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Struts example source code file (JakartaMultiPartRequest.java)

This example Struts source code file (JakartaMultiPartRequest.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 - Struts tags/keywords

arraylist, diskfileitemfactory, file, fileitem, fileitem, fileuploadexception, http, io, ioexception, ioexception, list, list, request, requestcontext, response, servlet, servletfileupload, string, string, util

The Struts JakartaMultiPartRequest.java source code

/*
 * $Id: JakartaMultiPartRequest.java 1062361 2011-01-23 10:17:42Z mcucchiara $
 *
 * 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.struts2.dispatcher.multipart;

import com.opensymphony.xwork2.inject.Inject;
import com.opensymphony.xwork2.util.logging.Logger;
import com.opensymphony.xwork2.util.logging.LoggerFactory;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileUploadException;
import org.apache.commons.fileupload.RequestContext;
import org.apache.commons.fileupload.disk.DiskFileItem;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import org.apache.struts2.StrutsConstants;

import javax.servlet.http.HttpServletRequest;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * Multipart form data request adapter for Jakarta Commons Fileupload package.
 */
public class JakartaMultiPartRequest implements MultiPartRequest {
    
    static final Logger LOG = LoggerFactory.getLogger(MultiPartRequest.class);
    
    // maps parameter name -> List of FileItem objects
    protected Map<String,List files = new HashMap>();

    // maps parameter name -> List of param values
    protected Map<String,List params = new HashMap>();

    // any errors while processing this request
    protected List<String> errors = new ArrayList();
    
    protected long maxSize;

    @Inject(StrutsConstants.STRUTS_MULTIPART_MAXSIZE)
    public void setMaxSize(String maxSize) {
        this.maxSize = Long.parseLong(maxSize);
    }

    /**
     * Creates a new request wrapper to handle multi-part data using methods adapted from Jason Pell's
     * multipart classes (see class description).
     *
     * @param saveDir        the directory to save off the file
     * @param request the request containing the multipart
     * @throws java.io.IOException  is thrown if encoding fails.
     */
    public void parse(HttpServletRequest request, String saveDir) throws IOException {
        try {
            processUpload(request, saveDir);
        } catch (FileUploadException e) {
            LOG.warn("Unable to parse request", e);
            errors.add(e.getMessage());
        }
    }

    private void processUpload(HttpServletRequest request, String saveDir) throws FileUploadException, UnsupportedEncodingException {
        for (FileItem item : parseRequest(request, saveDir)) {
            if (LOG.isDebugEnabled()) {
                LOG.debug("Found item " + item.getFieldName());
            }
            if (item.isFormField()) {
                processNormalFormField(item, request.getCharacterEncoding());
            } else {
                processFileField(item);
            }
        }
    }

    private void processFileField(FileItem item) {
        LOG.debug("Item is a file upload");

        // Skip file uploads that don't have a file name - meaning that no file was selected.
        if (item.getName() == null || item.getName().trim().length() < 1) {
            LOG.debug("No file has been uploaded for the field: " + item.getFieldName());
            return;
        }

        List<FileItem> values;
        if (files.get(item.getFieldName()) != null) {
            values = files.get(item.getFieldName());
        } else {
            values = new ArrayList<FileItem>();
        }

        values.add(item);
        files.put(item.getFieldName(), values);
    }

    private void processNormalFormField(FileItem item, String charset) throws UnsupportedEncodingException {
        LOG.debug("Item is a normal form field");
        List<String> values;
        if (params.get(item.getFieldName()) != null) {
            values = params.get(item.getFieldName());
        } else {
            values = new ArrayList<String>();
        }

        // note: see http://jira.opensymphony.com/browse/WW-633
        // basically, in some cases the charset may be null, so
        // we're just going to try to "other" method (no idea if this
        // will work)
        if (charset != null) {
            values.add(item.getString(charset));
        } else {
            values.add(item.getString());
        }
        params.put(item.getFieldName(), values);
    }

    private List<FileItem> parseRequest(HttpServletRequest servletRequest, String saveDir) throws FileUploadException {
        DiskFileItemFactory fac = createDiskFileItemFactory(saveDir);
        ServletFileUpload upload = new ServletFileUpload(fac);
        upload.setSizeMax(maxSize);
        return upload.parseRequest(createRequestContext(servletRequest));
    }

    private DiskFileItemFactory createDiskFileItemFactory(String saveDir) {
        DiskFileItemFactory fac = new DiskFileItemFactory();
        // Make sure that the data is written to file
        fac.setSizeThreshold(0);
        if (saveDir != null) {
            fac.setRepository(new File(saveDir));
        }
        return fac;
    }

