itemlibrary.java

一个带界面的在线测试系统

/**
 * IteMKubrart.java
 * create by ZZ, 2007.12.16
 */
package olts.application;
import java.util.*;
import java.sql.*;
import olts.persistent.*;
import olts.database.DatabaseUtil;
import olts.exception.*;
/**
 * 该类就是试题库，用于管理试题
 * @author ZZ
 * @version 1.0
 *
 */
public class ItemLibrary {
	
	private ItemMapper mapper;
	private List cache;
	private ItemFactory factory;
        private Random rd = new Random(47);
	
	public ItemLibrary(ItemMapper im,ItemFactory f)
	throws SQLException,ItemCreateException{
		this.mapper = im;

		this.factory = f;
		this.init();
	}
	
	private void init()throws SQLException{
		this.cache = new LinkedList();
		
		List buf = this.mapper.getAllItems();
		
		for (int i = 0; i < buf.size(); i++){
			Item item = (Item)buf.get(i);
			this.cache.add(item);
		}//得到所有的试题～
	}
	
	/**
	 * 得到题库里的所有试题,
	 * 得到的是试题库里所有试题的一份复制
	 */
	public List getAllItems()throws ItemCreateException, SQLException{
		this.init();//继续偷懒
		List temp = new LinkedList();
		
		for (int i = 0; i < this.cache.size(); i++){
			Item item = this.factory.makeConcreteItem((Item)this.cache.get(i));
			temp.add(item);
		}
		return temp;
	}
	
	/**
	 * 得到某一难度上的所有试题的一份复制
	 * @param difficulty 试题的难度
	 */
	public List getItemByDifficulty(int difficulty)throws ItemCreateException{
		List temp = new LinkedList();
		
		for (int i = 0; i < this.cache.size(); i++){
			Item item = (Item)this.cache.get(i);
			if (item.getDifficulty() == difficulty){
				item = this.factory.makeConcreteItem(item);
				temp.add(item);
			}
		}
		return temp;
	}
	
	/**
	 * 按照试题的标识取得一个试题
	 */
	public Item getItemById(int id)throws ItemCreateException{
		for (int i = 0; i < this.cache.size(); i++){
			Item item = (Item)this.cache.get(i);
			if (item.getId() == id){
				return this.factory.makeConcreteItem(item);
			}
		}
		return null;
	}
	
	/**
	 * 随机的抽取一条试题
	 */
	public Item getItemRandom()throws ItemCreateException{
		
		
		
		int i = this.cache.size();
		if (i == 0) return null;
		
		while (i >= this.cache.size()){
			i = rd.nextInt(this.cache.size());
		}
		
		Item item = (Item) this.cache.get(i);
		return this.factory.makeConcreteItem(item);
	}
	
	/**
	 * 往试题库里添加一条试题
	 */
	public void addItem(int id, int diff, int time, int score, String con, String ans,
			String type)throws ItemCreateException,SQLException,PersistItemException{
		Item item = this.factory.makeConcreteItem(id, diff, time, score, con, ans, type);
		this.mapper.persistItem(item);
		this.cache.add(item);//加入到缓存中去
	}
        
        public void addItem(Item i)throws ItemCreateException,SQLException,PersistItemException{
            Item item = this.factory.makeConcreteItem(i);
            this.mapper.persistItem(item);
            this.cache.add(item);
        }
	
	/**
	 * 往试题库里更新一条试题的信息
	 */
	public void updateItem(int oldId, int id, int diff, int time, int score, String con,
			String ans, String type)throws ItemCreateException,SQLException,PersistItemException{
		
		Item item = this.factory.makeConcreteItem(id, diff, time, score, con, ans, type);
		this.mapper.updateItem(oldId, item);
		this.init();//偷个小懒
	}
        
        public void updateItem(Item oldItem, Item newItem)throws ItemCreateException,SQLException,PersistItemException{
            Item item = this.factory.makeConcreteItem(newItem);
            this.mapper.updateItem(oldItem.getId(), item);
	    this.init();//偷个小懒
        }
	
	/**
	 * 删除一条试题信息
	 * @param id 要删除的试题
	 */
	public void removeItem(int id)throws SQLException{
		this.mapper.removeItem(id);
		this.init();//偷个小懒
	}
        
        /**
         *得到试题库里试题的所有类型信息
         */
        public Object[] getAllItemTypes(){
            return this.factory.getItemTypes();
        }


	public static void main(String[] args) {
		// 测试之～
		String driver = "sun.jdbc.odbc.JdbcOdbcDriver";
		String url = "jdbc:odbc:driver={Microsoft Access Driver (*.mdb)};";
		url += "DBQ=./db.mdb";
		DatabaseUtil du = null;
		ItemMapper im = null;
		ItemLibrary ilib = null;
		ItemFactory ifc = null;
		try{
			
			//测试连接
			du = new DatabaseUtil(driver,url,"","");
		    im = new ItemMapper(du);
			
			ifc = new OltsItemFactory();
			ilib = new ItemLibrary(im, ifc);
			
                    List l = ilib.getAllItems();
		    for(int i =0; i < l.size(); i++){
		    	Item temp =(Item)l.get(i);
		    	System.out.println(temp);
		    }
		    
		    System.out.println(ilib.getItemRandom());
                    
		    int id = 18848;
		    int diff = 1;
		    String con = "1";
		    String ans = "1";
		    int score = 1;
		    int time = 1;
		    String type = "TrueFalseItem";
                    
		    int oid = 3;
		  //测试插入命令
		    ilib.addItem(id, diff, time, score, con, ans, type);

		  //测试修改命令
			//ilib.updateItem(3, id, diff, time, score, con, ans, type);
			
		  //测试删除命令
			//ilib.removeItem(2);
		    //im.persistItem(item);
			//im.removeItem(item);
			
		  


			
		}catch(Exception e){
			
			System.out.println(e);
			
		}finally {
			if (du != null ){
				try{
					du.close();
				}catch(Exception e){
					System.out.println(e);
				}
			}
		}
		

	}

}