Allen 2006-01-13 23:10 å‘表评论
]]>
public class ClassDemo2
{ 3
public ClassDemo(){}4
5
public static void main(String[] args)6
{7
ClassDemo test=new ClassDemo();8
System.out.println("The class of test is:"+test.getClass().getName());9
try{10
Class c=Class.forName("java.lang.Object");11
System.out.println(c.getPackage()+"\t");12
System.out.println(c);13
java.lang.reflect.Method[] m=c.getMethods();14
System.out.println("The element in String[] is:"+String[].class.getComponentType());15
System.out.println((new int[3][4][5][6]).getClass().getName());16
System.out.println("The method defined in Object class:");17
for(int i=0; i<m.length; i++)18
{19
System.out.println(m[i]);20
}21
}22
catch(ClassNotFoundException e)23
{24
e.printStackTrace();25
}26
}27
}Allen 2006-01-09 20:50 å‘表评论
]]> 1public class ComplexNumber
2{
3 private double x,y;
4
5 public ComplexNumber(double real,double imaginary)
6 {
7 this.x=real;
8 this.y=imaginary;
9 }
10
11 public double real()
12 {
13 return x;
14 }
15
16 public double imaginary()
17 {
18 return y;
19 }
20
21 public double magnitude()
22 {
23 return Math.sqrt(x*x+y*y);
24 }
25
26 public String toString()
27 {
28 return "{"+x+","+y+"}";
29 }
30
31 public static ComplexNumber add(ComplexNumber a,ComplexNumber b)
32 {
33 return new ComplexNumber(a.x+b.x,a.y+b.y);
34 }
35
36 public ComplexNumber add(ComplexNumber a)
37 {
38 return new ComplexNumber(this.x+a.x,this.y+a.y);
39 }
40
41 public static ComplexNumber multiply(ComplexNumber a,ComplexNumber b)
42 {
43 return new ComplexNumber(a.x*b.x-a.y*b.y,a.x*b.y+a.y*b.x);
44 }
45
46 public ComplexNumber multiply(ComplexNumber a)
47 {
48 return new ComplexNumber(x*a.x-y*a.y,x*a.y+y*a.x);
49 }
50}
public class ComplexNumber2
{3
private double x,y;4
5
public ComplexNumber(double real,double imaginary) 6
{7
this.x=real;8
this.y=imaginary;9
}10
11
public double real()12
{13
return x; 14
}15
16
public double imaginary()17
{ 18
return y; 19
}20
21
public double magnitude()22
{ 23
return Math.sqrt(x*x+y*y); 24
}25
26
public String toString()27
{ 28
return "{"+x+","+y+"}"; 29
}30
31
public static ComplexNumber add(ComplexNumber a,ComplexNumber b) 32
{33
return new ComplexNumber(a.x+b.x,a.y+b.y);34
}35
36
public ComplexNumber add(ComplexNumber a) 37
{38
return new ComplexNumber(this.x+a.x,this.y+a.y);39
}40
41
public static ComplexNumber multiply(ComplexNumber a,ComplexNumber b) 42
{43
return new ComplexNumber(a.x*b.x-a.y*b.y,a.x*b.y+a.y*b.x);44
}45
46
public ComplexNumber multiply(ComplexNumber a) 47
{48
return new ComplexNumber(x*a.x-y*a.y,x*a.y+y*a.x);49
}50
}Allen 2006-01-09 20:22 å‘表评论
]]> 1import java.io.*;
2public class ArrayPrint
3{
4 private int N;
5 private int[][] intarray;
6 ArrayPrint()
7 {
8 N=5;
9 intarray=new int[N][N];
10 }
11 ArrayPrint(int n)
12 {
13 N=n;
14 intarray=new int[N][N];
15 }
16 public void Print()
17 {
18 int i=0,j=0;
19 int i0=0,j0=0;
20 int count=1;
21 int Num=N-1;
22 while(Num>0)
23 {
24 for(i=i0,j=j0;j<Num;j++,count++)
25 {
26 intarray[i][j]=count;
27 }
28 for(i=i0;i<Num;i++,count++)
29 {
30 intarray[i][j]=count;
31 }
