[SalesForce] Call static method from the same class

The correct URL would be...

https: //instance.salesforce.com/services/apexrest/Foo/bar

Note: The API version only applies to Salesforce REST URL's

For a HTTP GET request to the above URL you would write your Apex as follows.

@RestResource(urlMapping='/Foo/bar')
global with sharing class Foo 
{ 
    @HttpGet
    global static String bar() 
    {
        return 'bar';
    }   
}

The @RestResource annotation lets you define the URL associated with the class. And then the @HttpGet, @HttpPost etc.. annotations go on your methods. So you don't actually really specify the method name in the URL, its purely a mapping to your class, the method which gets called depends on the HTTP Method specified in the call. So you could change the Apex method to 'bob' and it wouldn't make any difference! :)

@RestResource(urlMapping='/Foo/bar')
global with sharing class Foo 
{
    @HttpGet
    global static String bob() 
    {
        return 'bar';
    }   
}

Finally have a good read through this section of the Apex documentation, defining custom Apex REST services is very well implemented by Salesforce! If you want to learn more about designing great REST API's a can recommend this blog and videos from ApiGee.

Yes :) this expected. De/serialization is a symmetrical process that doesn't "lose" data.

1. If that process were asymmetrical, objects would be inadvertently corrupted by serialization.

2. To prevent intentional object mutation, Salesforce prohibit serialization across namespaces.

   Object o = new Channel_Orders.ServiceOrderProcessor();
   Json.serialize(o);
   
   //System.JSONException:
   //Cannot serialize type from package: CHANNEL_ORDERS.ServiceOrderProcessor
   

I think the intention being (eg) one should be able to take the "dehydrated" string and write it away into storage, then hydrate it back into the original. The object himself should be none the wiser.

Similarly the constructor is not called when deserializing an object - that part of the lifecycle was "someone else's responsibility" independent of his existence for a while as JSON.

Note: using the transient keyword will exclude those properties when serialized.