java程序类方法的使用

The Second Experiment Java Object-Oriented programmingQ1. Design a class named Point3D, which is the subclass of Point2D discussed in the class. Besides the coordinates variables, the methods that support coordinates setting/getting, distance calculation and coordinates shifting should be provided.Java codes:package oop_java;public class point2D protected double x;protected double y;void Point2D(double x2, double y2) x = 0;y = 0;point2D(double x,double y) this.x = x;this.y = y;/These are two constructors and they are used to initialize. public double Distance() return Math.sqrt(x*x+y*y);package oop_java;public class point3D extends point2D/The point3d have inherited point2D.private double z;point3D(double x, double y,double z) super(x, y);/Point3D invoked the constructor of point2D by using “super”.this.z=z;/The variable “z” need to be initialized in point3D.public void setxy(double x,double y,double z)this.x=x;this.y=y;this.z=z;/This is the method of setting.public double getx()return x;public double gety()return y;public double getz()return z;/These are methods of getting.public double Distance() return Math.sqrt(x*x+y*y+z*z);/The method of Distance can get the result of the distance of two points.public double Distance(double a,double b,double c)return Math.sqrt(a-x)*(a-x)+(b-y)*(b-y)+(c-z)*(c-z);/This is the overloading of Distance.We can get the distance of (x,y,z) and (a,b,c).public void symmetry(double h,double i,double j) x=-h; y=-i; z=-j;/It is the method to get the coordinates after symmetry by (0.0). public void shift(double d,double e,double f)x=x+d;y=y+e;z=z+f;package oop_java;public class usepoint public static void main(String args) point2D p1 = new point2D(2.3,4.1);System.out.println(the distance between p1 and (0.0) is + + p1.Distance();point3D p2=new point3D(3.2,2.1,5.2);/We can define a new object by using “new”.System.out.println(the distance between p2 and (0.0) is + + p2.Distance(); point3D p3=new point3D(2.1,3.4,1.9); System.out.println(the distance between p2 and p3 is + + p2.Distance(2.1,3.4,1.9); point3D p4=new point3D(2.0,3.0,4.0); p4.symmetry(2.0,3.0,4.0); System.out.println(the coordinates after symmetry is + +(+p4.getx()+,+p4.gety()+,+p4.getz()+);/The method symmetry doesnt have the result,so we can get the result by using getting ways. point3D p5=new point3D(2.1,3.5,8.4); p5.shift(2.0,2.0,2.0); System.out.println(the coordinates after shifting is + +(+p5.getx()+,+p5.gety()+,+p5.getz()+);Screen shots: Fig 1.1 Q2. Design a class that provides the methods below:2.1 check whether an integer is an even.2.2 check whether a value is positive.2.3 return the times that a specified substring appears in a string.2.4 sort an array by bubble and selection algorithms.2.5 Left shift an array by K bits, i.e., left shift the array 2,4,6,8 by 2 bits, the array becomes 6,8,2,4.2.6 right shift an array by K bits, just like check whether an integer is a palindrome.2.8 split a double value into its integral part and fractional part.Java codes:/this class includes many methods.package oop_java;public class some_methods int x=2;public void even(int x) if(x%2=0) System.out.println(x+ +is an even); else System.out.println(x+ +is not an even); /The even method is used to check whether a number is an even. public void positive(int y) if (y0) System.out.println(y+ +is an positive); else System.out.println(y+ +is not an positive); /The methods positive is used to check whether a number is positive. public int times(String s,String sub) int n=0;/n is the total number of all the times that the substring appears in the string S. int position=0; while (s.indexOf(sub,position)=0)/The method indexof returns the position where the sub string appears first. n+; position=s.indexOf(sub,position)+sub.length(); /Set the position to where the position of the sub string and add the length of the sub string. return n; /The method bubblesort is used to sort the array. public void bubblesort() int A=2,3,28,14,23,8,76,44; for (int i = 0; i 8; i+) for (int j = i; j Aj) int t = Ai; Ai = Aj; Aj = t; /Compare each two numbers and set the smaller on the front .Traverse the whole array. for (int a= 0;a 8; a+) System.out.print(Aa + ,);/Output the array. System.out.println(); /It is another way to sort the array. public void selectionsort() int B=12,3,22,4,55,18,39,6; for(int i=0;i8;i+) int min = i; for(int j=i+1;j8;j+) if(BjBmin) min = j; /Find the smallest number and put it in the first position.And find the smallest number in the rest number,and so on. int t= Bi; Bi = Bmin; Bmin=t; System.out.println(selection sort); for(int a=0;aB.length;a+) System.out.print(Ba+ ); /Output the array. System.out.println(); /This method is used to check whether a number is a palindrome.If it is a palindrome,return true. public boolean palindrome(int number) String num=String.valueOf(number);/The method of valueof is used to translate the string to number. return new StringBuffer(num).reverse().toString().equalsIgnoreCase(num); /If the flip of the number equals to the number itself,it is a palindrome. public void spilt( String s1) String str=234.45; String ss=str.split(.); for(String s:ss) System.out.println(s); /The method spilt is used to separate a double number into integral part and fractional part. public void shift() x=this.x;/The x is the number that the array will shift. int a=new int 5; a=new int2,4,6,8,10; for(int i=0;i5;i+) System.out.print(ai+);/Output the known array. System.out.println(); System.out.println(shift to left.); for(int i=0;i5;i+) if(i+1+x5) System.out.print(ai+x+1+);/First,output the last two numbers. else System.out.print(ax-4+i+);/Then output the first 5-x numbers. System.out.println(); System.out.println(shift to right.); for(int i=0;i5;i+) if(i+x5) System.out.print(ai+x+);/First output the numbers except the first 2 numbers. else System.out.print(ai-x-1+);/Then output the first 2 numbers. package oop_java;public class usesomemethod /Invoke all the methods in the main method.public static void main(String args) some_methods A=new some_methods();/Produce a instance by the class.A.even(131);A.positive(-32);String s=aababbabab;String sub=ab;System.out.println(the sub string appears+ +A.times(s,sub)+ times);A.bubblesort(); A.selectionsort(); System.out.println(1234321 is a palindrome is + A.palindrome(1234321); String s1=234.45; A.spilt(s1); A.shift(); Screen shots: Fig 2.1Q3. Design a class named student, and use List, ArrayList and Iterator to traverse all the students records.Java codes:package oop_java;public class student /Define all the variables.private String id;private String name;private int age;private String major;/Define all the setters and getters.public String getId() return id;/The getters have no parameter.public void setId(String id) this.id = id;/The setters have parameters.public String getName() return name;public void setName(String name) = name;public int getAge() return age;public void setAge(int age) this.age = age;public String getMajor() return major;public void setMajor(String major) this.major = major;package oop_java;import java.util.*;public class usestudent public static void main(String args) List v = new ArrayList();/Define a arraylist class to implement the interface of list.boolean done = true;Scanner sc = new Scanner(System.in);/Define a instance to input the record.System.out.println(please input students records:);while(done)student stu = new student();System.out.print(ID:);stu.setId(sc.next();System.out.print(Name:);stu.setName(sc.next();System.out.print(Age:);stu.setAge(sc.nextInt();System.out.print(Major:);stu.setMajor(sc.next();v.add(stu);System.out.print(Need add another student?(Y/N)?);if(sc.next().equals(N)done=false;/We use a condition to control the input.If the condition is met,We will continue to input the record.sc.close();System.out.println(students number: + v.size();/Output the size of the record.System.out.println(all students record by Iterator:);Iterator it = v.iterator();/Produce a iterator by the interface of Iterator.while(it.hasNext() /Check whether there is a record in the list by “it,hasNext”.student sr = it.next();System.out.println(ID: + sr.getId();System.out.println(Name: +sr.getName();System.out.println(Age: +sr.getAge();System.out.println(Major: +sr.getMajor();Screen shots: Fig 3.1Q4. Design a class named AddressBook, includes name, cell phone number, company and