计算机网络专业自考Java 实践考核答案.docx
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计算机网络专业自考Java实践考核答案
Java语言
UnderMC-DOS
1)Path=C:
\Java\jdk1.6.0_05\bin
2)setClasspath=C:
\Java\jdk1.6.0_05\jre\lib\rt.jar;.;
第一题
classPeople
{protectedStringname;
protectedintage;
publicintgetAge()
{returnage;
}
}
classEmployeeextendsPeople
{protectedStringempno;
}
classTeacherextendsPeople
{Stringteano;
Stringzc;
}
第二题
Application:
publicclassHelloWorld
{publicstaticvoidmain(Stringargs[])
{System.out.println("HelloWorld!
");
}
}
Applet:
源程序:
importjava.applet.*;
importjava.awt.*;
publicclassHelloWorldAppletextendsApplet
{publicvoidpaint(Graphicsg)
{g.drawString("HelloWorld!
",10,20);
}
}
运行(编写html文件):
HelloWorldApplet
第三题
源程序:
RunningOK.
importjava.awt.*;
importjava.awt.event.*;
importjavax.swing.*;
importjava.lang.Double;
publicclassExampleThree
{publicstaticvoidmain(Stringargs[])
{ComputerFramefr=newComputerFrame();
fr.setTitle("求绝对值");
}
}
classComputerFrameextendsJFrameimplementsActionListener
{JTextFieldtext1,text2;
JButtonbutton;
publicComputerFrame()
{setLayout(newFlowLayout());
text1=newJTextField(10);
text2=newJTextField(10);
add(text1);
button=newJButton("绝对值");
add(button);
add(text2);
button.addActionListener(this);
setSize(400,320);
setVisible(true);
validate();
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
publicvoidactionPerformed(ActionEvente)
{Doublen;
if(e.getSource()==button)
{Doublem;
try{m=Double.parseDouble(text1.getText());
n=Math.abs(m);
text2.setText(String.valueOf(n));
}
catch(NumberFormatExceptionee)
{text2.setText("请输入数字字符");
}
}
validate();
}
}
运行(编写html文件):
Runningerror.
ExampleThree
第四题
importjava.lang.Double;
publicclassExampleFour
{publicstaticvoidmain(Stringargs[])
{Fractorr1;
r1=newFractor(-2,9);
Fractorr2;
r2=newFractor(3,7);
Fractorresult1=r1.add(r2);
Fractorresult2=r1.sub(r2);
System.out.printf("两分数之和:
");
r1.diplay();
System.out.printf("+");
r2.diplay();
System.out.printf("=");
result1.diplay();
System.out.printf("\n");
System.out.printf("两分数之差:
");
r1.diplay();
System.out.printf("-");
r2.diplay();
System.out.printf("=");
result2.diplay();
System.out.printf("\n");
}
}
classFractor
{intm;//分子
intn;//分母
Fractor(intm,intn)//设置分子和分母
{intc=f(Math.abs(m),Math.abs(n));//计算最大公约数
this.m=m/c;
this.n=n/c;
if(m<0&&n<0)
{m=-m;
n=-n;
}
}
intgetNumerator()//得到分子
{returnm;
}
intgetDenominator()//得到分母
{returnn;
}
publicintf(intk,intv)
{if(k{intc=k;
k=v;
v=c;
}
intr=k%v;
while(r!
