httpcgi.java

JAVA网络编程技术内幕一书的源代码

/*
 * Java Network Programming, Second Edition
 * Merlin Hughes, Michael Shoffner, Derek Hamner
 * Manning Publications Company; ISBN 188477749X
 *
 * http://nitric.com/jnp/
 *
 * Copyright (c) 1997-1999 Merlin Hughes, Michael Shoffner, Derek Hamner;
 * all rights reserved; see license.txt for details.
 */

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

public class HttpCGI implements HttpProcessor, Runnable {
  protected HttpInputStream in;
  protected String scriptName, pathInfo;
  protected File cgiScript;
  protected int contentLength;
  
  public HttpCGI (HttpInputStream in, InetAddress ip) throws IOException {
    this.in = in;
    extractScriptName ();
    if (!cgiScript.exists ())
      throw new HttpException (HTTP.STATUS_NOT_FOUND,
                               "CGI <TT>" + scriptName + "</TT> not found.");
    if (!cgiScript.isFile ())
      throw new HttpException (HTTP.STATUS_FORBIDDEN, scriptName);
    if (!cgiScript.getName ().startsWith ("nph-"))
      throw new HttpException (HTTP.STATUS_NOT_IMPLEMENTED,
                               "Parse-header CGI unimplemented");
    if (in.getMethod () == HTTP.METHOD_POST) {
      try {
        contentLength = Integer.parseInt (in.getHeader ("Content-length"));
      } catch (NumberFormatException ex) {
        throw new HttpException (HTTP.STATUS_BAD_REQUEST,
                                 "Invalid content-length");
      }
    }
    initEnv (ip);
  }

  protected void extractScriptName () {
    String path = in.getPath ();
    int pathIdx = path.indexOf ('/', 1);
    if ((pathIdx >= 0) && ((pathIdx = path.indexOf ('/', 1 + pathIdx)) >= 0)) {
      scriptName = path.substring (0, pathIdx);
      pathInfo = path.substring (pathIdx);
    } else {
      scriptName = path;
    }
    cgiScript = new File (HTTP.SERVER_LOCATION,
                          HTTP.translateFilename (scriptName.substring (1)));
  }

  protected String[] env;
  
  protected void initEnv (InetAddress ip) {
    Vector environment = (Vector) HTTP.environment.clone ();
    environment.addElement ("SERVER_PROTOCOL=" + "HTTP/" +
                            in.getVersion ());
    environment.addElement ("REQUEST_METHOD=" + in.getMethod ());
    if (pathInfo != null) {
      environment.addElement ("PATH_INFO=" + pathInfo);
      environment.addElement ("PATH_TRANSLATED=" + new File (
        HTTP.HTML_ROOT, HTTP.translateFilename (pathInfo)));
    }
    environment.addElement ("SCRIPT_NAME=" + scriptName);
    environment.addElement ("QUERY_STRING=" + in.getQueryString ());
    environment.addElement ("REMOTE_ADDR=" + ip.getHostAddress ());
    environment.addElement ("REMOTE_HOST=" + ip.getHostName ());
    if (in.getMethod () == HTTP.METHOD_POST) {
      environment.addElement ("CONTENT_LENGTH=" + contentLength);
      String type = in.getHeader ("Content-type");
      if (type != null)
        environment.addElement ("CONTENT_TYPE=" + type);
    }
    Enumeration headerNames = in.getHeaderNames ();
    while (headerNames.hasMoreElements ()) {
      String name = (String) headerNames.nextElement ();
      environment.addElement ("HTTP_" + name.toUpperCase ()
                              .replace ('-', '_') + "=" + in.getHeader (name));
    }
    env = new String [environment.size ()];
    environment.copyInto (env);
  }

  protected static Runtime jvm = Runtime.getRuntime ();
  protected Process cgi;

  public void processRequest (HttpOutputStream out) throws IOException {
    ReThread drain = null;
    try {
      if (in.getMethod () != HTTP.METHOD_POST) {
        cgi = jvm.exec (cgiScript.getPath (), env);
        cgi.getOutputStream ().close ();
        out.write (cgi.getInputStream ());
      } else {
        cgi = jvm.exec (cgiScript.getPath (), env);
        drain = new ReThread (this);
        drain.start ();
        out.write (cgi.getInputStream ());
      }
    } catch (IOException ex) {
      StringWriter trace = new StringWriter ();
      ex.printStackTrace (new PrintWriter (trace, true));
      HttpException httpEx = new HttpException
        (HTTP.STATUS_INTERNAL_ERROR, "<PRE>" + trace + "</PRE>");
      httpEx.processRequest (out);
    } finally {
      if (drain != null)
        drain.interrupt ();
      if (cgi != null)
        cgi.destroy ();
    }
  }

  public void run () {
    OutputStream out = cgi.getOutputStream ();
    try {
      byte [] buffer = new byte [256];
      int len;
      while (!Thread.interrupted () && (contentLength > 0) &&
             ((len = in.read (buffer)) != -1)) {
        out.write (buffer, 0, len);
        contentLength -= len;
      }
      out.flush ();
    } catch (IOException ex) {
      ex.printStackTrace ();
    } finally {
      try {
        out.close ();
      } catch (IOException ignored) {
      }
    }
  }
}