gender, and their setters/getters, use List, ArrayList and Iterator to:4.1 insert a new record.Screen shots: Fig 4.14.2 delete all the records named Jack.Screen shots: Fig 4.24.3 update the cell phone number toif the records name is Mary.Screen shots: Fig 4.34.4 output all the records which cell phone numbers take 139 as the prefix and names take M as the prefix.Screen shots: Fig 4.4Java codes:package oop_java;public class AddressBook /Define four variables.private String name;private String phonenum ; private String company;private String gender;/These are setters and getters.public String getName() return name;public void setName(String name) = name;public String getphonenum() return phonenum;public void setphonenum(String phonenum) this.phonenum =phonenum;public String getgender() return gender;public void setgender(String gender) this.gender = gender;public String getcompany() return company;public void setcompany(String company) pany = company;package oop_java;/Import all the packages you will use.import java.util.ArrayList;import java.util.Iterator;import java.util.List;import java.util.Scanner;public class useAddress public static void main(String args) List v = new ArrayList();/Define a arraylist class to implement the interface of list.Scanner sc = new Scanner(System.in);System.out.println(please input a new records:);AddressBook ab = new AddressBook();System.out.print(name);ab.setName(sc.next();System.out.print(phonenum);ab.setphonenum(sc.next();System.out.print(company);ab.setcompany(sc.next();System.out.print(gender);ab.setgender(sc.next();v.add(ab);sc.close();System.out.println(all the record by Iterator:);Iterator it = v.iterator();/Produce a iterator by the interface of Iterator. while(it.hasNext() AddressBook s = it.next();System.out.println(name + s.getName();System.out.println(phonenum +s.getphonenum();System.out.println(company +s.getcompany();System.out.println(gender +s.getgender();it = v.iterator();/Use iterator to traverse the array.while(it.hasNext() if(it.next().getName().equals(Jack)it.remove();/When the name is Jack,delete its record.Iteratora= v.iterator();a=v.iterator();while(a.hasNext() if(a.next().getName().equals(Mary)ab.setphonenum; ab.getphonenum();/When the name is Mary,invoke the setter and set her phone number to 1388888888. Iteratorb= v.iterator(); b=v.iterator(); while(b.hasNext() if(b.next().getName().startsWith(M, 1) &b.next().getphonenum().startsWith(139)/When name starts with M and the phone number starts with 139,output all his or her record. for(int i=0;iv.size();i+)System.out.println(name +v.get(i).getName();System.out.println(phonenum +v.get(i).getphonenum();System.out.println(company +v.get(i).getcompany();System.out.println(gender +v.get(i).getgender(); System.out.println(all the record by for:);for(int i=0;iv.size();i+)System.out.println(name +v.get(i).getName();System.out.println(phonenum +v.get(i).getphonenum();System.out.println(company +v.get(i).getcompany();System.out.println(gender +v.get(i).getgender();/Output the result by for cycle.Q5. Design an interface named Shape, which has a variable named shapeName, and two methods named perimeter and area, design two classes named rectangle and ellipse respectively to implement this interface.Java codes:package oop_java;public interface Shape final static String retangle=retangle;final static String ellipse =ellipse;public abstract void setShapeName(String shapeName);public abstract double ComputePerimeter();public abstract double ComputeArea();/Define a interface,and it includes three abstract methods.package oop_java;public class rectangle implements Shape/Define a rectangle class to implement the interface.private double x,y;private String ShapeName;rectangle(double x,double y)this.setSides(x,y);this.setShapeName(rectangle);private void setSides(double x, double y) if(x=0|y=0)System.out.println(the input is wrong); return;/The two sides of rectangle is positive.this.x=x;this.y=y;public double ComputePerimeter()return 2*(x+y);/Compute the perimeter of rectangle.public double ComputeArea()return x*y;/Compute the area of rectangle.public void setShapeName(String shapeName) this.ShapeName=rectangle;/Set its name.package oop_java