java机试真题综述

基本操作题1无题目：importjava.applet.*;//引入Applet类importjava.awt.Graphics;//引入Graphics类

//*********Found********publicclassJava_1extendsApplet{//*********Found********publicvoidpaint(Graphicsg){g.drawString("欢迎你参加Java考试!",25,25);}}基本操作无题目2.publicclassJava_1{//*********Found**********publicstaticvoidmain(_________________args[]){newSimpleThread("第1").start();newSimpleThread("第2").start();}}//*********Found**********classSimpleThreadextends________________{publicSimpleThread(Stringstr){super(str);}publicvoidrun(){for(inti=0;i<5;i++){//*********Found**********System.out.println(i+""+______________());try{sleep((int)(2*100));}catch(InterruptedExceptione){}}System.out.println("运行!"+getName());}}基本操作题3.importjavax.swing.JOptionPane;publicclassJava_1{publicstaticvoidmain(Stringargs[]){intx,result;StringxVal;//*********Found**********xVal=JOptionPane.showMessageDialog("输入第1个整数:");//*********Found**********x=Integer.parseInt(xVal);result=x*x;//*********Found**********JOptionPane.showMessageDialog(null,"该数的平方是"+result);System.exit(0);}}基本操作4/Java_1.java，字符串类的startsWith()和endsWith()方法importjavax.swing.*;publicclassJava_1{publicstaticvoidmain(Stringargs[]){Stringstrings[]={"started","starting","ended","ending"};Stringoutput="";//测试startsWith()方法

for(inti=0;i<strings.length;i++)if(strings[i].startsWith("st"))output+="\""+strings[i]+"\"开始于\"st\"\n";output+="\n";//从字符串第2个字符开始

for(inti=0;i<strings.length;i++)if(strings[i].startsWith("art",2))output+="\""+strings[i]+"\"开始于\"art\"第2个字符位置\n";代码未完，见下一页output+="\n";//测试endsWith()方法

for(inti=0;i<strings.length;i++)//*********Found********if(strings[i].endsWith("____________"))output+="\""+strings[i]+"\"结束于\"ed\"\n";JOptionPane.showMessageDialog(null,output,"显示字符串类的比较",//*********Found********JOptionPane._________________________);System.exit(0);}}基本操作5：对Java-1.java文件进行完善并调试，使程序的输出结果如下： 字符串“现在学习如何访问一个字符串” 字符串长度为：13

其中第7个字符是：问 从字节数组的第7个到12获取字符是：问一个字符publicclassJava_1{publicstaticvoidmain(Stringargs[]){Stringstring="现在学习如何访问一个字符串";System.out.println("字符串\""+string+"\"");//*********Found**********System.out.println("字符串长度："+_________________________);System.out.println("其中第7个字符是："+string.charAt(7));charsub[]=newchar[20];System.out.print("从字节数组的第7到12获取字符是：");string.getChars(7,12,sub,0);System.out.println(sub);}}基本操作无题目6：importjava.io.*;publicclassJava_1{//*********Found**********publicstaticvoidmain(String[]args)____________Exception{InputStreamReaderir;BufferedReaderin;//*********Found**********ir=newInputStreamReader(____________);in=newBufferedReader(ir);System.out.println("输入年份是:");Strings=in.readLine();//*********Found**********intyear=Integer.__________________(s);if(year%4==0&&year%100!=0||year%400==0){System.out.println(""+year+"年是闰年.");}else{System.out.println(""+year+"年不是闰年.");}}}基本操作无题目7：//*********Found********import__________________;publicclassJava_1{publicstaticvoidmain(Stringargs[]){Strings1="hashcode",s2="HashCode";Stringoutput="\""+s1+"\"的Hash码是"+s1.hashCode()+"\n\""+s2+"\"的Hash码是"+s2.hashCode();JOptionPane.showMessageDialog(null,output,"显示字符串类的hash码",//*********Found********JOptionPane.______________________________);System.exit(0);}}基本操作8：importjavax.swing.JOptionPane;publicclassJava_1{publicstaticvoidmain(Stringargs[]){Strings1,s2,s3,s4,output;s1=newString("hello");s2=newString("goodbye");s3=newString("HappyBirthday");s4=newString("happybirthday");output="s1="+s1+"\ns2="+s2+"\ns3="+s3+"\ns4="+s4+"\n\n";//测试字符串相等

