I have a program like below:
final String s1 = "AAA";
final String s2 = "AAA";
String s6 = s1+s2;
String s7 = "AAAAAA";
if ( s6 == s7 ){
System.out.println("s6 and s7 are same" );
}
On running, it prints "s6 and s7 are same". But if i remove the final modifier of s1 and s2 then it's not. What could be the reason?
I am trying to concatenate some strings via: String finalString="(User="+endUserCharge+")";endUserCharge is a string..I get the following error:
caused by: org.codehaus.jackson.JsonParseException: Unexpected character ('(' (code 40)): expected a valid value (number, String, array, object, 'true', 'false' or 'null')
at [Source: java.io.ByteArrayInputStream@3d9127a9; line: 1, column: 2]
I am trying to concatenate 4 strings together to later be able to make them all upper case, or lower case or get the length. I keep getting an error on line 16.
import java.util.Scanner;
public class userInput
{
public static void main(String[] arg)
{
Scanner keyboard;
keyboard = new Scanner(System.in);
String msg1, msg2, msg3, msg4;
[Code] ....
String pool puzzles me again. I think a==b and a==c are both true...
public class StringPoolTest {
public static void main(String[] args) {
String a = "abc";
String b = f() + "c";
String c = g();
[Code] .....
I need to use print not println to declare stuff and I need to have string literals I think that's /n. Now when I compile it just shows row1, row2 ect. Why does it work like that?
public class art {
public static void main(String[] args) {
//local variables
String row1= "***********************";
String row2= "** *** *** **";
String row3= "** ***** ***** **";
[Code] ...
I'm trying to insert some data of type date into database table using hibernate.i take the input date from an xhtml form as shown below
addEvent.xhtml
Event Date (dd-mon-yy) :
<br/>
<h:inputText id="eventdate" value="#{eventBean.eventDate}" p:required="required"
p:type="date"/>
<p/>
<h:commandButton value="Add Event" actionListener="#{eventBean.addEvent}" />
<p/>
This is my addEvent method in EventBean.java
public void addEvent(ActionEvent evt) {
uname = Util.getUname();
boolean a = EventDAO.add(this);
if ( a) {
message = "Event has been added!";
[Code] ....
While executing this..i get the following error: ORA-01861: literal does not match format string. Could it be due to any mismatch in date format (chrome browser automatically takes date in the format mm-dd-yyyy )? If yes, how do I resolve it? (I'm using Oracle database)
I am working with java project which is kind of charting room..but the problem is when am writing the query for listing the message in the conversation the error prevail in my eclipse...string literal is not properly closed by double quote...this is my java file
<%
String uname=session.getAttribute("username").toString();
String pword=session.getAttribute("password").toString();
java.util.Date dat=new Date();
int x=1;
try{
[code]....
string literal is not properly closed by a double quote
View Replies View RelatedUser inputs certain variables for the story, the problem I am having is the concatenation is not working as intended. the story part with the + parts all come back with an error. I thought I had it correct but obviously i don't.
import java.util.Scanner;
public class story
{
public static void main(String[] arg)
[code]....
I'm working with AffineTransforms, and am confused by one aspect of their behavior. It appears that the order in which two sequential concatenations are executed effects the final result. Here's a fragment of code to illustrate the concept:
public void draw() {
radius *= 1.1;
if (radius>800) {
radius = 10;
[Code].....
This code has dramatically different results if the two concatenations are reversed in order. I want to understand what's going on. Is it really true that the order of concatenations affects the final result? From my understanding of matrix multiplication, it shouldn't. Have I missed something here?
I have to implement an object pool that uses phantom references to collect objects abandoned by client threads. This is what I have. I'm really not sure about this implementation.
class ObjectPool<T extends CloneableObject<T>> {
private Queue<T> pool;
private List references = new ArrayList();
private ReferenceQueue rq = new ReferenceQueue();
private CloneableObject<T> prototype
[Code] .....
what is default literal for Boolean data type?
