實(shí)驗(yàn)項(xiàng)目編號(hào)實(shí)驗(yàn)項(xiàng)目名稱 Java語(yǔ)言面向?qū)ο蠡A(chǔ)編程實(shí)驗(yàn)學(xué)時(shí)實(shí)驗(yàn)日期成績(jī)實(shí)驗(yàn)地點(diǎn)指導(dǎo)老師實(shí)驗(yàn)四 Java語(yǔ)言面向?qū)ο蠡A(chǔ)編程一、實(shí)驗(yàn)?zāi)康?.理解Java語(yǔ)言是如何體現(xiàn)面向?qū)ο缶幊袒舅枷耄?.了解類的封裝方法，以及如何創(chuàng)建類和對(duì)象，3.了解成員變量和成員方法的特性。二、實(shí)驗(yàn)內(nèi)容1.類的定義、封裝和對(duì)象創(chuàng)建的使用。編寫(xiě)一個(gè)Java應(yīng)用程序，該程序中有3個(gè)類：Trangle、Leder和Circle，分別用來(lái)刻畫(huà)“三角形”、“梯形”和“圓形”。具體要求如下：（1）Trangle類具有類型為double的三個(gè)邊，以及周長(zhǎng)、面積屬性，Trangle類具有返回周長(zhǎng)、面積以及修改三個(gè)邊的功能。另外，Trangle類還具有一個(gè)boolean型的屬性，該屬性用來(lái)判斷三個(gè)屬能否構(gòu)成一個(gè)三角形。（2）Lader類具有類型double的上底、下底、高、面積屬性，具有求面積的功能。（3）Circle類具有類型為double的半徑、周長(zhǎng)和面積屬性，具有求周長(zhǎng)、面積的功能。package exercise;class Trangledouble sideA,sideB,sideC,area,length;boolean boo;/帶三個(gè)參數(shù)的構(gòu)造函數(shù)public Trangle(double a,double b,double c) sideA=a;/參數(shù)a,b,c 分別賦值給sideA,sideB,sideCsideB=b;sideC=c;if(sideA+sideB>sideC && sideA+sideC>sideB && sideB+sideC>sideA) /a,b,c 構(gòu)成三角形的條件表達(dá)式boo=true;/給boo 賦值。elseboo=false;/給boo 賦值。double getLength()return sideA+sideB+sideC;/方法體，要求計(jì)算出length 的值并返回/計(jì)算三角形的面積public double getArea()if(boo)double p=(sideA+sideB+sideC)/2.0;area=Math.sqrt(p*(p-sideA)*(p-sideB)*(p-sideC);return area;elseSystem.out.println("不是一個(gè)三角形,不能計(jì)算面積");return 0;public void setABC(double a,double b,double c)sideA=a;/參數(shù)a,b,c 分別賦值給sideA,sideB,sideCsideB=b;sideC=c;if(sideA+sideB>sideC && sideA+sideC>sideB && sideB+sideC>sideA)/a,b,c 構(gòu)成三角形的條件表達(dá)式boo=true;/給boo 賦值。 else boo=false;/給boo 賦值。/定義一個(gè)梯形類class Laderdouble above,bottom,height,area;Lader(double a,double b,double h)above=a;/方法體，將參數(shù)a,b,c 分別賦值給above,bottom,heightbottom=b;height=h;double getArea()return (above+bottom)*height/2.0;/方法體，,要求計(jì)算出area 返回/定義一個(gè)圓類class Circle double radius,area;Circle(double r)radius=r;/方法體double getArea() return Math.PI*Math.pow(radius, 2);/方法體，要求計(jì)算出area 返回double getLength()return 2*Math.PI*radius;/getArea 方法體的代碼,要求計(jì)算出length 返回void setRadius(double newRadius) radius=newRadius;double getRadius() return radius;public class shiyan4_1public static void main(String args)double length,area;Circle circle=null;Trangle trangle;Lader lader; circle=new Circle(3);/創(chuàng)建對(duì)象circle trangle=new Trangle(6,5,2);/創(chuàng)建對(duì)象trangle。 lader=new Lader(8,9,6);/創(chuàng)建對(duì)象laderlength=circle.getLength();/ circle 調(diào)用方法返回周長(zhǎng)并賦值給lengthSystem.out.println("圓的周長(zhǎng):"+length);area=circle.getArea();/ circle 調(diào)用方法返回面積并賦值給areaSystem.out.println("圓的面積:"+area);length=trangle.getLength();/ trangle 調(diào)用方法返回周長(zhǎng)并賦值給lengthSystem.out.println("三角形的周長(zhǎng):"+length);area=trangle.getArea();/ trangle 調(diào)用方法返回面積并賦值給areaSystem.out.println("三角形的面積:"+area);area=lader.getArea();/ lader 調(diào)用方法返回面積并賦值給areaSystem.out.println("梯形的面積:"+area);trangle=new Trangle(12,34,1);/ trangle 調(diào)用方法設(shè)置三個(gè)邊，要求將三個(gè)邊修改為12,34,1。