Java2实用教程(第二版)程序代码——第二十六章 常见数据结构的Java实现

  1None.gif//例子1
  2None.gifimport java.util.*;
  3None.gifpublic class LinkListOne
  4ExpandedBlockStart.gifContractedBlock.gifdot.gif{public  static void main(String args[])
  5ExpandedSubBlockStart.gifContractedSubBlock.gif dot.gif{ LinkedList mylist=new LinkedList();
  6InBlock.gif   mylist.add("It");          //链表中的第一个节点。
  7InBlock.gif   mylist.add("is");   //链表中的第二个节点。
  8InBlock.gif   mylist.add("a");      //链表中的第三个节点。
  9InBlock.gif   mylist.add("door");    //链表中的第四个节点。
 10InBlock.gif   int number=mylist.size();  //获取链表的长度。
 11InBlock.gif   for(int i=0;i<number;i++)
 12ExpandedSubBlockStart.gifContractedSubBlock.gif   dot.gif{String temp=(String)mylist.get(i);
 13InBlock.gif    System.out.println(""+i+"节点中的数据:"+temp);
 14ExpandedSubBlockEnd.gif   }
 
 15ExpandedSubBlockEnd.gif }

 16ExpandedBlockEnd.gif}

 17None.gif
 18None.gif//例子2
 19None.gifimport java.util.*;
 20None.gifpublic class LinkListTwo
 21ExpandedBlockStart.gifContractedBlock.gifdot.gif{public  static void main(String args[])
 22ExpandedSubBlockStart.gifContractedSubBlock.gif dot.gif{ LinkedList mylist=new LinkedList();
 23InBlock.gif   mylist.add("is"); mylist.add("a");
 24InBlock.gif   int number=mylist.size();
 25InBlock.gif   System.out.println("现在链表中有"+number+"个节点:");
 26InBlock.gif   for(int i=0;i<number;i++)
 27ExpandedSubBlockStart.gifContractedSubBlock.gif   dot.gif{String temp=(String)mylist.get(i);
 28InBlock.gif    System.out.println(""+i+"节点中的数据:"+temp);
 29ExpandedSubBlockEnd.gif   }

 30InBlock.gif   mylist.addFirst("It");mylist.addLast("door");
 31InBlock.gif   number=mylist.size(); 
 32InBlock.gif  System.out.println("现在链表中有"+number+"个节点:");
 33InBlock.gif   for(int i=0;i<number;i++)
 34ExpandedSubBlockStart.gifContractedSubBlock.gif   dot.gif{String temp=(String)mylist.get(i);
 35InBlock.gif    System.out.println(""+i+"节点中的数据:"+temp);
 36ExpandedSubBlockEnd.gif   }

 37InBlock.gif   mylist.remove(0);mylist.remove(1);
 38InBlock.gif   mylist.set(0,"open");
 39InBlock.gif   number=mylist.size();
 40InBlock.gif    System.out.println("现在链表中有"+number+"个节点:");
 41InBlock.gif   for(int i=0;i<number;i++)
 42ExpandedSubBlockStart.gifContractedSubBlock.gif   dot.gif{String temp=(String)mylist.get(i);
 43InBlock.gif    System.out.println(""+i+"节点中的数据:"+temp);
 44ExpandedSubBlockEnd.gif   }

 45ExpandedSubBlockEnd.gif }

 46ExpandedBlockEnd.gif}

 47None.gif
 48None.gif//例子3
 49None.gifimport java.util.*;
 50None.gifclass Student
 51ExpandedBlockStart.gifContractedBlock.gifdot.gif{String name ;int number;float score;
 52InBlock.gif  Student(String name,int number,float score)
 53ExpandedSubBlockStart.gifContractedSubBlock.gif  dot.gif{this.name=name;this.number=number;this.score=score;
 54ExpandedSubBlockEnd.gif  }

 55ExpandedBlockEnd.gif}

 56None.gifpublic class LinkListThree
 57ExpandedBlockStart.gifContractedBlock.gifdot.gif{public  static void main(String args[])
 58ExpandedSubBlockStart.gifContractedSubBlock.gif dot.gif{ LinkedList mylist=new LinkedList();
 59InBlock.gif   Student stu_1=new Student("赵好民" ,9012,80.0f),
 60InBlock.gif            stu_2=new Student("钱小青" ,9013,90.0f),  
 61InBlock.gif            stu_3=new Student("孙力枚" ,9014,78.0f),
 62InBlock.gif            stu_4=new Student("周左右" ,9015,55.0f);
 63InBlock.gif    mylist.add(stu_1); mylist.add(stu_2);
 64InBlock.gif    mylist.add(stu_3); mylist.add(stu_4);
 65InBlock.gif    Iterator iter=mylist.iterator();
 66InBlock.gif   while(iter.hasNext())
 67ExpandedSubBlockStart.gifContractedSubBlock.gif   dot.gif{  Student te=(Student)iter.next();
 68InBlock.gif      System.out.println(te.name+" "+te.number+"  "+te.score);
 69ExpandedSubBlockEnd.gif   }

