Is Type Irrelevant As Long As Value Is Within Boundaries Of Type Of Switch Expression

Apr 30, 2014

If you have final int i = 1;
short s = 1;
switch(s) {
case i: System.out.println(i);
}

it runs fine. Note that the switch expression is of type short (2 bytes) and the case constant is of type int (4 bytes).My question is: Is the type irrelevant as long as the value is within the boundaries of the type of the switch expression?I have the feeling that this is true since:

byte b = 127;
final int i = 127;
switch(b) {
case i: System.out.println(i);
}

This runs fine again, but if I change the literal assigned to i to 128, which is out of range for type byte, then the compiler complains.Is it true that in the first example the short variable and in the second example the byte variable (the switch expressions) are first implicitly converted to an int and then compared with the case constants?

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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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I tried to create file and write the output of my program in it in java when i use WriteLong then the file does not contain long value, how I create this file my program is to print prime numbers between 500000 to 10000000

public class primenumber {
public static void main(String[] args) {
long start = 5000000;
long end = 10000000;
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Below code I am using to typecast int to char.

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I have 38 similar issues in my workspace.

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Aug 14, 2014

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[Code] ....

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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) {
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[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:

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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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Dec 4, 2014

I'm trying to parse and compare the content of a zip file. However I'm stuck at what SHOULD be a very simple problem, however I can't seem to find a solution. I have done the following:

ZipInputStream zin1 = new ZipInputStream(fin);
ZipEntry ze1 = null;
fin2 = new FileInputStream(fileName2);
ZipInputStream zin2 = new ZipInputStream(fin2);
ZipEntry ze2 = null;
//fin.close();
ze1 = zin1.getNextEntry();
ze2 = zin2.getNextEntry();

Which gives me the first entry of each zipfile as a ZipEntry type object. I have tried getting the path of the file (inside the zip file) and using this to create a File type object. This does not seem to work though I get:

Exception in thread "main" java.io.FileNotFoundException: My DocumentsmetadatacoreProperties.xml (The system cannot find the file specified)
at java.io.FileInputStream.open(Native Method)
at java.io.FileInputStream.<init>(Unknown Source)
at java.io.FileReader.<init>(Unknown Source)

And this is because I get a null return from trying to create the File file1 = new File(correctLocation);

I guess I cannot access the file inside a zip file this way. So my question is how can I make a ZipEntry type object into a File type object?

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import java.io.File;
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[code]...

Now, in the following line: absoluteOrderFiles[absoluteIndex].length() < sizeOrderList.get(sizeIndex).length()

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How do I convert primitive long to Long?

and is it possible to do it in a single line?

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This error pops up for both the euclidian norm and the manhattan norm.

Here is the code:

package de.ostfalia.gdp.ss15;
public class Vektor {
public static void main(String[] args) {
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[code]...

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I am trying to understand Life time of a variable by writing a below program. But unable to compile it as it is throwing some error. Code snippet and error as follows,

// Understanding Lifetime of a variable.
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 public static void main(String args[]) {
int x;
for(x = 0; x <3 ; x++) {
int y = -1; // y is initialized each time block is entered
 
[Code] .....

Please refer to the print screen attached 'LifeTime.jpeg' to this thread to know more about error.

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Java Code:
with(Positionables){
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Now I was thinking Positionables could be a List<Positionable> and Positionable is an abstract class and Sphere and Box extends from it. But I don't know how to propagate the call of translate() to the subclasses.

What are the best approaches for this matter? It would be perfect if I could make it so I could somehow use the "with" construction like in the example above.

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For some reason when I try to run the program it gives me an "editor does not contain a main type" launch error.

/*
* A program that plays and scores a round of the game Poker Dice. In this game, five dice are rolled. The player is allowed to select a number of those five dice to re-roll. The dice are re-rolled and then scored as if they were a poker hand. The following hands MUST be scored in this assignment:
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What the difference is between those two lines:

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If I don't append the L, is the msb (most significant bit) somehow still carried over to the resulting long variable and in the latter case, where I append an L, it is not and instead the value is filled up with 32 leading zeros (4 Byte difference between int and long)?

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I figured I should give a little background on the program, this program is reading from a text file of names and decade numbers(for each name) and storing each line into an object array. From there, there are menus and based on the users decision they can type a name and get a histogram, compare names with histograms, ect. Below this main method, I have provided the area where I have gotten the null pointer exception.

Here is the main method for the Client "nameApp"

Also excuse the formatting and curly braces for now!

public class NameApp{

private static boolean validInput;
private static boolean done = false;
private static boolean validDecade;
private static boolean validName;

[Code] ....

And here is the method in the same Client that is getting the null pointer exception:

The pointer exception is on line 6 which is:

if (nameInput.equalsIgnoreCase(list[i].getName())){
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int nameLocation = -1;
int listLength = list.length;

[Code] ....

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