I have 2 classes
Mother and Newborn
Class Mother:
import java.util.ArrayList;
import java.util.List;
import java.util.Set;
public class Mother extends NewBorn {
private List<NewBorn> newBornList = new ArrayList<>();
private Set<NewBorn> children;
private int id;
private String name;
private int age;
public Mother(Mother mother, List<NewBorn> newBornList, Set<NewBorn> children, int id, String name, int age) {
super(mother);
this.newBornList = newBornList;
this.children = children;
this.id = id;
this.name = name;
this.age = age;
}
public Mother(int id, String name, int age) {
this.id = id;
this.name = name;
this.age = age;
}
public Mother(int id, String gender, String name, int birthdate, int weight, int height, List<NewBorn> newBornList, Set<NewBorn> children, int id1, String name1, int age) {
super(id, gender, name, birthdate, weight, height);
this.newBornList = newBornList;
this.children = children;
this.id = id1;
this.name = name1;
this.age = age;
}
public List<NewBorn> getNewBornList() {
return newBornList;
}
public void setNewBornList(List<NewBorn> newBornList) {
this.newBornList = newBornList;
}
public Set<NewBorn> getChildren() {
return children;
}
public void setChildren(Set<NewBorn> children) {
this.children = children;
}
#Override
public int getId() {
return id;
}
#Override
public void setId(int id) {
this.id = id;
}
#Override
public String getName() {
return name;
}
#Override
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
#Override
public String toString() {
return "Mother{" +
"newBornList=" + newBornList +
", children=" + children +
", id=" + id +
", name='" + name + '\'' +
", age=" + age +
'}';
}
}
Class NewBorn:
public class NewBorn {
private Mother mother;
public NewBorn(Mother mother) {
this.mother = mother;
}
public NewBorn() {
}
public Mother getMother() {
return mother;
}
public void setMother(Mother mother) {
this.mother = mother;
}
private int id;
private String gender;
private String name;
private int birthdate;
private int weight;
private int height;
private int motherId;
public NewBorn(int id, String gender, String name, int birthdate, int weight, int height) {
this.id = id;
this.gender = gender;
this.name = name;
this.birthdate = birthdate;
this.weight = weight;
this.height = height;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getGender() {
return gender;
}
public void setGender(String gender) {
this.gender = gender;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getBirthdate() {
return birthdate;
}
public void setBirthdate(int birthdate) {
this.birthdate = birthdate;
}
public int getWeight() {
return weight;
}
public void setWeight(int weight) {
this.weight = weight;
}
public int getHeight() {
return height;
}
public void setHeight(int height) {
this.height = height;
}
public int getMotherId() {
return motherId;
}
public void setMotherId(int motherId) {
this.motherId = motherId;
}
#Override
public String toString() {
return "NewBorn{" +
"mother=" + mother +
", id=" + id +
", gender='" + gender + '\'' +
", name='" + name + '\'' +
", birthdate=" + birthdate +
", weight=" + weight +
", height=" + height +
", motherId=" + motherId +
'}';
}
}
I have to get the mother older then 25years old that have child more then 4000g weigth
I did the following
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Comparator;
import java.util.List;
import java.util.stream.Collectors;
public class Main {
public static void main(String[] args) throws IOException {
List<Mother> motherabove = above25YoAndChildHeavierThen4000g(mothers, newBorns);
System.out.println("List with mothers above 25 years old and childs that are over 4000g weigth: " + motherabove + "\n");
}
public static List<Mother> parseMotherFileTxt() throws IOException {
List<Mother> mothers = new ArrayList<>();
BufferedReader bufferedReader = new BufferedReader(new FileReader("src\\mamy.txt"));
String line;
while ((line = bufferedReader.readLine()) != null) {
String[] s = line.split("\\s");
mothers.add(new Mother(Integer.parseInt(s[0]), s[1], Integer.parseInt(s[2])));
}
bufferedReader.close();
return mothers;
}
public static List<NewBorn> parseNewBornFileTxt() throws IOException {
List<NewBorn> newBorn = new ArrayList<>();
BufferedReader bufferedReader = new BufferedReader(new FileReader("src\\noworodki.txt"));
String line;
while ((line = bufferedReader.readLine()) != null) {
String[] s = line.split("\\s");
newBorn.add(new NewBorn(Integer.parseInt(s[0]), s[1], s[2], Integer.parseInt(s[4]), Integer.parseInt(s[5]), Integer.parseInt(s[6])));
}
bufferedReader.close();
return newBorn;
}
public static List<Mother> above25YoAndChildHeavierThen4000g(List<Mother> motherList, List<NewBorn> newBornList) {
return motherList.stream()
.filter(mother -> mother.getAge() > 25)//over 25yo
.filter(mother -> mother .getMotherId() == newBorn.getId())//get mother that have same id as child so assuming that means that this is the mother of the child
.filter(newBorn-> newBorn.getWeight() > 4000)//child over 4000g
.collect(Collectors.toList());// I expect to collect all the filters and return the correct output : Example Mother is : 112 Laura 38
and she have a child : 29 s Gabriel 1999-11-16 4100 54 112 = where 112 is the mother id that `I know is child of the mother`
}
I think something is wrong in the relation between the classes because I assume that the filter should work just fine if everything else is ok.
