Parametrized Array Type As Method Parameter?

Jul 31, 2014

I have the following method:

public static void doSomething(List<? extends GenericClass> input)
{
// op
}

^

This compiles and works, ensuring I can only pass in a List of a type extending GenericClass.But now I want it to accept an Array instead of List. This is where I'm stuck:

public static void doSomething(<? extends GenericClass>[] input)
{
// op
}

^

A wrong guess at the syntax which does not compile. One solution is to convert Array into ArrayList before calling the 1st method above, but I'd rather bypass this if possible.

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JSF :: Enum Type In Parametrized Class

Dec 4, 2014

I'm developing a JSF application.I have some enums, for example

public enum Gender {
MALE("Male"),
FEMALE("Female");
private final String label

[code]....

I want to put the enum value in <h:selectOneMenu>. I use a bean:

@Named(value = "genderBean")
@RequestScoped
public class GenderBean {
/**
* Creates a new instance of GenderBean
*/
public GenderBean() {

[code]...

How can i call the method .values() of enum for a generic enum T, like in the striked code?

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Generic Method And Bound Type Parameter Errors

Jul 14, 2014

I am following this article [URL] .... till now I have made some code

This is my Interface

public interface Comparable<T> {
public int compareTo(T o);
}

And this is my class where I am using Bound Type Parameter on Generic Methods

public class GenericMethodBoundType {
public static <T extends Comparable<T>> int countGreaterThan(T[] anArray, T elem) {
int count = 0;
for (T e : anArray)

[Code] .....

What else I need to do both in main method and at what parameterized types I need to pass at the class?

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How To Get Access To The Method With A Parameter Of Class Type Variable

Feb 19, 2014

how to get an access to the method with a parameter of class type variable, lets say: public void insert(Record newRecord, int pos)?

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Addition Of Generic Type Parameter Causes Member Type Clash

Apr 22, 2014

Got a problem with generics, which I'm still pretty new at. Here's a program that compiles fine:

import java.util.ArrayList;
import javax.swing.JComponent;
public class Experiments {
public static void main(String[] args) {
ListHolder holder = new ListHolder();

[Code] ....

It's useless, but it compiles. If I change Line 14, however, to add a generic type parameter to the ListHolder class, Line 10 no longer compiles:

import java.util.ArrayList;
import javax.swing.JComponent;
public class Experiments {
public static void main(String[] args) {
ListHolder holder = new ListHolder();

[Code] ....

I get this error:

Uncompilable source code - incompatible types: java.lang.Object cannot be converted to javax.swing.JComponent
at experiments.Experiments.main(Experiments.java:10)

Apparently, the introduction of the type parameter leaves the compiler thinking that aList is of type Object. I can cast it, like this:

JComponent c = ((ArrayList<JComponent>)holder.aList).iterator().next();

That makes the compiler happy, but why is it necessary? How does adding the (unused) type parameter to the ListHolder class end up making the compiler think the aList member of an instance of ListHolder is of type Object?

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Create A Recursion Method That Takes ONLY ARRAY As A Parameter

Mar 9, 2015

so i have this question where it wants me to create a recursion method that takes ONLY THE ARRAY as a parameter, and without using loops or static variables inside the method, and then the method returns the smallest value in that array. However, i tried making the simple if statements where i compare the first element of the array with the second element using the length of the array and decreasing it to get the next elements and compare it again by calling the recursion method, but the problem is when i call the method again, the length does not decrease, even if i store it in a variable, the variable will initialize itself again, and the length wont change.

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Write A Method Called AddToOverThirty Which Takes Array Nums3 As A Parameter

Apr 22, 2014

i have to "Write a method called addToOverThirty which takes the array nums3 as a parameter. It adds 1 to all numbers that have a value greater than 30 in the array.

Add a call to the addToOverThirty method, then display a message telling what the output is followed by the results For example:The nums3 array after adding 1 to all numbers greater than 30 is10 6 15 and so on (check with the values you assigned to nums3)"its pointless because we were told not to make the array have a number over 30.

import java.lang.*;
import java.util.*;
public class LastProject
public static void main(String[] args) {
int nums1[] = new int[15];
int nums2[] = new int[15];
int nums3[] = {5,2,15,8,26,22,1,29,4,23,30,11,19,6,24};

[code]....

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Public Method That Takes Array Of Type Object To Load Strings Into Linked List

Oct 13, 2014

I am having a little trouble with a part of my Java assignment that needs to have linked lists in it.

I need to write a public method that takes an array of type object to load strings into a linked list.

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JDBC :: How To Determine DATE Data Type Of Parameter If It Is Not Specified

Feb 2, 2015

Oracle JDBC driver determine the DATE data type of parameter correctly without any typecasting.

