HessianProxy.java

/*
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2001-2004 Caucho Technology, Inc.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:
 *       "This product includes software developed by the
 *        Caucho Technology (http://www.caucho.com/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "Hessian", "Resin", and "Caucho" must not be used to
 *    endorse or promote products derived from this software without prior
 *    written permission. For written permission, please contact
 *    info@caucho.com.
 *
 * 5. Products derived from this software may not be called "Resin"
 *    nor may "Resin" appear in their names without prior written
 *    permission of Caucho Technology.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL CAUCHO TECHNOLOGY OR ITS CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
 * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * @author Scott Ferguson
 */

package com.caucho.hessian.client;

import com.caucho.hessian.io.*;
import com.caucho.services.server.*;

import java.io.*;
import java.util.logging.*;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.util.WeakHashMap;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;

/**
 * Proxy implementation for Hessian clients.  Applications will generally
 * use HessianProxyFactory to create proxy clients.
 */
public class HessianProxy implements InvocationHandler {
  private static final Logger log
    = Logger.getLogger(HessianProxy.class.getName());
  
  protected HessianProxyFactory _factory;
  private WeakHashMap<Method,String> _mangleMap
    = new WeakHashMap<Method,String>();
  private URL _url;
  
  /**
   * Package protected constructor for factory
   */
  HessianProxy(HessianProxyFactory factory, URL url)
  {
    _factory = factory;
    _url = url;
  }

  /**
   * Protected constructor for subclassing
   */
  protected HessianProxy(URL url, HessianProxyFactory factory)
  {
    _factory = factory;
    _url = url;
  }

  /**
   * Returns the proxy's URL.
   */
  public URL getURL()
  {
    return _url;
  }

  /**
   * Handles the object invocation.
   *
   * @param proxy the proxy object to invoke
   * @param method the method to call
   * @param args the arguments to the proxy object
   */
  public Object invoke(Object proxy, Method method, Object []args)
    throws Throwable
  {
    String mangleName;

    synchronized (_mangleMap) {
      mangleName = _mangleMap.get(method);
    }

    if (mangleName == null) {
      String methodName = method.getName();
      Class []params = method.getParameterTypes();

      // equals and hashCode are special cased
      if (methodName.equals("equals")
	  && params.length == 1 && params[0].equals(Object.class)) {
	Object value = args[0];
	if (value == null || ! Proxy.isProxyClass(value.getClass()))
	  return new Boolean(false);

	HessianProxy handler = (HessianProxy) Proxy.getInvocationHandler(value);

	return new Boolean(_url.equals(handler.getURL()));
      }
      else if (methodName.equals("hashCode") && params.length == 0)
	return new Integer(_url.hashCode());
      else if (methodName.equals("getHessianType"))
	return proxy.getClass().getInterfaces()[0].getName();
      else if (methodName.equals("getHessianURL"))
	return _url.toString();
      else if (methodName.equals("toString") && params.length == 0)
	return "HessianProxy[" + _url + "]";
      
      if (! _factory.isOverloadEnabled())
	mangleName = method.getName();
      else
        mangleName = mangleName(method);

      synchronized (_mangleMap) {
	_mangleMap.put(method, mangleName);
      }
    }

    InputStream is = null;
    URLConnection conn = null;
    HttpURLConnection httpConn = null;
    
    try {
      if (log.isLoggable(Level.FINER))
	log.finer("Hessian[" + _url + "] calling " + mangleName);
      
      conn = sendRequest(mangleName, args);

      if (conn instanceof HttpURLConnection) {
	httpConn = (HttpURLConnection) conn;
        int code = 500;

        try {
          code = httpConn.getResponseCode();
        } catch (Exception e) {
        }

        parseResponseHeaders(conn);

        if (code != 200) {
          StringBuffer sb = new StringBuffer();
          int ch;

          try {
            is = httpConn.getInputStream();

            if (is != null) {
              while ((ch = is.read()) >= 0)
                sb.append((char) ch);

              is.close();
            }

            is = httpConn.getErrorStream();
            if (is != null) {
              while ((ch = is.read()) >= 0)
                sb.append((char) ch);
            }
          } catch (FileNotFoundException e) {
            throw new HessianConnectionException("HessianProxy cannot connect to '" + _url, e);
          } catch (IOException e) {
	    if (is == null)
	      throw new HessianConnectionException(code + ": " + e, e);
	    else
	      throw new HessianConnectionException(code + ": " + sb, e);
          }

          if (is != null)
            is.close();

          throw new HessianConnectionException(code + ": " + sb.toString());
        }
      }

      is = conn.getInputStream();

      if (log.isLoggable(Level.FINEST)) {
	PrintWriter dbg = new PrintWriter(new LogWriter(log));
	is = new HessianDebugInputStream(is, dbg);
      }

      AbstractHessianInput in = _factory.getHessianInput(is);

      in.startReply();

