Java:

E-mail:hpzhou@aust.edu.cn

Java 1.1 1.1.1 CPU

1.1.2 1 :"" PCDOSWindows 98Windows NTUNIXLinux

2 a. - - b. PC c. / d. /N

1.1.3 1 a. b. c. d. e.

2 a. b. c. 1.2 Java 1.2.1 Java 1995523Java SunJava

1.2.2 Java 1 1.1 Java MyFirstJavaProgram.javaimport java.io.* ;public class MyFirstJavaProgram// class {//public static void main(String args[]) //main{System.out.println("This is my first Java program ! "); //}}

1Java 2 3 4 .java

2 Java 1 2Java 3 .class

3 Java Java java.exe 1Java 2Java 3Java

1.2.3 Applet Application Java Application 1 Java Application 2 Java Application 3 Java Application public static void main(String args[])main Java Application 1.1

1.2 Java Applet MyFirstJavaApplet.java

import java.applet.Applet;//java.applet.Applet import java.awt.Graphics;// java.awt.Graphics public class MyFirstJavaApplet extends Applet// Applet { public void paint(Graphics g) { g.drawString("This is my first Java Applet!",15,20); }}

1 Java Applet WWW 2 Java Applet WWW 3 Java Applet main Java Applet java.applet.Applet 4 Java Applet AppletViewer Java Application 5 Java Applet

Java 2.1 Java 1. Java Application 2.1 SimpleCharInOut.java

import java.io.*;public class SinpleCharInOut {public static void main(String args[]){char c = ' ';

System.out.print("Enter a character please:"); try{ c=(char)System.in.read(); }catch(IOException e){}System.out.println(Youve entered character: + c);}}

a. " = " Java b. System.in java.io InputStream read() c. System.out java.io OutputStream print() d. read() e. read() int (char) char f. +

2 Java Applet 2.2 SimpleGraphicsInOut.javaimport java.applet.Applet;import java.awt.*;public class SimpleGraphicsInOut extends Applet {Label prompt;//TextField input;//Label output;//

public void init() // Applet {prompt = new Label("Enter a character pleasea: "); // input = new TextField(3);//output = new Label (" "); //add(prompt);//add(input);//add(output);//}public boolean action(Event e,Object o)//{output.setText("You've entered character:"+o.toString()); //return true;}}

a. Label : java.awt Label b. TextFeild : java.awt TextFeild c. add : Label TextFeild d. init() : Java Applet e. action() :

3Java Application 2.4 Application GraphicsApplicationInOut.javaimport java.awt.*;public class GraphicsApplctInOut {public static void main(String args[ ]) {ApplctFrame MyFrame = new ApplctFrame(); }}

class ApplctFrame extends Frame//FrameapplictFrame{Label prompt;//TextField input;//Label output;//ApplctFrame()//ApplctFrame{super("Application Graphics Frame");//setLayout(new FlowLayout());//prompt =new Label("Enter a character please:");//input = new TextField(4);//output = new Label(" ");//

add(prompt);//add(input);//add(output);//pack();//show();//}public boolean action(Event e,Object o)//{output.setText("You've entered character:"+o.toString()); //return true;}

public boolean handleEvent(Event e)//{if(e.id==Event.WINDOW_DESTROY)//id System.exit(0);return super.handleEvent(e);} }

1Java Application 2 1 public class GraphicsApplication main public static void main(String args[])) 2 class ApplctFrame extends Frame Frame 3Frame frame) java.awt

4 ApplctFrame 1 ApplctFrame() ApplctFrame 2action() 3handleEvent() 4action()handleEvent() Component 5Event eventAWT Event java.awt

6Component component java.awt 7Java Application main() ApplictFrame

2.2 2.2.1 Java a. b. int x ;char ch1,ch2; xch1ch2 int char 1$ 2$ 3

2.5 VariableDefinition.javaimport java.awt.*;import java.applet.Applet;public class VariableDefinition extends Applet {int x = 10; char char_MyClass_Flag = 'R';Label output1;Label output2;

public void init(){output1 = new Label(" int "+"x,"+x);output2 = new Label(" char "+"char_MyClass_Flag,"+char_MyClass_Flag); add(output1);add(output2);}}

2.6 VariableDefinition2.javaimport java.awt.*;import java.applet.Applet;public class VariableDefinition2 extends Applet{int x = 10;char char_MyClass_Flag = 'F';String prompt1 = "";String prompt2 = ;String prompt3 = " ";

public void paint(Graphics g){g.drawString(prompt1+"int"+prompt2+"x"+prompt3+x,10,20);

g.drawString(prompt1+"char"+prompt2+"char_MyClass_Flag"+prompt3+char_MyClass_Flag,10,50);}}

