core/src/main/java/com/orientechnologies/orient/core/db/ODatabasePoolBase.java
public DB acquire(final String iName, final String iUserName, final String iUserPassword,
      final Map<String, Object> iOptionalParams) {
    setup();
    return dbPool.acquire(iName, iUserName, iUserPassword, iOptionalParams);
  }
public DB acquire(final String iName, final String iUserName, final String iUserPassword,
      final Map<String, Object> iOptionalParams) {
    setup();
    return dbPool.acquire(iName, iUserName, iUserPassword, iOptionalParams);
  }
public DB acquire ( final String iName , final String iUserName , final String iUserPassword , final Map < String , Object > iOptionalParams ) { setup ( ) ; return dbPool . acquire ( iName , iUserName , iUserPassword , iOptionalParams ) ; }
Acquires a connection from the pool specifying options. If the pool is empty, then the caller thread will wait for it.

@param iName
Database name
@param iUserName
User name
@param iUserPassword
User password
@return A pooled database instance
Acquires a connection from the pool specifying options . If the pool is empty then the caller thread will wait for it .