32 for(j=Num;j>j0;j--,count++)
33 {
34 intarray[i][j]=count;
35 }
36 for(i=Num;i>i0;i--,count++)
37 {
38 intarray[i][j]=count;
39 }
40 i0++;
41 j0++;
42 Num--;
43 }
44 if(N%2!=0)
45 {
46 intarray[N/2][N/2]=count;
47 }
48 for(i=0;i<N;i++)
49 {
50 for(j=0;j<N;j++)
51 {
52 String ar="0";
53 if(intarray[i][j]/10<1)
54 {
55 ar=" "+intarray[i][j];
56 }
57 else if(intarray[i][j]/100<1 && intarray[i][j]/10>=1)
58 {
59 ar=" "+intarray[i][j];
60 }
61 System.out.print(ar+" ");
62 }
63 System.out.println();
64 }
65 }
66 public static void main(String[] args) throws IOException
67 {
68 int order=0;
69 System.out.println("Please input the order of the square:(<10:)");
70 order=System.in.read();
71 order=order-'0';
72 ArrayPrint arr=new ArrayPrint(order);
73 arr.Print();
74 }
75}
import java.io.*;2
public class ArrayPrint3
{4
private int N;5
private int[][] intarray;6
ArrayPrint()7
{8
N=5;9
intarray=new int[N][N];10
}11
ArrayPrint(int n)12
{13
N=n;14
intarray=new int[N][N];15
}16
public void Print()17
{18
int i=0,j=0;19
int i0=0,j0=0;20
int count=1;21
int Num=N-1;22
while(Num>0)23
{24
for(i=i0,j=j0;j<Num;j++,count++)25
{26
intarray[i][j]=count;27
}28
for(i=i0;i<Num;i++,count++)29
{30
intarray[i][j]=count;31
}32
for(j=Num;j>j0;j--,count++)33
{34
intarray[i][j]=count;35
}36
for(i=Num;i>i0;i--,count++)37
{38
intarray[i][j]=count;39
}40
i0++;41
j0++;42
Num--;43
}44
if(N%2!=0)45
{46
intarray[N/2][N/2]=count; 47
}48
for(i=0;i<N;i++)49
{50
for(j=0;j<N;j++)51
{52
String ar="0";53
if(intarray[i][j]/10<1)54
{55
ar=" "+intarray[i][j];56
}57
else if(intarray[i][j]/100<1 && intarray[i][j]/10>=1)58
{59
ar=" "+intarray[i][j];60
}61
System.out.print(ar+" ");62
}63
System.out.println();64
}65
}66
public static void main(String[] args) throws IOException67
{68
int order=0;69
System.out.println("Please input the order of the square:(<10:)");70
order=System.in.read();71
order=order-'0';72
ArrayPrint arr=new ArrayPrint(order);73
arr.Print();74
}75
}Allen 2006-01-09 18:04 å‘表评论
]]> 1public class StringBufferDemo
2{
3 public static void main(String[] args)
4 {
5 StringBuffer sb=new StringBuffer("Java");
6 double d=1.4;
7 sb.append(d).append("have").append(new String(" a lot of new features"));
8 System.out.println(sb);
9 sb.insert(4,"SDK");
10 System.out.println(sb);
11 sb.delete(4,10);
12 System.out.println(sb);
13 System.out.println(sb.reverse());
14 }
15}
public class StringBufferDemo2
{3
public static void main(String[] args)4
{5
StringBuffer sb=new StringBuffer("Java");6
double d=1.4;7
sb.append(d).append("have").append(new String(" a lot of new features"));8
System.out.println(sb);9
sb.insert(4,"SDK");10
System.out.println(sb);11
sb.delete(4,10);12
System.out.println(sb);13
System.out.println(sb.reverse());14
}15
}Allen 2006-01-09 13:27 å‘表评论
]]> 1public class StringDemo
2{
3 public static void main(String[] args)
4 {
5 String myName="G. Leeman";
6 int length="涂é™é?/SPAN>".length();
7 System.out.println("长度1åQ?/SPAN>"+myName.length());
8 System.out.println("长度2åQ?/SPAN>"+length);
9 String name1="programming in java";
10 String name2="Programming in Java";