    /* (non-Javadoc)
     * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getFileParameterNames()
     */
    public Enumeration<String> getFileParameterNames() {
        return Collections.enumeration(files.keySet());
    }

    /* (non-Javadoc)
     * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getContentType(java.lang.String)
     */
    public String[] getContentType(String fieldName) {
        List<FileItem> items = files.get(fieldName);

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

        List<String> contentTypes = new ArrayList(items.size());
        for (FileItem fileItem : items) {
            contentTypes.add(fileItem.getContentType());
        }

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

    /* (non-Javadoc)
     * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getFile(java.lang.String)
     */
    public File[] getFile(String fieldName) {
        List<FileItem> items = files.get(fieldName);

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

        List<File> fileList = new ArrayList(items.size());
        for (FileItem fileItem : items) {
            File storeLocation = ((DiskFileItem) fileItem).getStoreLocation();
            if(fileItem.isInMemory() && storeLocation!=null && !storeLocation.exists()) {
                try {
                    storeLocation.createNewFile();
                } catch (IOException e) {
                    if(LOG.isErrorEnabled()){
                        LOG.error("Cannot write uploaded empty file to disk: " + storeLocation.getAbsolutePath(),e);
                    }
                }
            }
            fileList.add(storeLocation);
        }

        return fileList.toArray(new File[fileList.size()]);
    }

    /* (non-Javadoc)
     * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getFileNames(java.lang.String)
     */
    public String[] getFileNames(String fieldName) {
        List<FileItem> items = files.get(fieldName);

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

        List<String> fileNames = new ArrayList(items.size());
        for (FileItem fileItem : items) {
            fileNames.add(getCanonicalName(fileItem.getName()));
        }

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

    /* (non-Javadoc)
     * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getFilesystemName(java.lang.String)
     */
    public String[] getFilesystemName(String fieldName) {
        List<FileItem> items = files.get(fieldName);

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

        List<String> fileNames = new ArrayList(items.size());
        for (FileItem fileItem : items) {
            fileNames.add(((DiskFileItem) fileItem).getStoreLocation().getName());
        }

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

    /* (non-Javadoc)
     * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getParameter(java.lang.String)
     */
    public String getParameter(String name) {
        List<String> v = params.get(name);
        if (v != null && v.size() > 0) {
            return v.get(0);
        }

        return null;
    }

    /* (non-Javadoc)
     * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getParameterNames()
     */
    public Enumeration<String> getParameterNames() {
        return Collections.enumeration(params.keySet());
    }

    /* (non-Javadoc)
     * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getParameterValues(java.lang.String)
     */
    public String[] getParameterValues(String name) {
        List<String> v = params.get(name);
        if (v != null && v.size() > 0) {
            return v.toArray(new String[v.size()]);
        }

        return null;
    }

    /* (non-Javadoc)
     * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getErrors()
     */
    public List getErrors() {
        return errors;
    }

    /**
     * Returns the canonical name of the given file.
     *
     * @param filename  the given file
     * @return the canonical name of the given file
     */
    private String getCanonicalName(String filename) {
        int forwardSlash = filename.lastIndexOf("/");
        int backwardSlash = filename.lastIndexOf("\\");
        if (forwardSlash != -1 && forwardSlash > backwardSlash) {
            filename = filename.substring(forwardSlash + 1, filename.length());
        } else if (backwardSlash != -1 && backwardSlash >= forwardSlash) {
            filename = filename.substring(backwardSlash + 1, filename.length());
        }

        return filename;
    }

    /**
     * Creates a RequestContext needed by Jakarta Commons Upload.
     *
     * @param req  the request.
     * @return a new request context.
     */
    private RequestContext createRequestContext(final HttpServletRequest req) {
        return new RequestContext() {
            public String getCharacterEncoding() {
                return req.getCharacterEncoding();
            }

            public String getContentType() {
                return req.getContentType();
            }

            public int getContentLength() {
                return req.getContentLength();
            }

            public InputStream getInputStream() throws IOException {
                InputStream in = req.getInputStream();
                if (in == null) {
                    throw new IOException("Missing content in the request");
                }
                return req.getInputStream();
            }
        };
    }

}

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