2.2.2 1 boolean true false 2.8 ShowBoolean.javaimport java.awt.* ;import java.applet.Applet;public class ShowBoolean extends Applet{ boolean b1 = true ; boolean b2 ;// false String prompt1 = "boolean" ; String prompt2 = "" ; String prompt3 = " , " ;

public void paint(Graphics g) { g.drawString( prompt1+prompt2+"b1"+prompt3+b1,10,20);

g.drawString( prompt1+prompt2+"b2"+prompt3+b2,10,50); }}

2 int char byte 8bit short 16bit int 32bit long64bit char16bit chrr c_char = 'A' ; char c_int = 65 ;

int i = 65 ;char c_char = i ; // i c_char int i = 65 ; char c_char = (char)i ;//

3 floatdouble float32bit double64bi float double 3.14E3 31403.14E-2 0.0314 float 0.0314f 0.0314F3.14E-2f 3.14E-2F double 0.0314d 0.0314D3.14E-2d 3.14E-2d fF dD double

double float float f = 3.14 ; // 3.14 double float f = 3.14F;//

4 1 2 long l = 5 000 000 000 ; int i = (int) l ; // l=5 000 000 000 i 2 147 483 647

2.3 2.3.1 ++ -- 2.9 ArithmeticOperation.javaimport java.applet.Applet ;import java.awt.*;public class ArithmetcOperation extends Applet {int i_x = 1;int i_y = 2;double d_x = 3.1415926;double d_y = 2.41;

public void paint(Graphics g){g.drawString(i_x+"+"+i_y+"="+(i_x+i_y),10,20);g.drawString(i_x+"-"+i_y+"="+(i_x-i_y),10,40);g.drawString(i_x+"*"+i_y+"="+(i_x*i_y),10,60);g.drawString(i_x+"/"+i_y+"="+(i_x/i_y),10,80);g.drawString(i_x+"%"+i_y+"="+(i_x%i_y),10,100);g.drawString(d_x+"+"+d_y+"="+(d_x+d_y),10,140);g.drawString(d_x+"-"+d_y+"="+(d_x-d_y),10,160);g.drawString(d_x+"*"+d_y+"="+(d_x*d_y),10,180);g.drawString(d_x+"/"+d_y+"="+(d_x/d_y),10,200);g.drawString(d_x+"%"+d_y+"="+(d_x%d_y),10,220);}}

2.3.2 1===> < >=

2.10 RelationOperation.javaimport java.applet.Applet ;import java.awt.*;public class RelatinOperation extends Applet{int i_x = 1;int i_y = 2;double d_x = 3.1415926;double d_y = 2.41;public void paint(Graphics g){g.drawString(i_x+">"+i_y+"="+(i_x>i_y),10,20);g.drawString(i_x+"="+i_y+"="+(i_x>=i_y),10,100);g.drawString(i_x+""+d_y+"="+(d_x>d_y),10,160);g.drawString(d_x+"

2 2.11 LogicalOperation.javaimport java.applet.Applet ;import java.awt.*;public class LogicalOperation extends Applet{boolean b1 = true;boolean b2 = false;int x1 = 3 ,y1 = 5;int x2 = 3,y2 = 5;boolean b3 = x1>y1 && x1++ == y1--;boolean b4 = x2>y2 & x2++ == y2 --;

public void paint(Graphics g){g.drawString (b1+"&"+b2+"="+(b1&b2),10,20);g.drawString (b1+"|"+b2+"="+(b1|b2),10,40);g.drawString (b1+"^"+b2+"="+(b1^b2),10,60);g.drawString ("!"+b2+"="+(!b2),10,80);g.drawString (b1+"&&"+b2+"="+(b1&&b2),10,100);g.drawString (b1+"||"+b2+"="+(b1||b2),10,120);g.drawString ("x="+x1+",y="+y1,10,140);g.drawString ("(x>y&&x++==y--)="+b3+" ;x="+x1+",y="+y1,10,160);g.drawString ("(x>y&x++==y--)="+b4+" ;x="+x2+",y="+y2,10,180);}}

2.3.3 2.3.4 1 : x ? y : z x x y x z int x = 5 , y = 8 , z = 2 ; int k = x < 3 ? y : z ; // x < 3 k z 2 . int y = x > 0 ? x : -x ; // y x 2 P.39 2.5