11 System.out.println("比较1åQ?/SPAN>"+name1.equals(name2));
12 System.out.println("比较2åQ?/SPAN>"+name2.equalsIgnoreCase(name2));
13 System.out.println("比较3åQ?/SPAN>"+name2.compareTo("Progam"));
14 System.out.println("å—符1åQ?/SPAN>"+name1.charAt(4));
15 System.out.println("å—符2åQ?/SPAN>"+name1.indexOf('a'));
16 System.out.println("å—符3åQ?/SPAN>"+name2.lastIndexOf('a'));
17 String subname="in";
18 System.out.println("å串1åQ?/SPAN>"+name1.substring(3,10));
19 System.out.println("å串2åQ?/SPAN>"+"abc".concat("123"));
20 System.out.println("å串3åQ?/SPAN>"+name2.startsWith("Pro"));
21 System.out.println("å串4åQ?/SPAN>"+name2.endsWith("in Java"));
22 System.out.println("å串5åQ?/SPAN>"+name1.indexOf(subname));
23 System.out.println("å串6åQ?/SPAN>"+name1.lastIndexOf(subname));
24 System.out.println("ž®å†™åQ?/SPAN>"+name2.toLowerCase());
25 System.out.println("大写åQ?/SPAN>"+name2.toUpperCase());
26 System.out.println("替æ¢åQ?/SPAN>"+name1.replace('a','A'));
27 }
28}
public class StringDemo2
{3
public static void main(String[] args)4
{5
String myName="G. Leeman";6
int length="涂é™é?/SPAN>".length();7
System.out.println("长度1åQ?/SPAN>"+myName.length());8
System.out.println("长度2åQ?/SPAN>"+length);9
String name1="programming in java";10
String name2="Programming in Java";11
System.out.println("比较1åQ?/SPAN>"+name1.equals(name2));12
System.out.println("比较2åQ?/SPAN>"+name2.equalsIgnoreCase(name2));13
System.out.println("比较3åQ?/SPAN>"+name2.compareTo("Progam"));14
System.out.println("å—符1åQ?/SPAN>"+name1.charAt(4));15
System.out.println("å—符2åQ?/SPAN>"+name1.indexOf('a'));16
System.out.println("å—符3åQ?/SPAN>"+name2.lastIndexOf('a'));17
String subname="in";18
System.out.println("å串1åQ?/SPAN>"+name1.substring(3,10));19
System.out.println("å串2åQ?/SPAN>"+"abc".concat("123"));20
System.out.println("å串3åQ?/SPAN>"+name2.startsWith("Pro"));21
System.out.println("å串4åQ?/SPAN>"+name2.endsWith("in Java"));22
System.out.println("å串5åQ?/SPAN>"+name1.indexOf(subname));23
System.out.println("å串6åQ?/SPAN>"+name1.lastIndexOf(subname));24
System.out.println("ž®å†™åQ?/SPAN>"+name2.toLowerCase());25
System.out.println("大写åQ?/SPAN>"+name2.toUpperCase());26
System.out.println("替æ¢åQ?/SPAN>"+name1.replace('a','A'));27
}28
}Allen 2006-01-09 12:57 å‘表评论
]]> 1public class CharacterDemo
2{
3 public CharacterDemo()
4 {
5 }
6
7 public static void main(String[] args)
8 {
9 Character c1=new Character('A');
10 Character c2=new Character('b');
11 System.out.println(c1.charValue()+0);
12 System.out.println(c2.charValue()+0);
13 int i=c1.compareTo(c2);
14 System.out.println(i);
15 if(i==0)
16 {
17 System.out.println("c1 is equal c2!");
18 }
19 else if(i<0)
20 {
21 System.out.println("c1 is smaller than c2!");
22 }
23 System.out.println(Character.toLowerCase('A')+""+Character.toUpperCase('a'));
24 System.out.println(Character.isDigit('9'));
25 }
26}
public class CharacterDemo2
{3
public CharacterDemo()4
{5
}6
7
public static void main(String[] args)8
{9
Character c1=new Character('A');10
Character c2=new Character('b');11
System.out.println(c1.charValue()+0);12