area=trangle.getArea();/ trangle 調(diào)用方法返回面積并賦值給areaSystem.out.println("三角形的面積:"+area);length=trangle.getLength();/ trangle 調(diào)用方法返回周長(zhǎng)并賦值給lengthSystem.out.println("三角形的周長(zhǎng):"+length);2實(shí)例成員與類成員的使用。按程序模板的要求編寫(xiě)源文件，要特別注意程序的輸出結(jié)果，并能正確解釋輸出的結(jié)果。package exercise;class Afloat a;static float b;void setA(float A)a = A;void setB(float B)b = B;float getA()return a;float getB()return b;void outputA()System.out.println(a);static void outputB()System.out.println(b);public class shiyan4_2 SuppressWarnings("static-access")public static void main(String args) / TODO Auto-generated method stubA.b = 100;A.outputB();A cat = new A();A dog = new A();cat.setA(200);cat.setB(400);dog.setA(150);dog.setB(300);cat.outputA();cat.outputB();dog.outputA();dog.outputB();3.方法中參數(shù)傳遞的練習(xí)在其它語(yǔ)言中，函數(shù)調(diào)用或過(guò)程調(diào)用時(shí)參數(shù)有傳值調(diào)用和傳地址調(diào)用之分。在Java 中，方法中的參數(shù)傳遞可以分為傳值調(diào)用或?qū)ο蠓椒ㄕ{(diào)用等方式。傳值調(diào)用即傳遞的參數(shù)是基本數(shù)據(jù)類型，調(diào)用方法時(shí)在方法中將不能改變參數(shù)的值，這意味著只能使用它們。對(duì)象調(diào)用是指先調(diào)用對(duì)象，再調(diào)用對(duì)象的方法，這種方式可以修改允許存取的成員變量。所以，如果不想改變參數(shù)的值，可以采用傳值調(diào)用的方法。如果想改變參數(shù)的值，可采用對(duì)象調(diào)用的方法，間接修改參數(shù)的值。（1）編寫(xiě)一個(gè)傳值調(diào)用的程序文件SY3_3.java。程序功能：程序首先給整型變量x 和y 賦一個(gè)初值10，然后使用傳值調(diào)用方式調(diào)用方法ff1 對(duì)x 和y 做乘方及輸出x 和y 的乘方值，最后再輸出x 和y 的乘方值。package exercise;public class shiyan4_3 public static void main(String args) / TODO Auto-generated method stubint x = 10, y = 10;swap(x, y);System.out.println("x = " + x + ", y = " + y);static void swap(int passX, int passY)passX = passX * passX;passY = passY * passY;System.out.println("passX = " + passX + ", passY = " + passY);（2）編寫(xiě)一個(gè)調(diào)用對(duì)象方法的程序文件SY3_4.java。package exercise;public class shiyan4_4 public static void main(String args) / TODO Auto-generated method stubPower p = new Power();p.swap(p.x, p.y);System.out.println("方法調(diào)用后 x = " + p.x + ", y = " + p.y);class Powerint x = 10, y = 10;void swap(int passX, int passY)System.out.println("初始時(shí) x = " + x + ", y = " + y);x = passX * passX;y = passY * passY;System.out.println("方法調(diào)用中 x = " + x + ", y = " + y);4定義一個(gè)名為MyRectangle的矩形類，類中有4 個(gè)私有的整型域，分別是矩形的左上角坐標(biāo)（xUp,yUp）和右下角坐標(biāo)（xDown,yDown）；類中定義沒(méi)有參數(shù)的構(gòu)造方法和有4 個(gè)int參數(shù)的構(gòu)造方法，用來(lái)初始化類對(duì)象。類中還有以下方法：getW( )計(jì)算矩形的寬度；getH( )計(jì)算矩形的高度；area( )計(jì)算矩形的面積；toString( )把矩形的寬、高和面積等信息作為為字符串返回。編寫(xiě)應(yīng)用程序使用MyRectangle類。