=0)
{k=v;
v=r;
r=k%v;
}
returnv;
}
Fractoradd(Fractora)
{intk=a.getNumerator();
intv=a.getDenominator();
intnewM=m*v+n*k;
intnewN=n*v;
Fractorresult=newFractor(newM,newN);
returnresult;
}
Fractorsub(Fractora)
{intk=a.getNumerator();
intv=a.getDenominator();
intnewM=m*v-n*k;
intnewN=n*v;
Fractorresult=newFractor(newM,newN);
returnresult;
}
voiddiplay()
{intm=getNumerator();
intn=getDenominator();
System.out.printf("\0"+m+"/"+n+"\0");
}
}
第五题第六题
publicclassExampleSix
{publicstaticvoidmain(Stringargs[])
{int[]arrayOfInts={32,87,3,589,12,1076,2000,8,622,127};
for(inti=0;i{for(intj=i+1;j{if(arrayOfInts[j]{inttemp=0;
temp=arrayOfInts[j];
arrayOfInts[j]=arrayOfInts[i];
arrayOfInts[i]=temp;
}
}
}
for(intk=0;k{System.out.printf("%6d",arrayOfInts[k]);
}
}
}
第七题
publicclassExampleSeven
{publicstaticvoidmain(Stringargs[])
{doublesum=0,a=1;
inti=1;
while(i<=20)
{sum=sum+a;
i++;
a=a*i;
}
System.out.println("sum="+sum);
}
}
第八题第九题
importjava.awt.*;
importjava.awt.event.*;
importjavax.swing.*;
importjava.lang.Double;
publicclassExampleNine
{publicstaticvoidmain(Stringargs[])
{ComputerFramefr=newComputerFrame();
fr.setTitle("计算");
}
}
classComputerFrameextendsJFrameimplementsActionListener
{JTextFieldtext1,text2;
JButtonbutton1,button2;
JLabellabel;
publicComputerFrame()
{setLayout(newFlowLayout());
text1=newJTextField(10);
text2=newJTextField(10);
label=newJLabel("",JLabel.CENTER);
label.setBackground(Color.green);
add(text1);
add(text2);
button1=newJButton("平均值");
button2=newJButton("最大值");
add(button1);
add(button2);
add(label);
button1.addActionListener(this);
button2.addActionListener(this);
setSize(400,320);
setVisible(true);
validate();
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
publicvoidactionPerformed(ActionEvente)
{Doublen;
if(e.getSource()==button1)
{Doublen1,n2;
try{n1=Double.parseDouble(text1.getText());
n2=Double.parseDouble(text2.getText());
n=(n1+n2)/2.0;
label.setText(String.valueOf(n));
}
catch(NumberFormatExceptionee)
{label.setText("请输入数字字符");
}
}
elseif(e.getSource()==button2)
{Doublen1,n2;
try{n1=Double.parseDouble(text1.getText());
n2=Double.parseDouble(text2.getText());
n=Math.max(n1,n2);
label.setText(String.valueOf(n));
}
catch(NumberFormatExceptionee)
{label.setText("请输入数字字符");
}
}
validate();
}
}
第十题
classPoint
{floatx,y;
Point()
{x=0.0f;
y=0.0f;
}
Point(floatx,floaty)
{this.x=x;
this.y=y;
}
floatgetX()
{returnx;
}
floatgetY()
{returny;
}
publicvoidshow()
{System.out.println("点的坐标:
"+"("+getX()+","+getY()+")");
}
}
publicclassExampleTen
{publicstaticvoidmain(Stringargs[])
{Pointpoint1=newPoint(10.3f,-20.6f);
Pointpoint2=newPoint();
point1.show();
point2.show();
}
}
第十一题
abstractclassShape
{abstractdoubleGetArea();
abstractdoubleGetPerimeter();
}
classRectangleextendsShape
{doublea,b;//长,宽;
Rectangle(doublea,doubleb)
{this.a=a;
this.b=b;
}
doubleGetArea()
{returna*b;
}
doubleGetPerimeter()
{return(a+b)*2;
}
}
classCircleextendsShape
{doubler;
Circle(doubler)
{this.r=r;
}
doubleGetArea()
{return3.14*r*r;
}
doubleGetPerimeter()
{return3.14*r*2;
}
}
publicclassExampleEleven
{publicstaticvoidmain(Stringargs[])
{Rectanglerectangle=newRectangle(10,20);
Circlecircle=newCircle(10);
System.out.println("长方形的面积:
"+rectangle.GetArea());
System.out.println("长方形的周长:
"+rectangle.GetPerimeter());
System.out.println("圆的面积:
"+circle.GetArea());
System.out.println("圆的周长:
"+circle.GetPerimeter());做好人力资源,企业无忧
}
}