System.out.println(c2.charValue()+0);13
int i=c1.compareTo(c2);14
System.out.println(i);15
if(i==0)16
{17
System.out.println("c1 is equal c2!");18
}19
else if(i<0)20
{21
System.out.println("c1 is smaller than c2!");22
}23
System.out.println(Character.toLowerCase('A')+""+Character.toUpperCase('a'));24
System.out.println(Character.isDigit('9'));25
}26
}Allen 2006-01-07 17:59 å‘表评论
]]> 1import java.util.*;
2
3public class CalendarDemo
4{
5 public static void main(String[] args)
6 {
7 Calendar instcalendar=Calendar.getInstance();
8
9 instcalendar.setTime(new Date());
10
11 String cyear=String.valueOf(instcalendar.get(Calendar.YEAR));
12 String cmonth=String.valueOf(instcalendar.get(Calendar.MONTH)+1);
13 String cdate=String.valueOf(instcalendar.get(Calendar.DAY_OF_MONTH));
14 String cday=String.valueOf(instcalendar.get(Calendar.DAY_OF_WEEK)-1);
15
16 int chour=instcalendar.get(Calendar.HOUR_OF_DAY);
17 int cminute=instcalendar.get(Calendar.MINUTE);
18 int csecond=instcalendar.get(Calendar.SECOND);
19
20 System.out.println("现在的时间是åQ?/SPAN>");
21 System.out.println(""+cyear+"òq?/SPAN>"+cmonth+"æœ?/SPAN>"+cdate+"æ—?/SPAN>"+"星期"+cday);
22 System.out.println(""+chour+"æ—?/SPAN>"+cminute+"åˆ?/SPAN>"+csecond+"¿U?/SPAN>");
23
24 instcalendar.set(2004,9,1);
25 long ctime2004=instcalendar.getTimeInMillis();
26 instcalendar.set(2005,9,1);
27 long ctime2005=instcalendar.getTimeInMillis();
28 long interdays=(ctime2005-ctime2004)/(1000*60*60*24);
29
30 System.out.println("2004òq?0æœ?日和2005òq?0æœ?日相éš?/SPAN>"+interdays+"å¤?/SPAN>");
31 }
32}
33
import java.util.*;2
3
public class CalendarDemo4
{5
public static void main(String[] args)6
{7
Calendar instcalendar=Calendar.getInstance();8
9
instcalendar.setTime(new Date());10
11
String cyear=String.valueOf(instcalendar.get(Calendar.YEAR));12
String cmonth=String.valueOf(instcalendar.get(Calendar.MONTH)+1);13
String cdate=String.valueOf(instcalendar.get(Calendar.DAY_OF_MONTH));14
String cday=String.valueOf(instcalendar.get(Calendar.DAY_OF_WEEK)-1);15
16
int chour=instcalendar.get(Calendar.HOUR_OF_DAY);17
int cminute=instcalendar.get(Calendar.MINUTE);18
int csecond=instcalendar.get(Calendar.SECOND);19
20
System.out.println("现在的时间是åQ?/SPAN>");21
System.out.println(""+cyear+"òq?/SPAN>"+cmonth+"æœ?/SPAN>"+cdate+"æ—?/SPAN>"+"星期"+cday);22
System.out.println(""+chour+"æ—?/SPAN>"+cminute+"åˆ?/SPAN>"+csecond+"¿U?/SPAN>");23
24
instcalendar.set(2004,9,1);25
long ctime2004=instcalendar.getTimeInMillis();26
instcalendar.set(2005,9,1);27
long ctime2005=instcalendar.getTimeInMillis();28
long interdays=(ctime2005-ctime2004)/(1000*60*60*24);29
30
System.out.println("2004òq?0æœ?日和2005òq?0æœ?日相éš?/SPAN>"+interdays+"å¤?/SPAN>");31
}32
}33
Allen 2006-01-07 17:58 å‘表评论
]]> 1class DayShower
2{
3 public static void main(String[] args)
4 {
5 int yearIn=2004;
6 int monthIn=2;
7 if(args.length>0)
8 {
9 monthIn=Integer.parseInt(args[0]);
10 }
11 if(args.length>1)
12 {
13 yearIn=Integer.parseInt(args[1]);
14 }
15 System.out.println(yearIn+"Äå^"+monthIn+"ÔÂÓÃ"+countDays(monthIn,yearIn)+"Ìì");
16 }
17 static int countDays(int month,int year)
