关于java程序和http__println_os_String_hasMoreElements_req_

当前位置: 技术问答>java相关

关于java程序和http

来源: 互联网发布时间：2015-05-26

本文导语: 怎样能在一个java写的socket web client 的程序里的get request加如If-modified-since的条件？又如何用If-modified-since和If-none-modified-since? 另外怎么才能把request header和respond header的信息用java socket client程序显示在dos下。 ...

怎样能在一个java写的socket web client 的程序里的get request加如If-modified-since的条件？又如何用If-modified-since和If-none-modified-since?

另外怎么才能把request header和respond header的信息用java socket client程序显示在dos下。

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

public class Info extends HttpServlet {

  ServletConfig config;

  public void init(ServletConfig tconfig) throws ServletException {
    super.init(tconfig);
    config=tconfig;}

  public String getServletInfo() {
  return "Info version 1.9: a demo and diagnostic servlet from vqSoft";}

  private void pp(PrintWriter os, String name, String value) {
  os.print(""+name+": ");
  if (value==null)
      os.print("none");
    else
      os.print(value);
    os.println("
");}

  private void pp(PrintWriter os, String name, int value) {
    pp(os, name, String.valueOf(value));}

  public void dostuff(HttpServletRequest req, HttpServletResponse rep) throws ServletException, IOException {
   log("invoked");
    rep.setContentType("text/html");
  PrintWriter os=rep.getWriter();
    os.println("");
  os.println("Info servlet");
  os.println("");
  os.println("");
    os.println("");
    os.println("Info servlet");
    os.println("");
    os.println("

This page was generated by Info version 1.9, a demo and diagnostic servlet supplied with vqServer. ");
os.println("Info lists its initialisation parameters, information about the http request which invoked it and the http request parameters passed to it.

");
    os.println("");

    os.println("Servlet initialisation parameters");
    Enumeration e=config.getInitParameterNames();
    if (!e.hasMoreElements())
      os.println("None!");
    else while (e.hasMoreElements()) {
      String name=(String) e.nextElement();
      String value=config.getInitParameter(name);
      pp(os, name, value);}
    os.println("");

    os.println("Request parameters");
    pp(os, "Request method", req.getMethod());
  pp(os, "Request URI", req.getRequestURI());
  pp(os, "Request protocol", req.getProtocol());
    pp(os, "Servlet path", req.getServletPath());
  pp(os, "Path info", req.getPathInfo());
  pp(os, "Path translated", req.getPathTranslated());
  pp(os, "Query string", req.getQueryString());
  pp(os, "Content length", req.getContentLength());
  pp(os, "Content type", req.getContentType());
  pp(os, "Server name", req.getServerName());
  pp(os, "Server port", req.getServerPort());
  pp(os, "Remote user", req.getRemoteUser());
    pp(os, "Remote address", req.getRemoteAddr());
  pp(os, "Remote host", req.getRemoteHost());
  pp(os, "Authorization scheme", req.getAuthType());
    os.println("");

    os.println("Request headers");
    e=req.getHeaderNames();
    if (!e.hasMoreElements())
      os.println("None!");
    else while (e.hasMoreElements()) {
      String name=(String) e.nextElement();
      String value=(String) req.getHeader(name);
      pp(os, name, value);}
    os.println("");

    os.println("Servlet parameters");
    e=req.getParameterNames();
    if (!e.hasMoreElements())
      os.println("None!");
    else while (e.hasMoreElements()) {
      String name=(String) e.nextElement();
      String value=req.getParameter(name);
      StringBuffer tbuffer=new StringBuffer();
      pp(os, name, value);}
    os.println("");

    os.println("Other servlets (by name)");
    ServletContext tcontext=config.getServletContext();
    e=tcontext.getServletNames();
    if (!e.hasMoreElements())
      os.println("None!");
    else while (e.hasMoreElements()) {
      os.println((String) e.nextElement()+"
");}
    os.println("");

    os.println("Other servlets");
    e=tcontext.getServlets();
    if (!e.hasMoreElements())
      os.println("None!");
    else while (e.hasMoreElements()) {
      Servlet tservlet=(Servlet) e.nextElement();
      os.println(tservlet.getServletInfo()+"
");}
    os.println("");

    os.println("

Info version 1.9. Info and vqServer are copyright © 1997-99 Steve Shering and vqSoft.");
    os.println("");
    os.println("");
    os.println("");
    os.println("Home page");
    os.println("");
    os.println("");
    os.println("");
    os.flush();}

  public void doGet(HttpServletRequest req, HttpServletResponse rep) throws ServletException, IOException {
    dostuff(req, rep);}

  public void doPost(HttpServletRequest req, HttpServletResponse rep) throws ServletException, IOException {
    dostuff(req, rep);}}

---------------
shmilu@sina.com

这是《java网络编程》一书中的实例，用于取html的头信息：

import java.net.*;
import java.io.*;
import java.util.*;

public class MIMEHeadersViewer {

public static void main(String args[]) {

for (int i=0; i