Java核心技術(shù)習(xí)題答案

1、Java核心技術(shù)習(xí)題答案馬志強(qiáng)張然李雷孝編清華大學(xué)出版社第一章Java語言概述3第二章Java語法基礎(chǔ)4第三章面向?qū)ο缶幊?5第四章數(shù)組38第五章高級類特性45第六章GUI編程51第七章集合框架62第九章集合框架77第十章IO流81第十一章JDBC訪問數(shù)據(jù)庫84第十二章線程85第十三章網(wǎng)絡(luò)編程90第一章Java語言概述一、選擇題1-5ABBBB6-8AAB二、填空題1. MyClassMyClass.class2. String數(shù)組(String)一3. javacA.javajavaA三、程序設(shè)計題1、搭建Java運(yùn)行環(huán)境，并寫一個Java程序打印輸出開始學(xué)習(xí)Java程序設(shè)計！”。1)首先安

2、裝JDK；2)配置環(huán)境變量path,classpath可配可不配；3)FirstJava.javapublicclassHelloWorldpublicstaticvoidmain(Stringargs)System.out.println("開始學(xué)習(xí)Java程序設(shè)計！")；2、修改下面四個Java源文件中的錯誤，使其能夠編譯和運(yùn)行。Test1.java：TestAnother1類不能再使用public修飾，一個源文件中只能有一個類或者接口用public修飾；Test2.java源文件中public修飾的類的名字為Testing2,和源文件名字不一致；Test3.javaT

3、est3類的main方法的形參類型為String口；Test4.javaTest4類的main方法必須使用static關(guān)鍵字修飾。第二章Java語法基礎(chǔ)一、選擇題1-5BCADB6-9DCCC二、填空題1. abc,al,_abc,_1a,ab1231 a,const,$abc,1abc,if,$#1sa,$_a,_$q12 .題目出現(xiàn)問題：代碼修改為ch=(char)(ch+1);結(jié)果為'B如果直接System.out.println(ch+1);結(jié)果為98。3 .true(M)false(假)4.45.22false26.m*20/100(double)m*20/100三、編程題1

4、、由命令行輸入一個成績，使用switch結(jié)構(gòu)求出成績的等級。A:90-100;B:8089;C:7079;D:6069;E:059。importjava.util.Scanner;publicclassIfElseTestpublicstaticvoidmain(String口args)Scannersc=newScanner(System.in);intgrade=sc.nextInt();if(grade<0|grade>100)System.out.println("aaaa");System.exit(0);inttemp=(int)Math.floor

5、(grade/10);switch(temp)case10:System.out.println("A");break;case9:System.out.println("A");break;case8:System.out.println("B");break;case7:System.out.println("C");break;case6:System.out.println("D");break;default:System.out.println("E");brea

6、k;3.1415小于 3.14162、計算圓周率：PI=44/3+4/5-4/7；打印出第一個大于的值。publicclassPITestpublicstaticvoidmain(Stringargs)doubleresult=0.0;for(inti=1;i+)doublem=4.0/(2*i-1);if(i%2)=0)result-=m;elseresult+=m;if(result>3.1415&&result<3.1416)System.out.println("result:"+result);break;3、輸入一個數(shù)據(jù)n,計算斐波那

7、契數(shù)列(Fibonacci)的第n個值。斐波那契數(shù)列：1、1、2、3、5、8、13、21、34、importjava.util.Scanner;publicclassFibonacciTestpublicstaticvoidmain(Stringargs)Scannersn=newScanner(System.in);intnum=sn.nextInt();inti=1;intn1=1,n2=1;while(i<=num)if(i=1|i=2)n2=1;elseinttemp=n2;n2=n1+n2;n1=temp;i+;System.out.println(n2);System.out

8、.println("第"+num+"個值為："+n2);4、計算多項(xiàng)式1-1/3+1/5-1/7+1/9的值。1)要求出前50項(xiàng)和值。2)要求出最后一項(xiàng)絕對值小于1e-5的和值。publicclassSumTestpublicstaticvoidmain(Stringargs)doublesum=0.0;for(inti=1;i<=50;i+)if(i%2=0)sum=sum-1.0/(2*i-1);elsesum=sum+1.0/(2*i-1);System.out.println("前50項(xiàng)和值:"+sum);doublei