Example:
ps = conn.prepareStatement("SELECT ? FROM DUAL");
ps.setObject(1, Date.valueOf("2014-01-11")) ;
 
I have tried the same example with other database driver but it gives error.

PostgreSQL JDBC driver:
org.postgresql.util.PSQLException: ERROR: could not determine data type of parameter $1
 
ps = conn.prepareStatement("SELECT ?");
ps.setObject(4, Date.valueOf("2005-01-01"));
 
so I want to know how Oracle JDBC driver determine the DATE data type of parameter.

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JDBC :: Determine DATE Data Type Parameter If It Is Not Specified?

Feb 2, 2015

Oracle JDBC driver determine the DATE data type of parameter correctly without any typecasting.

Example:
ps = conn.prepareStatement("SELECT ? FROM DUAL");
ps.setObject(1, Date.valueOf("2014-01-11"));
 
How Oracle JDBC driver determine the DATE data type of parameter.

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How To Convert Input Array Of Type Strings To Class Type

Aug 14, 2014

class Passenger{
String name;
int age;
char gender;
int weight;
public Passenger(){

[Code] ....

This is showing error.....error it gives isthat it cannot change from string type to passenger type......... How to do it??????

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Method Overridden In Method Parameter?

Jul 20, 2014

I was following a tutorial for libGdx and suddenly became confused by the following syntax:

up.addListener(new ClickListener(){
public void clicked(InputEvent event, float x, float y){
position.y += 1f;
//currentFrame = animation.getKeyFrame(12);
}
});

"up" is basically a text Button:

TextButton up = new TextButton("up", textButtonStyle);

and .addListener is just one of the methods "TextButton" has (actually I think its inherited from "Button" but that doesn't matter).

Basically my question is what's going on inside the parentheses? From what I see its a new instance of "ClickListener" but then suddenly they override an actual method within. Is this simply just a way to override a method from the ClickListener class or is it something else?

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Initializing Constructor As Parameter For A Method?

Jan 2, 2014

So, I am learning Swing, and Swing Layouts. I just came across a really confusing (for me) line of code.

Java Code:

setLayout(new BorderLayout()); mh_sh_highlight_all('java');

So, this is weird for me because I don't really understand why the BorderLayout class constructor is being initialized as a parameter for the setLayout..

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Passing A Boolean Parameter From One Method To Other

Jan 30, 2015

Java 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.

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Method That Accept Object As A Parameter

Jan 3, 2015

I have a method that accepts as a parameter an object:

public void addClient(Client c){ }

Client is a class which has a constructor that has two String parameters:

public Cliente (String name, String lastname){
this.name = name;
this.lastname = lastname;
}

In the main add a Client in this way:

addClient(new Cliente("first", "second"));

Now, i have an array of Client, so I would like to enter within this. Example:

public void addClient(Client c){
for (int i = 0; i<client.length ; i++) { // client is an array of Client object
client[i] = c; // Enter a c in the array, but does not work!
System.out.println("test "+clienti[i]); // print Client@15db9743
}
}

I have used the println for check if worked insertion, but the result shows no

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How Is Class Cast In Method Parameter

Jan 15, 2014

how is cast a class at a methods parameters? i have a problems in a methods paramter. i draw red line my exception and mymethods is orage color ....

Caffe drink = new Caffe();
CoffeCup cup = new CoffeCup();
cup.setTempeture(100);
drink.drinkcaffe((CaffeCup)(cup.getTempeture()));

[code]....

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Using Comparable Or Comparator As Parameter In Method

Jul 1, 2013

I was going through some lectures online and found that to compare or even swap, the use of comparable or comparator argument like
 
public static boolean less(Comparable v,Comparable w)
{
     return v.compareTo(w)<0;
}
 public static void swap(Comparable []a,int i,int j)
{
     Comparable swap=a[i];
     a[i]=a[j];
     a[j]=swap;
}
 
I did not get the use of passing Comparable or Comparator to the function as parameters. Object as parameter could have been used too?

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Type Of Expression Must Be Array Type

Dec 30, 2014

The objective of the code is to add new records based on existing records with a partial change to the key. I'm getting "type of the expression must be an array type but it resolved to DstidArray" on dsTidRecTbl[i]

String stMajor = request.getParameter("stMajorVersion");
String stMinor = request.getParameter("stMinorVersion");
String stPatch = request.getParameter("stPatchVersion");
StringBuffer stKeySB = new StringBuffer(stMajor+stMinor+stPatch);
String stKey = new String(stKeySB.toString());
DstidArray dsTidRecTbl = new DstidArray(stKey);
request.setAttribute("dsTidRecTbl", dsTidRecTbl);

[code]....

