-+-ڦ

新手可以看看

      (BorrowerInformation) Persistent.getObject(borrower);
   return ret;
   }

   public String getTitleName()
   {
   Item it = (Item) Persistent.getObject(item);
   return it.getTitleName();
   }

   public Item getItem()
   {
   Item it =
      (Item) Persistent.getObject(item);
   return it;
   }

   public int getItemId()
   {
   Item it = (Item) Persistent.getObject(item);
   return it.getId();
   }

   public void write(RandomAccessFile out)
   throws IOException
   {
   item.write(out);
   borrower.write(out);
   }

   public void read(RandomAccessFile in)
   throws IOException
   {
   item = new ObjId();
   item.read(in);
   borrower = new ObjId();
   borrower.read(in);
   }

}

Listing 2. TitleFrame Class. This is another, more detailed description of the collaboration described by the diagram in Figure 7.

//  TitleFrame.java
//
Package ui;

import bo.*;
import util.*;
import java.awt.*;

public class TitleFrame extends Frame {
   private Title current;
   void addButton_Clicked(Event event) {
   if (Title.findOnName(titleField.getText()) != null)
   {
      new MessageBox(
      this,"A Title with that name already exists!");
      return;
   }
   if (Title.findOnISBN(isbnField.getText()) != null)
   {
      new MessageBox(
      this,"A title with the
      same isbn/nr field already exists!");
      return;
   }

   int type = 0;
   if (bookButton.getState() == true)
      type = Title.TYPE_BOOK;
   else if (magazineButton.getState() == true)
      type = Title.TYPE_MAGAZINE;
   else
   {
      new MessageBox(this,"Please give type of title!");
      return;
   }
   current =
      new Title(
      titleField.getText(),
      authorField.getText(),
      isbnField.getText(),
      type);
   int itemno;
   if (itemsField.getText().equals(""))
      itemno = 0;
   else
      itemno = Integer.valueOf(
      itemsField.getText()).intValue();
   if (itemno > 25)
   {
      new MessageBox(this, "Maximum number of items is 25!");
      return;
   }
   for (int i = 0; i <\<> itemno; i++)
   {
      Item it = new Item(current.getObjId(),i+1);
      it.store();
      current.addItem(it.getObjId());
   }
   current.store();
   titleField.setText("");
   authorField.setText("");
   isbnField.setText("");
   itemsField.setText("");
   bookButton.setState(false);
   magazineButton.setState(false);
   }

   void cancelButton_Clicked(Event event) {
   dispose();
   }
   public TitleFrame() {
   //{{INIT_CONTROLS
   setLayout(null);
   addNotify();
   resize(
      insets().left + insets().right + 430,insets().top +
      insets().bottom + 229);
   titleLabel = new java.awt.Label("Title Name");
   titleLabel.reshape(
      insets().left + 12,insets().top + 24,84,24);
   add(titleLabel);
   titleField = new java.awt.TextField();
   titleField.reshape(
      insets().left + 132,insets().top + 24,183,24);
   add(titleField);
   authorField = new java.awt.TextField();
   authorField.reshape(
      insets().left + 132,insets().top + 60,183,24);
   add(authorField);
   isbnField = new java.awt.TextField();
   isbnField.reshape(
      insets().left + 132,insets().top + 96,183,24);
   add(isbnField);
   label1 = new java.awt.Label("ISBN / Nr");
   label1.reshape(
      insets().left + 12,insets().top + 96,84,24);
   add(label1);
   label2 = new java.awt.Label("Author");
   label2.reshape(
      insets().left + 12,insets().top + 60,84,24);
   add(label2);
   addButton = new java.awt.Button("Insert");
   addButton.reshape(
      insets().left + 348,insets().top + 24,60,24);
   add(addButton);
   cancelButton = new java.awt.Button("Close");
   cancelButton.reshape(
      insets().left + 348,insets().top + 192,60,24);
   add(cancelButton);
   label3 = new java.awt.Label("Items available");
   label3.reshape(
      insets().left + 12,insets().top + 192,108,24);
   add(label3);
   itemsField = new java.awt.TextField();
   itemsField.reshape(
      insets().left + 132,insets().top + 192,36,23);
   add(itemsField);
   Group1 = new CheckboxGroup();
   bookButton =
      new java.awt.Checkbox("Book", Group1, false);
   bookButton.reshape(
      insets().left + 132,insets().top + 132,108,24);
   add(bookButton);
   magazineButton =
      new java.awt.Checkbox("Magazine", Group1, false);
   magazineButton.reshape(
      insets().left + 132,insets().top + 156,108,24);
   add(magazineButton);
   label4 = new java.awt.Label("Type");
   label4.reshape(

     insets().left + 12,insets().top + 132,108,24);
   add(label4);
   setTitle("Insert Title Window");
   //}}
   bookButton.setState(true);
   titleField.requestFocus();
 
   //{{INIT_MENUS
   //}}
   }
  

   public TitleFrame(String title) {
   this();
  setTitle(title);
   }

   public synchronized void show() {
   move(50, 50);
   super.show();
   }
  
   public boolean handleEvent(Event event) {
   if (event.id == Event.WINDOW_DESTROY) {
      dispose();
      return true;
   }
   if (event.target == addButton && event.id ==
      Event.ACTION_EVENT) {
      addButton_Clicked(event);
      return true;
   }
   if (event.target == cancelButton && event.id ==
      Event.ACTION_EVENT) {
      cancelButton_Clicked(event);
      return true;
   }
   return super.handleEvent(event);
   }
  
   //{{DECLARE_CONTROLS
   java.awt.Label titleLabel;
   java.awt.TextField titleField;
   java.awt.TextField authorField;
   java.awt.TextField isbnField;
   java.awt.Label label1;
   java.awt.Label label2;
   java.awt.Button addButton;
   java.awt.Button cancelButton;
   java.awt.Label label3;
   java.awt.TextField itemsField;
   java.awt.Checkbox bookButton;
   CheckboxGroup Group1;
   java.awt.Checkbox magazineButton;
   java.awt.Label label4;
   //}}
  
   //{{DECLARE_MENUS
   //}}
}

 




 
 
 
 
 
  整理发布

 发言人:过客   日期：2002-12-14
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看上去错,但我还不够水平看明白


 发言人:过客   日期：2003-01-21
--------------------------------------------------------------------------------
好


 发言人:过客   日期：2003-03-31
--------------------------------------------------------------------------------
真的挺不错的，让我明白了以前一直困惑的问题，值得好好学习.