(s1.equals("hello"))//*********Found**********output=output+"s1equals\"hello\"\n";elseoutput=output+"s1doesnotequal\"hello\"\n";//用==测试相等

if(s1=="hello")output+="s1equals\"hello\"\n";elseoutput+="s1doesnotequal\"hello\"\n";//忽略字符格式测试相等

if(s3.equalsIgnoreCase(s4))output+="s3equalss4\n";elseoutput+="s3doesnotequals4\n";代码未完，见下一页//内容比较

output+="\pareTo(s2)is"+pareTo(s2)+"\pareTo(s1)is"+pareTo(s1)+"\pareTo(s1)is"+pareTo(s1)+"\pareTo(s4)is"+pareTo(s4)+"\pareTo(s3)is"+pareTo(s3)+"\n\n";//测试包含字符格式的域匹配

if(s3.regionMatches(0,s4,0,5))output+="First5charactersofs3ands4match\n";elseoutput+="First5charactersofs3ands4donotmatch\n";//忽略字符格式的域匹配

if(s3.regionMatches(true,0,s4,0,5))output+="First5charactersofs3ands4match";elseoutput+="First5charactersofs3ands4donotmatch";//*********Found**********JOptionPane.(null,output,"字符串构造方法示例",JOptionPane.INFORMATION_MESSAGE);System.exit(0);}}基本操作9：publicclassJava_1{publicstaticvoidmain(Stringargs[]){intx=4;//*********Found**********System.out.println("x的值是："+(x_____________4?9.0:99.99));}}基本操作无题目10：基本操作无题目11：简单应用无题目1：importjava.io.*;publicclassJava_2{publicstaticvoidmain(String[]args)throwsIOException{FileinputFile;FileoutputFile;FileInputStreamin;FileOutputStreamout;intc;

inputFile=newFile("source.txt");outputFile=newFile("dest.txt");in=newFileInputStream(inputFile);//*********Found********out=newFileOutputStream(outputFile);while((c=in.read())!=-1)//*********Found********breakin;in.close();out.close();}}简单应用无题目2：importjava.text.*;publicclassJava_2{publicstaticvoidmain(String[]args){Person[]people=newPerson[2];people[0]=newWorker("老张",30000);people[1]=newStudent("小王","计算机科学");for(inti=0;i<people.length;i++){Personp=people[i];//*********Found**********System.out.println(____________________()+","+p.getDescription());}}}//*********Found**********________________classPerson{publicPerson(Stringn){name=n;}//*********Found**********public___________________StringgetDescription();publicStringgetName(){returnname;}privateStringname;}代码未完，见下一页//*********Found**********classWorker_________________Person{publicWorker(Stringn,doubles){super(n);salary=s;}publicStringgetDescription(){NumberFormatformatter=NumberFormat.getCurrencyInstance();return"工人，年薪是"+formatter.format(salary)+"。";}privatedoublesalary;}//*********Found**********classStudent_________________Person{publicStudent(Stringn,Stringm){super(n);major=m;}publicStringgetDescription(){return"学生，专业是"+major+"。";}privateStringmajor;}简单应用3：importjavax.swing.*;publicclassJava_2{publicstaticvoidmain(Stringargs[]){StringBufferbuf=newStringBuffer("你好!祝你成功!");Stringoutput="buf="+buf.toString()+"\nCharacterat0:"+buf.charAt(0)+"\nCharacterat4:"+buf.charAt(4);//*********Found**********charcharArray[]=newchar[buf.length()];//*********Found**********buf.____________________(0,buf.length(),charArray,0);output+="\n\n在字符串缓存中的字符是:";//*********Found**********for(inti=0;i<charArray.length();++i)output+=charArray[i];buf.setCharAt(0,'您');buf.setCharAt(6,'材');output+="\n\nbuf="+buf.toString();//*********Found**********buf.______________________;output+="\n\nbuf="+buf.toString();JOptionPane.showMessageDialog(null,output,"字符串缓存的字符相关方法示范",JOptionPane.INFORMATION_MESSAGE);System.exit(0);}}简单应用4：publicclassJava_2{publicstaticvoidmain(Stringargs[]){inti=0;//*********Found********String_____________={"HelloWorld!","Hello!","HELLOWORLD!!"};while(i<4){try{System.out.println(greetings[i]);}//*********Found********_________________(ArrayIndexOutOfBoundsExceptione){//*********Found********System.out.println("Catch"+_____________.getMessage());System.out.println("Endingtheprint.");}finally{System.out.println("---------------------");}//*********Found********_______________;}}}简单应用5：importjava.io.*;publicclassJava_2{publicstaticvoidmain(String[]args){bytebuf[]=newbyte[5];intlen=0,c1=0,c2=0;//*********Found**********______________________{//*********Found**********FileInputStreamin=_________________________("test.txt");while((len=in.read(buf,0,5))>0){for(inti=0;i<len;i++)if(buf[i]>='0'&&buf[i]<='9'){c1++;}elseif((buf[i]>='a'&&buf[i]<='z')||buf[i]>='A'&&buf[i]<='Z')c2++;if(len<5)break;}//*********Found**********in.______________();}catch(Exceptione){}System.out.println("数字数是"+c1+"，字母数是"+c2);}}简单应用无题目6：importjava.io.File;publicclassJava_2{publicstaticvoidmain(Strings[]){//GettingtheCurrentWorkingDirectoryStringcurDir=System.getProperty("user.dir");System.out.println("当前的工作目录是:"+curDir);