9、tem=0.0;intj=1;sum=0.0;while(item<0.00001)item=1.0/(2*j-1);if(j%2=0)sum-=item;elsesum+=item;j+;System.out.println("最后一項(xiàng)絕對值小于1e-5的和值:"+sum);5、產(chǎn)生100個0-999之間的隨機(jī)整數(shù)，然后判斷這100個隨機(jī)整數(shù)哪些是素數(shù)，哪些不是？publicclassPrimeTestpublicstaticvoidmain(Stringargs)PrimeTestt=newPrimeTest();for(inti=0;i<100;i+)in

10、tnum=(int)(Math.random()*1000);if(t.isPrime(num)System.out.println(num+"是素數(shù)！");elseSystem.out.println(num+"不是素數(shù)！");System.out.println();publicbooleanisPrime(intnum)for(inti=2;i<=num/2;i+)if(num%i=0)System.out.println(num+"第一個被"+i+"整除！");returnfalse;returntr

11、ue;6、在屏幕上打印出n行的金字塔圖案，如，若n=3,則圖案如下：*importjava.util.Scanner;publicclassPrintStarpublicstaticvoidmain(Stringargs)Scannersn=newScanner(System.in);introws=sn.nextInt();for(inti=1;i<=rows;i+)for(intj=1;j<=rows-i;j+)System.out.print("");for(intk=1;k<=2*i-1;k+)System.out.print("*&qu

12、ot;);System.out.println();7、歌德巴赫猜想，任何一個大于六的偶數(shù)可以拆分成兩個質(zhì)數(shù)的和，打印出所有的可能。如輸入10，結(jié)果為：10=5+5；10=3+7。publicclassGedepublicstaticvoidmain(Stringargs)intn=Integer.parseInt(args0);if(n<=6|n%2!=0)System.out.println("錯誤的參數(shù)！")；return;Gedeg=newGede();/因?yàn)?不是素數(shù)，n-2是偶數(shù)，所以從3開始循環(huán)for(inti=3;i<=n/2;i+)if(i%2

13、=0)continue;if(g.isPrime(i)&&g.isPrime(n-i)System.out.println(i+"+"+(n-i)+"="+n);/*判斷num是否是素數(shù)*/publicbooleanisPrime(intnum)for(inti=2;i<=num/2;i+)if(num%i=0)returnfalse;returntrue;四、實(shí)訓(xùn)題萬年歷的設(shè)計與實(shí)現(xiàn)。本程序包含兩個類CalenderModelA和TestCalenderModelA。CalenderModelA實(shí)現(xiàn)了賽事日期設(shè)置等主要功能，程序文

14、件CalenderModelA.java。publicclassCalenderModelA/計算從公元始的天數(shù)publicintgetNumberOfDay(intyear,intmonth,intday)inttotal=0;intlimit=getTotalDaysOfMonth(year,month);if(day<=limit)for(inty=1;y<year;y+)total+=(this.isLeapYear(year)?366:365);for(intm=1;m<month;m+)total+=(this.getTotalDaysOfMonth(year,m

15、onth);total+=day;returntotal;elseSystem.out.println("您輸入的日期非法")；return-1;/打印萬年歷publicvoidshow(intyear,intmonth)inttotal=0;/計算從公元始到今年之前的總天數(shù)for(inty=1;y<year;y+)total+=(this.isLeapYear(y)?366:365);/計算今年到本月前的總天數(shù)for(intm=1;m<month;m+)total+=(this.getTotalDaysOfMonth(year,m);/計算本月1日是星期幾to

16、tal=total%7;intd1=(total+1)%7;intd2=this.getTotalDaysOfMonth(year,month);System.out.println("ttt"+year+"年"+month+"月");System.out.println("");Strings="日","一","二","三","四","五","六"for(inti=0;i&l

17、t;7;i+)System.out.print(si+"t");System.out.println();for(inti=0;i<d1;i+)System.out.print("t");/打印本月日歷for(inti=d1,j=1;i<d1+d2;i+,j+)System.out.print(j+"t");if(i+1)%7=0)System.out.println();System.out.println();/判斷是否為閏年publicbooleanisLeapYear(intyear)return(year%4=0

