {public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {request.setCharacterEncoding("utf-8");String checkcode=request.getParameter("checkcode");HttpSession session = request.getSession();String checkcode_session=(String) session.getAttribute("checkcode_session");if(!checkcode_session.equals(checkcode)) {request.setAttribute("loginInfo", "驗證碼錯誤");request.getRequestDispatcher("login.jsp").forward(request, response);return;}String username = request.getParameter("username");String password =request.getParameter("password");User user=login(username,password);//login是去數據庫查詢數據，查詢到返回Userif(user!=null) {//如果user存在則重定向到index.jspresponse.sendRedirect("/index.jsp");}else {//如果user沒有，則表示沒有查到request.setAttribute("loginInfo","密碼錯誤");//向request域中寫入數據，讓login.jsp獲取到request.getRequestDispatcher("/login.jsp").forward(request,response);//用轉發，因為只有轉發才能讓jsp獲取到login。info數據}}private User login(String username, String password) {QueryRunner qr=new QueryRunner(DataSourceUtils.getDataSource());String sql="select * from user where username=? and password=?";try {User user=qr.query(sql, new BeanHandler(User.class),username,password);return user;} catch (SQLException e) {// TODO Auto-generated catch blockthrow new RuntimeException();}}public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {doGet(request, response);}}
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