      Object value = in.readObject(method.getReturnType());

      if (value instanceof InputStream) {
	value = new ResultInputStream(httpConn, is, in, (InputStream) value);
	is = null;
	httpConn = null;
      }
      else
	in.completeReply();

      return value;
    } catch (HessianProtocolException e) {
      throw new HessianRuntimeException(e);
    } finally {
      try {
	if (is != null)
	  is.close();
      } catch (Exception e) {
	log.log(Level.FINE, e.toString(), e);
      }
      
      try {
	if (httpConn != null)
	  httpConn.disconnect();
      } catch (Exception e) {
	log.log(Level.FINE, e.toString(), e);
      }
    }
  }

  protected String mangleName(Method method)
  {
    Class []param = method.getParameterTypes();
    
    if (param == null || param.length == 0)
      return method.getName();
    else
      return AbstractSkeleton.mangleName(method, false);
  }

  /**
   * Method that allows subclasses to parse response headers such as cookies.
   * Default implementation is empty. 
   * @param conn
   */
  protected void parseResponseHeaders(URLConnection conn) {
	  
  }

  protected URLConnection sendRequest(String methodName, Object []args)
    throws IOException
  {
    URLConnection conn = null;
    
    conn = _factory.openConnection(_url);
    boolean isValid = false;

    try {
      // Used chunked mode when available, i.e. JDK 1.5.
      if (_factory.isChunkedPost() && conn instanceof HttpURLConnection) {
	try {
	  HttpURLConnection httpConn = (HttpURLConnection) conn;

	  httpConn.setChunkedStreamingMode(8 * 1024);
	} catch (Throwable e) {
	}
      }
    
      addRequestHeaders(conn);

      OutputStream os = null;

      try {
	os = conn.getOutputStream();
      } catch (Exception e) {
	throw new HessianRuntimeException(e);
      }

      if (log.isLoggable(Level.FINEST)) {
	PrintWriter dbg = new PrintWriter(new LogWriter(log));
	os = new HessianDebugOutputStream(os, dbg);
      }
      
      AbstractHessianOutput out = _factory.getHessianOutput(os);

      out.call(methodName, args);
      out.flush();

      isValid = true;

      return conn;
    } finally {
      if (! isValid && conn instanceof HttpURLConnection)
	((HttpURLConnection) conn).disconnect();
    }
  }

  /**
   * Method that allows subclasses to add request headers such as cookies.
   * Default implementation is empty. 
   */
  protected void addRequestHeaders(URLConnection conn) {
	  
  }
	

  static class ResultInputStream extends InputStream {
    private HttpURLConnection _conn;
    private InputStream _connIs;
    private AbstractHessianInput _in;
    private InputStream _hessianIs;

    ResultInputStream(HttpURLConnection conn,
		      InputStream is,
		      AbstractHessianInput in,
		      InputStream hessianIs)
    {
      _conn = conn;
      _connIs = is;
      _in = in;
      _hessianIs = hessianIs;
    }

    public int read()
      throws IOException
    {
      if (_hessianIs != null) {
	int value = _hessianIs.read();

	if (value < 0)
	  close();

	return value;
      }
      else
	return -1;
    }

    public int read(byte []buffer, int offset, int length)
      throws IOException
    {
      if (_hessianIs != null) {
	int value = _hessianIs.read(buffer, offset, length);

	if (value < 0)
	  close();

	return value;
      }
      else
	return -1;
    }

    public void close()
      throws IOException
    {
      HttpURLConnection conn = _conn;
      _conn = null;
      
      InputStream connIs = _connIs;
      _connIs = null;
      
      AbstractHessianInput in = _in;
      _in = null;
      
      InputStream hessianIs = _hessianIs;
      _hessianIs = null;

      try {
	if (hessianIs != null)
	  hessianIs.close();
      } catch (Exception e) {
	log.log(Level.FINE, e.toString(), e);
      }

      try {
	if (in != null) {
	  in.completeReply();
	  in.close();
	}
      } catch (Exception e) {
	log.log(Level.FINE, e.toString(), e);
      }

      try {
	if (connIs != null) {
	  connIs.close();
	}
      } catch (Exception e) {
	log.log(Level.FINE, e.toString(), e);
      }

      try {
	if (conn != null) {
	  conn.disconnect();
	}
      } catch (Exception e) {
	log.log(Level.FINE, e.toString(), e);
      }
    }
  }

  static class LogWriter extends Writer {
    private Logger _log;
    private Level _level = Level.FINEST;
    private StringBuilder _sb = new StringBuilder();

    LogWriter(Logger log)
    {
      _log = log;
    }

    public void write(char ch)
    {
      if (ch == '\n' && _sb.length() > 0) {
	_log.fine(_sb.toString());
	_sb.setLength(0);
      }
      else
	_sb.append((char) ch);
    }

    public void write(char []buffer, int offset, int length)
    {
      for (int i = 0; i < length; i++) {
	char ch = buffer[offset + i];
	
	if (ch == '\n' && _sb.length() > 0) {
	  _log.log(_level, _sb.toString());
	  _sb.setLength(0);
	}
	else
	  _sb.append((char) ch);
      }
    }

    public void flush()
    {
    }

    public void close()
    {
      if (_sb.length() > 0)
	_log.log(_level, _sb.toString());
    }
  }
}