user用户类
package .domain;public class User {private int id;private String username;private String password;private String yanzhengma;public int getId() {return id;}public void setId(int id) {this.id = id;}public String getUsername() {return username;}public void setUsername(String username) {this.username = username;}public String getPassword() {return password;}public void setPassword(String password) {this.password = password;}public String getYanzhengma() {return yanzhengma;}public void setYanzhengma(String yanzhengma) {this.yanzhengma = yanzhengma;}}
JDBCUtils工具类
连接数据库
package .utils;import com.alibaba.druid.pool.DruidDataSourceFactory;import javax.sql.DataSource;import java.io.IOException;import java.io.InputStream;import java.util.Properties;public class JDBCUtil {//声明连接池对象private static DataSource ds;//静态代码块加载资源static {Properties pro = new Properties();try {InputStream is = JDBCUtil.class.getClassLoader().getResourceAsStream("druid.properties");pro.load(is);//获取连接池对象try {ds = DruidDataSourceFactory.createDataSource(pro);} catch (Exception e) {e.printStackTrace();}} catch (IOException e) {e.printStackTrace();}}//getdspublic static DataSource getDs(){return ds;}}
然后根据用户输入信息查找数据库信息
package .dao;import .domain.User;import .utils.JDBCUtil;import org.springframework.dao.DataAccessException;import org.springframework.jdbc.core.BeanPropertyRowMapper;import org.springframework.jdbc.core.JdbcTemplate;import javax.sql.DataSource;public class Userdao {//声明获取连接池对象private JdbcTemplate template = new JdbcTemplate(JDBCUtil.getDs());//loginpublic User Login(User login){try{String sql = "select * from user where username = ? and password = ?";User user = template.queryForObject(sql, new BeanPropertyRowMapper<>(User.class), login.getUsername(), login.getPassword());return user;}catch (DataAccessException e){e.printStackTrace();return null;}}}
下面是验证码图片并将验证码以字符串的形式以session方式共享
package .web;import javax.imageio.ImageIO;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 javax.servlet.http.HttpSession;import java.awt.*;import java.awt.image.BufferedImage;import java.io.BufferedReader;import java.io.IOException;import java.util.Random;@WebServlet("/servletImage")public class ServletImage extends HttpServlet {protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {//画个长方型int width = 100;int height = 50;//new出来个图片对象BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);//画笔对象Graphics g = image.getGraphics();//填充g.setColor(Color.pink);g.fillRect(0,0,width,height);//画边框g.setColor(Color.black);g.drawRect(0,0,width-1,height-1);//写验证码String str = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";StringBuffer buffer = new StringBuffer();Random ran = new Random();for (int i = 1; i < 5; i++) {int index = ran.nextInt(str.length());char ch = str.charAt(index);buffer.append(ch);g.drawString(ch+"",(width/5)*i,(height/2));}String s = buffer.toString();//Session共享数据HttpSession session = request.getSession();session.setAttribute("session",s);//画干扰线for (int i = 0; i < 10; i++) {int x1 = ran.nextInt(width);int x2 = ran.nextInt(width);int y1 = ran.nextInt(height);int y2 = ran.nextInt(height);g.setColor(Color.green);g.drawLine(x1,y1,x2,y2);}//将图片输出ImageIO.write(image,"jpg",response.getOutputStream());}protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {this.doPost(request, response);}}
index.jsp首页
<%@ page contentType="text/html;charset=UTF-8" language="java" %><html><head><title>登录</title></head><style>div{color: red;}</style><script>window.onload=function () {var img = document.getElementById("image");img.onclick = function () {var date = new Date().getTime()img.src = "/day14/servletImage?time=" + date;}}</script><body><form action="/day14/servlet" method="post"><table><tr><td>用户名</td><td><input type="text" name="username"></td></tr><tr><td>密码</td><td><input type="password" name="password"></td></tr><tr><td>验证码</td><td><input type="text" name="yanzhengma"></td></tr><tr><td colspan="2"><img id="image" src="/day14/servletImage"></td></tr><tr><td><input type="submit" value="提交"></td></tr></table></form>//下面这两行接收的信息来自下面的servlet类<div><%=request.getAttribute("error_login") == null ? "" : request.getAttribute("error_login")%></div><div><%=request.getAttribute("error_y") == null ? "" : request.getAttribute("error_y")%></div></body></html>
下面重心所在，使用以上所写，判断验证码，判断登录信息
package .web;import .dao.Userdao;import .domain.User;import mons.beanutils.BeanUtils;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 javax.servlet.http.HttpSession;import java.io.IOException;import java.lang.reflect.InvocationTargetException;import java.util.Map;@WebServlet("/servlet")public class Servlet extends HttpServlet {protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {//设置编码，获取参数request.setCharacterEncoding("utf-8");Map<String, String[]> map = request.getParameterMap();User user = new User();try {BeanUtils.populate(user,map);String yanzhengma = user.getYanzhengma();//获取sesssion中的验证码HttpSession session = request.getSession();String s = (String) session.getAttribute("session");request.removeAttribute("session");//判断验证码是否相同if (s.equalsIgnoreCase(yanzhengma)){//相同则判断用户名Userdao userdao = new Userdao();User login = userdao.Login(user);if (login != null) {//用户名密码正确，跳转到success页面，重定向session.setAttribute("username",user.getUsername());response.sendRedirect(request.getContextPath()+"/success.jsp");}else {//失败，储存信息并转发request.setAttribute("error_login","亲，用户名或密码错误");request.getRequestDispatcher("/index.jsp").forward(request,response);}}else{//不相同验证码错误，储存信息并转发request.setAttribute("error_y","亲，验证码错误");request.getRequestDispatcher("/index.jsp").forward(request,response);}} catch (IllegalAccessException e) {e.printStackTrace();} catch (InvocationTargetException e) {e.printStackTrace();}}protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {this.doPost(request, response);}}
登陆成功，跳转到success页面
<%@ page contentType="text/html;charset=UTF-8" language="java" %><html><head><title>登陆成功</title></head><body><h1><%=request.getSession().getAttribute("username")%>，欢迎你哦</h1></body></html>
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