awtexample.java

一个很好的JAVA聊天室系统 可以在课堂里实践并且进行聊天

import java.applet.Applet;
import java.awt.*;
import java.awt.event.*;
import java.awt.List;
import java.util.*;

public class AWTExample extends Applet 
       implements TextListener, ActionListener,ItemListener
{
  Employee newEmp;
  Label prompt = new Label("Enter new employee information");
  TextField no = new TextField(4);
  TextField name = new TextField("name");
  Checkbox isMgr = new Checkbox("manager");
  CheckboxGroup sex = new CheckboxGroup();
  Checkbox maleSex = new Checkbox("male",true,sex);
  Checkbox femaleSex = new Checkbox("female",false,sex);
  TextField sal = new TextField("salary");
  SliderFrame sf;
  List year = new List(3,false);
  Choice month = new Choice();
  Choice date1 = new Choice();
  Choice date2 = new Choice();
  TextArea result = new TextArea("",5,30);
  Button reset = new Button("Reset");
  Button enter = new Button("Input");

  public void init() {

    add(prompt);
    no.setEditable(false);
    add(no);
    name.addTextListener(this);
    add(name);
    
    isMgr.addItemListener(this);
    add(isMgr);

    maleSex.addItemListener(this);
    add(maleSex);
    femaleSex.addItemListener(this);
    add(femaleSex);
    sal.addTextListener(this);
    add(sal);

    year.add("2000"); year.add("2001"); year.add("2002"); year.add("2003");
    year.addActionListener(this);  year.addItemListener(this);  add(year);

    month.add("Jan"); month.add("Feb"); month.add("Mar");  month.add("Apr");
    month.add("May"); month.add("Jun"); month.add("July"); month.add("Aug");
    month.add("Sep"); month.add("Oct"); month.add("Nov");  month.add("Dec");
    month.addItemListener(this);  add(month);

    date1.add("0"); date1.add("1"); date1.add("2"); date1.add("3");
    date2.add("0"); date2.add("1"); date2.add("2"); date2.add("3");
    date2.add("4"); date2.add("5"); date2.add("6"); date2.add("7");
    date2.add("8"); date2.add("9");

    date1.addItemListener(this);    add(date1);
    date2.addItemListener(this);    add(date2);  add(result);
    reset.addActionListener(this);  add(reset);
    enter.addActionListener(this);  add(enter);

}

public void textValueChanged(TextEvent e) {
  if (e.getSource() == name)
     result.setText("Response to TextValueChanged event, name: "+
                ((TextField) e.getSource()).getText());
  if (e.getSource() == sal) {
     double initSal;
     String s = ((TextField) e.getSource()).getText();
     if (s.compareTo("")==0 || s.compareTo("salary")==0 || s==null)
       initSal = 0;
     else
       initSal =
         Double.valueOf(((TextField) e.getSource()).getText()).doubleValue();
     // create Scrollbar window to adjust the salary
     sf = new SliderFrame(initSal,Employee.getMinSal(), sal);
  }
}

public void actionPerformed(ActionEvent e) {
  if (e.getActionCommand()=="Reset")
  {
   no.setText("");  name.setText("");  isMgr.setState(true);
   maleSex.setState(true); sal.setText("");
   year.deselect(year.getSelectedIndex());
   month.select(0); date1.select(0);   date2.select(0);
   result.setText("no message");
  }
  else if (e.getActionCommand() =="Input")
  {
   String n = name.getText();
   double s = Double.valueOf(sal.getText()).doubleValue();
   char ch;
   boolean mgr = isMgr.getState();
   int y, m, d;
   Calendar swd;

   if (maleSex.getState())  ch = 'm';
   else  ch = 'f';
   y = (year.getSelectedIndex())+2000;
   m = month.getSelectedIndex()+1;
   d = date1.getSelectedIndex() * 10 + date2.getSelectedIndex();
   swd = Calendar.getInstance();
   swd.set(y,m,d);
   newEmp = new Employee(n,s,ch,mgr,swd);
   no.setText(Integer.toString(newEmp.getEmpNo()));
   result.setText(newEmp.toString());
  }
  else { result.setText(e.getActionCommand()); }
}

