Which Method Is Used While Passing Or Returning A Object From The Native Method
Mar 5, 2014Which method is used while passing or returning a java object from the native method?
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Passing Unknown Type To A Method And Returning It
Feb 20, 2014So I want to know how in Java you can pass a unkown type into a method (type can be an int, double, or a user defined object) and return that unkown type.
example of what I want:
Java Code:
public (unknowntype)[] method2 ((unknowntype)[])
//Process Data
//unknowntype.process();
return (unknowntype);
} mh_sh_highlight_all('java');
I know in C you can use void pointers and in c++ we have templates but I do not know how java handles this. Also I want to know if it is possible to call a method in the unknowntype.
Returning Object That Has Been Removed Using Remove Method
Nov 18, 2014So i have used the "remove()" method in conjunction with an iterator to remove an object from a HashSet in my program, and part of my exercise requires me to return said object. What I can do to return an object that has been removed using "remove()" method?
View Replies View RelatedPassing Object Created In One Method To Another?
Oct 29, 2014I am working on an independent project it is a simple little text based rpg that will run in a counsel window. I have an object for Character that is creating during a CreateCharacter method. I want the play to be able to enter a character that will open up a menu that displays things like the name and health and stuff of the character from the object created in CreateCharacter, but because I have it in a different class I don't know how to reference the object made in CreateCharacter.
I have it in 6 files
Character --- Object with getters/setters for things like name, age, race, class, ect
MainMenu --- Displays title and promts for new game and quit
CreateCharacter --- Walks through and sets all values in Character
Stats --- Keeps the players stats (health, attack, ect) in an array
Intro --- Beginning demo thing (not really important for this question)
Menu --- Displays all current user stats (Having issues with this one)
Example I have this in Menu
System.out.println("Name: " + ????.getName());
Passing Object From JSP Page Through JSTL Into Controller Method
May 12, 2015I need to pass advanced object into controller from JSP page, but I always get null result.It's a controller method:
Java Code:
@RequestMapping(value="admin-user-edit", method=RequestMethod.POST)
public ModelAndView editUser(@ModelAttribute(value="user") UsersEntity user)
{
if (null == user)System.out.println("User is null");
else
System.out.println("User name = " + user.getName() + " | Users id = " + user.getId());
ModelAndView view = new ModelAndView();
return view;
} mh_sh_highlight_all('java');
And this is a JSP page snippet. I need to choose some user from user list and pass it to controller.
XML Code:
<c:forEach var="user" items="${user_list}">
<tr>
<td><c:out value="${user.id}" /></td>
<td><c:out value="${user.name}" /></td>
<td><c:out value="${user.login}" /></td>
<td><c:out value="${user.status}" /></td>
[code]...
I tried to pass it through HttpServletRequest argument but all the same.
Passing Object Argument To A Method - Unable To Call Methods On Argument
Feb 7, 2015I am trying to pass an object of type Product p to my editProduct method, however trying to call p.getName(); doesn't work and throws a NullPointerException. The same kind of thing works for my displayRecord method (in a different class) and I can call .getName() on Product p, also passed as an argument to that method. Below is my editProduct class. The NullPointerExcepion is being thrown at line 61 (i.e., nameField.setText(p.getName());).
I don't know if I explained right, so here's a line thing of how the classes relate:
Search >>>(field.getText())>>> displayRecord(Product p) >>>editProduct(p)>>> EditProduct
And as a side note: adding the line p = new Product(); fixes it and successfully runs the class (including the Save and Quit parts) but obviously I want it to specifically refer to the Product I pass to the method.
Java Code:
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.FocusEvent;
import java.awt.event.FocusListener;
import java.util.ArrayList;
import javax.swing.BorderFactory;
[Code] ....
I'm asking a question because I don't understand how Product p could possibly be null, because the argument is passed through my DisplayRecord class, which also takes a Product p argument and works. In that class, I have declared Product prod = p; and prod is what I am passing to editProduct.
Why Method Is Not Returning A Value
Apr 29, 2014I'm new to Java and I have a problem with a method, I can't see the code of the method, I just have a jar, but it should return a boolean, something like this:
boolean band = false;
band = TestClass.testMethod("blabla");
// band = false
The problem is that the method seems that is returning nothing (band remain false), and if I initialize band to true:
boolean band = false;
band = TestClass.testMethod("blabla");
// band = true
band remain true, in other words, the value of band is never modified, the question is, how is this possible? because it should return the same value on both calls, true or false, no matter the initial value of the variable that is receiving the returning value of the method.
Why Is Method Returning Null
Sep 25, 2014I am working on a project which manages an airport's airplanes and flights based on user input. The method printFlights() - lines 133-134 - is returning null and I can't figure out why. The method is supposed to print information about each flight. The logic is identical to the printPlanes() method which is working successfully.
