gwtupload.server.MemoryFileItemFactory.java Source code

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Here is the source code for gwtupload.server.MemoryFileItemFactory.java

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/*
 * Copyright 2010 Manuel Carrasco Moino. (manolo at apache/org)
 * http://code.google.com/p/gwtupload
 *
 * Licensed 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 gwtupload.server;

import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileItemFactory;
import org.apache.commons.fileupload.FileItemHeaders;

import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.Serializable;
import java.io.UnsupportedEncodingException;
import java.util.HashMap;

import static gwtupload.shared.UConsts.MULTI_SUFFIX;

/**
 * <p>
 * This factory stores the data of uploaded files in memory.
 * </p>
 *
 * It doesn't support large files.
 * Useful for systems where write to file-system is not allowed.
 *
 * @author Manolo Carrasco Moino
 *
 */
public class MemoryFileItemFactory implements FileItemFactory, Serializable {

    /**
     * A serializable OutputStream stored in memory.
     *
     */
    public class SerializableByteArrayOutputStream extends OutputStream implements Serializable {

        private static final long serialVersionUID = 1L;

        private byte[] buff = new byte[requestSize];
        private int size = 0;

        public byte[] get() {
            return buff;
        }

        public void reset() {
            size = 0;
        }

        public int size() {
            return size;
        }

        @Override
        public void write(int b) throws IOException {
            buff[size++] = (byte) b;
        }
    }

    private static final int DEFAULT_REQUEST_SIZE = 4096 * 1024;

    private static final long serialVersionUID = 1L;

    int requestSize;

    private HashMap<String, Integer> map = new HashMap<String, Integer>();

    public MemoryFileItemFactory() {
        this(DEFAULT_REQUEST_SIZE);
    }

    public MemoryFileItemFactory(int requestSize) {
        this.requestSize = requestSize;
    }

    public FileItem createItem(String fieldName, final String contentType, final boolean isFormField,
            final String fileName) {

        Integer cont = map.get(fieldName) != null ? (map.get(fieldName) + 1) : 0;
        map.put(fieldName, cont);
        final String fName = fieldName.replace(MULTI_SUFFIX, "") + "-" + cont;

        return new FileItem() {

            private static final long serialVersionUID = 1L;
            String ctype;
            SerializableByteArrayOutputStream data = new SerializableByteArrayOutputStream();
            String fname;

            boolean formfield;

            String name;
            {
                ctype = contentType;
                fname = fName;
                name = fileName;
                formfield = isFormField;
            };

            public void delete() {
                data.reset();
            }

            public byte[] get() {
                return data.get();
            }

            public String getContentType() {
                return ctype;
            }

            public String getFieldName() {
                return fname;
            }

            public InputStream getInputStream() throws IOException {
                return new ByteArrayInputStream(get());
            }

            public String getName() {
                return name;
            }

            public OutputStream getOutputStream() throws IOException {
                return data;
            }

            public long getSize() {
                return data.size();
            }

            public String getString() {
                return data.toString();
            }

            public String getString(String arg0) throws UnsupportedEncodingException {
                return new String(get(), arg0);
            }

            public boolean isFormField() {
                return formfield;
            }

            public boolean isInMemory() {
                return true;
            }

            public void setFieldName(String arg0) {
                fname = arg0;
            }

            public void setFormField(boolean arg0) {
                formfield = arg0;
            }

            public void write(File arg0) throws Exception {
                throw new UnsupportedOperationException("Writing to file is not allowed");
            }

            public FileItemHeaders getHeaders() {
                return null;
            }

            public void setHeaders(FileItemHeaders headers) {
            }

        };
    }
}