Java Tutorial/Servlet/Servlet Methods — различия между версиями

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Текущая версия на 05:07, 1 июня 2010

Date Servlet: doGet method

import java.io.IOException;
import java.io.PrintWriter;
import java.util.Date;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
public class DateServlet extends HttpServlet {
  public void doGet(HttpServletRequest request, HttpServletResponse response)
      throws ServletException, IOException {
    HttpSession hs = request.getSession(true);
    response.setContentType("text/html");
    PrintWriter pw = response.getWriter();
    pw.print("<B>");
    Date date = (Date) hs.getAttribute("date");
    if (date != null) {
      pw.print("Last access: " + date + "<br>");
    }
    date = new Date();
    hs.setAttribute("date", date);
    pw.println("Current date: " + date);
  }
}





Returns any parameters and lists server properties.

import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class Properties extends HttpServlet {
  public void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException,
      IOException {
    PrintWriter out = resp.getWriter();
    out.println("<html>");
    out.println("<head>");
    out.println("<title>My First Servlet</title>");
    out.println("</head>");
    out.println("<h2><center>");
    out.println("Information About You</center></h2>");
    out.println("<br>");
    out.println("<center><table border>");
    out.println("<tr>");
    out.println("<td>Method</td>");
    out.println("<td>" + req.getMethod() + "</td>");
    out.println("</tr>");
    out.println("<tr>");
    out.println("<td>User</td>");
    out.println("<td>" + req.getRemoteUser() + "</td>");
    out.println("</tr>");
    out.println("<tr>");
    out.println("<td>Client</td>");
    out.println("<td>" + req.getRemoteHost() + "</td>");
    out.println("</tr>");
    out.println("<tr>");
    out.println("<td>Protocol</td>");
    out.println("<td>" + req.getProtocol() + "</td>");
    out.println("</tr>");
    java.util.Enumeration e = req.getParameterNames();
    while (e.hasMoreElements()) {
      String name = (String) e.nextElement();
      out.println("<tr>");
      out.println("<td>Parameter "" + name + ""</td>");
      out.println("<td>" + req.getParameter(name) + "</td>");
      out.println("</tr>");
    }
    out.println("</table></center><br><hr><br>");
    out.println("<h2><center>");
    out.println("Server Properties</center></h2>");
    out.println("<br>");
    out.println("<center><table border width=80%>");
    java.util.Properties props = System.getProperties();
    e = props.propertyNames();
    while (e.hasMoreElements()) {
      String name = (String) e.nextElement();
      out.println("<tr>");
      out.println("<td>" + name + "</td>");
      out.println("<td>" + props.getProperty(name) + "</td>");
      out.println("</tr>");
    }
    out.println("</table></center>");
    out.println("</html>");
    out.flush();
  }
  public void init() throws ServletException {
    ServletConfig config = getServletConfig();
  }
  public void destroy() {
  }
}





Using Servlet Init Method

import java.util.*;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class MyServlet extends HttpServlet {
   
    String msg = "";
    public void init(ServletConfig config)
    {
        msg = "Hello from Java servlets!";
    }
    public void doGet(HttpServletRequest request,
        HttpServletResponse response)
        throws IOException, ServletException
    {
        response.setContentType("text/html");
        PrintWriter out = response.getWriter();
        out.println("<HTML>");
        out.println("<HEAD>");
        out.println("<TITLE>");
        out.println("Using the init Method");
        out.println("</TITLE>");
        out.println("</HEAD>");
        out.println("<BODY>");
        out.println("<H1>Using the init Method</H1>");
        out.println(msg);
        out.println("</BODY>");
        out.println("</HTML>");
    }
}


Источник — «http://jexp.ru/index.php?title=Java_Tutorial/Servlet/Servlet_Methods&oldid=4924»