Java: Save objects in a textfile? Are there readymade solutions?

I want to save the objects I generated in a program. After restart the App should load automaticly all Objects in an Array. I want to write them in a file and parse them after restart. Are the other smarter possibilities than do it by hand? Thank you

iPhone/iPad App Code Obfuscation - Is it Possible? Worth it?

I've researched quite a bit, both on SO, as well google-ing all over the place, but I can't seem to find a straight-forward answer in regards to code obfuscation for iPhone/iPad apps written in Objective-C.

My questions are these:

1. Is there a way to do it? If so, how?
2. Is it worth it?
3. Does Apple allow it, or have a problem with it, when the app is submitted to them?

EmberJS: Good separation of concerns for Models, Stores, Controllers, Views in a rather complex application?

I'm doing a fairly complex emberjs application, and tying it to a backend of APIs.

The API calls are not usually tied to any particular model, but may return objects of various types in different sections of the response, e.g. a call to Events API would return events, but also return media assets and individuals involved in those events.

I've just started with the project, and I'd like to get some expert guidance on how best to separate concerns to have a clean maintainable code base.

The way I am approaching this is:

• Models: essentially handle records with their fields, and other computed properties. However, models are not responsible for making requests.
  • e.g. Individual, Event, Picture, Post etc.
• Stores: They are essentially caches. For example, an eventStore would store all events received from the server so far (from possibly different requests) in an array, and also in an hash of events indexed by id.
  • e.g. individualStore, eventStore etc.
• Controllers: They tie to a set of related API calls, e.g. eventsController would be responsible for fetching events or a particular event, or creating a new event etc. They would 'route' the response to different stores for later retrieval. They don't keep the response once it has been sent to stores.
  • e.g. eventsController, userSearchController etc.
• Views: They are tied to a particular view. In general, my application may have several views at different places, e.g. latestEventsView on the Dashboard in addition to having a separate events page.
• Templates: are what they are.

Quite often, my templates require to be bound directly to the stores (e.g. peopleView wants to list all the individuals in the individualStore in a list, sorted by some order).

And sometimes, they bind to a computed property

alivePeople: function () { ... }.property('App.individualStore.content.@each'),

The various filtering and sorting options 'chosen' in the view, should return different lists from the store. You can see my last question at what is the right emberjs way to switch between various filtering options?

Who should do this filtering, the view themselves or the stores?

Is this kind of binding across layers okay, or a code smell? Is the separation of concerns good, or am I missing something? Shouldn't controllers be doing something more here? Should my views directly bind to stores?

Any particular special case of MVC more suited to my needs?

Update 17 April 2012 My research goes on, particularly from http://vimeo.com/user7276077/videos and http://jzajpt.github.com/2012/01/17/emberjs-app-architecture.html and http://jzajpt.github.com/2012/01/24/emberjs-app-architecture-data.html

Some issues with my design that I've figured out are:

• controllers making requests (stores or models or something else should do it, not controllers)
• statecharts are missing -- they are important for view-controller interactions (after sometime you realize your interactions are no more simple)

This is a good example of state charts in action: https://github.com/DominikGuzei/ember-routing-statechart-example

UPDATE 9th JANUARY 2013

Yes, it's been long but this question is lately getting lots of views, and that's why I'd like to edit it so that people may get a sense.

Ember's landscape has changed a lot since this question was framed, and the new guides are much improved. EmberJS has come up with conventions (like Rails) and the MVC is much more well defined now.

Anybody still confused should read all the guides, and watch some videos: Seattle Ember.js Meetup

At the moment, I'm upgrading my application to Ember.js 1.0.0-pre2.

Android/Eclipse: where can I find the /Users/USER_NAME/.android/debug.keystore folder?

To use the Google Maps API, I need to generate a debug API key. For this, I need to find the /Users/USER_NAME/.android/debug.keystore folder...but nothing on my Mac ! Do you know how to find this folder ???

Note that I run Eclipse on a Mac. I checked in Eclipse=>Preferences=>Android=>Debug that the default debug keystore is indeed /Users/USER_NAME/.android/debug.keystore but no way to find it.

Thanks !!

Bash script store command output into variable

I have a problem concerning storing the output of a command inside a variable within a bash script.
I know in general there are two ways to do this

either

foo=$(bar)
# or
foo=`bar`

but for the Java version query, this doesn't seem to work.

I did:

version=$(java --version)

This doesn't store the value inside the var. It even still prints it, which really shouldn't be the case.

I also tried redirecting output to a file but this also fails.

Using SQL Server as Image store

Is SQL Server 2008 a good option to use as an image store for an e-commerce website? It would be used to store product images of various sizes and angles. A web server would output those images, reading the table by a clustered ID. The total image size would be around 10 GB, but will need to scale. I see a lot of benefits over using the file system, but I am worried that SQL server, not having an O(1) lookup, is not the best solution, given that the site has a lot of traffic. Would that even be a bottle-neck? What are some thoughts, or perhaps other options?