18、)&&(year%100!=0)|(year%400=0);/計算某年某月天數(shù)publicintgetTotalDaysOfMonth(intyear,intmonth)inttotal=0;switch(month)case1:case3:case5:case 7:case 8:case10:case12:total=31;break;case2:total=this.isLeapYear(year)?29:28;break;case4:case6:case9:case11:total=30;break;returntotal;TestCalenderModelA實(shí)現(xiàn)main

19、方法，具有輸入大賽起始和終止日期，輸出日歷，并計算大賽周期的功能。程序文件TestCalenderModelA.java。importjava.util.Scanner;publicclassTestCalenderModelApublicstaticvoidmain(Stringargs)Scannerscan=newScanner(System.in);System.out.print("請輸入年份：")；intyear=scan.nextInt();System.out.print("請輸入月份:");intmonth=scan.nextInt()

20、;System.out.println("月歷如下");CalenderModelAtestBegin=newCalenderModelA();testBegin.show(year,month);第三章面向?qū)ο缶幊桃?、選擇題1-5CABDD2-10DCCBC11-12CC二、填空題1 .Packagemypackage;2 .final3.Object4 .packageimportclass5 .c三、程序設(shè)計題2、按下列要求編寫程序： 創(chuàng)建Teacher類要求：Teacher類要描述姓名、年齡、薪水，類型分別為String、int、double 創(chuàng)建TeacherTe

21、st類要求：在TeacherTest類中創(chuàng)建Teacher的對象；為該對象的屬性（姓名、性別、年齡）賦值；將該對象的屬性（姓名、性別、年齡）輸出； 為Teacher類添加一個方法，用于在教師原有薪水的基礎(chǔ)上增加5000; 修改TeacherTest類，增加對教師增加薪水方法的調(diào)用，并將增加后的薪水值輸出。Teacher.java：publicclassTeacherpublicStringname;publicintage;publicdoublesalary;publicStringgetName()returnname;publicvoidsetName(Stringname)this.n

22、ame=name;publicintgetAge()returnage;publicvoidsetAge(intage)this.age=age;publicdoublegetSalary()returnsalary;publicvoidsetSalary(doublesalary)this.salary=salary;publicTeacher()publicTeacher(Stringname,intage,doublesalary)=name;this.age=age;this.salary=salary;publicvoidaddSalary()this.salary

23、=this.salary+5000;TeacherTest.java：publicclassTeacherTestpublicstaticvoidmain(Stringargs)Teacherteacher=newTeacher();teacher.age=35;="zhangsan"teacher.salary=1234.5;System.out.println(teacher.age);System.out.println();System.out.println(teacher.salary);teacher.addSa

24、lary();System.out.println(teacher.salary);3、定義一個Person類。 包含以下屬性：Stringname;intage;booleangender;Personpartner 定義marry(Personp)方法，代表當(dāng)前對象和p結(jié)女昏，如若可以結(jié)女昏，則輸出恭賀信息，否則輸出不能結(jié)婚原因。下列情況不能結(jié)婚：結(jié)婚年齡，男<24，女<22；3，某一方已婚。 定義測試類，來測試以上程序。publicclassPersonprivateStringname;privateintage;privatebooleangender;Personpar

25、tner;publicPerson(Stringname,intage,booleangender,Personpartner)=name;this.age=age;this.gender=gender;this.partner=partner;publicvoidmarry(Personp)if(this.gender=p.gender)System.out.println("同性不能結(jié)婚！");return;if(this.gender=true&&this.age<24)|(this.gender=false&&

26、this.age<22)|(p.gender=true&&p.age<24)|(p.gender=false&&p.age<22)System.out.println("沒有達(dá)到結(jié)女昏年齡！”)；return;if(this.partner!=null|p.partner!=null)System.out.println("有一方已經(jīng)結(jié)女昏！");return;System.out.println(+","++","+"祝你們新女昏愉快

27、！");this.partner=p;p.partner=this;publicstaticvoidmain(Stringargs)Personp1=newPerson供之琳”,23,false,null);Personp2=newPerson網(wǎng)德華”,26,true,null);Personp3=newPerson例,楠”,70,true,null);p1.marry(p2);p1.marry(p3);4、定義一個Animal類，該類有兩個私有屬性，name(代表動物的名字)和legs(代表動物的腿的條數(shù))。兩個構(gòu)造方法，一個無參，默認(rèn)給name賦值為AAA,給legs賦值為4；另