Normally should have mother has a list of children and a specific child has a field mother so with this I should be able to filter through.
I think you are looking for something like:
public static List<Mother> above25YoAndChildHeavierThen4000g(List<Mother> motherList, List<NewBorn> newBornList) {
return motherList.stream()
.filter(mother -> mother.getAge() > 25)
.filter(mother -> mother.getChildren().stream()
.anyMatch(child -> child.getWeight() > 4000))
.collect(Collectors.toList());
}
However the code overall definitely needs cleaning as advised in the comments
public List motherMoreThan() {
List list = new ArrayList<>();
for (Mother mother : mothers) {
if (mother.getAge() > 25 && isChildOver4000(mother)) {
list.add(mother);
}
}
return list;
}
public boolean isChildOver4000(Mother mother) {
for (Newborn newborn : mother.getList()) {
if (newborn.getWeight() > 4000) {
return true;
}
}
return false;
}
you can call them like this :
System.out.println("\nMothers over 25 Years old with childer heavier than 4000g;");
app.motherMoreThan()
.forEach(System.out::println);
Related
We have POJO classes Employee and Projects. While the Master class has the object of Employee and ArrayList of Projects. We are also creating an Arraylist of Master in Main class where data is assigned and retrieved.
Employee POJO
public class Employee {
Integer empID;
String name;
String desig;
public Employee(Integer empID, String name, String desig) {
this.empID = empID;
this.name = name;
this.desig = desig;
}
#Override
public String toString() {
return "Employee{" +
"empID=" + empID +
", name='" + name + '\'' +
", desig='" + desig + '\'' +
'}';
}
public Integer getEmpID() {
return empID;
}
public void setEmpID(Integer empID) {
this.empID = empID;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getDesig() {
return desig;
}
public void setDesig(String desig) {
this.desig = desig;
}
}
Project POJO
public class Project {
Integer projID;
String projName;
String location;
Integer empID;
public Project(Integer projID, String projName, String location, Integer empID) {
this.projID = projID;
this.projName = projName;
this.location = location;
this.empID = empID;
}
public Integer getProjID() {
return projID;
}
public void setProjID(Integer projID) {
this.projID = projID;
}
public String getProjName() {
return projName;
}
public void setProjName(String projName) {
this.projName = projName;
}
public String getLocation() {
return location;
}
public void setLocation(String location) {
this.location = location;
}
public Integer getEmpID() {
return empID;
}
public void setEmpID(Integer empID) {
this.empID = empID;
}
#Override
public String toString() {
return "Project{" +
"projID=" + projID +
", projName='" + projName + '\'' +
", location='" + location + '\'' +
", empID=" + empID +
'}';
}
}
Master POJO
public class Master {
Employee employee;
ArrayList<Project> projects;
public Employee getEmployee() {
return employee;
}
public void setEmployee(Employee employee) {
this.employee = employee;
}
public ArrayList<Project> getProjects() {
return projects;
}
public void setProjects(ArrayList<Project> projects) {
this.projects = projects;
}
public Master(Employee employee, ArrayList<Project> projects) {
this.employee = employee;
this.projects = projects;
}
#Override
public String toString() {
return "Master{" +
"employee=" + employee +
", projects=" + projects +
'}';
}
}
Main class
public class Main {
public static void main(String[] args) {
ArrayList<Master> masters = new ArrayList<>();
addData(masters);
fetchData(masters);
}
private static void addData(ArrayList<Master> masters) {
// WE ARE INITIALIZING MASTERS IN THIS BLOCK WITH DATA FROM DB
}
private static void fetchData(ArrayList<Master> masters) {
for (int i = 0; i < masters.size(); i++) {
System.out.println("Employee "+(i+1)+" "+masters.get(i).getEmployee().getEmpID()+" "
+masters.get(i).getEmployee().getName()+" "+masters.get(i).getEmployee().getDesig());
for (int j = 0; j < masters.get(i).getProjects().size(); j++) {
System.out.println("Projects "+masters.get(i).getProjects().get(j).getProjID()+" "
+masters.get(i).getProjects().get(j).getProjName()+" "+masters.get(i).getProjects().get(j).getLocation()
+" "+masters.get(i).getProjects().get(j).getEmpID());
}
}
}
}
How to remove this nested for loop in the fetchData() method in the Main class, to improve the time complexity?
