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Tomcat example source code file (JspCServletContext.java)

This example Tomcat source code file (JspCServletContext.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Tomcat tags/keywords

enumeration, file, file, hashtable, inputstream, io, jspcservletcontext, malformedurlexception, net, network, object, servlet, string, string, throwable, throwable, url, url, util

The Tomcat JspCServletContext.java source code

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.jasper.servlet;


import java.io.File;
import java.io.InputStream;
import java.io.PrintWriter;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Enumeration;
import java.util.HashSet;
import java.util.Hashtable;
import java.util.Set;
import java.util.Vector;

import javax.servlet.RequestDispatcher;
import javax.servlet.Servlet;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;


/**
 * Simple <code>ServletContext implementation without
 * HTTP-specific methods.
 *
 * @author Peter Rossbach (pr@webapp.de)
 */

public class JspCServletContext implements ServletContext {


    // ----------------------------------------------------- Instance Variables


    /**
     * Servlet context attributes.
     */
    protected Hashtable myAttributes;


    /**
     * The log writer we will write log messages to.
     */
    protected PrintWriter myLogWriter;


    /**
     * The base URL (document root) for this context.
     */
    protected URL myResourceBaseURL;


    // ----------------------------------------------------------- Constructors


    /**
     * Create a new instance of this ServletContext implementation.
     *
     * @param aLogWriter PrintWriter which is used for <code>log() calls
     * @param aResourceBaseURL Resource base URL
     */
    public JspCServletContext(PrintWriter aLogWriter, URL aResourceBaseURL) {

        myAttributes = new Hashtable();
        myLogWriter = aLogWriter;
        myResourceBaseURL = aResourceBaseURL;

    }


    // --------------------------------------------------------- Public Methods


    /**
     * Return the specified context attribute, if any.
     *
     * @param name Name of the requested attribute
     */
    public Object getAttribute(String name) {

        return (myAttributes.get(name));

    }


    /**
     * Return an enumeration of context attribute names.
     */
    public Enumeration getAttributeNames() {

        return (myAttributes.keys());

    }


    /**
     * Return the servlet context for the specified path.
     *
     * @param uripath Server-relative path starting with '/'
     */
    public ServletContext getContext(String uripath) {

        return (null);

    }


    /**
     * Return the context path.
     */
    public String getContextPath() {

        return (null);

    }


    /**
     * Return the specified context initialization parameter.
     *
     * @param name Name of the requested parameter
     */
    public String getInitParameter(String name) {

        return (null);

    }


    /**
     * Return an enumeration of the names of context initialization
     * parameters.
     */
    public Enumeration getInitParameterNames() {

        return (new Vector().elements());

    }


    /**
     * Return the Servlet API major version number.
     */
    public int getMajorVersion() {

        return (2);

    }


    /**
     * Return the MIME type for the specified filename.
     *
     * @param file Filename whose MIME type is requested
     */
    public String getMimeType(String file) {

        return (null);

    }


    /**
     * Return the Servlet API minor version number.
     */
    public int getMinorVersion() {

        return (3);

    }


    /**
     * Return a request dispatcher for the specified servlet name.
     *
     * @param name Name of the requested servlet
     */
    public RequestDispatcher getNamedDispatcher(String name) {

        return (null);

    }


    /**
     * Return the real path for the specified context-relative
     * virtual path.
     *
     * @param path The context-relative virtual path to resolve
     */
    public String getRealPath(String path) {

        if (!myResourceBaseURL.getProtocol().equals("file"))
            return (null);
        if (!path.startsWith("/"))
            return (null);
        try {
            return
                (getResource(path).getFile().replace('/', File.separatorChar));
        } catch (Throwable t) {
            return (null);
        }

    }
            
            
    /**
     * Return a request dispatcher for the specified context-relative path.
     *
     * @param path Context-relative path for which to acquire a dispatcher
     */
    public RequestDispatcher getRequestDispatcher(String path) {

        return (null);