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Set Method Return Type Determined Inside Method

Dec 25, 2014

I need to write a method that will consume string representation of Object type and will return one object of this type. How to set return type for the method in this case?

Here is exmaple :

public <?> identifyType(String typeString){
if (typesString.matches("String")){
return new String("");
}else if (typeString.matches("Integer")){
return new Integer(0);
}
//....etc..}

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Implement Hash Of Hashes As Method Parameter

Apr 28, 2015

I have a drop-down which contains the four sections simple buttons(filters). When click any of these buttons some settings are applied. I have successfully auotmated it using simple if else and switch but in that case i have to use 8 parameters(8 are the number of button)

public void editFilters(WebElement filter1, WebElement filter2, WebElement filter3, WebElement filter4,WebElement filter5,WebElement filter6,WebElement filter7,WebElement filter8 String edit, String expectedColour) {
switch (edit) {
case "selectFilter":
if (filter1 != null) {

[Code] .....

But want to make it more effective by using hashes. I do not want to use 8 different parameters to perform action on the respective button.

So now what i want to implement.

Create a method in which i pass the parameter1 as hash and 2nd parameter as 0 or 1, 0 means unSelectFilter and 1 means select the filter.

With parameter 1, in code i want to pass the name or xpath or anything else for any number of filters , that those filters names should be stored into that hash and then by passing 0 or 1, i can select/unselect those filters.

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Method That Accepts Integer Parameter For Number Of Hops

Apr 9, 2014

The instructions:

Write a method named hopscotch that accepts an integer parameter for a number of "hops" and prints a hopscotch board of that many hops. A "hop" is defined as the split into two numbers and then back together again into one.For example, hopscotch(3); should print:

1
2 3
4
5 6
7
8 9
10

how to start this program.

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Assigning Int Literal To Byte Works But Not As Method Parameter

Apr 23, 2014

If you write

byte b = 100; it works (implicit conversion of implicit int literal 100 to byte.

But if you have a methodvoid bla(byte b){}

And want to invoke it with a literal (which is an int by default):bla(8) then there is no implicit conversion.

Is the byte b = 100; just an exception in Java? And is it the rule that one has to explicitely cast (narrow) integer literals when passing to smaller-than-int types?

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Create A Method Header Named ConvertTOKM That Take Int Parameter

Feb 7, 2015

In my book for learning java, one of the questions asks us to create a method header named convertTOKM that takes an int parameter, which is the number of miles, and returns a double value for the converted value in kilometers. I made one, but wanted to know if I was right in any way.

Here it is:public double convertTOKM(int miles, double kilometers){

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Method Receives Queue As Parameter - How To Print A Stack

Nov 4, 2014

I'm doing an assignment where a method receives a Queue as a parameter then convert it into a stack, I made it but now I want to try it in my main, but how can I do this? there's no toString and I cant use a for loop because I'm using a queue and not an array. This is the head of my method:

public static void QueueStack(Queue<Integer> q){

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Simple Recursion Method - Accept Integer Parameter N And Return Sum Of First N Reciprocals

Nov 1, 2014

I am practicing some basic recursion and I was trying to solve this problem

Write a method sumTo that accepts an integer parameter n and returns the sum of the first n reciprocals. In other words:

sumTo(n) returns: 1 + 1/2 + 1/3 + 1/4 + ... + 1/n

For example, the call of sumTo(2) should return 1.5. The method should return 0.0 if passed the value 0 and should throw an IllegalArgumentException if passed a value less than 0.

This is my attempt to do it , however my output is always a 0.0 , and i do not understand why :

public static double sumTo(int n ){
if(n<0){
throw new IllegalArgumentException();
}
else if (n==0){
return 0.0;

[Code] .....

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ASCII File - Passing Array As Parameter?

Feb 23, 2014

I am trying to make a class definition file for an ASCII File.

Ultimately, I want to be able to add methods to allow the image produced by the file to be printed normally, then printed with various manipulations.

However, for some reason, whenever I try to run the program to test my normalPrint method, it terminates without printing anything.

I think this is because the array's values width and height are not within the scope of the method. I tried passing the array as a parameter for the method like so:

Java Code:

public void normalPrint(char [][] poop){
//method here
} mh_sh_highlight_all('java');

But it gave me an error that stated

"The method normalPrint(char[][]) in the type asciiFile is not applicable for the arguments ()"

Class Definition:

Java Code:

import java.io.*;
import java.util.Scanner;
public class asciiFile {
int height;
int width;

[Code] .....

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