📄 loginservlet.java

📁 jsp 应用开发技术光盘是《jsp应用开发技术》这本书的源代码
💻 JAVA
字号:
package ch16;

import java.io.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;

/**
 *
 * 使用HttpSession管理会话的登录Servlet
 */
public class LoginServlet extends HttpServlet {

	protected void doGet(
		HttpServletRequest request,
		HttpServletResponse response)
		throws ServletException, IOException {
		doPost(request, response);
	}

	protected void doPost(
		HttpServletRequest request,
		HttpServletResponse response)
		throws ServletException, IOException {
 		response.setContentType("text/html;charset=GB2312");
		PrintWriter out = response.getWriter();

		out.println("<html>");
		out.println("<body>");
		out.println("<head>");
		out.println("<title>使用HttpSession管理会话的登录页面</title>");
		out.println("</head>");
		out.println("<body>");

		// 获取会话对象
		HttpSession session = request.getSession();
		// 从会话对象中读取数据
		Boolean isLogin = (Boolean) session.getAttribute("isLogin");

		if (isLogin == null) {
			isLogin = Boolean.FALSE;
		}

		String user = request.getParameter("user");
		String password = request.getParameter("pass");

		if (isLogin.booleanValue()) {
			// 从会话对象中读取数据
			user = (String) session.getAttribute("user");
			Date loginTime = new Date(session.getCreationTime());

			out.println("<h2>欢迎您，" + user + "！</h2>");
			out.println("<h2>您的登录时间是：" + loginTime + "！</h2>");
		} else if ((user != null) && (password != null)) {
			// 在会话对象中保存数据
			session.setAttribute("user", user);
			session.setAttribute("isLogin", Boolean.TRUE);
			Date loginTime = new Date(session.getCreationTime());

			out.println("<h2>欢迎您，" + user + "！</h2>");
			out.println("<h2>您的登录时间是：" + loginTime + "！</h2>");
		} else {
			out.println("<h2>请在下面输入登录信息</h2>");
			out.println("<form method=\"post\" action=\"login\">");
			out.println("<table>");

			out.println("<tr>");
			out.println("<td>用户名：</td>");
			out.println("<td><input name=\"user\" type=\"text\"></td>");
			out.println("</tr>");

			out.println("<tr>");
			out.println("<td>密码：</td>");
			out.println("<td><input name=\"pass\" type=\"password\"></td>");
			out.println("</tr>");

			out.println("<tr>");
			out.println("<td></td>");
			out.println("<td><input name=\"ok\" type=\"submit\" value=\"确定\">");
			out.println("<input name=\"cancel\" type=\"reset\" value=\"重置\"></td>");
			out.println("</tr>");

			out.println("</table>");
			out.println("</form>");
		}

		out.println("</body>");
		out.println("</html>");
	}

}
⌨️ 快捷键说明

复制代码 Ctrl + C
搜索代码 Ctrl + F
全屏模式 F11
切换主题 Ctrl + Shift + D
显示快捷键 ?
增大字号 Ctrl + =
减小字号 Ctrl + -