I'm new to programming and i'd like some help.
I want to make a class that can add name,age and multiple phone numbers ( in some cases it will be 1, in others 4, etc...) and then show all the info.
I don't want to make it by creating another class for the ArrayList,
I'd like to do it all inside this class, I guess it's something simple to do but I can't figure this out and I'm not finding the solution I want.
what can I do about it? thx in advance, first time posting If I did something wrong please tell me.
import java.util.ArrayList;
public class Athlete
{
private String name;
private int age;
private ArrayList<String> phones = new ArrayList();
public Athlete(String name, int age)
{
this.name = name;
this.age = age;
}
public int getAge()
{
return age;
}
public void setAge(int age)
{
this.age = age;
}
public String getName()
{
return name;
}
public void setName(String name)
{
this.name = name;
}
public ArrayList<String> getPhones()
{
return phones;
}
public void setPhones(ArrayList<String> phones)
{
this.phones = phones;
}
#Override
public String toString()
{
return "Athlete{" + "name=" + name + ", age=" + age + ", phones=" + phones + '}';
}
}
You could make an inner class for PhoneList and use that type instead of directly working with the ArrayList.
public class Athlete
{
private String name;
private int age;
private PhoneList phoneList;
public Athlete(String name, int age)
{
this.name = name;
this.age = age;
phoneList = new PhoneList();
}
public int getAge()
{
return age;
}
public void setAge(int age)
{
this.age = age;
}
public String getName()
{
return name;
}
public void setName(String name)
{
this.name = name;
}
// Maybe just return the toString (or a read only list)
public PhoneList getPhones()
{
return phoneList;
}
publicvoid addPhone(String phone)
{
phoneList.add(phone);
}
#Override
public String toString()
{
return "Athlete{" + "name=" + name + ", age=" + age + ", phones=" + phoneList + '}';
}
private class PhoneList
{
private ArrayList<String> list = new ArrayList<String>();
private void add(String phone)
{
list.add(phone);
}
#Override
public String toString()
{
StringBuffer b = new StringBuffer(32);
for (String ph : list)
{
b.append(ph + "\n"); // Or something
}
return b.toString();
}
}
}
I wrote a REST web service which is returning JSON as below
[{"id":0,"name":"Vishal","age":"23","dob":"21/1/1992","phone":"9966558","sslc":"90","hsc":"90","college":"90"},
{"id":0,"name":"Karthik","age":"27","dob":"14/8/1988","phone":"995674","sslc":"99","hsc":"100","college":"100"},
{"id":0,"name":"Jeeva","age":"29","dob":"10/1/1987","phone":"77422","sslc":"99","hsc":"99","college":"100"},
{"id":0,"name":"Arya","age":"26","dob":"10/1/1989","phone":"55668","sslc":"100","hsc":"99","college":"99"}]
But I want the output with the "student" appended as below.
{"student":[{"id":0,"name":"Vishal","age":"23","dob":"21/1/1992","phone":"9966558","sslc":"90","hsc":"90","college":"90"},
{"id":0,"name":"Karthik","age":"27","dob":"14/8/1988","phone":"995674","sslc":"99","hsc":"100","college":"100"},
{"id":0,"name":"Jeeva","age":"29","dob":"10/1/1987","phone":"77422","sslc":"99","hsc":"99","college":"100"},
{"id":0,"name":"Arya","age":"26","dob":"10/1/1989","phone":"55668","sslc":"100","hsc":"99","college":"99"}]}
how can I achieve this output?