18 {
19 int count=-1;
20 switch(month)
21 {
22 case 1:
23 case 3:
24 case 5:
25 case 7:
26 case 8:
27 case 10:
28 case 12: count=21;break;
29 case 4:
30 case 6:
31 case 9:
32 case 11: count=30;break;
33 case 2:
34 if(year%4==0)
35 {
36 count=29;
37 }
38 else
39 {
40 count=28;
41 }
42 if((year%100==0)&(year%400!=0))
43 {
44 count=28;
45 }
46 }
47 return count;
48 }
49}
class DayShower2
{3
public static void main(String[] args)4
{5
int yearIn=2004;6
int monthIn=2;7
if(args.length>0)8
{9
monthIn=Integer.parseInt(args[0]);10
}11
if(args.length>1)12
{13
yearIn=Integer.parseInt(args[1]);14
}15
System.out.println(yearIn+"Äå^"+monthIn+"ÔÂÓÃ"+countDays(monthIn,yearIn)+"Ìì");16
}17
static int countDays(int month,int year)18
{19
int count=-1;20
switch(month)21
{22
case 1:23
case 3:24
case 5:25
case 7:26
case 8:27
case 10:28
case 12: count=21;break;29
case 4:30
case 6:31
case 9:32
case 11: count=30;break;33
case 2:34
if(year%4==0)35
{36
count=29;37
}38
else39
{40
count=28;41
} 42
if((year%100==0)&(year%400!=0))43
{44
count=28;45
}46
}47
return count;48
}49
}Allen 2006-01-07 17:56 å‘表评论
]]> 1public class MathDemo
2{
3 public static void main(String[] args)
4 {
5 System.out.println("abs(-5)="+Math.abs(-5));
6 System.out.println("max(2.72,3.14)="+Math.max(2.72,3.14));
7 System.out.println("min(256,286)="+Math.min(256,286));
8
9 System.out.println("round(3.8)="+Math.round(3.8));
10 System.out.println("round(-3.8)="+Math.round(-3.8));
11
12 System.out.println("sqrt(2)="+Math.sqrt(2));
13 System.out.println("pow(2,3)="+Math.pow(2,3));
14
15 System.out.println("E="+Math.E);
16 System.out.println("exp(1)="+Math.exp(1));
17 System.out.println("log(e*e*e)="+Math.log((Math.E)*(Math.E)*(Math.E)));
18
19 System.out.println("ceil(3.14)="+(int)Math.ceil(3.14));
20 System.out.println("floor(3.14)="+(int)Math.floor(3.14));
21
22 System.out.println("pi="+Math.PI);
23 System.out.println("sin(pi/2)="+Math.sin(Math.PI/2));
24 System.out.println("cos(0)="+Math.cos(0));
25 }
26}
public class MathDemo2
{3
public static void main(String[] args)4
{5
System.out.println("abs(-5)="+Math.abs(-5));6
System.out.println("max(2.72,3.14)="+Math.max(2.72,3.14));7
System.out.println("min(256,286)="+Math.min(256,286));8
9
System.out.println("round(3.8)="+Math.round(3.8));10
System.out.println("round(-3.8)="+Math.round(-3.8));11
12
System.out.println("sqrt(2)="+Math.sqrt(2));13
System.out.println("pow(2,3)="+Math.pow(2,3));14
15
System.out.println("E="+Math.E);16
System.out.println("exp(1)="+Math.exp(1));17
System.out.println("log(e*e*e)="+Math.log((Math.E)*(Math.E)*(Math.E)));18
19
System.out.println("ceil(3.14)="+(int)Math.ceil(3.14));20
System.out.println("floor(3.14)="+(int)Math.floor(3.14));21
22
System.out.println("pi="+Math.PI);23
System.out.println("sin(pi/2)="+Math.sin(Math.PI/2));24
System.out.println("cos(0)="+Math.cos(0));25
}26
}Allen 2006-01-07 17:56 å‘表评论
]]> 1public class MaxVariables
2{
3 public static void main(String[] args)
4 {
5 byte largestByte=Byte.MAX_VALUE;
6 short largestShort=Short.MAX_VALUE;
7 int largestInteger=Integer.MAX_VALUE;