28、一個需要兩個參數(shù)，分別用這兩個參數(shù)給私有屬性賦值。兩個重載的move()方法，其中一個無參，在屏幕上輸出一行文字:XXXMoving!(XXX為該動物的名字)；另一個需要一個int參數(shù)n,在屏幕上輸出n次XXXMoving!publicclassAnimal1privateStringname;privateintlegs;publicAnimal1()="AAA"this.legs=4;publicAnimal1(Stringname,intlegs)super();=name;this.legs=legs;publicStringge

29、tName()returnname;publicvoidsetName(Stringname)=name;publicintgetLegs()returnlegs;publicvoidsetLegs(intlegs)this.legs=legs;publicvoidmove()System.out.println("Animalmoving!");publicvoidmove(intn)inti=1;while(i<=n)i+;5、定義一個Fish類，繼承自Animal類。legs賦XXX提供一個構(gòu)造方法，該構(gòu)造方法需要一個參數(shù)name,并給默認(rèn)值0

30、；覆蓋Animal類中的無參move()方法，要求輸出：Swimming!publicclassFishextendsAnimalprivateStringname;privateintlegs;publicFish(Stringname)=name;this.legs=0;publicvoidmove()System.out.println("Fishisswimming!");publicclassBirdextendsAnimalprivateStringname;privateintlegs;publicBird(Stringname)this.n

31、ame=name;this.legs=2;publicvoidmove()System.out.println("Birdisflying!");6、寫一個類Zoo,要求分別生成若干個Animal、Fish和Bird。并調(diào)用他們的屬性和方法。publicclassZoopublicstaticvoidmain(Stringargs)Animala=newAnimal("dog",4);a.move();a.move(3);Fishf=newFish("smallfish");f.move();Birdb=newBird("x

32、ique");b.move();Animalaf=newFish("smallfish");af.move();7、某公司的雇員分為以下若干類： Employee：這是所有員工總的父類，屬性：員工的姓名，員工的生日月份。方法：getSalary(intmonth)根據(jù)參數(shù)月份來確定工資，如果該月員工過生日，則公司會額外獎勵100元。 SalariedEmployee：Employee的子類，拿固定工資的員工。屬性：月薪； HourlyEmployee：Employee的子類，按小時拿工資的員工，每月工作超出160小時的部分按照1.5倍工資發(fā)放。屬性：每小時的工資、

33、每月工作的小時數(shù)； SalesEmployee：Employee的子類，銷售人員，工資由月銷售額和提成率決定。屬性：月銷售額、提成率。 BasedPlusSalesEmploye：eSalesEmployee的子類，有固定底薪的銷售人員，工資由底薪加上銷售提成部分。屬性：底薪。寫一個程序，把若干各種類型的員工放在一個Employee數(shù)組里，寫一個函數(shù)，打印出某月每個員工的工資數(shù)額。注意：要求把每個類都做成完全封裝，不允許非私有化屬性。classEmployeeprivateStringname;privateintmonth;publicEmployee(Stringname,intmonth

34、)=name;this.month=month;publicStringgetName()returnname;publicdoublegetSalary(intmonth)if(this.month=month)return100.0;return0.0;classSalariedEmployeeextendsEmployeeprivatedoublemonthSalary;publicSalariedEmployee(Stringname,intmonth,doublemonthSalary)super(name,month);this.monthSalary=month

35、Salary;publicdoublegetSalary(intmonth)returnmonthSalary+super.getSalary(month);classHourlyEmployeeextendsEmployeeprivateinthours;privatedoublehourSalary;publicHourlyEmployee(Stringname,intmonth,inthours,doublehourSalary)super(name,month);this.hours=hours;this.hourSalary=hourSalary;publicdoublegetSal

36、ary(intmonth)doubleresult;if(hours<=160)result=hours*hourSalary;elseresult=160*hourSalary+(hours-160)*1.5*hourSalary;returnresult+super.getSalary(month);classSalesEmployeeextendsEmployeeprivatedoublesalesCount;privatedoublerate;publicSalesEmployee(Stringname,intmonth,doublesalesCount,doublerate)s