 70ExpandedSubBlockEnd.gif }

 71ExpandedBlockEnd.gif}

 72None.gif
 73None.gif//例子4
 74None.gifimport java.util.*;import java.awt.event.*;import java.awt.*;
 75None.gifimport javax.swing.*;import java.io.*;
 76None.gifclass 商品 extends Panel
 77ExpandedBlockStart.gifContractedBlock.gifdot.gif{String 代号,名称;int 库存;float 单价;
 78InBlock.gif  商品(String 代号,String 名称,int 库存,float 单价)
 79ExpandedSubBlockStart.gifContractedSubBlock.gif  dot.gif{this.代号=代号;this.名称=名称;this.库存=库存;this.单价=单价;
 80ExpandedSubBlockEnd.gif  }

 81ExpandedBlockEnd.gif}

 82None.gif
 83None.gifclass ShowWin extends JFrame implements ActionListener
 84ExpandedBlockStart.gifContractedBlock.gifdot.gif{  LinkedList goods_list=null;
 85InBlock.gif  JTextField 代号文本框=new JTextField(),
 86InBlock.gif名称文本框=new JTextField(),
 87InBlock.gif            库存文本框=new JTextField(),
 88InBlock.gif单价文本框=new JTextField(),
 89InBlock.gif            删除文本框=new JTextField();
 90InBlock.gif  JButton   b_add=new JButton("添加商品"),
 91InBlock.gifb_del=new JButton("删除商品"),
 92InBlock.gif            b_show =new JButton("显示商品清单");
 93InBlock.gif  JTextArea  显示区=new JTextArea();
 94InBlock.gif  ShowWin()
 95ExpandedSubBlockStart.gifContractedSubBlock.gif  dot.gif{goods_list=new LinkedList();
 96InBlock.gif   Container con=getContentPane(); 
 97InBlock.gif   JScrollPane pane=new JScrollPane(显示区); 
 98InBlock.gif显示区.setEditable(false);
 99InBlock.gif   JPanel save=new JPanel();save.setLayout(new GridLayout(5,2));
100InBlock.gif   save.add(new Label("输入代号:"));save.add(代号文本框);
101InBlock.gif   save.add(new Label("输入名称:"));save.add(名称文本框);
102InBlock.gif   save.add(new Label("输入库存:"));save.add(库存文本框);
103InBlock.gif   save.add(new Label("输入单价:"));save.add(单价文本框);
104InBlock.gif   save.add(new Label("点击添加:"));save.add(b_add);
105InBlock.gif   JPanel del=new JPanel();del.setLayout(new GridLayout(2,2));
106InBlock.gif   del.add(new Label("输入删除的代号:"));del.add(删除文本框);
107InBlock.gif   del.add(new Label("点击删除:"));del.add(b_del);
108InBlock.gif   JPanel show=new JPanel();show.setLayout(new BorderLayout());
109InBlock.gif   show.add(pane,BorderLayout.CENTER);show.add(b_show,BorderLayout.SOUTH);
110InBlock.gif   JSplitPane split_one,split_two;
111InBlock.gif   split_one=new JSplitPane(JSplitPane.VERTICAL_SPLIT,save,del);
112InBlock.gif   split_two=new JSplitPane(JSplitPane.HORIZONTAL_SPLIT,true,split_one,show);
113InBlock.gif   con.add(split_two,BorderLayout.CENTER);
114InBlock.gif   b_add.addActionListener(this);b_del.addActionListener(this);
115InBlock.gif   b_show.addActionListener(this);
116ExpandedSubBlockEnd.gif  }

117InBlock.gif public void actionPerformed(ActionEvent e)
118ExpandedSubBlockStart.gifContractedSubBlock.gif dot.gif{if(e.getSource()==b_add)
119ExpandedSubBlockStart.gifContractedSubBlock.gif  dot.gif{String daihao=null,mingcheng=null;int kucun=0;float danjia=0.0f;
120InBlock.gif   daihao=代号文本框.getText();mingcheng=名称文本框.getText();
121InBlock.gif   kucun=Integer.parseInt(库存文本框.getText());
122InBlock.gif   danjia=Float.valueOf(单价文本框.getText()).floatValue();
123InBlock.gif   商品 goods=new 商品(daihao,mingcheng,kucun,danjia);
124InBlock.gif   goods_list.add(goods);
125ExpandedSubBlockStart.gifContractedSubBlock.gif   try dot.gif{FileOutputStream file=new FileOutputStream("goods.txt");
126InBlock.gif        ObjectOutputStream out=new  ObjectOutputStream(file);
127InBlock.gif        out.writeObject(goods_list);out.close();
128ExpandedSubBlockEnd.gif       }

129ExpandedSubBlockStart.gifContractedSubBlock.gif   catch(IOException event)dot.gif{}
130ExpandedSubBlockEnd.gif  }

131InBlock.gif  else if(e.getSource()==b_del)
132ExpandedSubBlockStart.gifContractedSubBlock.gif  dot.gif{String daihao=删除文本框.getText();
133ExpandedSubBlockStart.gifContractedSubBlock.gif   try dot.gif{FileInputStream come_in=new FileInputStream("goods.txt");
134InBlock.gif        ObjectInputStream in=new  ObjectInputStream(come_in);
135InBlock.gif        goods_list=(LinkedList)in.readObject();in.close();
136ExpandedSubBlockEnd.gif       }

