So method invia call the method popolaScompiute, inside popolaScompiute there is an iteration through some id and for some id can occur an error; what i want is the getting the value of id in the first method invia, using the block try/catch. Is there a way to accomplish this?
So method invia call the method popolaScompiute, inside popolaScompiute there is an iteraction through some id and for some id can occur an error; what i want is the getting the value of id in the first method invia, using the block try/catch. Is there a way to accomplish this?
I'm using Java in BlueJ where I'm trying to write a class to store cycling club membership details in a map. I'm trying to pass a map as a parameter to a function that will iterate over the map and print out the member details. My code is:
public class CtcMembers { //instance variables private Map<String, Set<String>> memberMap; /** * Constructor for objects of class CtcMembers
[Code] ....
When I execute the following in the OU workspace:
CtcMembers c = new CtcMembers(); c.addCyclists();
I can see a map populated with the expected details.
When I execute the following in the OU workspace:
c.printMap(c.getMap());
I get the following error:
java.lang.ClassCastException: java.util.HashSet cannot be cast to java.lang.String in CtcMembers.printMap(CtcMembers.java:81) in (OUWorkspace:1)
I wasn't aware I was trying to cast anything so this has got me baffled.
I am trying to run an example in which I pass a parameter to imported file but its not working.
This is my header.jspf file which I will include in a jsp file.
<img > <br>${param.sub}
And This is the JSP file contact.jsp
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %> <html> <body> <c:import url="header.jspf"> <c:param name="sub" value="We love to hear from our clients------------" /> </c:import> <br><br>
Now this is JSP page content
</body> </html>
When I hit the contact.jsp file , It does show me the image I have on header.jspf , but its not able to print the parameter that I am setting in <c:param>
So after showing image it just shows ${param.sub}. So EL is not translated properly.
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.
combo is the private CombinationLocker object I created within the Locker class. Do I need to pass the combo object on to the CombinationLock class? For reason, I do not comprehend, the combination password from the main class is not passing through to the CombinationLock class, and the combination values are all zero.
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;
There is a method taken from a class with several try and catch blocks. If you think it is possible, add one more catch block to the code to catch all possible exceptions, otherwise say 'Not possible' with your reason.
Assuming that we have two classes B and C which inherit from class A. What is the best way to pass a parameter from an object of class B to an object of class C by the use of class A without using static variable and without defining a get function in B?
I wrote a program using switchcase.I used do while to show the menu to the user until the user decides to exit the menu.I used try catch to prevent ant exception and it worked properly.But i got one problem.When exception occurs,desired msg is printed but i am unable to display the menu to the user.So user wont be able to continue after an exception is caused.
public class ThrowException { public static void main (String[] args) { var x=prompt("Enter a number between 0 and 10:",""); try { if (x>10){ throw "Err1"; } else if (x<0){ throw "Err2"; } else if (isNaN(x)){ throw "Err3"; } } catch(er){
[code]...
It's telling me where catch(er) is: <identifier> expected..I've watched videos, but no one seems to encounter this error....am I missing a segment of code?
In the following piece of code Iam confused as to where the InputMismatchException in the catch block is thrown on the first place? Is the InputMismatchException thrown automatically with declaring to throw the exception?
import java.util.*;
public class InputMismatchExceptionDemo { public static void main(String[] args) { Scanner input = new Scanner(System.in); boolean continueInput = true;
Is it a best practice to return from try block or place return statement after try-catch when we intend to return a value from a method(* Catch block is being also used to rethrow the exception)??
Regarding return statements within methods. So I have a method containing try and catch block (as required) and much like when you have an if else statement... I noted you have to return an object for both the try and catch blocks. Now in my case my method should return a List object.
The way I have tried to overcome this:
- I've initialised a List object to null as an attribute of the class I'm working in. - Therefore in the catch block would just simply return the null List object, where as the try block would return the non-empty List (which is what I want). - I then just test to see if the List != null, when the method is invoked... and that is that.
However the method always seems to return null (when it shouldn't).
I've been assigned to write a program that will convert binary to decimal that uses the try/catch block. In the program that I have written, I was wondering if it is possible to write an addition catch statement that will present an error if any number other than a 0 or 1 is entered by the user. I have already done this in the binaryToDecimal method, but I am just messing around to see if it is, in fact, possible.