37、uper(name,month);this.salesCount=salesCount;this.rate=rate;publicdoublegetSalary(intmonth)returnsalesCount*rate+super.getSalary(month);classBasedPlusSalesEmployeeextendsSalesEmployeeprivatedoublebasedPlus;publicBasedPlusSalesEmployee(Stringname,intmonth,doublesalesCount,doublerate,doublebasedPlus)su

38、per(name,month,salesCount,rate);this.basedPlus=basedPlus;publicdoublegetSalary(intmonth)returnbasedPlus+super.getSalary(month);publicclassEmployeeTestpublicstaticvoidmain(Stringargs)Employeee=newEmployee4;e0=newSalariedEmployee("zhangsan",9,3222.90);e1=newHourlyEmployee("lisi",5,

39、230,23.90);e2=newSalesEmployee("wangwu",11,2330000.0,0.005);e3=newBasedPlusSalesEmployee("zhaoliu",2,2000000.0,0.0001,3200.0);for(inti=0;i<e.length;i+)System.out.println(ei.getName()+""+"9月份的工資總額為："+ei.getSalary(9);四、實(shí)訓(xùn)題班級成績管理系統(tǒng)實(shí)體類設(shè)計。publicclassTestpublicst

40、aticvoidmain(Stringargs)Studentstu=newStudent("20101007001",姚明")；stu.setXueyuan('信息工程學(xué)院");stu.setZhuanye(軟件工程");stu.setBanjiC軟件10-1");Gradestugrade=newGrade();stugrade.setKcm("Web程序設(shè)計")；stugrade.setXq("2011-2012T)")；stugrade.setCj(90.5f);stu.getG

41、rades().addGrade(stugrade);stugrade=newGrade();/1口這旬的區(qū)另stugrade.setKcmC計算機(jī)網(wǎng)絡(luò)");stugrade.setXq("2011-2012(h)");stugrade.setCj(86.5f);stu.getGrades().addGrade(stugrade);stugrade=newGrade();/1口這旬的區(qū)另stugrade.setKcmC計算機(jī)組成原理");stugrade.setXq("2011-2012(h)");stugrade.setCj(66.

42、5f);stu.getGrades().addGrade(stugrade);stugrade=newGrade();/1口這旬的區(qū)另stugrade.setKcm('數(shù)據(jù)結(jié)構(gòu)");stugrade.setXq("2010-2011(h)");stugrade.setCj(76.5f);stu.getGrades().addGrade(stugrade);stugrade=newGrade();/1口這旬的區(qū)另stugrade.setKcm(數(shù)據(jù)庫原理");stugrade.setXq("2010-201lT)")；stugr

43、ade.setCj(76.5f);stu.getGrades().addGrade(stugrade);stugrade=newGrade();/1口這旬的區(qū)另stugrade.setKcm('高等數(shù)學(xué)(1)");stugrade.setXq("2009-2010(h)");stugrade.setCj(88.5f);stu.getGrades().addGrade(stugrade);stugrade=newGrade();/1口這旬的區(qū)另stugrade.setKcm('高等數(shù)學(xué)(2)");stugrade.setXq("2

44、009-2010T)")；stugrade.setCj(68.5f);stu.getGrades().addGrade(stugrade);stugrade=newGrade();/1口這旬的區(qū)另stugrade.setKcm(軟件工程專業(yè)外語");stugrade.setXq("2011-2012T)")；stugrade.setCj(88.0f);stu.getGrades().addGrade(stugrade);puteZc("2011-2012T)")；stu.getGrades().sortByxq();System.ou

45、t.println(stu);publicclassStudentpublicstaticlongid=20101007001l;privateStringsid;privateStringsname;privateStringxueyuan;/優(yōu)使用具體的字符串,然后轉(zhuǎn)化成編碼xyidprivateStringzhuanye;privateStringbanji;/privateGradeArraygrades;privateZcGradezcGrade;privatevoidautoId()id+;publicStudent()sid=newLong(id).toString();auto