137ExpandedSubBlockStart.gifContractedSubBlock.gif   catch(ClassNotFoundException event)dot.gif{}
138ExpandedSubBlockStart.gifContractedSubBlock.gif   catch(IOException event)dot.gif{}
139InBlock.gif   for(int i=0;i<goods_list.size();i++)
140ExpandedSubBlockStart.gifContractedSubBlock.gif    dot.gif{商品 temp=(商品)goods_list.get(i);
141ExpandedSubBlockStart.gifContractedSubBlock.gif      if(temp.代号.equals(daihao)) dot.gif{goods_list.remove(i);}
142ExpandedSubBlockStart.gifContractedSubBlock.gif      try  dot.gif{FileOutputStream file=new FileOutputStream("goods.txt");
143InBlock.gif            ObjectOutputStream out=new  ObjectOutputStream(file);
144InBlock.gif             out.writeObject(goods_list);
145InBlock.gif             out.close();
146ExpandedSubBlockEnd.gif           }

147ExpandedSubBlockStart.gifContractedSubBlock.gif       catch(IOException event)dot.gif{}
148ExpandedSubBlockEnd.gif      }

149ExpandedSubBlockEnd.gif  }

150InBlock.gif else if(e.getSource()==b_show)
151ExpandedSubBlockStart.gifContractedSubBlock.gif  dot.gif{ 显示区.setText(null);
152ExpandedSubBlockStart.gifContractedSubBlock.gif    try dot.gif{FileInputStream come_in=new FileInputStream("goods.txt");
153InBlock.gif        ObjectInputStream in=new  ObjectInputStream(come_in);
154InBlock.gif        goods_list=(LinkedList)in.readObject();
155ExpandedSubBlockEnd.gif       }

156ExpandedSubBlockStart.gifContractedSubBlock.gif   catch(ClassNotFoundException event)dot.gif{}
157ExpandedSubBlockStart.gifContractedSubBlock.gif   catch(IOException event)dot.gif{}
158InBlock.gif   Iterator iter=goods_list.iterator();
159InBlock.gif   while(iter.hasNext())
160ExpandedSubBlockStart.gifContractedSubBlock.gif    dot.gif{  商品 te=(商品)iter.next();
161InBlock.gif       显示区.append("商品代号:"+te.代号+"     ");
162InBlock.gif       显示区.append("商品名称:"+te.名称+"     ");
163InBlock.gif       显示区.append("商品库存:"+te.库存+"     ");
164InBlock.gif       显示区.append("商品单价:"+te.单价+"     ");
165InBlock.gif       显示区.append("\n");
166ExpandedSubBlockEnd.gif    }

167ExpandedSubBlockEnd.gif  }

168ExpandedSubBlockEnd.gif }

169ExpandedBlockEnd.gif}
 
170None.gifpublic class LinkListFour 
171ExpandedBlockStart.gifContractedBlock.gifdot.gif{public  static void main(String args[])
172ExpandedSubBlockStart.gifContractedSubBlock.gif dot.gif{ ShowWin win=new ShowWin();
173InBlock.gif   win.setSize(100,100);
174InBlock.gif   win.setVisible(true);
175InBlock.gif   win.addWindowListener(new WindowAdapter()
176ExpandedSubBlockStart.gifContractedSubBlock.gif      dot.gif{public void windowClosing(WindowEvent e)
177ExpandedSubBlockStart.gifContractedSubBlock.gif        dot.gif{System.exit(0);}}
);
178ExpandedSubBlockEnd.gif }

179ExpandedBlockEnd.gif}

180None.gif
181None.gif//例子5
182None.gifimport java.util.*;
183None.gifclass StackOne
184ExpandedBlockStart.gifContractedBlock.gifdot.gif{public static void main(String args[])
185ExpandedSubBlockStart.gifContractedSubBlock.gif dot.gif{Stack mystack=new Stack();
186InBlock.gif  mystack.push(new Integer(1)); mystack.push(new Integer(2));
187InBlock.gif  mystack.push(new Integer(3)); mystack.push(new Integer(4));
188InBlock.gif  mystack.push(new Integer(5)); mystack.push(new Integer(6));
189InBlock.gif  while(!(mystack.empty()))
190ExpandedSubBlockStart.gifContractedSubBlock.gif  dot.gif{Integer temp=(Integer)mystack.pop();
191ExpandedSubBlockEnd.gif   System.out.print("   "+temp.toString());}

