1.新建一个Dynamic Web Project项目，里面新建两个java文件和一个jsp文件，整体的框架如下所示： 2.login .jsp里面的代码如下所示： %@ page language="java" contentType="text/html; charset=UTF-8"pageEncoding=
1.新建一个Dynamic Web Project项目，里面新建两个java文件和一个jsp文件，整体的框架如下所示：
2.login.jsp里面的代码如下所示：
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title></title> </head> <body> <form action="login" method="post"> <table> <tr> <td>用户名：</td> <td><input type="text" name="user" /></td> </tr> <tr> <td><input type="submit" value="提交" /></td> </tr> </table> </form> </body> </html>
3. GreetServlet.java文件里面的代码如下所示:
package servlet;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
@WebServlet(name = "greet", urlPatterns = { "/greet" })
public class GreetServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
@Override
public void init(ServletConfig config) throws ServletException {
super.init(config);
}
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=utf-8");
PrintWriter out = response.getWriter();
request.setCharacterEncoding("utf-8");
String name = request.getParameter("user");
if (name == null || name.trim().length() == 0) {
response.sendRedirect("login.jsp");
} else {
out.println("<html><body>");
out.println("<br>您的姓名是：" + name);
out.println("<br><a href=login.jsp" + ">重新登录</a>");
out.println("</html></body>");
}
}
}
4. LoginServlet.java文件里面的代码如下所示：
package servlet;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
@WebServlet(name = "login", urlPatterns = { "/login" })
public class LoginServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
@Override
public void init(ServletConfig config) throws ServletException {
super.init(config);
}
@Override
protected void doGet(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
doPost(request, response);
}
@Override
protected void doPost(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/html;charset=utf-8");
PrintWriter out = response.getWriter();
request.setCharacterEncoding("utf-8");
String name = request.getParameter("user");
if (name == null || name.trim().length() == 0) {
response.sendRedirect("login.jsp");
} else {
out.println("<html><head><title>第二个页面</title></head><body>");
out.println("<form action='greet'" + " method='post'");
out.println("<input type='hidden' name='user' value=" + name + ">");
out.println(name + "<br>");
out.println("<input type='submit' value='转向下一个页面看看'>");
out.println("</form>");
out.println("</body></html>");
}
}
}
5.在浏览器里面输入http://localhost:8080/Servlet/login.jsp运行得到的结果如下所示：