46、Id();grades=newGradeArray();publicStudent(Stringsid)this(sid,null);publicStudent(Stringsid,Stringsname)this(sid,sname,null);publicStudent(Stringsid,Stringsname,Stringxueyuan)this.sid=sid;this.sname=sname;this.xueyuan=xueyuan;grades=newGradeArray();publicStringgetSid()returnsid;publicvoidsetSid(Strin

47、gsid)this.sid=sid;publicStringgetSname()publicvoidsetSname(Stringsname)this.sname=sname;publicStringgetXueyuan()returnxueyuan;publicvoidsetXueyuan(Stringxueyuan)this.xueyuan=xueyuan;publicStringgetZhuanye()returnzhuanye;publicvoidsetZhuanye(Stringzhuanye)this.zhuanye=zhuanye;publicStringgetBanji()re

48、turnbanji;publicvoidsetBanji(Stringbanji)this.banji=banji;publicGradeArraygetGrades()returngrades;publicvoidsetGrades(GradeArraygrades)this.grades=grades;publicZcGradegetZcGrade()returnzcGrade;publicvoidsetZcGrade(ZcGradezcGrade)this.zcGrade=zcGrade;publicvoidcomputeZc(Stringxqid)zcGrade=newZcGrade(

49、xqid);floatsum=0;for(inti=0;i<grades.getCurrent();i+)if(xqid.equals(grades.getGrade()i.getXq()sum+=grades.getGrade()i.getCj();zcGrade.setZcresult(sum);Overridepublicbooleanequals(Objectobj)/TODOAuto-generatedmethodstubbooleanresult=false;if(obj!=null)if(objinstanceofStudent)Studenttemp=(Student)o

50、bj;if(sid.equals(temp.sid)result=true;returnresult;OverridepublicStringtoString()/TODOAuto-generatedmethodstubStringresult=""+sid+"r"/*for(KsGradetemp:grades.getGrade()result+=""result+=temp;result+=","*/for(inti=0;i<grades.getCurrent();i+)result+="&qu

51、ot;result+=grades.getGrade()i;result+=""result+="r"/result=result.substring(0,result.length()-1);/醫(yī)掉最后一個逗號result+=zcGrade;result+=""returnresult;publicclassGradeprivateStringkcm;privateStringxq;privatefloatcj;publicGrade()super();publicGrade(Stringkcm)this(kcm,null);pub

52、licGrade(Stringkcm,Stringxq)this(kcm,xq,0.0f);publicGrade(Stringkcm,Stringxq,floatcj)this.kcm=kcm;this.xq=xq;this.cj=cj;publicfloatgetCj()returncj;publicvoidsetCj(floatcj)this.cj=cj;publicStringgetKcm()returnkcm;publicvoidsetKcm(Stringkcm)this.kcm=kcm;publicStringgetXq()returnxq;publicvoidsetXq(Stri

53、ngxq)this.xq=xq;OverridepublicStringtoString()/TODOAuto-generatedmethodstubreturnkcm+":"+xq+":"+cj;Overridepublicbooleanequals(Objectobj)/TODOAuto-generatedmethodstubbooleanresult=false;if(obj!=null)if(objinstanceofGrade)Gradetemp=(Grade)obj;if(kcm.equals(temp.kcm)result=true;ret

54、urnresult;publicclassGradeArraypublicfinalstaticintKECHMENSHU=50;privateGradegrades=newGradeKECHMENSHU;privateintcurrent=0;publicGradeArray()super();publicintgetCurrent()returncurrent;publicvoidsetCurrent(intcurrent)this.current=current;publicvoidaddGrade(Gradeg)/存在問題：課程重復(fù)if(current<KECHMENSHU)if

55、(!contain(g)gradescurrent+=g;publicGradegetGrade()returngrades;publicvoidsetGrade(Gradegrade)this.grades=grade;privatebooleancontain(Gradeg)booleanresult=false;for(inti=0;i<current;i+)if(gradesi.equals(g)result=true;break;returnresult;/增加成績的刪除、修改/按照學(xué)期排序課程publicvoidsortByxq()/冒泡排序for(inti=current-1;i>0;i-)for(intj=0;j<i;j+)if(gradesj.getXq().compareToIgnoreCase(gradesj+1.getXq()>0)Gradetemp=gradesj+1;gradesj+1=gradesj;gradesj=temp;importjava.util.Stack;publicclassGradeListStack/*paramargs*/privat