View Replies View RelatedReturning Multiple Variables From A Method
Nov 18, 2014Now that I have figured out how to return a single variable from a method I am on to the next step, I need to return 2 or 3 variables from a method. I have searched the internet on how to do this to no avail (am I doing the wrong search? I do not know) but what I need to do is return a second (and eventually a third variable)
Here is what I have
private static String Engine() {
String engine = "";
int enginePrice = 0;
System.out.println("Choose a engine size:");
System.out.println("[4] cylinder");
[Code] .....
Which does not work.
Apache POI Method Returning Wrong Value
May 20, 2014I'm using apache POI to input data from a excel database. I have a method that is supposed to count the number of rows containing data so I can use that number to initialize an object array. It's returning one more than the actual number of rows and I can't figure out why.
public int getDataRange() throws IOException{
int rowCount = 0;
Iterator<Row> rows = sheet.rowIterator();
while(rows.hasNext()){
HSSFRow row = (HSSFRow) rows.next();
rowCount++;
[Code] .....
I get an array index out of bounds exception at the highlighted line.
Method Is Not Returning Array - Null Error
May 18, 2015I am trying to return an array and I keep getting a null error. The below class sets the material numbers into an array and should return that array if called :
public class Jobs {
private int[] materialsNumber;
//change to parts and create another class that gets the materials for the parts
public int[] job1() {
materialsNumber[0] = 11960120;
[Code] ....
I later try to call the method. The program executes but stops after I println "test in loop"
public class PurchaseOrdersToParts {
private Jobs job = new Jobs();
int[] getPartsForPurchaseOrder(BigDecimal purchaseOrder) {
System.out.println("inside getparts");
BigDecimal testNum = new BigDecimal(123.0);
[Code] ....
This is the method that is calling the method in the GenerateOrdersToParts class
private PurchaseOrdersToParts purchaseOrdersToParts = new PurchaseOrdersToParts();
@Inject
PoRepository poRepository;
public GenerateShopJobTickets() {
[Code] .....
Passing A Value Into A Method
May 8, 2014Does the following code pass a value into a method?
/code
lnValue[x][y] = computelnValue();
Passing More Than One Array In A Method?
Nov 3, 2014Can we pass more than one array in a method?
View Replies View RelatedPassing Information To A Method Or Constructor
Feb 28, 2014Passing Information to a Method or a Constructor
They show a line of code that goes like this:
public Polygon polygonFrom(Point[] corners) {
// method body goes here
}
So from what I understand this is a constructor method for a Polygon object from the Polygon class. What I dont get is the name of the method polygonFrom()
Shouldn't a constructor for a Polygon just have the same name as the class? Because from earlier examples in the tutorial it seems to me that this is what has been done
For example:
public Bicycle(int startCadence, int startSpeed, int startGear) {
gear = startGear;
cadence = startCadence;
speed = startSpeed;
}
Passing A Boolean Parameter From One Method To Other
Jan 30, 2015Java SE Runtime Environment build 1.8.0..This is part of the code:
public static int addAddress (String[] number, boolean[] front, double[] total) {
int num = 0;
double ffee = 0;
/*boolean value = false;*/
[code]...
I have tried using the line of code commented out, /*boolean value = false;*/. However, another error is displayed. The compiler shows the following...
Inspection.java:33: error: incompatible types: boolean cannot be converted to boolean[]
front[num]= defineFront(num, value);
^
Note: Some messages have been simplified; recompile with -Xdiags:verbose to get full output error...I know that boolean values are by default stored as false, once you create the array. However, I'm having trouble passing the variable to the method.
Passing A Method And Searching Array
Apr 22, 2014How to pass the methods listed below.
public ArrayList<Person> findPerson(String searchFor)
^ this method is suppose to search an array and find whatever you search (numerical or alphabetical)
I have this
public ArrayList<Person> findPerson(String searchFor) {
Main.handleSearchPerson(keyboard, searchFor);
ArrayList<Person> matches = new ArrayList<>();
for (Person p : personList) {
boolean isAMatch = false;
[Code] .....
I am not sure if how i am searching the method is correct or how to pass that to another class to put it inside of a switch statement.
Passing A Method And Searching Array
Apr 22, 2014How to pass the methods listed below.
public ArrayList<Person> findPerson(String searchFor)
^ this method is suppose to search an array and find whatever you search (numerical or alphabetical)
i have this
public ArrayList<Person> findPerson(String searchFor) {
Main.handleSearchPerson(keyboard, searchFor);
ArrayList<Person> matches = new ArrayList<>();
for (Person p : personList) {
boolean isAMatch = false;
if (p.getFirstName().equalsIgnoreCase(searchFor)) {
isAMatch = true;
[Code] ....
I am not sure if how i am searching the method is correct or how to pass that to another class to put it inside of a switch statement.
Passing Java Bean Name In A Method
Jun 13, 2014Here I am taking response data from JSON using jackson API.I found a feature like using Jackson the properties can be set to bean properties.
private static String readUrl(String urlString) throws Exception {
BufferedReader reader = null;
try {
URL url = new URL(urlString);
reader = new BufferedReader(new InputStreamReader(url.openStream()));
[Code] ....