192ExpandedSubBlockEnd.gif }

193ExpandedBlockEnd.gif}

194None.gif
195None.gif//例子6
196None.gifimport java.util.*;
197None.gifclass StackTwo
198ExpandedBlockStart.gifContractedBlock.gifdot.gif{public static void main(String args[])
199ExpandedSubBlockStart.gifContractedSubBlock.gif dot.gif{Stack mystack=new Stack();
200InBlock.gif  mystack.push(new Integer(1)); mystack.push(new Integer(1));
201InBlock.gif  int k=1;
202InBlock.gif  while(k<=10)
203InBlock.gif  for(int i=1;i<=2;i++)
204ExpandedSubBlockStart.gifContractedSubBlock.gif   dot.gif{Integer F1=(Integer)mystack.pop();int f1=F1.intValue();
205InBlock.gif    Integer F2=(Integer)mystack.pop();int f2=F2.intValue();
206InBlock.gif    Integer temp=new Integer(f1+f2);
207InBlock.gif    System.out.println(""+temp.toString()); 
208InBlock.gif    mystack.push(temp);mystack.push(F2);k++;
209ExpandedSubBlockEnd.gif   }

210ExpandedSubBlockEnd.gif }

211ExpandedBlockEnd.gif}

212None.gif
213None.gif//例子7
214None.gifimport java.util.*;
215None.gifclass TreeOne
216ExpandedBlockStart.gifContractedBlock.gifdot.gif{public static void main(String args[])
217ExpandedSubBlockStart.gifContractedSubBlock.gif dot.gif{ TreeSet mytree=new TreeSet();
218InBlock.gif   mytree.add("boy");mytree.add("zoo");
219InBlock.gif   mytree.add("apple"); mytree.add("girl");
220InBlock.gif   Iterator te=mytree.iterator();
221InBlock.gif   while(te.hasNext())
222InBlock.gif    System.out.println(""+te.next());
223ExpandedSubBlockEnd.gif  }

224ExpandedBlockEnd.gif}

225None.gif
226None.gif//例子8
227None.gifimport java.util.*;import java.awt.*;
228None.gifclass TreeTwo
229ExpandedBlockStart.gifContractedBlock.gifdot.gif{public static void main(String args[])
230ExpandedSubBlockStart.gifContractedSubBlock.gif dot.gif{ TreeSet mytree=new TreeSet(new Comparator()
231ExpandedSubBlockStart.gifContractedSubBlock.gif   dot.gif{public int compare(Object a,Object b)
232ExpandedSubBlockStart.gifContractedSubBlock.gif    dot.gif{Student stu1=(Student)a;Student stu2=(Student)b;
233ExpandedSubBlockEnd.gif     return stu1.compareTo(stu2);}

234ExpandedSubBlockEnd.gif   }
);
235InBlock.gif   Student st1,st2,st3,st4;
236InBlock.gif   st1=new Student(90,"zhan ying");st2=new Student(66,"wang heng");
237InBlock.gif   st3=new Student(86,"Liuh qing");st4=new Student(76,"yage ming");
238InBlock.gif   mytree.add(st1);mytree.add(st2);mytree.add(st3);mytree.add(st4);
239InBlock.gif   Iterator te=mytree.iterator();
240InBlock.gif   while(te.hasNext())
241ExpandedSubBlockStart.gifContractedSubBlock.gif    dot.gif{Student stu=(Student)te.next();
242InBlock.gif     System.out.println(""+stu.name+"  "+stu.english);
243ExpandedSubBlockEnd.gif     }

244ExpandedSubBlockEnd.gif  }

245ExpandedBlockEnd.gif}

246None.gifclass Student  implements Comparable 
247ExpandedBlockStart.gifContractedBlock.gifdot.gifint english=0;String name;
248InBlock.gif Student(int e,String n)
249ExpandedSubBlockStart.gifContractedSubBlock.gif dot.gif{english=e;name=n;
250ExpandedSubBlockEnd.gif }

251InBlock.gif public int compareTo(Object b)
252ExpandedSubBlockStart.gifContractedSubBlock.gif dot.gif{ Student st=(Student)b;
253InBlock.gif   return (this.english-st.english);
254ExpandedSubBlockEnd.gif }

255ExpandedBlockEnd.gif}

256None.gif
257None.gif//例子9 
258None.gifimport java.util.*;import java.awt.event.*;
259None.gifimport java.awt.*
260None.gifclass 节目  implements Comparable
261ExpandedBlockStart.gifContractedBlock.gifdot.gif{String name;double time;
262InBlock.gif  节目(String 名称,double 演出时间)
263ExpandedSubBlockStart.gifContractedSubBlock.gif  dot.gif{name=名称;time=演出时间;
264ExpandedSubBlockEnd.gif  }

265InBlock.gif  public int compareTo(Object b)
266ExpandedSubBlockStart.gifContractedSubBlock.gif  dot.gif{节目 item=(节目)b;
267InBlock.gif   return (int)((this.time-item.time)*1000);
268ExpandedSubBlockEnd.gif  }

