I am developing a Client/Server java application, where CSMessage is sent through socket.CSMessage has some data like String type and HashMap<String, String> type.the Client send message:
private ObjectInputStream in;
private ObjectOutputStream out;
out = new ObjectOutputStream(socket.getOutputStream());
in = new ObjectInputStream(socket.getInputStream());
[code]....
When this happen, the only way to make the system to work is to kill the process and restart it, that's bad!
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)??
I'm doing project in area of "Cryptography and Network security". I'm having a file with binary Unicode (mean file contain Unicode value of corresponding data (text file)), want to divide that as blocks with the size of 144bits.
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).
Modify the program in Assign4 to synchronize access to the instance variable, balance. Save the program as SyncBank.java. Because balance is a double and not an object, it cannot be used as the monitor. Use synchronized methods or synchronized blocks of code as appropriate. Simultaneously test two threads as was done in Assign4. Because the threads can complete too quickly to determine if they are interfering with each other, delay the adding of a deposit by inserting the following code within the synchronized block or method:
It's always good to keep functions smaller and focused on one behavior. So is this safe:
Java Code:
public Unit findBySql(int id){ Unit unit=null; DbConnectionPool dbPool = DbConnectionPool.getInstance(); HashMap<String, String> conditions = new HashMap<String, String>(); conditions.put("id", String.valueOf(id)); String sql = buildSelect("units", "*", conditions);
[Code] ......
As you can see a pass ResultSet to a function which populates the item. But I also make sure that the ResultSet that the passed object is pointing to is closed, so it doesn't leak resources.
My current lesson in Java is about ArrayLists and I'm having a tough time to understand this bit of code: This exercise is concerned with the problem of deleting a block of items from an ArrayList.
public static void deleteBlock( ArrayList<String> strings, int n ) { for ( int i = 0; i < n; i++ ) { if ( strings.size() > 0 ) strings.remove( i );
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?
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 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.
/* * To change this license header, choose License Headers in Project Properties. * To change this template file, choose Tools | Templates * and open the template in the editor. */ package part1; import java.awt.*; import java.applet.*; import java.awt.event.*; import javax.swing.*; class brick {
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?
I don't know how to write a code to pong ball, when it touch red block.
public class bounc2 extends JPanel implements ActionListener,KeyListener{ double x = 0,y=0,velX=3,velY=3; double x2 = 5,y2=145,velX2=0,velY2=0; double x3= 473,y3=145,velX3=0,velY3=0; Timer t = new Timer(5,this); public bounc2(){ setBackground(Color.GREEN);
class MultipleReturn { int getInt() { int returnVal = 10; try { String[] students = {"Harry", "Paul"}; //System.out.println(students[5]); //if i remove comment
I am trying to make a custom texture system for a block in Minecraft, I am not too advanced with Java and am not sure how to make this work the way I want it to.
/** The list of the types of step blocks. */ public static final String[] blockStepTypes = new String[] {"stone", "sand", "wood", "cobble", "brick", "smoothStoneBrick", "netherBrick", "quartz"}; private Icon missing; private Icon icon1;
/** * From the specified side and block metadata retrieves the blocks texture. Args: side, metadata */
[Code] .....
Alright, so basically I figured I could just tell the code to see if the block is made out of Stone, then to set the texture to Stone, or if it's made out of Sand, then set it to Sand.
What I usually get is Eclipse telling me to "insert '!= null' check", "insert '!= null' check", and then just error out saying "Opperator != is undefined for the argument type(s) boolean null"
Is there any way I could make this work for me? Maybe some other way to make it do what I am trying to do?
If I put the highlighted text in try/catch block it is throwing NullPointerException , if I am using command line arguments then also it is showing the same exception.
java 7 feature (Multicatch and final rethrow ).. how to print user defined message in catch block with respect to multiple exceptions in single catch block...
Ex: }catch (IOException | SQLException ex) { System.out.println("Exception thrown"); /** * i want like this, if IOException is thrown then System.out.println("File not Found"); * if SQLException is thrown then System.out.println("DataBase Error"); */ }