View Replies View Relatedchar c=(char)-65;
This is legal but how ?? what is the value actually being stored in c ? The output is shown as .
I have installed and configured Oracle Business Intelligence Applications on top of one demo eBS instance as a source. Now I would like to change the OLTP to a different eBS instance but am not sure which steps to take. I don't know if I can add new EBS connection pool and a new DataWarehouse Connection Pool in the administration and have old ones preserved or I need to overwrite the old ones? Or (ideally) can I just change the OLTP and overwrite the old DWH?
Any document supporting the process of changing the eBS OLTP database without new installation of the OBIAPPS?
I am working on netbeans IDE , but I understand how the application know the parametres for the connections. I understand what is a Context , specifically i understand this code about the init method
Context initCtx = new InitialContext();
Context envCtx = (Context) initCtx.lookup("java:comp/env");
servicioConexiones = (DataSource) envCtx.lookup("jdbc/bd_tutorias");
I want to know how the application knows to use these connection parameters, on the Context.xml
<?xml version="1.0" encoding="UTF-8"?>
<Context antiJARLocking="true" path="/tutorias_pag480">
<Resource auth="Container" driverClassName="com.mysql.jdbc.Driver"
maxActive="8" maxIdle="4" name="jdbc/bd_tutorias" password="mysqladmin"
type="javax.sql.DataSource" removeAbandoned="true"
url="jdbc:mysql://localhost:3306/bd_tutorias" username="root"/>
</Context>
While doing trial and error got caught in the below scenario.
public class Crypt {
public static void main (String args[])
{
/*all I want is calculate a binary number (ex -: 22 , 34) using decimal base (10n).
*So, I have to convert 2 p into 10n form so I have to find n in terms of p . We have x as the input.
* The formula works as below.
*2p =10n
*p ln (2) =n ln (10)
*n = p [ln(2) / ln(10)]
*2 p = 10 p [ln(2) / ln(10)]
[Code] ....
Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit Production0PL/SQL Release 12.1.0.2.0 - Production0CORE12.1.0.2.0Production0TNS for Linux: Version 12.1.0.2.0 - Production0NLSRTL Version 12.1.0.2.0 - Production0
Using JavaSE-1.7
Using ucp.jar,ons.jar and OJDBC7.jar
I set up the datasource as follows :
pds = PoolDataSourceFactory.getPoolDataSource();
pds.setConnectionFactoryClassName(factoryClassName);
pds.setMaxPoolSize(maxPoolSize); maxPoolSize 10
pds.setMinPoolSize(minPoolLimit); minPoolLimit 1
[Code] ....
In the class that actually uses it I create a method variable for the connection object.
Closing the connection as well as pds.getConnection().close();e
I am thinking that at the most I should have only one inactive connection showing up when I monitor the session. How do I configure the pool as to only show on inactive connection? I am running the test queries once every five minutes. But I am opening three connections each time.
in Operator/Literals, it says "There is no literal representation for binary numbers in C, C++, or Java." seems "0b11001" could reprensent binary numbers?
int i = 0b100;
System.out.println(i);
the output should be 4.
I thought numeric literal were by default int or doubles, depending on if have a . and numbers after the But I wrote a quick test program as listed below. I understand the float float floatA = 5.5; failed to compile since 5.5 is a literal of type double and you are trying to assign this to a floag
What I am having problems with is byte byteA = 5; 5 is a literal of type int and this is being assigned to a byte and compiler should complain.The compiler does not allow two byte values to be added and assigned to a byte since the result of the addition is an int
class literalTesting{
public static void main(String[] arg){
byte byteA = 5; // allowed WHY I thought literal is an int and assigning int to byte
byte byteB = 10; // allowed
[code]...
We have a J2EE business web application that runs in WebLogic. We noticed in application log files errors messages that seems like "No resource available in db pool", it means all the connection objects (to Oracle database) are used. Then the application is unstable and unseable.
