ExtJS 4.2 - Internal Server Error 500 When Loading Store - extjs

Question

I keep on getting an internal server 500 error every time I attempt to load my store. I am currently trying to connect to our API endpoint that contains the data that I need. This is the error I'm getting every time (FYI, checking the 'Accept' Header, it seems it's empty. I am not sure how I can have an application/json there to correctly connect to it):
My Store is setup like this:
Ext.define('EcommBackoffice.store.TierCapacity', {
extend: 'Ext.data.Store',
model: 'EcommBackoffice.model.TierCapacityModel',
storeId: 'tier-capacity-id',
autoLoad: true,
sorters: [{
property: 'name',
direction: 'ASC'
}],
proxy: {
type: 'rest',
url: EcommBackoffice.Global.getAPIEndPoints().tier_capacity + '?siteCode=bgp88',
reader: {
type: 'json',
root: ''
},
listeners: {
exception: function(proxy, response, op) {
if (response.status === 403 || response.status === 401) return; /*skip this exception handler and check App exception handler*/
Ext.Msg.alert('ERROR', response.responseText + ' ' + response.statusText);
}
}
}
});
And my model like this:
Ext.define('EcommBackoffice.model.TierCapacityModel', {
extend: 'Ext.data.Model',
fields: [{
name: 'id'
}, {
name: 'paymentOption',
type: Ext.data.SortTypes.asUCString
}, {
name: 'tier',
type: Ext.data.SortTypes.asUCString
}, {
name: 'media',
type: Ext.data.SortTypes.asUCString
}, {
name: 'channels',
type: Ext.data.SortTypes.asUCString
}]
});
The API contains something like this:
[{
"name": "DEBIT",
"tiers": [{
"name": "Default",
"media": [{
"name": "OFFICE",
"channels": [{
"name": "CHANNEL-001",
"currentVolume": 0,
"maxVolume": 0,
"yesterdayVolume": 0
}]
}]
}]
}]
Moreover, I am a bit unfamiliar with setting up the models and stores. I am assuming that is where I'm missing something. Am I structuring the model correctly based on the API response? I tried reading the docs, but I still can't wrap my head around it.

Answer 1

Error Code 500 tells :
The server encountered an unexpected condition which prevented it from fulfilling the request.
As I can see that while processing code at your Java end , you are getting NullPointerException .
So when an unexpected exception occurs , Http 500 error code is thrown which is shown on your browser. This error code has nothing to be done from client side.

Answer 2

The error 500 is not an ExtJS issue. It's a backend issue. You should check what backend technologies you use and add these to the tags to get any help.
checking the 'Accept' Header, it seems it's empty. I am not sure how I can have an application/json there to correctly connect to it)
proxy: {
headers: {
Accept: 'application/json'
},