dynamic reload in apache DatabaseConfiguration

Question

Has anyone developed a dynamic reload mechanism for the apache commons database configuration object?

score 3 · Accepted Answer · answered Jul 24 '11 at 21:13

3

Actually this is not necessary because DatabaseConfiguration doesn't cache the values from the database. A request is performed every time a property is fetched. There is a RFE to cache the values for improved performance, and this will indeed require a reloading mechanism.

https://issues.apache.org/jira/browse/CONFIGURATION-180

answered Jul 24 '11 at 21:13

Emmanuel Bourg

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I love how this ticket was filed back in '05. Still waiting...8 years later. :) – Mark G. Mar 05 '13 at 21:30
:) I actually just wrapped this class with a cache provider (ehcache) for the time being. But this would be awesome to have provided by the lib! – Mark G. Mar 21 '13 at 20:32

score 0 · Answer 2 · answered Jul 15 '13 at 09:29

apache commons database configuration does not support caching.

I extend DatabaseConfiguration to support caching so it does not hit my database all the time. As for reloads, I instantiate my config where I need it and throw it away when I am done with it.

MyConfig cfg = new MyConfig("jdbc/configdatabase");


public class MyConfig extends DatabaseConfiguration {

    private WeakHashMap<String,Object> cache = new WeakHashMap<String,Object>();

    public MyConfig(String datasourceString,String section) throws NamingException {
        this((DataSource) new InitialContext().lookup(datasourceString),section);
    }

    protected MyConfig(DataSource datasource,String section) {
        super(datasource, "COMMON_CONFIG","PROP_SECTION", "PROP_KEY", "PROP_VALUE",section);
    }

    @Override
    public Object getProperty(String key){
        Object cachedValue = cache.get(key);
        if (cachedValue != null){
            return cachedValue;
        }
        Object databaseValue = super.getProperty(key);
        cache.put(key, databaseValue);
        return databaseValue;

    }
}

dynamic reload in apache DatabaseConfiguration

2 Answers2