org.atombeat.xquery.functions.util.SaveUploadAs.java Source code

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Here is the source code for org.atombeat.xquery.functions.util.SaveUploadAs.java

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/*
 *  eXist Open Source Native XML Database
 *  Copyright (C) 2001-09 Wolfgang M. Meier
 *  wolfgang@exist-db.org
 *  http://exist.sourceforge.net
 *  
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser 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 Lesser General Public License for more details.
 *  
 *  You should have received a copy of the GNU Lesser General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *  
 *  $Id: GetData.java 9749 2009-08-09 23:18:12Z ixitar $
 */
package org.atombeat.xquery.functions.util;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.math.BigInteger;
import java.security.DigestInputStream;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.exist.dom.QName;
import org.exist.http.servlets.RequestWrapper;
import org.exist.xquery.BasicFunction;
import org.exist.xquery.Cardinality;
import org.exist.xquery.FunctionSignature;
import org.exist.xquery.Variable;
import org.exist.xquery.XPathException;
import org.exist.xquery.XQueryContext;
import org.exist.xquery.functions.request.RequestModule;
import org.exist.xquery.value.FunctionParameterSequenceType;
import org.exist.xquery.value.FunctionReturnSequenceType;
import org.exist.xquery.value.JavaObjectValue;
import org.exist.xquery.value.Sequence;
import org.exist.xquery.value.SequenceType;
import org.exist.xquery.value.StringValue;
import org.exist.xquery.value.Type;

/**
 */
public class SaveUploadAs extends BasicFunction {

    protected static final Log logger = LogFactory.getLog(SaveUploadAs.class);

    public final static FunctionSignature signature = new FunctionSignature(
            new QName("save-upload-as", AtomBeatUtilModule.NAMESPACE_URI, AtomBeatUtilModule.PREFIX),
            "Saves an uploaded file to a given path.",
            new SequenceType[] {
                    new FunctionParameterSequenceType("param-name", Type.STRING, Cardinality.EXACTLY_ONE,
                            "The form part name, i.e., param name for the uploaded file to save."),
                    new FunctionParameterSequenceType("path", Type.STRING, Cardinality.EXACTLY_ONE,
                            "The file system path where the data is to be stored.") },
            new FunctionReturnSequenceType(Type.STRING, Cardinality.ZERO_OR_ONE,
                    "an MD5 digest of the content, or empty if there was a problem"));

    public SaveUploadAs(XQueryContext context) {
        super(context, signature);
    }

    /* (non-Javadoc)
     * @see org.exist.xquery.BasicFunction#eval(org.exist.xquery.value.Sequence[], org.exist.xquery.value.Sequence)
     */
    public Sequence eval(Sequence[] args, Sequence contextSequence) throws XPathException {

        RequestModule reqModule = (RequestModule) context.getModule(RequestModule.NAMESPACE_URI);

        // request object is read from global variable $request
        Variable var = reqModule.resolveVariable(RequestModule.REQUEST_VAR);

        if (var == null || var.getValue() == null)
            throw new XPathException(this, "No request object found in the current XQuery context.");

        if (var.getValue().getItemType() != Type.JAVA_OBJECT)
            throw new XPathException(this, "Variable $request is not bound to an Java object.");

        JavaObjectValue value = (JavaObjectValue) var.getValue().itemAt(0);

        if (!(value.getObject() instanceof RequestWrapper)) {
            throw new XPathException(this, "Variable $request is not bound to a Request object.");
        }

        RequestWrapper request = (RequestWrapper) value.getObject();

        // try to copy upload
        try {
            String paramName = args[0].getStringValue();
            String path = args[1].getStringValue();
            File upload = request.getFileUploadParam(paramName);
            File file = new File(path);
            InputStream in = new FileInputStream(upload);
            MessageDigest md5 = MessageDigest.getInstance("MD5");
            in = new DigestInputStream(in, md5);
            OutputStream out = new FileOutputStream(file);

            Stream.copy(in, out);

            String signature = new BigInteger(1, md5.digest()).toString(16);
            return new StringValue(signature);

        } catch (IOException ioe) {
            throw new XPathException(this, "An IO exception ocurred: " + ioe.getMessage(), ioe);
        } catch (NoSuchAlgorithmException e) {
            throw new XPathException(this, "A message digest exception ocurred: " + e.getMessage(), e);
        }

    }

}