package exercise;class MyRectangleprivate int xUp, yUp;private int xDown, yDown;public MyRectangle()xUp = yUp = xDown = yDown = 0;public MyRectangle(int xu, int yu, int xd, int yd)xUp = xu;yUp = yu;xDown = xd;yDown = yd;public int getW()return Math.abs(xUp - xDown);public int getH()return Math.abs(yUp - yDown);public int area()return this.getW() * this.getH();public String toString()String tempStr = "width = " + this.getW() + " height = " + this.getH() + " area = " + this.area();return tempStr;public class shiyan4_5public static void main(String args) / TODO Auto-generated method stubMyRectangle tempRec1 = new MyRectangle();MyRectangle tempRec2 = new MyRectangle(-1, 5, 4, 7);System.out.println("This first rectangle information " + tempRec1.toString();System.out.println("This second rectangle information " + tempRec2.toString();5請(qǐng)定義一個(gè)名為Card 的撲克牌類，該類有兩個(gè)private 訪問(wèn)權(quán)限的字符串變量face 和suit：face 描述一張牌的牌面值（如："Ace", "Deuce", "Three","Four","Five", "Six", "Seven", "Eight", "Nine", "Ten", "Jack", "Queen", "King"）；suit描述一張牌的花色（如："Hearts", "Diamonds", "Clubs", "Spades"）。定義Card 類中的public 訪問(wèn)權(quán)限的構(gòu)造方法，為類中的變量賦值；定義protected 訪問(wèn)權(quán)限的方法getFace()，得到撲克牌的牌面值; 定義protected 訪問(wèn)權(quán)限的方法getSuit()，得到撲克牌的花色; 定義方法toString()，返回表示撲克牌的花色和牌面值字符串（如“Ace ofHearts”、“Ten of Clubs”等）。package exercise;class Cardprivate String face;private String suit;public Card(String f, String s)face = f;suit = s;protected String getFace()return face;protected String getSuit()return suit;public String toString()return face + " of " + suit;public class shiyan4_6public static void main(String args) / TODO Auto-generated method stubCard card1 = new Card("Ace", "Hearts");Card card2 = new Card("Ten", "Clubs");System.out.println(card1.toString();System.out.println(card2.toString();6設(shè)計(jì)一個(gè)Worker 類，其成員變量有：身份證號(hào)、姓名、性別、年齡、入職時(shí)間、工資/月、獎(jiǎng)金/月、加班費(fèi)/月、電話費(fèi)/月、生活費(fèi)/月、交通費(fèi)/月、房租/月；用構(gòu)造方法進(jìn)行初始化；其他成員方法：輸出工人信息的方法（包括輸出凈收入），當(dāng)某個(gè)信息沒(méi)有被賦值（初始化）時(shí)，輸出信息為“未知”；計(jì)算總收入的方法，總收入中要考慮扣除國(guó)家現(xiàn)行的個(gè)人所得稅法規(guī)定的稅金；計(jì)算總支出的方法。package exercise;class Workerprivate String number;private String name;private String sex;private int age;private String entry;private double salary;private double bonus;private double overtimeMoney;private double phoneMoney;private double liveMoney;private double trafficMoney;private double rent;public Worker()number = name = sex = entry = ""age = 0; salary = bonus = overtimeMoney = phoneMoney = liveMoney = trafficMoney = rent = 0;public Worker(String num, String nam, String se,int ag, String ent, double sal, double bon,double ove, double pho, double liv, double tra, double ren)number = num;name = nam;sex = se;age = ag;entry = ent;salary = sal;bonus = bon;overtimeMoney = ove;phoneMoney = pho;liveMoney = liv;trafficMoney = tra;rent = ren;public void showInfo()if(number.equals("")System.out.println("");elseSystem.out.println(number + "member infomation list :");System.out.println(name);System.out.println(sex);System.out.println(age);System.out.println(entry);double money = salary + bonus + overtimeMoney - phoneMoney - liveMoney - trafficMoney - rent;System.out.println(money);public class shiyan4_7 public static void main(String args) Worker worker1 = new Worker();Worker worker2 = new Worker("0715646", "leafspace", "women", 22, "20160901", 5000, 500, 1200, 50, 800, 150, 1500);worker1.showInfo();worker2.showInfo();7設(shè)計(jì)一個(gè)汽車Car類，其成員變量有：商標(biāo)、型號(hào)、系列、箱式（三廂、兩廂）、顏色、出廠日期、門(mén)數(shù)、排量、價(jià)格、可優(yōu)惠價(jià)、百公里耗油量、最高時(shí)速、最大功率、最大扭矩、加速時(shí)間、剎車距離；用構(gòu)造方法進(jìn)行初始化；其他成員方法：輸出汽車信息的方法，當(dāng)某個(gè)信息沒(méi)有被賦值（初始化）時(shí)，輸出信息為“未知”；計(jì)算行駛一定距離總耗油量，以及給定油價(jià)計(jì)算燃油費(fèi)用的方法。package exercise;class Carprivate String logo;private String model;private String series;private String boxN;private String color;private String outDate;private int doorN;private long outN;private double price;private double sellprice;private double oil;private int speed;private double maxpower;private double maxspace;private double time;private double tspace;public Car(String log, String mod, String ser, String box, String col, String outd,int doorn, long outn, double pri, double sell, double oi, int spe, double maxpo, double maxsp, double tim, double tsp)logo = log;model = mod;series = ser;boxN = box;color = col;outDate = outd;doorN = doorn;outN = outn;price = pri;sellprice = sell;oil = oi;speed = spe;maxpower = maxpo;maxspace = maxsp;time = tim;tspace = tsp;public void showInfo()System.out.println(logo);System.out.println(model);System.out.println(series);System.out.println(boxN);System.out.println(color);System.out.println(outDate);System.out.println(doorN);System.out.println(outN);System.out.println(price);System.out.println(sellprice);System.out.println(oil);System.out.println(speed);System.out.println(maxpower);System.out.println(maxspace);System.out.println(time);System.out.println(tspace);public double outoil(int length)return oil / 100 * length;public double selmoney(int length)return 80 * outoil(length);public class shiyan4_8 public static void main(String args) / TODO Auto-generated method stubCar car = new Car("abc", "abcd", "asfag", "asdg", "sadh", "sdaf",10, 4665, 165, 1561, 165, 1651, 64, 4894, 894, 151);car.showInfo();三、實(shí)驗(yàn)心得通過(guò)本次試驗(yàn)，我理解了Java語(yǔ)言是如何體現(xiàn)面向?qū)ο缶幊袒舅枷爰邦惖姆庋b方法，以及如何創(chuàng)建類和對(duì)象。