269ExpandedBlockEnd.gif}

270None.gif
271None.gifclass Win extends Frame implements ActionListener
272ExpandedBlockStart.gifContractedBlock.gifdot.gif{  TreeSet 节目清单=null;
273InBlock.gif  TextField  名称文本框=new TextField(10),
274InBlock.gif              时间文本框=new TextField(5),
275InBlock.gif              删除文本框=new TextField(5);
276InBlock.gif  Button   b_add=new Button("添加节目"),
277InBlock.gif            b_del=new Button("删除节目"),
278InBlock.gif            b_show =new Button("显示节目清单");
279InBlock.gif  TextArea 显示区=new TextArea();
280InBlock.gif  Win()
281ExpandedSubBlockStart.gifContractedSubBlock.gif  dot.gif{  节目清单=new TreeSet(new Comparator()
282ExpandedSubBlockStart.gifContractedSubBlock.gif             dot.gif{public int compare(Object a,Object b)
283ExpandedSubBlockStart.gifContractedSubBlock.gif                dot.gif{节目  item_1=(节目)a;
284InBlock.gif                 节目  item_2=(节目)b;
285InBlock.gif                 return item_1.compareTo(item_2);
286ExpandedSubBlockEnd.gif                }

287ExpandedSubBlockEnd.gif              }
);
288InBlock.gif   Panel  节目单输入区=new Panel();
289InBlock.gif          节目单输入区.add(new Label("节目名称:"));
290InBlock.gif          节目单输入区.add(名称文本框);
291InBlock.gif          节目单输入区.add(new Label("演出时间:"));
292InBlock.gif          节目单输入区.add(时间文本框);
293InBlock.gif          节目单输入区.add(new Label("点击添加:"));
294InBlock.gif          节目单输入区.add(b_add);
295InBlock.gif          节目单输入区.add(b_show);
296InBlock.gif   Panel 节目单删除区=new Panel();
297InBlock.gif          节目单删除区.add(new Label("输入演出的时间:"));
298InBlock.gif          节目单删除区.add(删除文本框);
299InBlock.gif          节目单删除区.add(new Label("点击删除:"));
300InBlock.gif          节目单删除区.add(b_del);
301InBlock.gif   Panel  节目单显示区=new Panel();
302InBlock.gif          节目单显示区.add(显示区);
303InBlock.gif   显示区.setBackground(Color.pink);      
304InBlock.gif   b_add.addActionListener(this);b_del.addActionListener(this);
305InBlock.gif   b_show.addActionListener(this);
306InBlock.gif   add(节目单输入区,"North");add(节目单显示区,"Center");
307InBlock.gif   add(节目单删除区,"South");
308ExpandedSubBlockEnd.gif }

309InBlock.gif public void actionPerformed(ActionEvent e)
310ExpandedSubBlockStart.gifContractedSubBlock.gif dot.gif{if(e.getSource()==b_add)
311ExpandedSubBlockStart.gifContractedSubBlock.gif  dot.gif{String 名称=null;double 时间=0.0;
312InBlock.gif   名称=名称文本框.getText();
313ExpandedSubBlockStart.gifContractedSubBlock.gif   trydot.gif{时间=Double.valueOf(时间文本框.getText()).doubleValue();
314ExpandedSubBlockEnd.gif      }

315InBlock.gif   catch(NumberFormatException ee)
316ExpandedSubBlockStart.gifContractedSubBlock.gif      dot.gif{时间文本框.setText("请输入代表时间的实数");
317ExpandedSubBlockEnd.gif      }

318InBlock.gif   节目 programme=new 节目(名称,时间);
319InBlock.gif   节目清单.add(programme);
320InBlock.gif   showing();
321ExpandedSubBlockEnd.gif  }

322InBlock.gif  else if(e.getSource()==b_del)
323ExpandedSubBlockStart.gifContractedSubBlock.gif  dot.gif{节目 待删除节目=null;
324InBlock.gif    double time=Double.valueOf(删除文本框.getText()).doubleValue();
325InBlock.gif    Iterator te=节目清单.iterator();
326InBlock.gif    while(te.hasNext())
327ExpandedSubBlockStart.gifContractedSubBlock.gif    dot.gif{节目 item=(节目)te.next();
328InBlock.gif      if(Math.abs(item.time-time)<=0.000001d)
329ExpandedSubBlockStart.gifContractedSubBlock.gif      dot.gif{待删除节目=item; }
330ExpandedSubBlockEnd.gif    }

331InBlock.gif   if(待删除节目!=null) 节目清单.remove(待删除节目);
332InBlock.gif   showing();
333ExpandedSubBlockEnd.gif  }

334InBlock.gif else if(e.getSource()==b_show)
335ExpandedSubBlockStart.gifContractedSubBlock.gif  dot.gif{ showing();
336ExpandedSubBlockEnd.gif  }

337ExpandedSubBlockEnd.gif }

338InBlock.gif void showing()
339ExpandedSubBlockStart.gifContractedSubBlock.gif dot.gif{ 显示区.setText(null);
340InBlock.gif    Iterator iter=节目清单.iterator();
341InBlock.gif    while(iter.hasNext())
342ExpandedSubBlockStart.gifContractedSubBlock.gif    dot.gif{节目 item=(节目)iter.next();
343InBlock.gif     显示区.append("节目名称:"+item.name+"演出时间: "+item.time);
344InBlock.gif     显示区.append("\n");
345ExpandedSubBlockEnd.gif    }

