JDBC :: Simple Java Program Execution Time Varies All Over The Place
Mar 5, 2012
I've got a very simple java program (J.java, see below) on my application server that successfully connects to an Oracle 11.2 database on a database server (both servers are Linux CentOS) using JDBC thin driver from Oracle.
As you can see from the setURL command in the Java code below, I've configured the application and database servers to sit next to each other, and they're on the same network (cross-cable connected to each other), so there's no network traffic on these (development) boxes except my code.
The problem is the execution time varies a lot. If I run it 5 times, it (seemingly randomly) could take 0.01 seconds, or 10 seconds, or 50 seconds, or over a minute to execute. If it takes over a minute (roughly), the program doesn't complete, but the error shown below is returned instead.
------error returned when execution take more than about 1 minute-------
gf@host9 [~/dbwork]# java -cp ./ojdbc6_g.jar:. J
Exception in thread "main" java.sql.SQLRecoverableException: IO Error: Connection reset
at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:494)
at oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java:547)
[Code] ....
----------the java code for: J.java-------
// To compile: # javac -cp ./ojdbc6_g.jar:. J.java
// To run: # java -cp ./ojdbc6_g.jar:. J
import java.sql.*;
import oracle.jdbc.*;
import oracle.jdbc.pool.OracleDataSource;
class J {
public static void main(String args[]) throws SQLException {
[Code] ....
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Jul 14, 2014
i want to write a class in such a way that i should get the current execution time of another class which is running. I searched in net but it shows only how to calculate the time duration of the current class which is running. But as per my way, i need the execution time of one class from another class. How to do this ?
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Apr 10, 2014
I'm having trouble formatting my output and issues with the decimal places. Here's my code:
import java.util.Scanner;
import java.text.DecimalFormat; // Imports DecimalFormat class for one way to round
public class lab3 {
public static void main(String[] args) {
String heading1 = "Hour", heading2 = "Distance Traveled";
int timeElapsed, hour, speed;
[Code] ....
And here's my output (Click on the image since it's pretty small):
javaIssues.png
Issue:
1) The Hours 2 and 3 aren't aligned to 1.
2) The 80 and 120 in Distance Traveled have 6 decimal places when it should not have decimals.
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Oct 10, 2014
Ex. If I type 5943, the program will say
mill = 5
hun = 9
ten = 4
uni = 3
get the picture I had to translate the decimal value names from a different language.
This is what I have tried...,
Java Code:
import java.util.Scanner;//Permite el uso de leer el teclado del usuario
public class DeterminarValorDecimal//Nombra el documento
{
public static void main(String [] args)//Podemos ver la clase
{
[Code].....
But what this does is I have to enter the single digits one by one. I want to be able to type the whole number. Is there a method that reads the length of the whole number and lets me classify each digit so I can do what I want to do?
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Apr 10, 2014
I've made a simple program in Java (Eclipse) that converts Fahrenheit to Celsius.The class is:
Java Code: package ehu.student;
public class ConversorTemperaturas {
/*--------------------------------------------------------------*/
/*Clase que dado una temperatura en Fahrenheit la canvierte en C*/
/*--------------------------------------------------------------*/
public float farenheit2celsius (float d){
float celsius, aux;
[code]...
When I write t.farenheit2celsius(25.6), appears the following error: "The method farenheit2celsisus(float) in the type ConversorTemperaturas is not applicable for the arguments (double)"If i change in the class the type float for double there is not problem. Why can't i use the type float?
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* program to practice about comparison operators */
public class compoperators {
public static void main(String[] args) {
boolean result;
}
[code]....
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I would like to ask you how can i execute the next code without errors.
I am trying to execute a jar (myFile.jar) file multiple times with different inputs from another jar file. More simple i have game with many players and i create a Round Robin scheduling for the tournament, i need to execute all the mach's of a round together.
When i run the next code it execute on the first game with the first players multiple times.
Java Code:
public class RunJARFile {
//10 player
//5 game per round
public static void main(String[] args) throws IOException {
for (int Tour = 0; Tour < 9 ; Tour++) {
for (int Game = 0; Game < 5; Game++) {
[Code] ....
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Jul 23, 2014
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java.lang.StringIndexOutOfBoundsException: String index out of range: 0
at java.lang.String.charAt(String.java:658)
at sentence.main(sentence.java:22)
[Code] ....
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May 17, 2014
calling a parameterized stored procedure in java jdbc from sql server.The stored procedure goes like this in sql
create proc patientreg
@id int
as
begin
select [patient_id],[Psurname], [pFirstname], [pMiddlename], [reg_date], [DOB], [Sex], [Phone_num], [Addr],[Email],[dbo].[fncomputeage](DOB) from [dbo].[Patient_registration] where [patient_id] = @id
end
please note dbo.fncompute(DOB) is a function
To call it in jdbc it goes like this
try{
String str = "{call patientreg(?)}";
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
con = DriverManager.getConnection("jdbcdbc:GeneralHospit al");
cstmt = con.prepareCall(str);
cstmt.setInt(1, Integer.parseInt(t.getText()));
[code]....
after doing it this way it throwing an exception: Error:java.sql.SQLException: Parameter 1 is not an OUTPUT parameter.
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Nov 23, 2014
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at java.awt.Container.addImpl(Unknown Source)
at java.awt.Container.add(Unknown Source)
at Input.buildPanel(Input.java:53)
at Input.<init>(Input.java:27)
at InputDemo.main(InputDemo.java:5)
I've created two classes
import javax.swing.*;
public class Input extends JFrame {
private JPanel panel;
private JLabel messageLabel;
private JLabel messageLabel1;
private JLabel messageLabel2;
private JTextField shiftHrs;
[code]....