3 [] 4 instanceof true false boolean b = MyObject instanceof MyClass ;

2.3.5 + x + y + z ( x + y ) + z !!x !(!x)

Java 3.1 1 "12"2

3.2 Java if switch

3.2.1 if if if // if else // else else if if if ( // if

3.1 import java.applet.*;import java.awt.*;public class ClassScore extends Applet {Label prompt;TextField input;int PassCount = 0;int FailureCount = 0;int TotalNumber = 0;int TotalScore = 0;double AverageScore = 0;

public void init(){prompt = new Label("Enter next student score(-1 for reset):");input = new TextField(4);add(prompt);add(input);}

public void paint(Graphics g)//{g.drawString ("Total student number is: "+TotalNumber,10,80);g.drawString ("The pass number is : "+PassCount,10,100);g.drawString ("The failure number is: "+FailureCount,10,120);g.drawString ("The average score of whole class is : "+AverageScore,10,140);}

public boolean action(Event e,Object o){int score;if(e.target == input){score = Integer.parseInt(input.getText());if(score == -1){PassCount = 0;FailureCount = 0;TotalNumber = 0;TotalScore = 0;AverageScore = 0;}

else{if(score>=60)PassCount ++;elseFailureCount ++;TotalNumber ++;TotalScore += score;AverageScore = TotalScore/TotalNumber;}input.setText("");repaint();}return true;}}

3.2.2 switch switch switch { case 1 1 // 1 case 2 2 // 2 ...... case 3 n // n default n+1 // n+1} switch case case case case ...... case default default switch

switch case switch ( MyGrade ){ case 'A' : MyScore = 5 ; break ; case 'B' : MyScore = 4 ; break ; case 'C' : MyScore = 3 ; break ; default : MyScore = 0 ;}

3.3 1 while

while while

2 do - while do - while do while

do - while while while do - while do - while

showCharValue.javaimport java.io.* ;public class showCharValue{public static void main(String args[]){char ch ;try{System.out.println("''");do{ch = (char)System.in.read() ;System.out.println("" + ch + "" + (int)ch);System.in.skip(2) ; // }while(ch!='#');}catch(IOException e){System.err.println(e.toString());}}}

3 for for Java for

for (123

2 1 3

10000 PerfectNum.java 1import java.io.*;public class PerfectNum{public static void main(String args[]){int count = 1 ;for (int i = 1 ; i < 1000 ; i++ ){int y = 0 ;for (int j = 1 ; j < i ; j ++ )if ( i % j == 0 )y += j ;if ( y == i ){System.out.print(i + String.valueOf( '\t')) ;count ++ ;if (count % 3 == 0 )System.out.println() ;}}try{System.in.read();}catch(IOException e){}}}

41continue continue continue continue continue ;2break break

3.4 Java 1 1 2 ...... throw [] { } 1 1 2 3 ......

2boolean isPrime(int n)int n boolean isPrime()isPrime()f_i = isPrime(i);if_i

3 return void public void init()

4 1 f_i = isPrime(); 2 public boolean action(Event e,Object o)

4.1

4.1.2

4.2OOAOODOOP

4.3

4.4

Java5.1

[] class [extends ] [implements ]{}

1.classclassJava

(1)extendsJava

class Employee{int m_EmpNo;int m_DeptNo;}

class CommonEmployee extends Employee{int m_ManagerNo;}

class ManagerEmployee extends Employee{int m_SecretaryNo;}

2implementsJava

3

2.1[] [=][] [=new ()]

staticfinalvolatiletransient

2Java[]Throws12{}

staticabstractfinalsynchronousnative

5.2new =new ();

5.1

5.3Java

5.4 1 Nclass 1 N 1 N

publicpublicprivateprotectedprivate protected

1.publicpublicimportpublicpublicpublic

public

2.

3.privateprivate

4.protectedprotectedprotected

5.private protectedPrivateprotected

5.5 1.staticch05/Employee.java

2.staticstaticstatic

staticstaticstaticStaticstatic

3.static(1)(2)new(3)

5.6 1.abstract

2.abstractabstract

5.7 1.final2.finalfinal

final123static

3.finalfinalprivatefinalfinal

4.protected void finalize(){}

5.8 1.volatilevolatilevolatile

2.nativenativeCC++fortrannativenativejavanative

3.synchronizedsynchronizedstaticClasssynchronizedstaticsynchronized

4.abstractfinalabstractprivatestaticfinalnativeabstractprivateabstractabstractstaticstatic