Below is the Product Class
#XmlRootElement(name="student")
public class Student implements Serializable{
/**
*
*/
private static final long serialVersionUID = 1L;
public Student() {
super();
}
public Student(int id, String name, String age, String dob, String phone,
String sslc, String hsc, String college) {
super();
this.id = id;
this.name = name;
this.age = age;
this.dob = dob;
this.phone = phone;
this.sslc = sslc;
this.hsc = hsc;
this.college = college;
}
private int id;
private String name;
private String age;
private String dob;
private String phone;
private String sslc;
private String hsc;
private String college;
#XmlElement
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
#XmlElement
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
#XmlElement
public String getAge() {
return age;
}
public void setAge(String age) {
this.age = age;
}
#XmlElement
public String getDob() {
return dob;
}
public void setDob(String dob) {
this.dob = dob;
}
#XmlElement
public String getPhone() {
return phone;
}
public void setPhone(String phone) {
this.phone = phone;
}
#XmlElement
public String getSslc() {
return sslc;
}
public void setSslc(String sslc) {
this.sslc = sslc;
}
#XmlElement
public String getHsc() {
return hsc;
}
public void setHsc(String hsc) {
this.hsc = hsc;
}
#XmlElement
public String getCollege() {
return college;
}
public void setCollege(String college) {
this.college = college;
}
#Override
public String toString() {
return "Student [id=" + id + ", name=" + name + ", age=" + age
+ ", dob=" + dob + ", phone=" + phone + ", sslc=" + sslc
+ ", hsc=" + hsc + ", college=" + college + "]";
}
}
Below is the service class.
#GET
#Path("/student.srv")
#Produces("application/json")
public Response getStudentJson(){
DAOLayer daoLayer=new DAOLayer();
List<Student> studentsList=null;
try {
studentsList=daoLayer.getStudents();
} catch (SQLException e) {
e.printStackTrace();
}
return Response.ok(studentsList).build();
}
Kindly help me to achieve the above mentioned output.
Thanks in Advance.
To get the desired output, you will have to create one single root object containing a List<Student> student and return it:
Root.java
#XmlRootElement(name="root")
public class Root implements Serializable {
#XmlList
private List<Student> student = new ArrayList<Student>();
// getter and setter
}
Service.java
#GET
#Path("/student.srv")
#Produces("application/json")
public Response getStudentJson(){
DAOLayer daoLayer=new DAOLayer();
List<Student> studentsList=null;
try {
studentsList=daoLayer.getStudents();
} catch (SQLException e) {
e.printStackTrace();
}
Root root = new Root();
root.setStudent(studentsList),
return Response.ok(root).build();
}
I have 5 classes (they're small). PersonDemo (test class), Person (superclass), and Student, Instructor and Graduate Student (sub classes). All the classes except for PersonDemo are finished.
I need to read in a file (data.txt) and store it to array Person. Then need I need to determine which object to initialize depending on the first value of the array. ( 1 - person, 2 - student, 3 - instructor or 4 - graduate student ) - I'm having trouble with this part.
Can someone point me in the right direction? My classes are below along with what the input file (data.txt) looks like and what the output file should look like.
PersonDemo.Java
public class PersonDemo
{
public static void main ()
{
JFileChooser chooser = new JFileChooser();
Scanner fileScanner = null;
Person [] ins = new Person [10];
try {
if (chooser.showOpenDialog(null) == JFileChooser.APPROVE_OPTION)
{
File selectedFile = chooser.getSelectedFile();
fileScanner = new Scanner(selectedFile);
while(fileScanner.hasNextLine())
{
// Need to load "data.txt" into array
// Then need I need to determine which object to initialize depending on the
// first value of the array in "data.txt"
//( 1 - person, 2 - student, 3 - instructor or 4 - graduate student )
}
fileScanner.close();
}
}
catch (FileNotFoundException e)
{
System.out.println("Could not find file");
}
}
public static void showAll(Person [] ins)
{
// Future code here
}
}
Person.java (superclass)
public class Person
{
private String name;
private int age;
public Person()
{
name="";
age=0;
}
public Person(String name, int age)
{
this.name = name;
this.age = age;
}
public String getName()
{
return name;
}
public void setName(String name)
{
this.name = name;
}
public int getAge()
{
return age;
}
public void setAge(int age)
{
this.age = age;
}
public String toString()
{
return "Name: " + name + "\t" + "Age: " + age;
}
}
Student.java (subclass)
public class Student extends Person
{
private int studentID;
private String major;
public Student()
{
studentID = 0;
major = "";
}
public Student(String name, int age, int studentID, String major)
{
super(name, age);
this.major = major;
this.studentID = studentID;
}
public int getID()
{
return studentID;
}
public void setID(int studentID)
{
this.studentID = studentID;
}
public String getMajor()
{
return major;
}
public void setMajor(String major)
{
this.major = major;
}
public String toString()
{
return super.toString() + "Student ID: " + studentID + "Major: " + major;
}
}
GraduateStudent.java (subclass)
public class GraduateStudent extends Student
{
private String researchArea;
public GraduateStudent()
{
researchArea = "";
}
public GraduateStudent(String name, int age, int studentID, String major, String researchArea)
{
super(name, age, studentID, major);
this.researchArea = researchArea;
}
public String getArea()
{
return researchArea;
}
public void setArea(String researchArea)
{
this.researchArea = researchArea;
}
public String toString()
{
return super.toString() + "Research Area: " + researchArea;
}
}
Instructor.java (subclass)
public class Instructor extends Person
{
private int salary;
public Instructor()
{
salary = 0;
}
public Instructor(String name, int age, int salary)
{
super(name, age);
this.salary = salary;
}
public int getSalary()
{
return salary;
}
public void setSalary(int salary)
{
this.salary = salary;
}
public String toString()
{
return super.toString() + "Salary: " + salary;
}
}
Well so I'm trying to parse a bit of JSon. I succeeded to parse:
Member.json:
{"member":{"id":585897,"name":"PhPeter","profileIconId":691,"age":99,"email":"peter#adress.com "}}
but what if I need to parse:
{"Members":[{"id":585897,"name":"PhPeter","profileIconId":691,"age":99,"email":"peter#adress.com"},{"id":645231,"name":"Bill","profileIconId":123,"age":56,"email":"bill#adress.com"}]}
Ofcourse I searched the web, I think, I need to use "List<>" here private List<memberProfile> member;but how do I "get" this from my main class??