//*********Found**********Fileff=newFile(____________________);String[]files=ff.list();for(inti=0;i<files.length;i++){Stringss=curDir+"\\"+files[i];traverse(0,ss); }}/**递归地遍历目录树*@paramlevel目录的层次*@params当前目录路径名*/代码未完，见下一页publicstaticvoidtraverse(intlevel,Strings){Filef=newFile(s);for(inti=0;i<level;i++)System.out.print("");if(f.isFile()){System.out.println(f.getName());}elseif(f.isDirectory()){//*********Found**********System.out.println("<"+f._____________________+">");String[]files=f.list();level++;//*********Found**********for(inti=0;i<files.length;________________________){Stringss=s+"\\"+files[i];//*********Found**********traverse(_____________________,ss);}}else{System.out.println("ERROR!");}}}简单应用无题目7：

//*********Found********publicclassJava_2____________FrameimplementsActionListener{publicstaticvoidmain(Stringargs[]){Java_2fr=newJava_2("Hello!");fr.setLayout(newFlowLayout());fr.setSize(200,100);fr.setBackground(Color.blue);Buttonb=newButton("确定");//*********Found********b._____________________(newJava_2());fr.add(b);fr.setVisible(true);}publicvoidactionPerformed(ActionEvente){System.exit(0);}publicJava_2(Stringstr){super(str);}publicJava_2(){}}简单应用8：publicclassJava_2{publicstaticvoidmain(Stringargs[]){try{Sleepa=newSleep();Threadt=newThread(a);//*********Found**********t.start();t.join();intj=a.i;System.out.println("j="+j+",a.i="+a.i);}catch(Exceptione){}}}//*********Found**********classSleepimplementsRunnable{inti;publicvoidrun(){try{//*********Found**********Thread.sleep(50);i=10;}catch(InterruptedExceptione){}}}简单应用9：importjava.awt.*;importjavax.swing.*;//*********Found********publicclassJava_2extends________________{publicvoidinit(){ContainercontentPane=getContentPane();JLabellabel=newJLabel("Java的诞生是对传统计算模式的挑战！",SwingConstants.CENTER);contentPane.add(label);}}简单应用无题目10：简单应用无题目11：代码未完，见下一页综合运用无题目1.importjavax.swing.JOptionPane;publicclassJava_3{publicstaticvoidmain(Stringargs[]){StringfirstNumber,//用户输入第1个字符串

secondNumber,//用户输入第2个字符串

result;//astringcontainingtheoutputintnumber1,//比较的第1个数

number2;//比较的第2个数

//读用户输入的第1个字符串readfirstnumberfromuserasastringfirstNumber=JOptionPane.showInputDialog("Enterfirstinteger:");//读用户输入的第2个字符串readsecondnumberfromuserasastringsecondNumber=JOptionPane.showInputDialog("Entersecondinteger:");//将字符串类型转换成整数类型

number1=Integer.parseInt(firstNumber);number2=Integer.parseInt(secondNumber);result="";

