ServletUtil.java

/*-*- mode: Java; tab-width:8 -*-*/

package php.java.servlet;

import java.io.File;
import java.io.IOException;
import java.io.OutputStream;
import java.lang.reflect.Constructor;
import java.lang.reflect.Method;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.Set;

import javax.servlet.ServletContext;
import javax.servlet.ServletRequest;
import javax.servlet.http.HttpServletResponse;

import php.java.bridge.Util;
import php.java.bridge.http.WriterOutputStream;

/*
 * Copyright (C) 2003-2007 Jost Boekemeier
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */

/**
 * Miscellaneous servlet functions.
 * @author jostb
 *
 */
public class ServletUtil {
    private ServletUtil() {}
    
   /**
     * Identical to context2.getRealPath(pathInfoCGI). On BEA
     * WebLogic, which has a broken getRealPath() implementation, we
     * use context2.getResource(pathInfoCGI)) instead.
     * @param context2 The servlet context.
     * @param pathInfoCGI  may be "" or "/" for example.
     * @return a valid path or null
     */
    public static String getRealPath(ServletContext context2, String pathInfoCGI) {
        String ret = context2.getRealPath(pathInfoCGI);
        if(ret!=null) return ret;
    
        // The following is the workaround for BEA WebLogic
        if(!pathInfoCGI.startsWith("/")) {
            pathInfoCGI = "/"+pathInfoCGI;
        }
        URL url = null;
        try { 
            url = context2.getResource(pathInfoCGI);
        } catch (MalformedURLException e) {
            Util.printStackTrace(e);
        }
        if(url != null && !"file".equals(url.getProtocol())) url = null;
        if (url == null) throw new IllegalStateException("Cannot access "+pathInfoCGI+" within the current web application. Please explode it: Unzip the application .war file into a directory and deploy the directory instead.");
        
        ret = url.getPath();
        return ret.replace('/', File.separatorChar);
    }

    /**
     * Only for internal use.
     * 
     * Returns the port# of the local port
     * @param req The servlet request
     * @return The local port or the value from the server port variable.
     */
    public static int getLocalPort(ServletRequest req) {
    	int port = -1;
    	try {
    	    port = req.getLocalPort(); 
    	} catch (Throwable t) {/*ignore*/}
    	if(port<=0) port = req.getServerPort();
    	return port;
    }

    public static boolean isJavaBridgeWc(String contextPath) {
        return (contextPath!=null && contextPath.endsWith("JavaBridge"));
    }

    public static String nullsToBlanks(String s) {
        return ServletUtil.nullsToString(s, "");
    }

    public static String nullsToString(String couldBeNull,
        			   String subForNulls) {
        return (couldBeNull == null ? subForNulls : couldBeNull);
    }

    public static String getHeaders (StringBuffer buf, Enumeration enumeration) {
        while (enumeration.hasMoreElements()){
            buf.append (enumeration.nextElement());
            if (enumeration.hasMoreElements())
        	buf.append ("; ");
        }
        String result = buf.toString();
        buf.setLength(0);
        return result;
    }

    public static OutputStream getServletOutputStream(HttpServletResponse response) throws IOException {
        try {
            return response.getOutputStream();
        } catch (IllegalStateException e) {
            WriterOutputStream out = new WriterOutputStream(response.getWriter ());
            out.setEncoding(response.getCharacterEncoding());
            return out;
        }
    }

    /**
     * Return an mbean property.
     * Example: <code>Util.getMBeanProperty("*:type=ThreadPool,name=http*", "maxThreads")</code> or 
     * <code>Util.getMBeanProperty("*:ServiceModule=*,J2EEServer=*,name=JettyWebConnector,j2eeType=*", "maxThreads");</code>
     * @param pattern the pattern string 
     * @param property the property key
     * @return the property value
     */
    public static int getMBeanProperty(String pattern, String property) {
            try {
             Class objectNameClazz = Class.forName("javax.management.ObjectName");
             Constructor constructor = objectNameClazz.getConstructor(new Class[]{String.class});
             Object objectName = constructor.newInstance(new Object[]{pattern});
             
             
             Class clazz = Class.forName("javax.management.MBeanServerFactory");
             Method method = clazz.getMethod("findMBeanServer", new Class[]{String.class});
             ArrayList servers = (ArrayList)method.invoke(clazz, new Object[]{null});
             Object server = servers.get(0);
             
             Class mBeanServerClazz = Class.forName("javax.management.MBeanServer");
             clazz = Class.forName("javax.management.QueryExp");
             method = mBeanServerClazz.getMethod("queryMBeans", new Class[]{objectNameClazz, clazz});
             
             Set s = (Set)method.invoke(server, new Object[]{objectName, null});
             Iterator ii = s.iterator(); 
             
             if (ii.hasNext()) {
        	     clazz = Class.forName("javax.management.ObjectInstance");
             method = clazz.getMethod("getObjectName", Util.ZERO_PARAM);
             objectName = method.invoke(ii.next(), Util.ZERO_ARG);
             
             method = mBeanServerClazz.getMethod("getAttribute", new Class[]{objectNameClazz, String.class});
        	     Object result = method.invoke(server, new Object[]{objectName, property});
        	     return Integer.parseInt(String.valueOf(result));
             }
	} catch (Exception t) {
		if (Util.logLevel>5) Util.printStackTrace(t);
	}
	return 0;
   }
}