I think the maximum number of connections configured in Weblogic pool has been reached due to an increase of users and activity. But when the workload decreases the application is still out of service. It seems connections objects are not relased to the pool. What can be the explanation for this issue ? Normally it is managed by the container (EJB3 for the business tier).
Once the limit of the pool is reached it is necessary to restart the server to solve this kind of error ?
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?
This program is for a swimming pool filling service company. They charge 2 cents per gallon and $50 per hour to fill a pool. The truck can fill at a rate of 730 gallons per hour.
Create the Pool class that calculates the cost to fill a pool based on it's Shape, length, width and depth. (Input order is S L W D)
The pool class will need data fields for String shape, double length, double width, double depth, static double GallonsPerSqFoot = 7.4805, static double price per gallon = .02, static double FillingFeePerHour = 50.0, and static double FillingRate = 730gal/hr.
Create a No-Arg constructor and a constructor that accepts the non-static values, and has the methods: getShape, getLength, getWidth, getDepth, getGallons, getHours, getFillingFeePerHour, getHourlyCost and getTotalCost.
At the end of the class, create a main() method that asks for the input and returns the output based on the Pool class gets.. methods.
The shape options are oblong or rectangle. (A round pool would be oblong with the same width and height, a square pool would have the same width and height)
Formulas:
Rectangle cubic ft = length * width * depth.
Oblong cubic ft= ((Math.PI * Math.pow(width/2,2)* depth) +((length-width) * width * depth))
Gallons = cubic ft * 7.4805.
hours = total gallons/730.
Total cost = (total Gallons * .02)+(hours * $50)
Example Output
An oblong pool 18.00 feet long by 12.00 feet wide and 5.00 feet deep will use 6923.10 gallons of water and take 9.48 hours to fill. The total cost will be 612.65.
Here is my code:
import java.util.Scanner;
import java.util.*;
public class Pool
{
private String poolshape1 = "oblong";
private String poolshape1 = "rectangle";
private double length;
private double width;
private double depth;
private static double GallonsPerSqFoot = 7.4805;
[Code] .....
I have created a JSP page, on click of a particular button, the control moves to the servlet "TestServlet".
This is the code under TestServlet:
import java.io.IOException;
import java.io.PrintWriter;
import java.security.Principal;
import java.sql.Connection;
import java.sql.SQLException;
import java.sql.Statement;
[Code]...
Now, I have got a comment saying I should get the database connection from connection pool. And one more issue is that I have used the function System.getProperty("user.name") to get the username which i have logged in. But this code will be run on Unix which will not support this function. Any function where I can get the windows username. There is a function getUserPrincipal(), but this function returns a NULL. How to resolve this.
I configured a connection pool in tomcat 7. For every database activity I get a connection from the pool. Do I have to close the connection like other regular connection after the database operation is done? If I close the connection will it have any effect on the connection pool?
View Replies View RelatedHow can I write a method that takes a string with duplicates letters and returns the same string which does not contain duplicates. For example, if you pass it radar, it will return rad. Also i would like to know how can I Write a method that takes as parameters the secret word and the good guesses and returns a string that is the secretword but has dashes in the places where the player has not yet guessed that letter. For example, if the secret word is radar and the player has already guessed the good guesses letters r and d, the method will return r-d-r.
View Replies View RelatedI am currently trying to make a calculator in Java. I want to use the String split method to tokenize the string of characters inputted. I thought I was using the String split method wrongly, because I had surrounded the characters I wanted to delimit with square brackets. However, when I removed the square brackets, the code threw an exception when I pressed the equal button. The exception was a PatternSyntaxException exception. Am I using the String split method wrongly? And why is the exception thrown? Here is my code:
import javax.swing.*;//import the packages needed for gui
import java.awt.*;
import java.awt.event.*;
import java.util.Arrays;
import java.util.List;
import static java.lang.Math.*;
public class CalculatorCopy {
public static void main(String[] args) {
[Code] .....