A simple file upload and renderBinary example using Play! 1.2.3 and GAE (google appengine) 1.5.6

Application.java

package controllers;

import play.*;
import play.data.Upload;
import play.db.Model.BinaryField;
import play.libs.MimeTypes;
import play.mvc.*;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.util.List;

import com.google.appengine.api.datastore.Blob;
import com.google.apphosting.utils.remoteapi.RemoteApiPb.Response;

import models.*;

public class Application extends Controller {

    public static void index() {
    	List images = Picture.all().fetch();
        render(images);
    }
    
    public static void uploadPicture(Upload data) {
    	Picture picture = new Picture();
    	Logger.info(data.getContentType());
    	Logger.info(data.getFieldName());
    	Logger.info(data.getFileName());
    	picture.contentType = data.getContentType();
    	picture.fileName = data.getFileName();
    	picture.file = data.asBytes();
    	picture.save();
    	Logger.info("saving id=%s", picture.id);
    	index();
    }
    
    public static void show(Long id) {
    	Logger.info("loading id=%s", id);
    	Picture picture = Picture.findByKey(id);
    	response.setContentTypeIfNotSet(picture.contentType);
		renderBinary(new ByteArrayInputStream(picture.file), picture.file.length);
    }

}

index.html

#{extends 'main.html' /}
#{set title:'Home' /}

#{list items:images, as:'image'}
	<a href="@{show(image.id)}">
		<img border="0" src="@{show(image.id)}" width="50px" />
		${image.fileName}
	</a>
	<br />
#{/list}

<br />
#{form @Application.uploadPicture(), enctype:'multipart/form-data'}
    <input type="file" name="data" />
    <input type="submit" name="submit" value="Aggiungi" />
#{/form}

Picture.java

package models;

import siena.*;

@Table("picture")
public class Picture extends Model {
	@Id(Generator.AUTO_INCREMENT)
	public Long id;
    public byte[] file;
	public String fileName;
	public String contentType;
    
    public static Query<Picture> all() {
        return Model.all(Picture.class);
    }
    
    public static Picture findByKey(Long id) {
    	return all().getByKey(id);
    }
}