To Decrypt Data - File Containing Keys Is Not Being Read

Aug 27, 2014

I am developing a java code using netbeans for encryption decryption by RSA algorithm. Swings and file handling play a major role in these code. My encryption code is working nicely but the code for decryption is not since keys file is not being read. That is why variable mod and pri are getting null values and the following error stack is coming. I know where the problem is somewhere in void readkeys() function but cannot solve it.

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at java.math.BigInteger.modPow(BigInteger.java:1579)
at rsakeydecryption1.RsaKeyDecryption.decryption(RsaKeyDecryption1.java:167)
at rsakeydecryption1.RsaKeyDecryption.read_output(RsaKeyDecryption1.java:294)
at rsakeydecryption1.RsaKeyDecryption.actionPerformed(RsaKeyDecryption1.java:330)

[Code] .....

My code for decryption is

package rsakeydecryption1;
import java.math.BigInteger;
import java.util.Random;
import java.io.*;
import javax.swing.*;

[Code] ....

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New to programming. Am supposed to create a program that reads a text file (of integers) and computes a series of computations on these integers. I don't have the code for the integers in my code yet, (i know how to do those), but am struggling getting the array to simply print in the print writer. I have the user select a text file, read the file with a scanner, and then save the computations done from my code into another file. specifically, the problem is as follows: Write a program that uses a file chooser dialog to select a file containing some integers. The file contains an integer N followed by N integers. The program then uses a file chooser dialog to let the user specify the name and location of an output file to write results to.The data written to the output file will be as follows

(1) The original list of N numbers from the input file,
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in the input file.
(3) The sum and average of these numbers,
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[import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.Writer;

[Code]....

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The following code is doing it already on one host:
 
package test;
import java.io.FileInputStream;import java.io.FileOutputStream;import java.io.ObjectInputStream;import java.io.ObjectOutputStream;import java.io.Serializable;import java.security.Provider;
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[Code] ....

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The problem with my program is a variable that I have initialized, is being said its not being initialized.

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Nov 15, 2014

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Java Code:

public void readOSMWay(File osm){
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Scanner output = new Scanner(osm);
while(output.hasNext()){
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[Code]...

I am having problem with the else if block. I am supposed to add all the Long values into the array.

error: Java Code: The method add(Long) in the type ArrayList<Long> is not applicable for the arguments (String) mh_sh_highlight_all('java');

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Sep 10, 2014

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I'm yet to discover how I will get the info from the textfile using scanners but I don't know how to "create instances of a reference type".

This is the code of Product.java that came with the exercise.

public class Product {
private String productCode = "";
private String productName = "";
private int quantity;
private String supplierName = "";
private String supplierAddress = "";
private double price;

[Code] .....

By the way, the exercise also required me to use the abstract class ProductLister. To be clearer, the text file is kinda like this:

54643
Rizer Mouse
Mark5s Merchandising
Marquee Mall
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205.50
23412
Acer Ultrabook
JohnJade Merchandise
Cornal City
2
62200.00
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Dell Ultrabook
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Cornal City
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68900.00
22126
Macbook Air Pro
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San Beda, Chad
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Jun 13, 2014

I have 3 csv files as follows -

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magazine file Columns - title | isbn | author_email | releasedate

I need to display -

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I am using Buffered reader as of now -

String csvFileToRead = "csvFiles/authors.csv";
BufferedReader br = null;
String line = "";
String splitBy = ";";

[Code] ....

I am confused about how to proceed with multiple files. Here are the approaches that i have considered -

1) change string csv csvFileToRead to a string array -

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Pass each index each time to a method returning all rows but getting stuck with DS to use. I think ArrayList wont suffice since i need separated data. Should i use a 2D array? Do i need to read and store data in a DS in order to achieve the goal?

2) Should i make 3 different classes with getters and setters for authors, book and magazine?

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java.io.RandomAccessFile random=new java.io.RandomAccessFile("D:/input.txt","rw");
//Position the pointer to a seek
try {
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long pointer=random.getFilePointer();
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int a;
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Where am I wrong? Although it is returning actual position of pointer in pointer using

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Nov 17, 2014

I need to read a csv file from the disk and manipulate the data inside. My problem is that if the csv (excel format) contains "" in any of it's values the whole string line gets saved/displayed incorrectly . For example for the line in the csv file :

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it gets read in java as :

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instead as :

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My code is :

String csvFile = "resources/testcsxs.csv" ;
String l = "";
try {
BufferedReader cz = new BufferedReader(new FileReader(csvFile));
while ((l = cz.readLine()) != null ){
System.out.println(l);
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Nov 15, 2014

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Quote
Temperature Data

Week 1: 73 71 68 69 75 77 78
Week 2: 76 73 72 72 75 79 76
Week 3: 79 82 84 84 81 78 78
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Oct 11, 2014

I'm having a bit of trouble with using the Scanner and the Printwriter. I start with a file like this (1 = amount of Houses in the file)

1
FOR SALE:
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The user gets (let's say for simplicity) 3 options:

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This is how I start:

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while (!endLoop) {
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For this, I use try (PrintWriter out = new PrintWriter(new BufferedWriter(new FileWriter("Makelaar.txt", false)))). This works perfectly (at least so it seems.)

If the user chose option 1, and all requirements are inputted and scanned, the Houses will be read (scanner) from the file and outputted. For this I use the same Scanner sc. This also works perfectly (so it seems atleast).

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import java.io.*;
import java.util.*;
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[code]....

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public class Storm {
private final double KnotsToMPH = 1.15;
// global user-defined types:
private int beginDate;
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[Code] .....

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[code]...

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import java.io.*;
import java.util.Scanner;
import java.text.DecimalFormat;
public class Output {
public static void main(String[]args) throws IOException {

[Code] .....

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import java.util.Scanner;
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[Code] ....

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package com.example.bluetoothtest2;
import android.app.Activity;
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[Code] ....

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import java.io.File;

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

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Java Code:

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

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[Code] .....

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Sep 24, 2014

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Heres is the code:

import java.io.*;
import java.lang.*;
import java.util.*;

/* This program will read a file given by the user, read the words within the file and determine anagrams of the given words. If the file that the user inputs is empty, then the program will output "The input file is empty."
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[Code] ....

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