I used this to parse the first string:
memeberClass.java
public class memberClass {
private memberProfile member;
public memberProfile getMember() {
return member;
}
public class memberProfile{
int id;
String name;
int profileIconId;
int age;
String email;
//Getter
public int getId() {
return id;
}
public String getName() {
return name;
}
public int getProfileIconId() {
return profileIconId;
}
public int getAge() {
return age;
}
public String getEmail() {
return email;
}
}
}
memberToJava.java
public class memberToJava {
public static void main(String[] args) {
Gson gson = new Gson();
try {
BufferedReader br = new BufferedReader(new FileReader("...Member.json"));
//convert the json string back to object
memberClass memberObj = gson.fromJson(br, memberClass.class);
System.out.println("Id: " + memberObj.getMember().getId());
System.out.println("Namw: " + memberObj.getMember().getName());
System.out.println("ProfileIconId: " + memberObj.getMember().getProfileIconId());
System.out.println("Age: " + memberObj.getMember().getAge());
System.out.println("Email: " + memberObj.getMember().getEmail());
} catch (IOException e) {
e.printStackTrace();
}
}
}
see below code
MemberClass.java
import java.util.List;
public class MemberClass {
private List<MemberProfile> member;
public List<MemberProfile> getMember() {
return member;
}
public void setMember(List<MemberProfile> member) {
this.member = member;
}
public class MemberProfile {
int id;
String name;
int profileIconId;
int age;
String email;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getProfileIconId() {
return profileIconId;
}
public void setProfileIconId(int profileIconId) {
this.profileIconId = profileIconId;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
}
}
Main Class
import com.google.gson.Gson;
public class MemTest {
public static void main(String[] args) {
String json = "{'member':[{'id':585897,'name':'PhPeter','profileIconId':691,'age':99,'email':'peter#adress.com'},{'id':645231,'name':'Bill','profileIconId':123,'age':56,'email':'bill#adress.com'}]}";
MemberClass memberClass = new Gson().fromJson(json, MemberClass.class);
System.out.println(new Gson().toJson(memberClass));
}
}
Output
{"member":[{"id":585897,"name":"PhPeter","profileIconId":691,"age":99,"email":"\u0027peter#adress.com\u0027"},{"id":645231,"name":"Bill","profileIconId":123,"age":56}]}
Hi I made some changes to your application and it seems to work now ! You where quite close alls you need is a wrapper for the array.
public class memberWrapper {
private List<memberClass> Members;
public List<memberClass> getMembers() {
return Members;
}
public void setMembers(List<memberClass> members) {
this.Members = members;
}
}
Then I changed youir original class a little:
public class memberClass {
int id;
String name;
int profileIconId;
int age;
String email;
//Getter
public int getId() {
return id;
}
public String getName() {
return name;
}
public int getProfileIconId() {
return profileIconId;
}
public int getAge() {
return age;
}
public String getEmail() {
return email;
}
}
and then in the main:
BufferedReader br = new BufferedReader(new FileReader("stuff.json"));
//convert the json string back to object
memberWrapper memberObj = gson.fromJson(br, memberWrapper.class);
System.out.println("Id: " + memberObj.getMembers().get(0).getId());
It should work now the important thing when dealing with JSOn is to just make sure the key matches the name of your variables.