代码未完，见下一页//*********Found********if(number1==number2)//本行有错需修改

result=number1+"=="+number2;if(number1!=number2)result=number1+"!="+number2;if(number1<number2)result=result+"\n"+number1+"<"+number2;if(number1>number2)result=result+"\n"+number1+">"+number2;if(number1<=number2)result=result+"\n"+number1+"<="+number2;//*********Found********if(number1>=number2)//本行有错需修改

result=result+"\n"+number1+">="+number2;//显示结果

//*********Found********JOptionPane.showMessageDialog(null,result,"ComparisonResults",//*********Found********Font.INFORMATION_MESSAGE);//程序正常退出

//*********Found********System.exit(0);}}/*JOptionPane类的常用静态方法如下：

showInputDialog()showConfirmDialog()showMessageDialog()showOptionDialog()*/综合运用无题目2.importjava.awt.*;importjava.awt.event.*;importjava.io.*;importjavax.swing.*;publicclassJava_3{publicstaticvoidmain(String[]args){JFrameframe=newImageViewerFrame();frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);frame.setVisible(true);}}classImageViewerFrameextendsJFrame{publicImageViewerFrame(){setTitle("ImageViewer");setSize(DEFAULT_WIDTH,DEFAULT_HEIGHT);label=newJLabel();ContainercontentPane=getContentPane();contentPane.add(label,BorderLayout.CENTER);chooser=newJFileChooser();chooser.setCurrentDirectory(newFile("."));JMenuBarmenuBar=newJMenuBar();setJMenuBar(menuBar);JMenumenu=newJMenu("File");menuBar.add(menu);JMenuItemopenItem=newJMenuItem("Open");

代码未完，见下一页//*********Found**********_______________.add(openItem);//*********Found**********openItem.___________________________(newActionListener(){publicvoidactionPerformed(ActionEventevt){intr=chooser.showOpenDialog(null);if(r==JFileChooser.APPROVE_OPTION){//*********Found**********Stringname=__________________.getSelectedFile().getPath();label.setIcon(newImageIcon(name));}}});labelT=newJLabel("红军不怕远征难");labelT.setFont(newFont("隶书",Font.PLAIN,DEFAULT_SIZE));contentPane.add(labelT,BorderLayout.NORTH);faceCombo=newJComboBox();faceCombo.setEditable(true);faceCombo.addItem("隶书");faceCombo.addItem("华文新魏");faceCombo.addItem("华文行楷");faceCombo.addItem("华文隶书");

代码未完，见下一页//*********Found**********faceCombo.________________________(newActionListener(){publicvoidactionPerformed(ActionEventevent){//*********Found**********labelT.setFont(newFont((String)____________________.getSelectedItem(),Font.PLAIN,DEFAULT_SIZE));}});JPanelcomboPanel=newJPanel();comboPanel.add(faceCombo);contentPane.add(comboPanel,BorderLayout.SOUTH);}privateJLabellabel;privateJLabellabelT;privateJFileChooserchooser;privateJComboBoxfaceCombo;privatestaticfinalintDEFAULT_SIZE=24;publicstaticfinalintDEFAULT_WIDTH=570;publicstaticfinalintDEFAULT_HEIGHT=400;}综合运用3.//Java_3.java:二分法检索算法importjava.util.*;publicclassJava_3{privateStringcolors[]={“红”,“白”,“蓝“,"黑","黄","紫","茶色","粉红"};privateArrayListaList;//ArrayList引用

publicJava_3(){aList=newArrayList(Arrays.asList(colors));Collections.sort(aList);//ArrayList分类

