olapmodel.java

OLAP 的客户端代码

/*
 * ====================================================================
 * This software is subject to the terms of the Common Public License
 * Agreement, available at the following URL:
 *   http://www.opensource.org/licenses/cpl.html .
 * Copyright (C) 2003-2004 TONBELLER AG.
 * All Rights Reserved.
 * You must accept the terms of that agreement to use this software.
 * ====================================================================
 *
 * 
 */
package com.tonbeller.jpivot.olap.model;

import javax.servlet.ServletContext;

import com.tonbeller.jpivot.core.Model;

/**
 * Provides access to extensions, result and metadata. It does not specify
 * what data are displayed (the query). Supports navigations thru Extensions.
 * 
 * @see com.tonbeller.jpivot.core.Extension
 * @see com.tonbeller.jpivot.olap.model.Result
 */
public interface OlapModel extends Model {

  /** 
   * thrown if too many result positions would be returned
   * @see OlapModel#getResult()
   */
  public class ResultTooLargeException extends RuntimeException {
    public ResultTooLargeException() {
      super();
    }
    public ResultTooLargeException(Throwable cause) {
      super(cause);
    }
    public ResultTooLargeException(String message, Throwable cause) {
      super(message, cause);
    }
  }

  /** 
   * thrown if the result can not be computed because the cube is
   * empty.
   * @see OlapModel#getResult()
   */
  public class EmptyCubeException extends RuntimeException {
    public EmptyCubeException() {
      super();
    }
    public EmptyCubeException(Throwable cause) {
      super(cause);
    }
    public EmptyCubeException(String message, Throwable cause) {
      super(message, cause);
    }
  }
    
  /**
   * runs the query and returns the result
   */
  public Result getResult() throws OlapException;
  
  /**
   * @return all dimensions of the cube for navigation
   */
  Dimension[] getDimensions();

  /**
   * @return all measures of the cube for navigation
   */
  Member[] getMeasures();
  
  /**
   * called once after creation. E.g. open DB connection
   */
  void initialize() throws OlapException;

  /**
   * called once when the not used any longer. E.g. close DB connection
   *
   */
  void destroy();
  
  /**
   * @return an ID string for this model
   */
  String getID();
  
  /**
   * sets an ID string for this model
   */
  void setID(String ID);
  
  /**
   * store a servlet context to the model
   */
  void setServletContext(ServletContext servletContext);
  
}