C3p0连接池Tomcat Apache概念

Question

1) Difference between the constructors of InitialContext.

public InitialContext(Hashtable<?,?> environment)

what does this constructor do and what will environment parameter do .

2)

    Hashtable<Object, String> environment= new Hashtable<Object, String> (2);
     --
     --   
    Context ctx = new InitialContext( environment);
    ComboPooledDataSource comboPooledDataSource = new ComboPooledDataSource();
    comboPooledDataSource.setJdbcUrl(----);
    comboPooledDataSource.setDriverClass(----);
    ctx.bind (__);

please explain each line what does it do..

3)Why to create combopooldatasource object ,instead we can create datasource object..??

Answer 1

Answer for 3rd question : Datasource can not be created for ordinary domains,its only for JNDI domains.

For 1st : InitialContext is used to set the environment to create the pooled datasource by creating .bindings file

For 2nd : Context sets the environment. ComboPooledDataSource object is created. For that object the url and jdbc driver class wll be set to take the connections from DB to the Pool. Above set things will be binded to the context and it will be wriiten in .bindings file in encoded format