346ExpandedSubBlockEnd.gif }

347ExpandedBlockEnd.gif}
 
348None.gifpublic class Tree_3 
349ExpandedBlockStart.gifContractedBlock.gifdot.gif{public  static void main(String args[])
350ExpandedSubBlockStart.gifContractedSubBlock.gif dot.gif{ Win win=new Win();
351InBlock.gif   win.setSize(500,250);win.setVisible(true);
352InBlock.gif   win.addWindowListener(new WindowAdapter()
353ExpandedSubBlockStart.gifContractedSubBlock.gif      dot.gif{public void windowClosing(WindowEvent e)
354ExpandedSubBlockStart.gifContractedSubBlock.gif        dot.gif{System.exit(0);}}
);
355ExpandedSubBlockEnd.gif }

356ExpandedBlockEnd.gif}

357None.gif
358None.gif//例子10
359None.gifimport java.util.*;
360None.gifclass Student  
361ExpandedBlockStart.gifContractedBlock.gifdot.gifint english=0; String  name,number;
362InBlock.gif Student(String na,String nu,int e)
363ExpandedSubBlockStart.gifContractedSubBlock.gif dot.gif{english=e;name=na;number =nu;}
364ExpandedBlockEnd.gif}

365None.gifpublic class HT
366ExpandedBlockStart.gifContractedBlock.gifdot.gifpublic static void main(String args[])
367ExpandedSubBlockStart.gifContractedSubBlock.gif  dot.gif{ Hashtable hashtable=new Hashtable();
368InBlock.gif   hashtable.put("199901",new Student("199901","王小林",98));
369InBlock.gif   hashtable.put("199902",new Student("199902","能林茂",70));
370InBlock.gif   hashtable.put("199903",new Student("199903","多种林",93));
371InBlock.gif   hashtable.put("199904",new Student("199904","围林蛤",46));
372InBlock.gif   hashtable.put("199905",new Student("199905","夹贸林",77));
373InBlock.gif   hashtable.put("199906",new Student("199906","噔林可",55));
374InBlock.gif   hashtable.put("199907",new Student("199907","降王林",68));
375InBlock.gif   hashtable.put("199908",new Student("199908","纠林咯",76));
376InBlock.gif   Student stu=(Student)hashtable.get("199902");//检索一个元素。 
377InBlock.gif   System.out.println(stu.number+"  "+stu.name+"  "+stu.english);
378InBlock.gif   hashtable.remove("199906"); //删除一个元素
379InBlock.gif  System.out.println("散列表中现在含有:"+hashtable.size()+"个元素");
380InBlock.gif    Enumeration enum=hashtable.elements(); 
381InBlock.gif    while(enum.hasMoreElements())   //遍历当前散列表。
382ExpandedSubBlockStart.gifContractedSubBlock.gif    dot.gif{Student s=(Student)enum.nextElement();
383InBlock.gif     System.out.println(s.number+"  "+s.name+"  "+s.english);
384ExpandedSubBlockEnd.gif    }

385ExpandedSubBlockEnd.gif  }
     
386ExpandedBlockEnd.gif}

387None.gif
388None.gif//例子11
389None.gifimport java.util.*;import java.awt.event.*;import java.awt.*;
390None.gifimport javax.swing.*;import java.io.*;
391None.gifclass  学生 extends JPanel 
392ExpandedBlockStart.gifContractedBlock.gifdot.gif{String 学号,姓名;float 分数;
393InBlock.gif   学生(String 学号,String 姓名,float 分数)
394ExpandedSubBlockStart.gifContractedSubBlock.gif  dot.gif{this.学号=学号;this.姓名=姓名;this.分数=分数;
395ExpandedSubBlockEnd.gif  }

396ExpandedBlockEnd.gif}

397None.gifclass ShowWin extends JFrame implements ActionListener
398ExpandedBlockStart.gifContractedBlock.gifdot.gif{ Hashtable hashtable=new Hashtable();
399InBlock.gif  JTextField 学号文本框=new JTextField(),
400InBlock.gif姓名文本框=new JTextField(),
401InBlock.gif            分数文本框=new JTextField(),
402InBlock.gif            查询文本框=new JTextField();
403InBlock.gif  JButton  b_add=new JButton("添加成绩"),
404InBlock.gif          b_show =new JButton("显示成绩");
405InBlock.gif  JTextField 成绩显示条=new JTextField();
406InBlock.gif  ShowWin()
407ExpandedSubBlockStart.gifContractedSubBlock.gif  dot.gif{Container con=getContentPane(); 
408InBlock.gif   JPanel 成绩输入区=new JPanel();
409InBlock.gif          成绩输入区.setLayout(new GridLayout(5,2));
410InBlock.gif          成绩输入区.add(new Label("成绩输入区:"));
411InBlock.gif          成绩输入区.add(new Label());
412InBlock.gif          成绩输入区.add(new Label("考生学号:"));
413InBlock.gif          成绩输入区.add(学号文本框);
414InBlock.gif          成绩输入区.add(new JLabel("考生姓名:"));
415InBlock.gif          成绩输入区.add(姓名文本框);
416InBlock.gif          成绩输入区.add(new Label("考生成绩:"));
417InBlock.gif          成绩输入区.add(分数文本框);
418InBlock.gif          成绩输入区.add(new Label("点击添加:"));
419InBlock.gif          成绩输入区.add(b_add);
420InBlock.gif   JPanel  查询显示区=new JPanel();
421InBlock.gif          查询显示区.setLayout(new GridLayout(3,2));
422InBlock.gif          查询显示区.add(new Label("成绩查询区:"));
423InBlock.gif          查询显示区.add(new Label());
424InBlock.gif          查询显示区.add(new Label("输入考生的学号:"));
425InBlock.gif          查询显示区.add(查询文本框);
426InBlock.gif          查询显示区.add(b_show);
427InBlock.gif          查询显示区.add(成绩显示条);
428InBlock.gif  JSplitPane split;
429InBlock.gifsplit=new JSplitPane(JSplitPane.VERTICAL_SPLIT,成绩输入区,查询显示区);
430InBlock.gif   con.add(split,BorderLayout.CENTER);
431InBlock.gif   con.add(new Label("成绩输入和查询系统"),BorderLayout.NORTH);
432InBlock.gif   b_add.addActionListener(this);b_show.addActionListener(this);
433ExpandedSubBlockEnd.gif  }

