RestExpress MultiPart File Upload support

Configuration.java

package org.zenithar.restexpress.config;

import com.strategicgains.restexpress.Format;
import com.strategicgains.restexpress.RestExpress;
import com.strategicgains.restexpress.util.Environment;
import org.apache.commons.fileupload.FileUpload;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.io.FileCleaningTracker;

import java.io.File;
import java.util.Properties;

/**
 * @author Thibault NORMAND
 * @date 25/06/13
 */
public class Configuration
        extends Environment {

    private FileUpload fileUpload = new FileUpload();
    private DeleteFilesOnEndUploadCleaningTracker fileCleaningTracker = new DeleteFilesOnEndUploadCleaningTracker();

    @Override
    protected void fillValues(Properties p) {
        DiskFileItemFactory diskFileItemFactory = new DiskFileItemFactory();
        diskFileItemFactory.setRepository(new File("./tmp"));
        diskFileItemFactory.setFileCleaningTracker(fileCleaningTracker);

        this.fileUpload.setFileItemFactory(diskFileItemFactory);
    }

    public FileUpload getFileUpload() {
        return fileUpload;
    }
}

DeleteFilesOnEndUploadCleaningTracker.java

package org.zenithar.restexpress.utils;

import org.apache.commons.io.FileCleaningTracker;
import org.apache.commons.io.FileDeleteStrategy;

import java.io.File;
import java.util.ArrayList;
import java.util.List;

public class DeleteFilesOnEndUploadCleaningTracker extends FileCleaningTracker {

     private List<String> filesToDelete = new ArrayList();

     public void deleteTemporaryFiles() {
         for (String file : filesToDelete) {
             new File(file).delete();
         }
         filesToDelete.clear();
     }

     @Override
     public synchronized void exitWhenFinished() {
         deleteTemporaryFiles();
     }

     @Override
     public int getTrackCount() {
         return filesToDelete.size();
     }

     @Override
     public void track(File file, Object marker) {
         filesToDelete.add(file.getAbsolutePath());
     }

     @Override
     public void track(File file, Object marker, FileDeleteStrategy deleteStrategy) {
         filesToDelete.add(file.getAbsolutePath());
     }

     @Override
     public void track(String path, Object marker) {
         filesToDelete.add(path);
     }

     @Override
     public void track(String path, Object marker, FileDeleteStrategy deleteStrategy) {
         filesToDelete.add(path);
     }
 }

FileUploadController.java

package org.zenithar.restexpress.controller;

import org.zenithar.restexpress.utils.RestUploadContext;
import com.strategicgains.restexpress.Request;
import com.strategicgains.restexpress.Response;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileUpload;
import org.apache.commons.fileupload.FileUploadException;

/**
 * @author Thibault NORMAND
 * @date 25/06/13
 */
public class DeliveryController {

    private FileUpload fileUpload;
    private DeleteFilesOnEndUploadCleaningTracker tracker;

    public DeliveryController(FileUpload fileUpload, DeleteFilesOnEndUploadCleaningTracker tracker) {
        super();
        this.fileUpload = fileUpload;
        this.tracker = tracker;
    }

    public void create(Request request, Response response) {

        RestUploadContext context = RestUploadContext.fromRequest(request);

        try {
            List<FileItem> items = fileUpload.parseRequest(context);
            Map<String , List<FileItem>> parts = MultiPartDecoder.getParts(items);

            for(FileItem file : parts.get("files")) {
               // File operation
            }
        catch (FileUploadException e) {
            // Handle errors
        } finally {
            tracker.deleteTemporaryFiles();
        }
    }
}

MultiPartDecoder.java

package org.zenithar.restexpress.utils;

import org.apache.commons.fileupload.FileItem;

import java.util.LinkedHashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;

/**
 * @author t_no
 * @date 25/06/13
 */
public final class MultiPartDecoder {

    private MultiPartDecoder() {
        throw new AssertionError();
    }

    public static Map<String, List<FileItem>> getParts(List<FileItem> request) {

        Map<String, List<FileItem>> parts = new LinkedHashMap<String, List<FileItem>>();

        for(FileItem it : request) {
            final String partName = it.getFieldName();

            if(parts.containsKey(partName)) {
                parts.get(partName).add(it);
            } else {
                List<FileItem> items = new LinkedList<FileItem>();
                items.add(it);
                parts.put(partName, items);
            }
        }

        return parts;
    }
}

RestUploadContext.java

package org.zenithar.restexpress.utils;

import com.strategicgains.restexpress.Request;
import org.apache.commons.fileupload.UploadContext;
import org.jboss.netty.buffer.ChannelBuffer;
import org.jboss.netty.buffer.ChannelBufferInputStream;

import java.io.IOException;
import java.io.InputStream;

/**
 * @author Thibault NORMAND
 * @date 25/06/13
 */
public class RestUploadContext implements UploadContext {

    private final long contentLength;
    private final String characterEncoding;
    private final String contentType;
    private final InputStream inputStream;

    private RestUploadContext(long contentLength, String characterEncoding, String contentType, InputStream inputStream) {
        this.contentLength = contentLength;
        this.characterEncoding = characterEncoding;
        this.contentType = contentType;
        this.inputStream = inputStream;
    }

    public static RestUploadContext fromRequest(Request request) {
        return new Builder()
                .withChannelBuffer(request.getBody())
                .withContentType(request.getHeader("Content-Type"))
                .withContentLength(Long.valueOf(request.getHeader("Content-length")))
                .build();
    }

    public static class Builder {

        private Long contentLength = 0L;
        private String characterEncoding = "UTF-8";
        private String contentType = "multipart/form-data";
        private InputStream inputStream;

        public Builder() {
        }

        public Builder withContentLength(long length) {
            this.contentLength = length;
            return this;
        }

        public Builder withCharacterEncoding(String encoding) {
            this.characterEncoding = encoding;
            return this;
        }

        public Builder withContentType(String contentType) {
            this.contentType = contentType;
            return this;
        }

        public Builder withChannelBuffer(ChannelBuffer channel) {
            this.inputStream = new ChannelBufferInputStream(channel);
            return this;
        }

        public RestUploadContext build() {
            return new RestUploadContext(contentLength, characterEncoding, contentType, inputStream);
        }
    }

    @Override
    public long contentLength() {
        return this.contentLength;
    }

    @Override
    public String getCharacterEncoding() {
        return this.characterEncoding;
    }

    @Override
    public String getContentType() {
        return this.contentType;
    }

    @Override
    public int getContentLength() {
        return Long.valueOf(this.contentLength).intValue();
    }

    @Override
    public InputStream getInputStream() throws IOException {
        return inputStream;
    }

}

Can you write a sample for upload images?