Java Code:
import java.io.IOException; import java.util.Scanner; public class BinaryToDecimal { public static void main(String[] args){ Scanner input = new Scanner(System.in);
So I'm pretty sure this is correct, as it follows most examples I can find online, but I keep getting an error that my return variable cannot be resolved. The error is on the return conn; statement. It says conn cannot be resolved. If I place it above within the try block it allows it but then I receive an error saying the method getDBConnection must return type Connection.
I don't want to create this method. Basically I want to connect to the database in the main program, but I do want methods that can access the DB too. But however I place it, it doesn't let me touch any of the DB variables outside of the Try block.
I was practicing my java skills and came across an exercise in which a non parameter constructor calls a two parameter constructor. I tried a few searches online but they all came back unsuccessful. This is the part I am working on:
public PairOfDice(int val1, int val2) { // Constructor. Creates a pair of dice that // are initially showing the values val1 and val2. die1 = val1; // Assign specified values die2 = val2; // to the instance variables. } public PairOfDice() { // Constructor that calls two parameter constructor }
I tried calling the two constructor using the line "this(val1, val2)" but I get an error because val1 and val2 are local variables.
Then I tried to use the same signature: "this(int val1, int val2)" but that didn't work either.
public class hello { /** * @param args */ public static void main(String[] args) { int s = new hello().h(); System.out.println(s); } public int h(){ try{ int g = 10/0;
[Code] .....
the output is 7. how the flow is working. i understand that there is a divide by zero exception after which the control goes to catch. what about the return statement in catch . why is it overridden by finally..........
I'm not even sure if I'm trying to place it in the correct area in the code. However I like to perform this prior to the receipt being displayed so if there a issue the user can correct this before the final receipt has been sent .......
I came across a code where the exceptions can be thrown from catch and finally block too. I never gave a thought on what scenarios that can be required. Some practical examples when/where it can be required to throw the exception from catch and finally blocks.
I want to use a try catch block, but I am not sure how to fix this problem:
int a;
try{ a = Integer.parseInt(A.getText()); } catch (Exception e){ Output1.setText("Error"); }
//do someting with a here
The purpose of the try-catch is to catch blank input.The problem with this is that underneath the try - catch I get an error saying that the variable might not have been initialized. I know why this happens. I know I could initialize the varaible before the try - catch, but there is no default or null I can set an int as. If I initialized it as 0, the blank input will no longer be catched.how to make this problem disappear?
Right now we are learning about arrays and using the try/catch. Code below, I am trying to just display information about buildings. The application is good but not with the try and catch statement. I'm trying to just display the message of "please enter a building number" when a user puts a letter instead of a number(InputMismatchException) and then the user would have to put in one of the numbers. But when it runs and i put in a letter, it reads the message, but it always outputs the first building information ...
package username; import java.util.InputMismatchException; import java.util.Scanner; //TallBuildings public class TallBuildings { //compare heights of buildings
I want to write classes with methods that perform JDBC operations that throw SQL exceptions. For many of the methods, I'd ideally like to be able to have them catch exceptions and just send them to a standard Logging system "IF" the code that calls the methods is not going to catch the same exception. However, I'd like the "option" to have code that calls these methods catch the same errors if I want to but not "Require" the calling routines to catch them.... so I don't want to declare the methods with a "throws" that would require all calling code to Try/catch.
For some background, the logic behind what I'm looking to do is that there will be lots of places where these classes and their methods may be used where the code is basically "throw away" scripting code where just having error logs generated is more than sufficient. However there are also places I want to use the same classes/methods that I would want to handle the exception differently. So, for at least half the places I want to use these methods, there's no good reason to require cluttering the calling code with Try/catch, but when I DO want to handle the exceptions, I'd like them to get passed up to the calling routine so I can handle them in a way that is appropriate for the calling routine. Does that make sense?
I guess I'm kind of looking for is the ability to "override" the catch of a called method "IF" I want to but to treat the method as though it doesn't throw any exception "IF" I don't want to override the called routines catch logic.