Android - Where should we save username and password in device memory?

What is a good practice to save username and password on device?

I have gone through many answers on Stackoverflow and now i am bit confused.

I am working on an email app and i want my user to feel absolutely safe while using it.

Some people suggest that we should encrypt it and save it in SharedPreference. Some suggest we shouldn't save it on device at all.

I just want user's details to be stored at safest place possible.

Any help, suggestions would be highly appreciated.

Thanks.

Reliable and efficient key--value database for Linux? [closed]

I need a fast, reliable and memory-efficient key--value database for Linux. My keys are about 128 bytes, and the maximum value size can be 128K or 256K. The database subsystem shouldn't use more than about 1 MB of RAM. The total database size is 20G (!), but only a small random fraction of the data is accessed at a time. If necessary, I can move some data blobs out of the database (to regular files), so the size gets down to 2 GB maximum. The database must survive a system crash without any loss in recently unmodified data. I'll have about 100 times more reads than writes. It is a plus if it can use a block device (without a filesystem) as storage. I don't need client-server functionality, just a library. I need Python bindings (but I can implement them if they are not available).

Which solutions should I consider, and which one do you recommend?

Candidates I know of which could work:

• Tokyo Cabinet (Python bindings are pytc, see also pytc example code, supports hashes and B+trees, transaction log files and more, the size of the bucket array is fixed at database creation time; the writer must close the file to give others a chance; lots of small writes with reopening the file for each of them are very slow; the Tyrant server can help with the lots of small writes; speed comparison between Tokyo Cabinet, Tokyo Tyrant and Berkeley DB)
• VSDB (safe even on NFS, without locking; what about barriers?; updates are very slow, but not as slow as in cdb; last version in 2003)
• BerkeleyDB (provides crash recovery; provides transactions; the bsddb Python module provides bindings)
• Samba's TDB (with transactions and Python bindings, some users experienced corruption, sometimes mmap()s the whole file, the repack operation sometimes doubles the file size, produces mysterious failures if the database is larger than 2G (even on 64-bit systems), cluster implementation (CTDB) also available; file grows too large after lots of modifications; file becomes too slow after lots of hash contention; no built-in way to rebuild the file; very fast parallel updates by locking individual hash buckets)
• aodbm (append-only so survives a system crash, with Python bindings)
• hamsterdb (with Python bindings)
• C-tree (mature, versatile commercial solution with high performance, has a free edition with reduced functionality)
• the old TDB (from 2001)
• bitcask (log-structured, written in Erlang)
• various other DBM implementations (such as GDBM, NDBM, QDBM,, Perl's SDBM or Ruby's; probably they don't have proper crash recovery)

I won't use these:

• MemcacheDB (client-server, uses BereleleyDB as a backend)
• cdb (needs to regenerate the whole database upon each write)
• http://www.wildsparx.com/apbcdb/ (ditto)
• Redis (keeps the whole database in memory)
• SQLite (it becomes very slow without periodic vacuuming, see autocompletion in the in the location bar in Firefox 3.0, even though versions 3.1 and later of sqlite allow auto_vacuuming; beware: small writing transactions can be very slow; beware: if a busy process is doing many transactions, other processes starve, and they can never get the lock)
• MongoDB (too heavy-weight, treats values as objects with internal structure)
• Firebird (SQL-based RDBMS, too heavy-weight)

FYI, a recent article about key--value databases in the Linux magazine.

FYI, an older software list

FYI, a speed comparison of MemcacheDB, Redis and Tokyo Cabinet Tyrant

Related questions on StackOverflow:

• Key Value Database For Windows?
• Is there a business proven cloud store / Key=>Value Database? (Open Source)

Compile lua code, store bytecode then load and execute it

I'm trying to compile a lua script that calls some exported functions, save the resulting bytecode to a file and then load this bytecode and execute it, but I haven't found any example on how to do this. Is there any example available on how to do this? How can I do this?

Edit: I'm using Lua + Luabind (C++)

Find Certificate by hash in Store C#

How to get Certificate by hash in Windows Store using C#?

sha1 example:7a0b021806bffdb826205dac094030f8045d4daa

this loop works but:

X509Store store = new X509Store(StoreName.My);

store.Open(OpenFlags.ReadOnly);

foreach (X509Certificate2 mCert in store.Certificates)
{
    Console.WriteLine( mCert.Thumbprint);
}

store.Close();

Is there a direct method?

PhoneGap in regards to App Store approval

I read that PhoneGap is approved by Apple as a framework for building native apps, but I'm not clear on how this does not constitute a "website wrapped as an app," something that Apple specifically doesn't like, as per their App Store guidelines. I'm assuming it is because the JS is contained in the application, rather than running on a remote server?

Any clarification on this issue would be most appreciated.

Linux equivalent for the Windows certificate store

Is there any fixed or known location for storing certificates in Linux, something like the Windows certificate store?

Thanks.

ExtJs - How to get value from the Store by id?