434InBlock.gif public void actionPerformed(ActionEvent e)
435ExpandedSubBlockStart.gifContractedSubBlock.gif dot.gif{if(e.getSource()==b_add)
436ExpandedSubBlockStart.gifContractedSubBlock.gif  dot.gif{String 学号=null,姓名=null;float 分数=0.0f;
437ExpandedSubBlockStart.gifContractedSubBlock.gif    try dot.gif{学号=学号文本框.getText();
438InBlock.gif         姓名=姓名文本框.getText();
439ExpandedSubBlockEnd.gif        }

440InBlock.gif    catch(NullPointerException ee)
441ExpandedSubBlockStart.gifContractedSubBlock.gifdot.gif{ 学号文本框.setText("请输入学号");
442InBlock.gif姓名文本框.setText("请输入姓名");
443ExpandedSubBlockEnd.gif      }

444ExpandedSubBlockStart.gifContractedSubBlock.gif    trydot.gif{分数=Float.valueOf(分数文本框.getText()).floatValue();}
445InBlock.gif    catch(NumberFormatException ee)
446ExpandedSubBlockStart.gifContractedSubBlock.gifdot.gif{分数文本框.setText("请输入数字字符");} 
447InBlock.gif    学生 stu=new 学生(学号,姓名,分数);
448InBlock.gif    hashtable.put(学号,stu);
449ExpandedSubBlockStart.gifContractedSubBlock.gif    try dot.gif{FileOutputStream file=new FileOutputStream("score.txt");
450InBlock.gif         ObjectOutputStream out=new  ObjectOutputStream(file);
451InBlock.gif         out.writeObject(hashtable);  out.close();
452ExpandedSubBlockEnd.gif        }

453ExpandedSubBlockStart.gifContractedSubBlock.gif        catch(IOException event)dot.gif{}
454ExpandedSubBlockEnd.gif   }

455InBlock.gif else if(e.getSource()==b_show)
456ExpandedSubBlockStart.gifContractedSubBlock.gif  dot.gif{ String temp=null;
457InBlock.gif    temp=查询文本框.getText();
458InBlock.gif    成绩显示条.setText(null);
459ExpandedSubBlockStart.gifContractedSubBlock.gif    try dot.gif{FileInputStream come_in=new FileInputStream("score.txt");
460InBlock.gif         ObjectInputStream in=new  ObjectInputStream(come_in);
461InBlock.gif         hashtable=(Hashtable)in.readObject();in.close();
462ExpandedSubBlockEnd.gif        }

463ExpandedSubBlockStart.gifContractedSubBlock.gif   catch(ClassNotFoundException event)dot.gif{}
464ExpandedSubBlockStart.gifContractedSubBlock.gif   catch(IOException event)dot.gif{System.out.println("文件无法读出");}
465InBlock.gif  学生 s=(学生)hashtable.get(temp);
466InBlock.gif  成绩显示条.setText("姓名:"+s.姓名+"学号:"+s.学号+"成绩:"+s.分数);
467ExpandedSubBlockEnd.gif  }

468ExpandedSubBlockEnd.gif }

469ExpandedBlockEnd.gif}
 
470None.gifpublic class HT_2
471ExpandedBlockStart.gifContractedBlock.gifdot.gif{public  static void main(String args[])
472ExpandedSubBlockStart.gifContractedSubBlock.gif dot.gif{ ShowWin win=new ShowWin();
473InBlock.gif   win.setSize(100,100); win.setVisible(true);
474InBlock.gif   win.addWindowListener(new WindowAdapter()
475ExpandedSubBlockStart.gifContractedSubBlock.gif      dot.gif{public void windowClosing(WindowEvent e)
476ExpandedSubBlockStart.gifContractedSubBlock.gif        dot.gif{System.exit(0);}}
);
477ExpandedSubBlockEnd.gif }

