member.java

图书馆检索系统

/*
 * Member.java
 *
 */
 
package library;
import java.util.*;
import java.sql.*;

/** 
 * This bean represents a member.
 * Class <code>Member</code> inherits
 * from class <code>SystemUser</code>.
 *
 * @author  dms
 * @version 1.0
 */
public class Member extends SystemUser {

	public static int MAXIMUM_ALLOWED_CHECKOUT = 2;
	
	private String driverLicState;
	private String driverLicNumber;

	/**
	* Class constructor
	*/
	public Member() {super();}
	
	/**
	* Class constructor which retrieves specified member
	* @param ssn int containing ssn of the member to retrieve
	*/
    public Member(int ssn) {
    	super();
    	getMember(ssn);	
    }
    
    protected void setVariables(ResultSet r) throws SQLException {
    	super.setVariables(r);	
    	driverLicState = r.getString("driverlicstate");
    	driverLicNumber = r.getString("driverlicnum");
    }
    
    /**
    * Retrieves the member specified by the ssn
    * @param ssn  int containing ssn of the member to retrieve
    * @return <b>boolean</b> - true if success, false if otherwise
    */
    public boolean getMember(int ssn) {
      
      ensureconnection();
      
	  try {
	  	
	  	String sql = "SELECT * FROM Member WHERE ssn = " + ssn;
	  	ResultSet r = db.runQuery(sql);
	    if (r.next()) {
	      setVariables(r);
	      return true;
	    }
	    else
	      return false;
	     
	  }
	  catch (SQLException e) {
	    System.err.println("Exception occurred when trying to retrive member:\n" + e.toString());
	    return false;
	  }
	 
    }
    
    /**
    * To validate a member's id and password use this method
    * with the member's ssn and password.
    * @param ssn  int containing member's ssn
    * @param pass String containing password
    * @return boolean, true if validated, false if otherwise
    */
    public boolean validate(int ssn, String pass) {
    	
    	ensureconnection();
    	
    	try {
    		String sql = "SELECT * FROM Member WHERE ssn = " + ssn +
    					  " AND passwd = '" + pass + "'";
			ResultSet r = db.runQuery(sql);
			
			if (r.next()) {
				setVariables(r);
				return true;	
			} else
				return false;    					  
    		
    	} catch (SQLException se) {
    		System.err.println(se.toString());
    		return false;	
    	}
    	
    }
  
  	/**
  	* Determines the number of books this member has 
  	* checked out.
  	* @return int containing number of books checked out
  	*/
  	public int getCheckedOutBookCount() {
  		
  		ensureconnection();
		
		String sql = "";
		sql = "SELECT Count(*) as counted FROM Book WHERE borrowerssn = " + this.getSSN();
				
		try {
			ResultSet r = db.runQuery(sql);
		  	r.next();
		  	return r.getInt("counted");
		}
		catch (SQLException e) {
		  	System.err.println(e.toString()); 
		  	return 0;
		}	
  		
  	}
  
  	/** 
  	* To iterate through all of the checked out books
  	* for a given member, call this method, then use
  	* method <code>getNext</code> on the resulting
  	* <code>Book</code> object.
  	* 
  	* @return Book containing the first checked out book
  	*/
  	public Book getCheckedOutBooks() throws SQLException {
  		
  		String sql = "SELECT * FROM Book WHERE borrowerssn = " + this.getSSN();
  		return new Book(sql);
  	}

  	/**
  	* Determines the number of books this member has 
  	* held.
  	* @return int containing number of books held out
  	*/
  	public int getHoldCount() {
  		
  		ensureconnection();
		
		String sql = "SELECT Count(*) as counted FROM Hold WHERE ssn = " + this.getSSN();
				
		try {
			ResultSet r = db.runQuery(sql);
		  	r.next();
		  	return r.getInt("counted");
		}
		catch (SQLException e) {
		  	System.err.println(e.toString()); 
		  	return 0;
		}	
  		
  	}

  	/**
  	* 
  	* To iterate through all of the holds for
  	* a given member, call this method, then use
  	* method <code>getNext</code> on the resulting
  	* <code>Hold</code> object.
  	*
  	* @return Hold containing the first Hold for this member.
  	*/
  	public Hold getHolds() throws SQLException {
  		
  		String sql = "SELECT * FROM Hold WHERE ssn = " + this.getSSN();
  		return new Hold(sql);
  	}

  	/**
  	* 
  	* To iterate through all of the holds for
  	* a given member, call this method, then use
  	* method <code>getNext</code> on the resulting
  	* <code>Favorite</code> object.
  	*
  	* @return Favorite containing the first Hold for this member.
  	*/
  	public Favorite getFavorites() throws SQLException {
  		
  		String sql = "SELECT * FROM FavoriteTitles WHERE customerid = " + this.getSSN();
  		return new Favorite(sql);
  	}
  
  	/**
  	* This method is a test for equality between this member and another.
  	* @param m   Member to test equality on
  	* @return boolean, true if members are equal, false if otherwise
  	*/
  	public boolean equals(Member m) {
  		
  		if (this.getSSN() == m.getSSN())
  			return true;
  		else
  			return false;	
  	}
  
  	/**
  	* Places a hold on a title.
  	* @param cn  callnumber of title
  	* @return boolean true if success, false otherwise
  	*/
  	public boolean placeHold(String cn) throws SQLException {
  		
  		// Make sure hold doesn't already exist for this title.
  		Hold hold = this.getHolds();
  		boolean held = false;
  		while (hold.getNext()) {
  			if (hold.getCallNumber().equals(cn)) held = true;	
  		}
  		
  		// Make sure this member doesn't already have a
  		// copy of this checked out.	
  		Book book = this.getCheckedOutBooks();
  		boolean checkedOut = false;
  		while (book.getNext()) {
  			if (book.getCallNumber().equals(cn)) checkedOut = true;	
  		} 
  		
  		if (held || checkedOut)
  			return false;
  		else {
  			db.executeQuery("INSERT INTO Hold VALUES (" + this.getSSN() + ", '" + cn + "', CURRENT_TIMESTAMP)");  			
  			return true;
  		}
  		
  	}

  	/**
  	* Add a title to member's favorites list.
  	* @param cn  callnumber of title
  	* @return boolean true if success, false otherwise
  	*/
  	public boolean addFav(String cn) throws SQLException {
  		
  		// Make sure hold doesn't already exist for this title.
  		Favorite fav = this.getFavorites();

  		while (fav.getNext()) {
  			if (fav.getCallNumber().equals(cn)) {
 			  return false;
			}
  		}
  		
            	db.executeQuery("INSERT INTO FavoriteTitles VALUES ('" + cn + "', " + this.getSSN() + ")");

  		return true;
  	}

  	/**
  	* Accessor method for driver license number
  	* @return String containing Driver License Number
  	*/
  	public String getDriverLicNumber() {return driverLicNumber;}
  	
  	/**
  	* Accessor method for driver license state
  	* @return String containing Driver License state
  	*/
  	public String getDriverLicState() {return driverLicState;}
  	
  	
}