MultipartFilter.java

/*
 * GovWay - A customizable API Gateway 
 * https://govway.org
 * 
 * Copyright (c) 2005-2025 Link.it srl (https://link.it). 
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 3, as published by
 * the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */
package org.openspcoop2.utils.transport.http;

import java.io.ByteArrayInputStream;
import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ReadListener;
import javax.servlet.ServletException;
import javax.servlet.ServletInputStream;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;

import org.openspcoop2.utils.Utilities;

/**
* MultipartFilter
*
* @author Andrea Poli (apoli@link.it)
* @author $Author$
* @version $Rev$, $Date$
*/
public class MultipartFilter  implements Filter{

    /** Multipart request start */
    public static final String MULTIPART = "multipart/";

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
            throws IOException, ServletException {

        HttpServletRequest httpServletRequest = (HttpServletRequest) request;
        BufferedRequestWrapper reqWrapper = null;
        if(isMultipartRequest(httpServletRequest)){
//          log.debug("Ricevuta Richiesta Multipart..."); 
            reqWrapper = new BufferedRequestWrapper((HttpServletRequest) request);
//          log.debug("Contenuto: [" +new String(reqWrapper.getBuffer())+"]");
            chain.doFilter(reqWrapper, response);
        }else {
            chain.doFilter(request, response);
        }
    }

    private boolean isMultipartRequest(HttpServletRequest request) {
        if (!"post".equals(request.getMethod().toLowerCase())) {
            return false;
        }

        String contentType = request.getContentType();
        if (contentType == null) {
            return false;
        }

        if (contentType.toLowerCase().startsWith(MULTIPART)) {
            return true;
        }

        return false;
    }

    @Override
    public void destroy() { 
    }


    private class BufferedRequestWrapper extends HttpServletRequestWrapper {

        private ByteArrayInputStream bais;

        private BufferedServletInputStream bsis;

        private byte[] buffer;

        public BufferedRequestWrapper(HttpServletRequest req) throws IOException {
            super(req);
            try {
                this.buffer = Utilities.getAsByteArray(req.getInputStream());
            }catch(Exception e) {
                throw new IOException(e);
            }
        }

        @Override
        public ServletInputStream getInputStream() {
            try {
                this.bais = new ByteArrayInputStream(this.buffer);
                this.bsis = new BufferedServletInputStream(this.bais);
            } catch (Exception ex) {
                ex.printStackTrace(System.err);
            }

            return this.bsis;
        }

        @SuppressWarnings("unused")
        public byte[] getBuffer() {
            return this.buffer;
        }
    }

    class BufferedServletInputStream extends ServletInputStream {

        private ByteArrayInputStream bais;

        public BufferedServletInputStream(ByteArrayInputStream bais) {
            this.bais = bais;
        }

        @Override
        public int available() {
            return this.bais.available();
        }

        @Override
        public int read() {
            return this.bais.read();
        }

        @Override
        public int read(byte[] buf, int off, int len) {
            return this.bais.read(buf, off, len);
        }

        @Override
        public boolean isFinished() {
            return false;
        }

        @Override
        public boolean isReady() {
            return true;
        }

        @Override
        public void setReadListener(ReadListener arg0) {
            
        }

    }

}