I got the correct output here. But now I want to generalize my method into a utility class so that I can reuse the same method for setting response data directly to respective beans as given below:-
My question is how will I pass the bean object in my utility class?
public static Object getResponseData(String response,[b]String bean[/b]) throws Exception {
ObjectMapper mapper = new ObjectMapper();
mapper.configure(DeserializationConfig.Feature.FAIL_ON_UNKNOWN_PROPERTIES, false);
JsonNode root = mapper.readTree(response);
[Code] ....
Servlets :: How To Change URL To JSP Name After Passing To DoPost Method
Aug 12, 2014I have a log in page accessed by: localhost/Security/Login.jsp
When I click a log in button, doPost() method is executed from Login.java and displays the contents from main.jsp.
However,its url on my browser is localhost/Security/Login.
Generally, the pattern is the address of Login servlet.
So if I click a button from main.jsp, error occurs because it is trying to locate a servlet from /Security/[Servlet name].
What I want is to change the url as I go to main.jsp to localhost/Home/main.jsp.
Is this possible?
Passing Values Into Constructors Using Main Or Static Method Functionality
Jan 24, 2014I just kinda get stuck when it comes to passing values into constructors, using main method or static method functionality. In theory i kind of understand how it work but when i type it, it's totally different! I have to have a junit test too but i guess i could do that in the end.
I have attached the assignment. So, how to proceed with this:
public class Flight {
int flight_number, capacity, number_of_seats_left;
String origin, destination;
String departure_time;
double original_price;
[Code] ....
Passing File Path To Servlet Using Drag And Drop Method In Java Web
Jun 18, 2014currently I am doing my java web application project ,and it has following steps 1) Upload the txt files 2) java servlet gets the txt file's url , read the data and do the calculation 3) pass the results
I almost finished the second step , and working on the first step .Since there are so many input files at a given time , i have to use drag and drop method to get the file's location.how to pass file's path to servlet.( servlet code can read the data from the given txt file path )software used - tomcat and netbeans 8.0
Equals Method - Take Object Reference And Return True If Given Object Equals This Object
Mar 28, 2014Create an equals method that takes an object reference and returns true if the given object equals this object.
Hint: You'll need 'instanceof' and cast to a (Geocache)
So far I have:
public boolean equals(Object O){
if(O instanceof Geocache){
Geocache j=(Geocache) O;
if (this.equals(j)) //I know this is wrong... but I can't figure it out
return true;
}
else return false;
}
I think I have it correct up to the casting but I don't understand what I'm suppose to do with the this.equals(). Also I'm getting an error that I'm not returning a boolean... I get this all the time in other problems. I don't get why since I have to instances of returning booleans in this. "returns true if the given object equals this object" makes no sense to me. I assume the given object, in my case, is 'O'. What is 'this' object referring to?
Calling Object Method From Another Object
Oct 26, 2014I've been trying to learn Java for the last 36 hours or so (after applying for a HTML/CSS job saying "Java knowledge preferred"), and decided to experiment a bit making a graphical tic-tac-toe game. I eventually managed to get that done and it's working. Working code below:
[Java] tic tac toe 1 - Pastebin
So, it works to an extent, however, the way I am capturing which cell is selected seems very sloppy, and would not work if the cells weren't squares or rectangles. So I made a copy of the project and restructured it adding the mouse event to the cells, but now I can't get JComponent to repaint. New code below:
tic tac toe 2 - Pastebin
Curiously, clicking triggers the action for all 9 cells, but I presume it's because I haven't bounded them making it think I've clicked all 9 simultaneously.
What I've tried:
Make the Cell class extend the game class and call this.repaint()- causes stack overflow.
Calling Game.GameState() within the cell clicking event and making that function static - compiler doesn't like calling repaint() inside a static function.
Making another class to make a clone of the Game object and then refresh- was never going to work....
Error Passing Value Of A Variable From One Class To Main Method Of Another Class
Jan 8, 2014I've 3 classes.
1. Circle
2. GetInputFromUser
3. testCircle
package ABC;
public class Circle {
private double radius;
public double getRadius() {
return radius;
[Code] .....
In the testCircle class, in the line: getRadius = ui1.GetInput();
It's showing the error: The method GetInput(float) in the type GetInputFromUser is not applicable for the arguments ()
And when I do: getRadius = ui1.GetInput(rad);
It's showing the error: rad cannot be resolved
Object Method Override
Mar 7, 2014I read the following comment at stackoverflow.com. It is not clear to me why equals in the code below does not override - i looked up Object class equals() and the signature is same.
public class Foo {
private String id;
public boolean equals(Foo f) { return id.equals(f.id);}
}
This class compiles as written, but adding the @Override tag to the equals method will cause a compilation error as it does not override the equals method on Object.
Cannot Convert From Object To E In Last Line Of Pop Method
Jul 20, 2014I am getting this error "Type mismatch: cannot convert from Object to E" in the last line of the pop() method.
package stack;
public class Node<E> {
E item;
Node next;
Node(E item) {
this.item = item;
this.next = null;
}
[code]....
I don't understand why that error occurs despite item being declared as type E in the Node class.