8 long largestLong=Long.MAX_VALUE;
9 float largestFloat=Float.MAX_VALUE;
10 double largestDouble=Double.MAX_VALUE;
11 char aChar='S';
12 boolean aBoolean=true;
13
14 System.out.println("最大的byte值是åQ?/SPAN>"+largestByte);
15 System.out.println("最大的short值是åQ?/SPAN>"+largestShort);
16 System.out.println("最大的integer值是åQ?/SPAN>"+largestInteger);
17 System.out.println("最大的long值是åQ?/SPAN>"+largestLong);
18 System.out.println("最大的float值是åQ?/SPAN>"+largestFloat);
19 System.out.println("最大的doubble值是åQ?/SPAN>"+largestDouble);
20 if(Character.isUpperCase(aChar))
21 {
22 System.out.println("å—符"+aChar+"是大写å—æ¯?/SPAN>");
23 }
24 else
25 {
26 System.out.println("å—符"+aChar+"是å°å†™å—æ¯?/SPAN>");
27 }
28 System.out.println("布尔型å˜é‡çš„值是"+aBoolean);
29 }
30}
public class MaxVariables2
{3
public static void main(String[] args)4
{5
byte largestByte=Byte.MAX_VALUE;6
short largestShort=Short.MAX_VALUE;7
int largestInteger=Integer.MAX_VALUE;8
long largestLong=Long.MAX_VALUE;9
float largestFloat=Float.MAX_VALUE;10
double largestDouble=Double.MAX_VALUE;11
char aChar='S';12
boolean aBoolean=true;13
14
System.out.println("最大的byte值是åQ?/SPAN>"+largestByte);15
System.out.println("最大的short值是åQ?/SPAN>"+largestShort);16
System.out.println("最大的integer值是åQ?/SPAN>"+largestInteger);17
System.out.println("最大的long值是åQ?/SPAN>"+largestLong);18
System.out.println("最大的float值是åQ?/SPAN>"+largestFloat);19
System.out.println("最大的doubble值是åQ?/SPAN>"+largestDouble);20
if(Character.isUpperCase(aChar))21
{22
System.out.println("å—符"+aChar+"是大写å—æ¯?/SPAN>");23
}24
else25
{26
System.out.println("å—符"+aChar+"是å°å†™å—æ¯?/SPAN>");27
}28
System.out.println("布尔型å˜é‡çš„值是"+aBoolean);29
}30
}Allen 2006-01-07 17:55 å‘表评论
]]>1public class Test_java
2{
3 public static void main(String[] args)
4 {
5 System.out.println("This is a Test'javapro!");
6 }
7}
8
public class Test_java2
{3
public static void main(String[] args)4
{5
System.out.println("This is a Test'javapro!");6
}7
}8
Allen 2006-01-07 17:52 å‘表评论
]]> 1public class IntegerDemo
2{
3 public IntegerDemo(){}
4 public static void main(String[] agrs)
5 {
6 Integer[] Integerarray={new Integer(20),new Integer(40),new Integer("110")};
7 for(int i=0;i<Integerarray.length;i++)
8 {
9 System.out.print(Integer.toBinaryString(Integerarray[i].intValue())+"\t");
10 System.out.print(Integer.toHexString(Integerarray[i].intValue())+"\t");
11 System.out.print(Integer.toOctalString(Integerarray[i].intValue())+"\t");
12 System.out.print(Integerarray[i]+"\r\n");
13 }
14 }
15}
public class IntegerDemo2
{3
public IntegerDemo(){}4
public static void main(String[] agrs)5
{6
Integer[] Integerarray={new Integer(20),new Integer(40),new Integer("110")};7
for(int i=0;i<Integerarray.length;i++)8
{9
System.out.print(Integer.toBinaryString(Integerarray[i].intValue())+"\t");10
System.out.print(Integer.toHexString(Integerarray[i].intValue())+"\t");11
System.out.print(Integer.toOctalString(Integerarray[i].intValue())+"\t");12
System.out.print(Integerarray[i]+"\r\n");13
}14
} 15
}Allen 2006-01-07 17:44 å‘表评论
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