jsp.zip_jsp增删改查_图书的增删改查_增删改查

package shzu.web.books; import java.io.IOException; import java.io.PrintWriter; import java.io.UnsupportedEncodingException; import java.security.MessageDigest; import java.security.NoSuchAlgorithmException; import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.Statement; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import sun.misc.BASE64Encoder; public class loginServlet extends HttpServlet { public String password = null; public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html"); PrintWriter out = response.getWriter(); try { Connection con; Statement stmt; ResultSet rs; String dbUrl = ("jdbc:mysql://localhost:3306/books_db?useUnicode=true&characterEncoding=gb2312"); String dbUser = "root"; String dbPwd = "6660590"; Class.forName("com.mysql.jdbc.Driver"); DriverManager.registerDriver(new com.mysql.jdbc.Driver()); con = java.sql.DriverManager.getConnection(dbUrl, dbUser, dbPwd); stmt = con.createStatement(); String username = request.getParameter("loginusr"); String password = request.getParameter("loginpsw"); // stmt.execute("select username form userinfo where "+password+" = // md5('password');" ); // -------------------------------- 从表userinfo中挑出 密码是 password 的 用户名 rs = stmt.executeQuery("select password from userinfo where password = '" + username + "';"); if (!rs.next() ) { response.sendRedirect("/app/login.html"); } else while (rs.next()) { // if (stmt.executeQuery("select username from userinfo // where password = md5('" + password + "');") // .getString(1).equals(username) == true) // response.sendRedirect("/app"); // else // response.sendRedirect("/app/login.html"); String psw = rs.getString(1); if (psw.equals(EncoderByMd5(password))) { response.sendRedirect("/app"); } } // if(stmt.execute("select username form userinfo where "+password+" // = md5('password');" )); // select * from user where uName="lihua" and passwd=md5("123321"); rs.close(); stmt.close(); con.close(); } catch (Exception e) { e.printStackTrace(); } } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } public String EncoderByMd5(String str) throws NoSuchAlgorithmException, UnsupportedEncodingException { //-------------------------确定计算方法---------------------------------- MessageDigest md5 = MessageDigest.getInstance("MD5"); BASE64Encoder base64en = new BASE64Encoder(); //------------------------加密后的字符串-------------------------------------- String code = base64en.encode(md5.digest(str.getBytes("utf-8"))); return code; } }