[说明]下面是一个Appkt程序,其功能是从3~100之间(包括3和100)每隔0.5秒显示一个新的数字,如果数字为素数,则显示为灰色,其他为绿色。程序运行结果如图4所示。import java. awt. *import java. applet. Applet< applet code = ex2_7, class width = 800 height = 400 ></applet >public class ex2_7 extends Applet {public Color color2_7 = Color. black;private iht n2_7 = 3;public myPrime thPrime2_7;public void init( ) {thPrime2_7 = new myPrime(this);thPrime2_7, start( );}public void paint(Graphics g) {g, setColor( color2_7 );g. drawString( (1),50,50);}public int getlnt( ) {return n2_7;}public void setlnt (int i) {n2_7 = i;}}class myPrime extends Thread Iex2_7 obj2_7;myPrime (ex2_7 o) {this. obj2_7 = o;}public boolean isPrime(int n){boolean bPrime = true;iht i =2;if((2))return false;while( i < n - ]bPrime) {if((3))bPrime = false;i++;}return bPrime;}public void run( ) {int i;for (i = 3; (4);i++) {if (isPrime(i) )obj2 _7, color2_7 = Color, gray;elseobj2_7, color2_7 = Color. green;(5);obj2_7, repaint( );try {sleep(S00);} catch (InterruptedException ie) {}}} }ex2_7, html< HTML >< HEAD ><TITLE > ex2_7 </TITLE ></HEAD >< BODY ><appletcode =" ex2_?, class" width =800 height =400 ></applet ></BODY ></HTML >
[说明]
下面是一个Appkt程序,其功能是从3~100之间(包括3和100)每隔0.5秒显示一个新的数字,如果数字为素数,则显示为灰色,其他为绿色。
程序运行结果如图4所示。
import java. awt. *
import java. applet. Applet
< applet code = ex2_7, class width = 800 height = 400 >
</applet >
public class ex2_7 extends Applet {
public Color color2_7 = Color. black;
private iht n2_7 = 3;
public myPrime thPrime2_7;
public void init( ) {
thPrime2_7 = new myPrime(this);
thPrime2_7, start( );
}
public void paint(Graphics g) {
g, setColor( color2_7 );
g. drawString( (1),50,50);
}
public int getlnt( ) {
return n2_7;
}
public void setlnt (int i) {
n2_7 = i;
}
}
class myPrime extends Thread I
ex2_7 obj2_7;
myPrime (ex2_7 o) {
this. obj2_7 = o;
}
public boolean isPrime(int n){
boolean bPrime = true;
iht i =2;
if((2))
return false;
while( i < n - ]&&bPrime) {
if((3))
bPrime = false;
i++;
}
return bPrime;
}
public void run( ) {
int i;
for (i = 3; (4);i++) {
if (isPrime(i) )
obj2 _7, color2_7 = Color, gray;
else
obj2_7, color2_7 = Color. green;
(5);
obj2_7, repaint( );
try {
sleep(S00);
} catch (InterruptedException ie) {
}
}
} }
ex2_7, html
< HTML >
< HEAD >
<TITLE > ex2_7 </TITLE >
</HEAD >
< BODY >
<appletcode =" ex2_?, class" width =800 height =400 >
</applet >
</BODY >
</HTML >