public void itemStateChanged(ItemEvent e) {
  ItemSelectable is = e.getItemSelectable();
  if (is==isMgr)
    {
     result.setText("Changed checkbox state: ");
     if (e.getStateChange() == ItemEvent.SELECTED)
        result.append("Selected");
     else
        result.append("Unselected");
  }
  else if (is == maleSex)
     result.setText("Selected " + maleSex.getLabel());   
  else if (is == femaleSex)
     result.setText("Selected " + femaleSex.getLabel());   
  else if (is == year)
     result.setText("Selected year(index): " + ((List)is).getSelectedIndex());   
  else if (is == month)
     result.setText("Selected month(index): " + ((Choice)is).getSelectedIndex());   
  else if (is == date1)
     result.setText("Selected date1(index): " + ((Choice)is).getSelectedIndex());   
  else if (is == date2)
     result.setText("Selected date2(index): " + ((Choice)is).getSelectedIndex());   
 }
}

class SliderFrame extends Frame
                  implements ActionListener,AdjustmentListener {
    Scrollbar salSlider;
    TextField salValue, sal_ref;
    double value;
    Button close = new Button("Close");

    SliderFrame(double initSal, double minSal, TextField return_sal)
    {
     super("Enter salary");
     sal_ref = return_sal;
     setLayout(new BorderLayout());
     salSlider = 
       new Scrollbar( Scrollbar.HORIZONTAL,(int)initSal,1,
                      (int)minSal,(int)minSal*20 );
     salSlider.setUnitIncrement(1);  salSlider.setBlockIncrement(50);
     salSlider.addAdjustmentListener(this);
   
     add("North", salSlider);
     salValue = new TextField(Double.toString(initSal),6);
     add("Center", salValue);
     add("South",  close);
     close.addActionListener(this);
     pack();
     setVisible(true);
  }

  public void actionPerformed(ActionEvent e){
    if (e.getActionCommand() == "Close")
       { 
         sal_ref.setText(new Integer((int) value).toString());
         dispose();
       }
  }

  public void adjustmentValueChanged(AdjustmentEvent e) {
    if (e.getAdjustable() == salSlider)
       {
        value = e.getValue();
        salValue.setText(new Integer((int)value).toString());
       }    
  }
  double getValue() {
    return value;
  }
}
 
class Employee {
  int m_EmpNo;
  String m_EmpName;
  boolean m_isMgr;
  char m_EmpGender;
  static int m_NextEmpNo;
  static final double m_MinSalary =250;
  Calendar m_StartWorkDate;
  double m_EmpSalary;

  static { m_NextEmpNo =1001; }
  Employee(String name,double initSal,char sex,boolean mgr,Calendar wdate){
    m_EmpNo = m_NextEmpNo++;
    m_EmpName = new String(name);
    m_isMgr = mgr;
    if (initSal < m_MinSalary)   System.exit(0);
    m_EmpSalary = initSal;
    m_EmpGender = sex;
    m_StartWorkDate = wdate;
  }
  int getEmpNo() { return m_EmpNo; }
  static double getMinSal() { return m_MinSalary; }
  public String toString() {
    String s;
    s = "EmpNo: "+m_EmpNo +" ; Name: "+m_EmpName;
    if (m_isMgr)  s = s+"; manager";
    if (m_EmpGender == 'm') s = s+";\nSex: male";
    else s = s+";\nSex: female";
    s = s + ";\nSalary: "+m_EmpSalary;
    if (m_StartWorkDate != null)
       s=s+";\nStart date: " + m_StartWorkDate.get(Calendar.YEAR)
         +"/" + m_StartWorkDate.get(Calendar.MONTH)
         +"/" + m_StartWorkDate.get(Calendar.DATE);
    return s;
  }
}