ActiveMQ example source code file (RestFilter.java)

This example ActiveMQ source code file (RestFilter.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 - ActiveMQ tags/keywords

delete, file, fileoutputstream, httpservletrequest, httpservletresponse, httpservletresponse, io, ioexception, ioexception, net, network, put, request, response, restful, servlet, servletexception, servletexception, string, string

The ActiveMQ RestFilter.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.
 */
//========================================================================
//Copyright 2007 CSC - Scientific Computing Ltd.
//========================================================================
package org.apache.activemq.util;


import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.URL;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.UnavailableException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;


/**
 * <p>
 * Adds support for HTTP PUT, MOVE and DELETE methods. If init parameters
 * read-permission-role and write-permission-role are defined then all requests
 * are authorized using the defined roles. Also GET methods are authorized.
 * </p>
 * 
 * @author Aleksi Kallio
 */
public class RestFilter implements Filter {
    private static final Logger LOG = LoggerFactory.getLogger(RestFilter.class);

    private static final String HTTP_HEADER_DESTINATION = "Destination";
    private static final String HTTP_METHOD_MOVE = "MOVE";
    private static final String HTTP_METHOD_PUT = "PUT";
    private static final String HTTP_METHOD_GET = "GET";
    private static final String HTTP_METHOD_DELETE = "DELETE";

    private String readPermissionRole;
    private String writePermissionRole;
    private FilterConfig filterConfig;

    public void init(FilterConfig filterConfig) throws UnavailableException {
        this.filterConfig = filterConfig;
        readPermissionRole = filterConfig.getInitParameter("read-permission-role");
        writePermissionRole = filterConfig.getInitParameter("write-permission-role");
    }

    private File locateFile(HttpServletRequest request) {
        return new File(filterConfig.getServletContext().getRealPath(request.getServletPath()), request.getPathInfo());
    }

    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        if (!(request instanceof HttpServletRequest && response instanceof HttpServletResponse)) {
            if (LOG.isDebugEnabled()) {
                LOG.debug("request not HTTP, can not understand: " + request.toString());
            }
            chain.doFilter(request, response);
            return;
        }

        HttpServletRequest httpRequest = (HttpServletRequest)request;
        HttpServletResponse httpResponse = (HttpServletResponse)response;

        if (httpRequest.getMethod().equals(HTTP_METHOD_MOVE)) {
            doMove(httpRequest, httpResponse);
        } else if (httpRequest.getMethod().equals(HTTP_METHOD_PUT)) {
            doPut(httpRequest, httpResponse);
        } else if (httpRequest.getMethod().equals(HTTP_METHOD_GET)) {
            if (checkGet(httpRequest, httpResponse)) {
                chain.doFilter(httpRequest, httpResponse); // actual processing
                                                            // done elsewhere
            }
        } else if (httpRequest.getMethod().equals(HTTP_METHOD_DELETE)) {
            doDelete(httpRequest, httpResponse);
        } else {
            chain.doFilter(httpRequest, httpResponse);
        }
    }

    protected void doMove(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        if (LOG.isDebugEnabled()) {
            LOG.debug("RESTful file access: MOVE request for " + request.getRequestURI());
        }

        if (writePermissionRole != null && !request.isUserInRole(writePermissionRole)) {
            response.sendError(HttpURLConnection.HTTP_FORBIDDEN);
            return;
        }

        File file = locateFile(request);
        String destination = request.getHeader(HTTP_HEADER_DESTINATION);

        if (destination == null) {
            response.sendError(HttpURLConnection.HTTP_BAD_REQUEST, "Destination header not found");
            return;
        }

        try {
            URL destinationUrl = new URL(destination);
            IOHelper.copyFile(file, new File(destinationUrl.getFile()));
            IOHelper.deleteFile(file);
        } catch (IOException e) {
            response.sendError(HttpURLConnection.HTTP_INTERNAL_ERROR); // file
                                                                        // could
                                                                        // not
                                                                        // be
                                                                        // moved
            return;
        }

        response.setStatus(HttpURLConnection.HTTP_NO_CONTENT); // we return no
                                                                // content
    }

    protected boolean checkGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        if (LOG.isDebugEnabled()) {
            LOG.debug("RESTful file access: GET request for " + request.getRequestURI());
        }

        if (readPermissionRole != null && !request.isUserInRole(readPermissionRole)) {
            response.sendError(HttpURLConnection.HTTP_FORBIDDEN);
            return false;
        } else {
            return true;
        }
    }

    protected void doPut(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        if (LOG.isDebugEnabled()) {
            LOG.debug("RESTful file access: PUT request for " + request.getRequestURI());
        }

        if (writePermissionRole != null && !request.isUserInRole(writePermissionRole)) {
            response.sendError(HttpURLConnection.HTTP_FORBIDDEN);
            return;
        }

        File file = locateFile(request);

        if (file.exists()) {
            boolean success = file.delete(); // replace file if it exists
            if (!success) {
                response.sendError(HttpURLConnection.HTTP_INTERNAL_ERROR); // file
                                                                            // existed
                                                                            // and
                                                                            // could
                                                                            // not
                                                                            // be
                                                                            // deleted
                return;
            }
        }

        FileOutputStream out = new FileOutputStream(file);
        try {
            IOHelper.copyInputStream(request.getInputStream(), out);
        } catch (IOException e) {
            LOG.warn("Exception occured" , e);
            out.close();
            throw e;
        }

        response.setStatus(HttpURLConnection.HTTP_NO_CONTENT); // we return no
                                                                // content
    }

    protected void doDelete(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        if (LOG.isDebugEnabled()) {
            LOG.debug("RESTful file access: DELETE request for " + request.getRequestURI());
        }

        if (writePermissionRole != null && !request.isUserInRole(writePermissionRole)) {
            response.sendError(HttpURLConnection.HTTP_FORBIDDEN);
            return;
        }

        File file = locateFile(request);

        if (!file.exists()) {
            response.sendError(HttpURLConnection.HTTP_NOT_FOUND); // file not
                                                                    // found
            return;
        }

        boolean success = IOHelper.deleteFile(file); // actual delete operation

        if (success) {
            response.setStatus(HttpURLConnection.HTTP_NO_CONTENT); // we return
                                                                    // no
                                                                    // content
        } else {
            response.sendError(HttpURLConnection.HTTP_INTERNAL_ERROR); // could
                                                                        // not
                                                                        // be
                                                                        // deleted
                                                                        // due
                                                                        // to
                                                                        // internal
                                                                        // error
        }
    }

    public void destroy() {
        // nothing to destroy
    }
}