478ExpandedBlockEnd.gif}

479None.gif
480None.gif//例子12
481None.gifimport java.util.*;
482None.gif class Example26_12
483ExpandedBlockStart.gifContractedBlock.gif dot.gif{public static void main(String args[])
484ExpandedSubBlockStart.gifContractedSubBlock.gif  dot.gif{ Vector vector=new Vector(); Date date=new Date();
485InBlock.gif    vector.add(new Integer(1));vector.add(new Float(3.45f)); 
486InBlock.gif    vector.add(new Double(7.75));vector.add(new Boolean(true));
487InBlock.gif    vector.add(date);
488InBlock.gif    System.out.println(vector.size());
489InBlock.gif    Integer number1=(Integer)vector.get(0);
490InBlock.gif    System.out.println("向量的第1个元素: "+number1.intValue());
491InBlock.gif    Float number2=(Float)vector.get(1);
492InBlock.gif    System.out.println("向量的第2个元素: "+number2.floatValue());
493InBlock.gif    Double number3=(Double)vector.get(2);
494InBlock.gif    System.out.println("向量的第3个元素: "+number3.doubleValue());
495InBlock.gif    Boolean number4=(Boolean)vector.get(3);
496InBlock.gif    System.out.println("向量的第4个元素: "+number4.booleanValue());
497InBlock.gif    date=(Date)vector.lastElement();
498InBlock.gif    System.out.println("向量的第5个元素: "+date.toString()); 
499InBlock.gif    if(vector.contains(date))
500InBlock.gif      System.out.println("ok"); 
501ExpandedSubBlockEnd.gif  }

502ExpandedBlockEnd.gif }
    
503None.gif
504None.gif//例子13
505None.gifimport java.applet.*;
506None.gifimport java.awt.*;import java.util.*;
507None.gifimport java.awt.event.*;
508None.gifclass Point
509ExpandedBlockStart.gifContractedBlock.gifdot.gif{int x,y;
510InBlock.gif Point(int x,int y)
511ExpandedSubBlockStart.gifContractedSubBlock.gif dot.gif{this.x=x;this.y=y;
512ExpandedSubBlockEnd.gif }

513ExpandedBlockEnd.gif}

514None.gifpublic class Example26_13 extends Applet 
515None.gifimplements MouseMotionListener,MouseListener
516ExpandedBlockStart.gifContractedBlock.gifdot.gifint x=-1,y=-1;
517InBlock.gif   Vector v=null;int n=1;
518InBlock.gif  public void init()
519ExpandedSubBlockStart.gifContractedSubBlock.gif dot.gif{ setBackground(Color.green);
520InBlock.gif   addMouseMotionListener(this);  addMouseListener(this);
521InBlock.gif    v=new Vector(); 
522ExpandedSubBlockEnd.gif }

523InBlock.gif public void paint(Graphics g)
524ExpandedSubBlockStart.gifContractedSubBlock.gif dot.gif{if(x!=-1&&y!=-1)
525ExpandedSubBlockStart.gifContractedSubBlock.gif  dot.gif{  n=v.size();
526InBlock.gif    for(int i=0;i<n-1;i++)
527ExpandedSubBlockStart.gifContractedSubBlock.gif       dot.gif{Point p1=(Point)v.elementAt(i); 
528InBlock.gif        Point p2=(Point)v.elementAt(i+1); 
529InBlock.gif        g.drawLine(p1.x,p1.y,p2.x,p2.y);
530ExpandedSubBlockEnd.gif       }

531ExpandedSubBlockEnd.gif   }

532InBlock.gif  
533ExpandedSubBlockEnd.gif }

534InBlock.gifpublic void mouseDragged(MouseEvent e)
535ExpandedSubBlockStart.gifContractedSubBlock.gif dot.gif{ x=(int)e.getX();y=(int)e.getY();
536InBlock.gif   Point p=new Point(x,y);
537InBlock.gif   v.addElement(p);
538InBlock.gif   repaint();
539ExpandedSubBlockEnd.gif }

540InBlock.gif public void mouseMoved(MouseEvent e)
541ExpandedSubBlockStart.gifContractedSubBlock.gif  dot.gif{} 
542ExpandedSubBlockStart.gifContractedSubBlock.gif  public void mousePressed(MouseEvent e)dot.gif{} 
543InBlock.gif  public void mouseReleased(MouseEvent e)
544ExpandedSubBlockStart.gifContractedSubBlock.gifdot.gif{v.removeAllElements();}
545ExpandedSubBlockStart.gifContractedSubBlock.gif  public void mouseEntered(MouseEvent e)dot.gif{}
546ExpandedSubBlockStart.gifContractedSubBlock.gif  public void mouseExited(MouseEvent e)dot.gif{}
547ExpandedSubBlockStart.gifContractedSubBlock.gif  public void mouseClicked(MouseEvent e)dot.gif{}
548InBlock.gif  public void update(Graphics g)
549ExpandedSubBlockStart.gifContractedSubBlock.gif  dot.gif{ paint(g);
550ExpandedSubBlockEnd.gif  }
 
551ExpandedBlockEnd.gif}

552None.gif
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