How to get value from the Store by id?

store in such fields

    fields: [
    {name: "id", type: 'int'},
    {name: "name", type: 'String'},...

I need to get the id - name value.

I try so:

    var rec = Ext.StoreMgr.lookup("MyStore").getById(id);
    alert(rec.data.name);

what am I doing wrong?

Switching from iOS Development to Mac Development

I want to update my developing knowledge from iOS to Mac for distributing my apps to Mac App Store. What are the differences? What are the limitations?

For example, if I want to port my iPhone app that syncs contacts with social network the various NSRequest or ABAddressBook are the same? It changes only views and corresponding view controllers? Does exists some sort of "adapters" from iOS to Mac to easily convert iOS apps to Mac?

In general, what challenges Mac apps arise respect to iOS apps? Thanks

ExtJS 4: Models with Associations and Stores

Introduction

I'm facing an application design problem with the Ext.data.Model class in ExtJS. I will try to develop my ideas to a very common online store scenario here, so you can follow me. I would really appreciate any comments on my thoughts and conclusions!

Models

Let's suppose you want to map the fact that "Every customer can order multiple products" to ExtJS. From the bare words one can identify these three models involved: Customer, Order, and Product. The Order in this case is what connects Customers and Products.

Associations

I found that ExtJS actually allows you to specify this (Customer)1-n(Order)1-n(Product) relation using the Ext.data.HasManyAssociation and Ext.data.BelongsToAssociation classes. But is this what one wants? Would you want to that a Product always belongs to an Order? What if you want to have a list of Products without any connection to Orders whatsoever?

Stores

This is where it get's more ExtJS specific. In ExtJS you have Ext.data.Stores to hold all your data. To me a natural way to organize my data is to have an Ext.data.Store for each of my models:

1. CustomerStore
2. OrderStore
3. ProductStore

Consider having a three Ext.grid.Panels side-by-side; one for each store. When selecting a customer in the one grid, his orders automatically show up in the second grid. When selecting an order in the second grid the associated products appear in the third grid.

Does this sound natural to you? If not, please comment!

Bringing it all together

So now we have three things that we need to bring together:

1. Models and their
2. Associations (hasMany, belongsTo) and the
3. Data (Stores)

Is it possible to define an association only from one side of a Model-Model relation? For instance, can I specify that an Order hasMany Products but leave out that a Product belongsTo an Order? Because a Product can actually belong to more than one Order. Therefore I specify that the Product model hasMany Orders below.

Here are the models in ExtJS:

Customer

Ext.define('Customer', {
    extend   : 'Ext.data.Model',
    requires : [
        'Order',
    ],
    fields   : [
           {name : 'id',          type : 'int'},
           {name : 'lastname',    type : 'string'}
           {name : 'firstname',   type : 'string'}
    ],
    hasMany: 'Order' /* Generates a orders() method on every Customer instance */
});

Order

Ext.define('Order', {
    extend   : 'Ext.data.Model',
    fields   : [
            {name : 'id',          type : 'int'},
            {name : 'customer_id', type : 'int'}, /* refers to the customer that this order belongs to*/
            {name : 'date',        type : 'date'}
    ],
    belongsTo: 'Customer', /* Generates a getCustomer method on every Order instance */
    hasMany: 'Product' /* Generates a products() method on every Order instance */
});

Product

Ext.define('Product', {
    extend   : 'Ext.data.Model',
    fields   : [
            {name : 'id',          type : 'int'},
            {name : 'name',        type : 'string'},
            {name : 'description', type : 'string'},
            {name : 'price',       type : 'float'}
    ],
    /*
        I don't specify the relation to the "Order" model here
        because it simply doesn't belong here.

        Will it still work?
    */
    hasMany: 'Order'
});

And here are the stores:

CustomerStore

Ext.define('CustomerStore', {
    extend      : 'Ext.data.Store',
    storeId     : 'CustomerStore',
    model       : 'Customer',
    proxy   : {
        type   : 'ajax',
        url    : 'data/customers.json',
        reader : {
            type           : 'json',
            root           : 'items',
            totalProperty  : 'total'
        }
    }
});

OrderStore

Ext.define('OrderStore', {
    extend      : 'Ext.data.Store',
    storeId     : 'OrderStore',
    model       : 'Order',
    proxy   : {
        type   : 'ajax',
        url    : 'data/orders.json',
        reader : {
            type           : 'json',
            root           : 'items',
            totalProperty  : 'total'
        }
    }
});

ProductStore

Ext.define('ProductStore', {
    extend      : 'Ext.data.Store',
    storeId     : 'ProductStore',
    model       : 'Product',
    proxy   : {
        type   : 'ajax',
        url    : 'data/products.json',
        reader : {
            type           : 'json',
            root           : 'items',
            totalProperty  : 'total'
        }
    }
});

Here is an example (not by me) with companies and their products http://superdit.com/2011/05/23/extjs-load-grid-from-another-grid/ . It uses two Models and two stores but there are no associations define.

Thank you in advance

-Konrad