net.sourceforge.vulcan.web.ParameterParsingHttpServletRequestWrapper.java Source code

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Here is the source code for net.sourceforge.vulcan.web.ParameterParsingHttpServletRequestWrapper.java

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/*
 * Vulcan Build Manager
 * Copyright (C) 2005-2014 Chris Eldredge
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
package net.sourceforge.vulcan.web;

import java.io.BufferedReader;
import java.io.IOException;
import java.net.URLDecoder;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;

import org.apache.commons.collections.MultiHashMap;
import org.apache.commons.collections.MultiMap;
import org.apache.commons.collections.iterators.IteratorEnumeration;
import org.apache.commons.io.IOUtils;
import org.apache.commons.lang.StringUtils;

/**
 * When HttpServletRequest.getReader() or getInputStream() is invoked,
 * the default behavior of parsing x-www-form-urlencoded form data
 * into parameters is skipped.
 * 
 * When any variant of HttpServletRequest.getParameter() is invoked,
 * attempting to read from getReader() or getInputStream() will read
 * zero bytes.
 * 
 * This class allows getReader() / getInputStream() to be used and still
 * parse form data into parameters.
 */
public class ParameterParsingHttpServletRequestWrapper extends HttpServletRequestWrapper {
    private MultiMap parameterMultiMap;
    private Map<String, String> parameterMap;

    public ParameterParsingHttpServletRequestWrapper(HttpServletRequest delegate) {
        super(delegate);
    }

    @Override
    @SuppressWarnings("rawtypes")
    public Enumeration getParameterNames() {
        getParameterMap();
        return new IteratorEnumeration(parameterMultiMap.keySet().iterator());
    }

    @Override
    @SuppressWarnings("unchecked")
    public String[] getParameterValues(String name) {
        getParameterMap();
        List<String> values = (List<String>) parameterMultiMap.get(name);

        if (values == null) {
            return null;
        }

        return (String[]) values.toArray(new String[values.size()]);
    }

    @Override
    public String getParameter(String name) {
        String[] values = getParameterValues(name);
        return (values != null && values.length > 0) ? values[0] : null;
    }

    @SuppressWarnings({ "rawtypes", "unchecked" })
    @Override
    public Map getParameterMap() {
        if (parameterMap != null) {
            return parameterMap;
        }

        parameterMap = new HashMap<String, String>(super.getParameterMap());
        parameterMultiMap = new MultiHashMap();

        for (Enumeration e = super.getParameterNames(); e.hasMoreElements();) {
            String name = (String) e.nextElement();
            for (String v : super.getParameterValues(name)) {
                parameterMultiMap.put(name, v);
            }
        }

        if (!StringUtils.equals(getContentType(), "application/x-www-form-urlencoded")) {
            return parameterMultiMap;
        }

        String encoding = getCharacterEncoding();

        if (StringUtils.isBlank(encoding)) {
            encoding = "UTF-8";
        }

        try {
            BufferedReader reader = getReader();
            reader.mark(8192);
            String formData = IOUtils.toString(reader);
            reader.reset();

            for (String kvp : formData.split("&")) {
                String[] kv = kvp.split("=");
                String key = URLDecoder.decode(kv[0], encoding);
                String value = kv.length > 1 ? URLDecoder.decode(kv[1], encoding) : StringUtils.EMPTY;
                parameterMultiMap.put(key, value);
                if (!parameterMap.containsKey(key)) {
                    parameterMap.put(key, value);
                }
            }
        } catch (IOException ex) {
            throw new RuntimeException(ex);
        }

        return parameterMap;
    }

}