    }


    /**
     * Return a URL object of a resource that is mapped to the
     * specified context-relative path.
     *
     * @param path Context-relative path of the desired resource
     *
     * @exception MalformedURLException if the resource path is
     *  not properly formed
     */
    public URL getResource(String path) throws MalformedURLException {

        if (!path.startsWith("/"))
            throw new MalformedURLException("Path '" + path +
                                            "' does not start with '/'");
        URL url = new URL(myResourceBaseURL, path.substring(1));
        InputStream is = null;
        try {
            is = url.openStream();
        } catch (Throwable t) {
            url = null;
        } finally {
            if (is != null) {
                try {
                    is.close();
                } catch (Throwable t2) {
                    // Ignore
                }
            }
        }
        return url;

    }


    /**
     * Return an InputStream allowing access to the resource at the
     * specified context-relative path.
     *
     * @param path Context-relative path of the desired resource
     */
    public InputStream getResourceAsStream(String path) {

        try {
            return (getResource(path).openStream());
        } catch (Throwable t) {
            return (null);
        }

    }


    /**
     * Return the set of resource paths for the "directory" at the
     * specified context path.
     *
     * @param path Context-relative base path
     */
    public Set getResourcePaths(String path) {

        Set thePaths = new HashSet();
        if (!path.endsWith("/"))
            path += "/";
        String basePath = getRealPath(path);
        if (basePath == null)
            return (thePaths);
        File theBaseDir = new File(basePath);
        if (!theBaseDir.exists() || !theBaseDir.isDirectory())
            return (thePaths);
        String theFiles[] = theBaseDir.list();
        for (int i = 0; i < theFiles.length; i++) {
            File testFile = new File(basePath + File.separator + theFiles[i]);
            if (testFile.isFile())
                thePaths.add(path + theFiles[i]);
            else if (testFile.isDirectory())
                thePaths.add(path + theFiles[i] + "/");
        }
        return (thePaths);

    }


    /**
     * Return descriptive information about this server.
     */
    public String getServerInfo() {

        return ("JspCServletContext/1.0");

    }


    /**
     * Return a null reference for the specified servlet name.
     *
     * @param name Name of the requested servlet
     *
     * @deprecated This method has been deprecated with no replacement
     */
    public Servlet getServlet(String name) throws ServletException {

        return (null);

    }


    /**
     * Return the name of this servlet context.
     */
    public String getServletContextName() {

        return (getServerInfo());

    }


    /**
     * Return an empty enumeration of servlet names.
     *
     * @deprecated This method has been deprecated with no replacement
     */
    public Enumeration getServletNames() {

        return (new Vector().elements());

    }


    /**
     * Return an empty enumeration of servlets.
     *
     * @deprecated This method has been deprecated with no replacement
     */
    public Enumeration getServlets() {

        return (new Vector().elements());

    }


    /**
     * Log the specified message.
     *
     * @param message The message to be logged
     */
    public void log(String message) {

        myLogWriter.println(message);

    }


    /**
     * Log the specified message and exception.
     *
     * @param exception The exception to be logged
     * @param message The message to be logged
     *
     * @deprecated Use log(String,Throwable) instead
     */
    public void log(Exception exception, String message) {

        log(message, exception);

    }


    /**
     * Log the specified message and exception.
     *
     * @param message The message to be logged
     * @param exception The exception to be logged
     */
    public void log(String message, Throwable exception) {

        myLogWriter.println(message);
        exception.printStackTrace(myLogWriter);

    }


    /**
     * Remove the specified context attribute.
     *
     * @param name Name of the attribute to remove
     */
    public void removeAttribute(String name) {

        myAttributes.remove(name);

    }


    /**
     * Set or replace the specified context attribute.
     *
     * @param name Name of the context attribute to set
     * @param value Corresponding attribute value
     */
    public void setAttribute(String name, Object value) {

        myAttributes.put(name, value);

    }



}

Other Tomcat examples (source code examples)

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