java 数据结构 遍历链表程序

import java.util.*; import java.awt.*; import java.awt.event.*; import javax.swing.*; import java.io.*; class shop extends Panel{ String number,name; int shuliang; float danjia; shop(String number,String name,int shuliang,float danjia){ this.number=number; this.name=name; this.shuliang=shuliang; this.danjia=danjia; } } class shopping extends JFrame implements ActionListener{ LinkedList goods_list=null; JTextField numbertxt=new JTextField(); JTextField nametxt=new JTextField(); JTextField danjiatxt=new JTextField(); JTextField shuliangtxt=new JTextField(); JTextField deletetxt=new JTextField(); JButton b_add=new JButton("添加商品"); JButton b_del=new JButton("删除商品"); JButton b_show=new JButton("显示商品"); JTextArea show=new JTextArea(); shopping(){ goods_list=new LinkedList(); Container con=getContentPane(); JScrollPane pane=new JScrollPane(show); show.setEditable(false); JPanel save=new JPanel(); save.setLayout(new GridLayout(5,2)); save.add(new Label("输入代码")); save.add(numbertxt); save.add(new Label("输入名称")); save.add(nametxt); save.add(new Label("输入库存")); save.add(shuliangtxt); save.add(new Label("输入单价")); save.add(danjiatxt); save.add(new Label("单击添加")); save.add(b_add); JPanel del=new JPanel(); del.setLayout(new GridLayout(2,2)); del.add(new Label("输入删除的代码")); del.add(deletetxt); del.add(new Label("单击删除")); del.add(b_del); JPanel show1=new JPanel(); show1.setLayout(new BorderLayout()); show1.add(pane,BorderLayout.CENTER); show1.add(b_show,BorderLayout.SOUTH); JSplitPane split_one,split_two; split_one=new JSplitPane(JSplitPane.VERTICAL_SPLIT,save,del); split_two=new JSplitPane(JSplitPane.HORIZONTAL_SPLIT,true,split_one,show1); con.add(split_two,BorderLayout.CENTER); b_add.addActionListener(this); b_del.addActionListener(this); b_show.addActionListener(this); } public void actionPerformed(ActionEvent e){ if(e.getSource()==b_add){ String daihao,mingcheng; int kucun; float danjia; daihao=numbertxt.getText(); mingcheng=nametxt.getText(); kucun=Integer.parseInt(shuliangtxt.getText()); danjia=Float.valueOf(danjiatxt.getText()).floatValue(); shop goods=new shop(daihao,mingcheng,kucun,danjia); goods_list.add(goods); try{ FileOutputStream file=new FileOutputStream("goods.txt"); ObjectOutputStream out=new ObjectOutputStream(file); out.writeObject(goods_list); out.close(); }catch(IOException ex1){} } else if(e.getSource()==b_del){ String daihao=deletetxt.getText(); try{ FileInputStream come_in= new FileInputStream("goods.txt"); ObjectInputStream in=new ObjectInputStream(come_in); goods_list=(LinkedList)in.readObject(); in.close(); }catch(ClassNotFoundException e1){} catch(IOException e2){} int num=goods_list.size(); for(int i=0;i<num;i++){ shop temp=(shop)goods_list.get(i); if(temp.number.equals(daihao)){ goods_list.remove(i);} try{ FileOutputStream file_out=new FileOutputStream("goods.txt"); ObjectOutputStream out=new ObjectOutputStream(file_out); out.writeObject(goods_list); out.close(); }catch(IOException ex){} } } else if(e.getSource()==b_show){ show.setText(null); try{ FileInputStream come_in= new FileInputStream("goods.txt"); ObjectInputStream in=new ObjectInputStream(come_in); goods_list=(LinkedList)in.readObject(); }catch(ClassNotFoundException e1){} catch(IOException e2){} Iterator iter=goods_list.iterator(); while(iter.hasNext()){ shop te=(shop)iter.next(); show.append("商品代码："+te.number); show.append("商品名称："+te.name); show.append("商品库存："+te.shuliang); show.append("商品单价："+te.danjia); show.append("\n"); } } } } public class LinkListFour{ public static void main(String args[]){ shopping sp=new shopping(); sp.setSize(100,100); sp.setVisible(true); sp.addWindowListener(new WindowAdapter(){ public void windowClosing(WindowEvent e){ System.exit(0);}}); } }