System.out.println("对ArrayList分类:"+aList);}publicvoidprintSearchResults(){printSearchResultsHelper(colors[3]);//首项

printSearchResultsHelper(colors[0]);//中间项

printSearchResultsHelper(colors[7]);//最后项

printSearchResultsHelper("绿");//最低

printSearchResultsHelper("灰");//不存在

//*********Found********printSearchResultsHelper("____________");//不存在

}privatevoidprintSearchResultsHelper(Stringkey){intresult=0;System.out.println("\n检索关键字:"+key);result=Collections.binarySearch(aList,key);System.out.println((result>=0?"找到下标"+result:"没有找到("+result+")"));}publicstaticvoidmain(Stringargs[]){//*********Found********newJava_3().____________________________;}}综合运用4//程序的功能是，判断用户以命令行方式键盘输入的路径类名是否在Java类库中。publicclassJava_3{publicstaticvoidmain(String[]args){StringclassName;if(args.length>0)className=args[0];elseclassName="java.lang.Name";//*********Found********____________//*********Found********{Classc=Class.forName(_______________);System.out.println(className+"是Java类库中已有的类。");}//*********Found********catch(ClassNotFound_______________e){System.out.println(className+"不在Java类库中。");}}}综合运用5importjava.io.*;publicclassJava_3{publicstaticintdata[]={32,18,41,23,2,56,36,67,59,20};publicstaticvoidmain(Stringargs[]){inti;//*********Found**********intindex=data.__________________;System.out.println("排序前:");for(i=0;i<index;i++)System.out.print(""+data[i]+"");System.out.println();//*********Found**********BubbleSort(_________________);System.out.println("排序后:");for(i=0;i<index;i++)System.out.print(""+data[i]+"");System.out.println();}//冒泡法排序

publicstaticvoidBubbleSort(intindex){inti,j;inttemp;for(j=1;j<index;j++){for(i=index-1;i>=j;i--){ if(data[i]<data[i-1]){//比较相邻的两个数

temp=data[i];data[i]=data[i-1];//*********Found**********data[i-1]=__________________;}}}}}综合运用无题目6importjavax.swing.*;importjava.awt.*;importjava.awt.event.*;//*********Found**********publicclassJava_3extends__________________implementsActionListener{privateJFrameframe;privateJTextFieldname;privateJPasswordFieldpass;privateJLabelnameLabel;privateJLabelpassLabel;privateJPaneltextPanel;privateJPanellabelPanel;privateJButtonbutton;privateJTextAreatextArea;

publicvoidinitGUI(){frame=newJFrame("FramewithDialog");//*********Found**********frame.________________(this);button=newJButton("JDialog");//*********Found**********button._______________(this);textArea=newJTextArea("",3,10);

frame.getContentPane().add(textArea,BorderLayout.CENTER);frame.getContentPane().add(button,BorderLayout.NORTH);

frame.setSize(400,300);frame.setVisible(true); }代码未完，见下一页publicvoidactionPerformed(ActionEvente){finalJDialogdia=newJDialog(frame,"logininformation");JButtonok=newJButton("ok");ok.addActionListener(newActionListener(){publicvoidactionPerformed(ActionEvente){textArea.setText("");textArea.append("name:"+name.getText()+"\r\n");textArea.append("passWord:"+newString(pass.getPassword())+"\r\n");//*********Found**********dia.setVisible(________________);//隐藏对话框

}}); name=newJTextField("",10);pass=newJPasswordField("",10); pass.setEchoChar('*');textPanel=newJPanel();textPanel.setLayout(newGridLayout(2,1,10,10));textPanel.add(name);textPanel.add(pass);

nameLabel=newJLabel("name");passLabel=newJLabel("passWord");labelPanel=newJPanel();labelPanel.setLayout(newGridLayout(2,1,20,20));labelPanel.add(nameLabel);labelPanel.add(passLabel);

代码未完，见下一页dia.getContentPane().add(labelPanel,BorderLayout.WEST);dia.getContentPane().add(textPanel,BorderLayout.CENTER); dia.getContentPane().add(ok,BorderLayout.SOUTH);dia.setSize(200,130);dia.setVisible(true);}

publicvoidwindowClosing(WindowEventevent){frame.setVisible(false);System.exit(0);}

publicstaticvoidmain(Stringargs[]){Java_3example=newJava_3();//*********Found**********example.____________;}}综合运用7importjava.text.*;publicclassJava_3{publicstaticvoidmain(String[]args){Personp=newStudent("王甜甜","计算机科学");System.out.println(p.getName()+","+p.getDescription());}}abstractclassPerson{publicPerson(Stringn){name=n;}//*********Found********public_______________StringgetDescription();publicStringgetName(){returnname;}privateStringname;}//*********Found********classStudent___________Person{publicStudent(Stringn,Stringm){super(n);major=m;}//*****