PartItem

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.util.Iterator;

import javax.servlet.http.Part;

import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileItemHeaders;
import org.apache.commons.fileupload.util.FileItemHeadersImpl;
import org.apache.commons.io.IOUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class PartItem implements FileItem {
    // defaut uid
    private static final long serialVersionUID = 1L;

    // get the logger
    private static final Logger LOGGER = LoggerFactory
            .getLogger(PartItem.class);

    /**
     * The delegate part
     */
    private Part part;

    /**
     * Storing the content of the part since the inputstream may be only read
     * one.
     */
    private byte[] content;

    /**
     * Is this part a form or a file field?
     */
    private boolean formField = false;

    /**
     * Create a new partItem with the given part.
     *
     * @param part
     *            The part to delegate.
     */
    public PartItem(Part part) {
        this.part = part;
    }

    /*
     * (non-Javadoc)
     *
     * @see org.apache.commons.fileupload.FileItemHeadersSupport#getHeaders()
     */
    @Override
    public FileItemHeaders getHeaders() {
        Iterator<String> s = part.getHeaderNames().iterator();

        FileItemHeadersImpl f = new FileItemHeadersImpl();

        while (s.hasNext()) {
            String key = s.next();
            f.addHeader(key, part.getHeader(key));
        }

        return f;
    }

    /*
     * (non-Javadoc)
     *
     * @see
     * org.apache.commons.fileupload.FileItemHeadersSupport#setHeaders(org.apache
     * .commons.fileupload.FileItemHeaders)
     */
    @Override
    public void setHeaders(FileItemHeaders headers) {
        // may be ignored. The headers of a part cannot be changed
    }

    /*
     * (non-Javadoc)
     *
     * @see org.apache.commons.fileupload.FileItem#getInputStream()
     */
    @Override
    public InputStream getInputStream() throws IOException {
        return part.getInputStream();
    }

    /*
     * (non-Javadoc)
     *
     * @see org.apache.commons.fileupload.FileItem#getContentType()
     */
    @Override
    public String getContentType() {
        return part.getContentType();
    }

    /*
     * (non-Javadoc)
     *
     * @see org.apache.commons.fileupload.FileItem#getName()
     */
    @Override
    public String getName() {
        return part.getSubmittedFileName();
    }

    /*
     * (non-Javadoc)
     *
     * @see org.apache.commons.fileupload.FileItem#isInMemory()
     */
    @Override
    public boolean isInMemory() {
        return true; // these parts should not be written to disk
    }

    /*
     * (non-Javadoc)
     *
     * @see org.apache.commons.fileupload.FileItem#getSize()
     */
    @Override
    public long getSize() {
        return part.getSize();
    }

    /*
     * (non-Javadoc)
     *
     * @see org.apache.commons.fileupload.FileItem#get()
     */
    @Override
    public byte[] get() {

        if (content == null) {
            try {
                content = IOUtils.toByteArray(getInputStream());
            } catch (IOException e) {
                LOGGER.error("Failed to read content from the part", e);
            }
        }

        return content;
    }

    /*
     * (non-Javadoc)
     *
     * @see org.apache.commons.fileupload.FileItem#getString(java.lang.String)
     */
    @Override
    public String getString(String encoding)
            throws UnsupportedEncodingException {
        return new String(get(), encoding);
    }

    /*
     * (non-Javadoc)
     *
     * @see org.apache.commons.fileupload.FileItem#getString()
     */
    @Override
    public String getString() {
        return new String(get());
    }

    /*
     * (non-Javadoc)
     *
     * @see org.apache.commons.fileupload.FileItem#write(java.io.File)
     */
    @Override
    public void write(File file) throws Exception {
        // file will stay in memory
    }

    /*
     * (non-Javadoc)
     *
     * @see org.apache.commons.fileupload.FileItem#delete()
     */
    @Override
    public void delete() {
        // file only exists in memory therefor delete() is not implemented
    }

    /*
     * (non-Javadoc)
     *
     * @see org.apache.commons.fileupload.FileItem#getFieldName()
     */
    @Override
    public String getFieldName() {
        return part.getName();
    }

    /*
     * (non-Javadoc)
     *
     * @see
     * org.apache.commons.fileupload.FileItem#setFieldName(java.lang.String)
     */
    @Override
    public void setFieldName(String name) {
        LOGGER.info("setFieldName()");

    }

    /*
     * (non-Javadoc)
     *
     * @see org.apache.commons.fileupload.FileItem#isFormField()
     */
    @Override
    public boolean isFormField() {
        return formField;
    }

    /*
     * (non-Javadoc)
     *
     * @see org.apache.commons.fileupload.FileItem#setFormField(boolean)
     */
    @Override
    public void setFormField(boolean state) {
        this.formField = state;

    }

    /*
     * (non-Javadoc)
     *
     * @see org.apache.commons.fileupload.FileItem#getOutputStream()
     */
    @Override
    public OutputStream getOutputStream() throws IOException {
        // the part cannot be changed.
        return null;
    }

}