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//set final sizes for window
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public class pyramid extends GraphicsProgram {
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private static final int BRICK_HEIGHT = 12;
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[code]...
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Apr 9, 2014
This is a simple project that i was using to test my current java knowledge (kinda like revision) and for that i used two classes to make a simple averaging program. i know i0m making it more difficult but like i said i'm testing myself but i come up with an unexpected error. Here's the code:
- 1st Class
import java.util.Scanner;
public class Main {
public static int num;
public static int total = 0;
public static int average;
[Code].....
Now the problem is after inputing the numbers it doesn't give me the average but the value of 0.
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import java.util.StringTokenizer;
import java.io.*;
[Code].....
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Encryption
*/
public class Encryption extends java.swing.JFrame{
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public class Connect
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Jan 22, 2014
I am having a difficult time writing what started out as a simple vending machine program. As I go on though, it seems that I'm overcomplicating it and it is getting messy, so I have resorted to the forum before I really get off the path. how to clean it up? I'm going to list a few of the problems I am having with the code below:
1. The user is supposed to enter his/her money and the program is to read each value separately (Do-While loop) and keep a running total of the money entered. I can't seem to get the right code format to do this. I was trying to do this with the variable total and so that is why the total exists in the switch statement, but it did not work.
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package practice;
import java.util.Scanner;
public class Practice {
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Sep 13, 2014
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Everything has been going really well, except that my mirrors only reflect the first ray that comes in contact with them.
Here's a screenshot : 2014-09-13 at 7.39.23 PM.jpg
I wrote 7 classes:
Main class to create the optics objectOptics class. the most important class that uses a recursive function to detect the nearest intersection point of a ray with the nearest optics object. It then calculates a reflected ray and inputs it back into the function until no intersections are found or the max recursion depth is met.Ray. creates a rays (in parametric form O + tD where O is the origin, D is the direction and t is a non-negative scalar)Object. empty abstract class used for polymorphism (so when i add more optics objects like prisms and lenses they'll share the object type)Mirror. Basically a line segment created with the Line classLine. Creates a line segmentDraw. JComponent with paintComponent function that loops through an array of shapes and draws them to the screen.
What I know so far is that the problem boils down to the checkRay() function in the Optics class. When a mirror has already reflected a ray, the line:
Intersection sec = new Intersection(ray,(Mirror)obj);
creates an intersection with a null point.
I debugged it line by line and found the problem was that my variable 't' (that is the parameter for the parametric line which represents the mirror) in the Intersection class got big values when it's meant to be between 0 and 1 (since it's a line segment), which resulted in the function returning null (as it should when 't' is not between 0 and 1).
I've confirmed with tests that this has nothing to do with the specific mirror or angle of incidence. It only occurs when a mirror has already been intersected with by a ray.
I've found out that my function:
public PVector getNormal(PVector D){
D.normalize();
return new PVector(D.y,-D.x);
}
Changes the value of the 'D' PVector of the mirror inside my 'objects' ArrayList. How can it access the private PVector 'D' from outside the Mirror class? This normalization to the direction vector is what causes the Intersection class to return null the second time around!
The problem was that in the getNormal function, the input vector argument was a reference to the 'D' vector for the mirror in my 'objects' ArrayList so the .normalize() function acted upon the original vector, changing it's value and screwing things up. The two classes I talked about:
Optics: (note line 64. this line returns a null intersection when it shouldn't)
package ofer.davidson;
import java.util.ArrayList;
public class Optics {
//Arrays to store all the optics objects and rays that are created
ArrayList<Object> objects;
ArrayList<Ray> rays;
[Code] .....
Also why doesn't my background turn white??
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May 12, 2015
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For some reason, the program is always returning -1, rather than the index of the string within the ArrayList when there is one which matches the search criteria.
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[Code].....
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Feb 26, 2015
I'm having problem with my code when it comes to Restore Database in Java. This is my code:
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Process runtimeProcess;
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[Code] ....
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Aug 12, 2014
I need getting started designing and creating a program that calculates simple and compound interest. Simple interest in this case means that interest is only applied to the original amount. For instance, if a person deposits $1000 at 10% annual interest, then after one year they would have $1100 (the original $1000 plus the $100 interest) and after two years they would have $1200 (the original $1000, plus the $100 earned the first year, plus the $100 earned the second year).
With compound interest, the interest is applied to all money earned. So, starting with $1000 at 10% annual interest, after one year the user would have $1100 (the original amount plus $100 interest) and after two years the user would have $1210 (the $1100 they started with at the beginning of the year plus the $110 interest).
The requirements of this program are:
-Create a class that will hold methods to calculate the interest. Do not include the main method in this class.
-In the class that is used to calculate the interest, include a method to print to the screen, by interest period, the starting amount for the period, the interest earned for the period, and the total amount at the end of the period. Note that each period represents the time frame for how often it is updated. If annual is selected the period is every year. If it is semi-annual it is every six months. If it is quarterly it is every three months.
-Create a demo class that will use your interest calculation class. Prompt the user for the original amount, the type of interest (simple or compound), the annual interest rate, and whether it is updated annually, semi-annually, or quarterly. Use method calls to your calculate interest class to do all calculations and display the result. Loop the program until the user chooses to quit.
Sample output ($10000 initial investment, 10% simple interest, annual, for 4 years):
Period Beginning Amount Interest Earned Ending Amount
1 10000.00 1000.00 11000.00
2 11000.00 1000.00 12000.00
3 12000.00 1000.00 13000.00
4 13000.00 1000.00 14000.00
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Feb 13, 2015
When I Start Server and login from client everything goes fine but as soon as I want to send amessage or use showIn or even logOut .
Get below error
Exception creating new Input/output Streams: java.io.EOFException
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