It is still possible with 3.1. The approach is the same - find all classes that
use DataSource and replace it (the set of affected classes may be different).
And you've discovered one way of doing that already.
Another more DI'ish way is to implement MyDataSourceFactory to return a
"dynamic" DataSource that changes the returned connection under the covers
based on a system property or a ThreadLocal value. So when you switch to
processing a new DB, you start by setting that value, and your DataSource picks
it up and returns connections pointing to the new DB. The advantage of that is
that your code doesn't need to know Cayenne internals to work, it is all
encapsulated in your own classes.
Andrus
On May 26, 2011, at 9:50 AM, Wernke zur Borg wrote:
>
> Thanks, but I am not sure whether this is what I need.
>
> I have hundreds of MS Access Database files (*.mdb), which I need to process
> in a single run of my program. Obviously I am using the JdbcOdbc bridge,
> which is working fine with Cayenne so far. My intention is to create a single
> ServerRuntime and then switch the data source dynamically for every file.
>
> This used to be possible with 3.0 according to the FAQ entry - is it no
> longer possible with 3.1 ?
>
> Thanks, Wernke
>
>
> On 26/05/2011 15:25, Andrus Adamchik wrote:
>> Yeah, the Wiki page refers to Cayenne 3.0 and earlier. In 3.1 it is much
>> easier and can be done via a DI container. And you don't have to remember
>> all the classes that might use the DataSource. So you would create a custom
>> module, bind a custom DataSourceFactory, and pass it to ServerRuntime
>> constructor:
>>
>> Module m = new Module() {
>> public void configure(Binder binder) {
>> binder.bind(DataSourceFactory.class).to(MyDataSourceFactory.class);
>> }
>> };
>>
>> ServerRuntime r = new ServerRuntime("cayenne-myconfig.xml", m);
>>
>> On May 26, 2011, at 6:19 AM, Wernke zur Borg wrote:
>>
>>> Hi all,
>>>
>>> I am referring to FAQ "Setting Database Connection" here:
>>> https://cwiki.apache.org/CAY/setting-database-connection.html
>>>
>>> Firstly, in 3.1 the SharedConfiguration no longer exists, so we have to use
>>> the ServerRuntime instead:
>>>
>>> ServerRuntime runtime = ...;
>>> DataDomain domain = runtime.getDataDomain();
>>> DataNode node = domain.getNode("DB1");
>>> node.setDataSource(dataSource);
>>>
>>> However, this setting does not have the desired effect. When the connection
>>> to the database is established, still the original definition from the
>>> config file is taken.
>>>
>>> I have traced down this problem and found that the DataNode has a
>>> DbAdapter, which has its own DataSource object. This gets set in the
>>> ServerRuntime.getDataDomain() call above.
>>>
>>> The only way I found around this is by explicitly creating a new adapter
>>> with my data source:
>>>
>>> node.setAdapter(new AutoAdapter(dataSource));
>>>
>>> However, the AutoAdapter default constructor is deprecated, and I could not
>>> find an easy way to use the recommended method with a DbAdapterFactory.
>>>
>>> Any ideas?
>>>
>>> Thanks for any hint.
>>>
>>> Wernke
>
>
>
