slugmandrew's BlobServiceImpl

package com.utilitiessavings.testapp.server;

import java.io.IOException;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;

import javax.inject.Singleton;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.google.appengine.api.blobstore.BlobInfo;
import com.google.appengine.api.blobstore.BlobInfoFactory;
import com.google.appengine.api.blobstore.BlobKey;
import com.google.appengine.api.blobstore.BlobstoreService;
import com.google.appengine.api.blobstore.BlobstoreServiceFactory;
import com.google.appengine.api.datastore.DatastoreService;
import com.google.appengine.api.datastore.DatastoreServiceFactory;
import com.google.appengine.api.datastore.Entity;
import com.google.appengine.api.datastore.EntityNotFoundException;
import com.google.appengine.api.datastore.Key;
import com.google.appengine.api.datastore.KeyFactory;
import com.google.appengine.api.utils.SystemProperty;
import com.google.gwt.user.server.rpc.RemoteServiceServlet;
import com.google.inject.Inject;
import com.utilitiessavings.testapp.client.service.BlobService;
import com.utilitiessavings.testapp.shared.BlobFile;

@Singleton
@SuppressWarnings("serial")
public class BlobServiceImpl extends RemoteServiceServlet implements BlobService
{
    // Start a GAE BlobstoreService, DatastoreService and Objectify session
    BlobstoreService blobstoreService = BlobstoreServiceFactory.getBlobstoreService();
    DatastoreService datastoreService = DatastoreServiceFactory.getDatastoreService();

    private Dao dao;

    @Inject
    public BlobServiceImpl(Dao dao)
    {
        super();

        System.out.println("BlobServiceImpl constructed");

        this.dao = dao;
    }

//  @Override
//  public void init() throws ServletException
//  {
//      super.init();
//
//      System.out.println("BlobServiceImpl init");
//  }

    @Override
    public void deleteAllBlobs()
    {
        // get blobinfos and delete all
        Iterator<BlobInfo> blobIterator = new BlobInfoFactory().queryBlobInfos();
        while(blobIterator.hasNext())
        {
            blobstoreService.delete(blobIterator.next().getBlobKey());
        }

        // get BlobFiles and delete all
        dao.emptyDatastoreOfType(BlobFile.class);
    }

    @Override
    public void deleteBlob(String id)
    {
        // convert id to Long
        Long lid = Long.parseLong(id); // 51

        // get BlobFile
        // BlobFile blobFile = ofy().load().type(BlobFile.class).id(lid).get();
        BlobFile blobFile = dao.get(BlobFile.class, lid);

        // get BlobInfo
        BlobInfo blobInfo = new BlobInfoFactory(this.datastoreService).loadBlobInfo(new BlobKey(blobFile.getBlobKey()));

        // delete BlobInfo
        blobstoreService.delete(blobInfo.getBlobKey());

        // delete the BlobFile
        dao.delete(blobFile);
        // dao.ofy.delete(BlobFile.class, lid);
    }

    @Override
    public List<String> getBlobs()
    {
        List<String> blobsStrings = new LinkedList<String>();
        Iterator<BlobInfo> blobIterator = new BlobInfoFactory().queryBlobInfos();

        while(blobIterator.hasNext())
        {
            blobsStrings.add(blobIterator.next().getBlobKey().getKeyString());
        }

        return blobsStrings;
    }

    // Generate a Blobstore Upload URL from the GAE BlobstoreService
    @Override
    public String getBlobStoreUploadUrl()
    {

        // Map the UploadURL to the uploadservice which will be called by
        // submitting the FormPanel
        String url = blobstoreService.createUploadUrl("/testapp4/uploadservice");

        // change the computer name to standard localhost ip address, if in dev mode
        if(SystemProperty.environment.value() == SystemProperty.Environment.Value.Development)
        {
            url = url.replace("UtilitiesSav-PC", "127.0.0.1");
        }

        return url;
    }

    // Retrieve a file's metadata from the Datastore using Objectify
    @Override
    public BlobFile getFile(String id)
    {
        Long lid = Long.parseLong(id);

        // BlobInfo b = dao.ofy.get(BlobInfo.class, lid);

        // BlobFile blobFile = dao.ofy.load().type(BlobFile.class).id(lid).get();

        BlobFile blobFile = dao.get(BlobFile.class, lid);

        return blobFile;
    }

    @Override
    public List<BlobFile> getExistingFiles(String code)
    {
        // CODE FOR MIGRATION
        /*
         * try
         * {
         * // migrate supplierfiles
         * List<SupplierFile> mList = new ArrayList<SupplierFile>();
         *
         * Query<SupplierFile> mQuery = dao.ofy.query(SupplierFile.class).filter("supplierCode", code);
         *
         * Iterator<SupplierFile> mIterator = mQuery.iterator();
         * while(mIterator.hasNext())
         * {
         * BlobFile tempFile = new BlobFile(mIterator.next());
         * dao.ofy.put(tempFile);
         * }
         *
         * } catch(Exception e)
         * {
         * System.out.println(e.getMessage() + " | " + e.getCause());
         * }
         */

        List<BlobFile> list = dao.getListByFilter(BlobFile.class, "code", code);

        // Query<BlobFile> query = dao.query(BlobFile.class).filter("code", code);
        //
        // // Query<BlobFile> query = ofy().load().type(BlobFile.class).filter("code", code);
        // // Query<BlobFile> query = dao.ofy.query(BlobFile.class).filter("code", code);
        //
        // Iterator<BlobFile> iterator = query.iterator();
        // while(iterator.hasNext())
        // {
        // list.add(iterator.next());
        // }

        return list;
    }

    // Override doGet to serve blobs. This will be called automatically by the Image Widget in the client
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException
    {
        BlobKey blobKey = new BlobKey(req.getParameter("blob-key"));
        String filename = "file";

        // use low-level API to get filename and filesize from BlobInfo entity
        Entity entity = null;
        Key k = KeyFactory.createKey("__BlobInfo__", blobKey.getKeyString());

        try
        {
            entity = datastoreService.get(k);
        }
        catch(EntityNotFoundException e)
        {
            e.printStackTrace();
        }

        filename = (String) entity.getProperty("filename");

        resp.addHeader("Content-Disposition", "filename=\"" + filename + "\"");

        blobstoreService.serve(blobKey, resp);
    }

}