What I'm tasked to do, is to make a simple Java class that forms a "V" based on whatever height the user would desire, made out of stars "*", and spaces " ".
For example, if a user desires a "V" with a height of 3, it would look print out something like;
* *
* *
*
Where a "V" with a height of 5 would look something like:
* *
* *
* *
* *
*
(That one didn't look too good, but you get the point, it's suppose to be 5 "high" and shaped like a "V"). The problem I have, is that I don't see what loops within loops within loops I would need to build something like this.
All the easy stuff like asking the user what height they want and such, I can handle, but I don't see how this thing is suppose to be coded, to print out a decent-looking and right-sized "V" in the console.
public static void main(String[] args) {
int height = 3;
for (int i = 0; i < height; i++) {
for (int j = 0; j < 2/(height+1)+1; j++) {
if(j == i) {
[Code] ....
Looked like something of a good start, and it drew me half (!) of the "V" in the size I wanted. Am I on to it here, or am I on the moon in terms of progress? I need the entire "V", not just a nice "".
I am attempting to write a application that asks user input of a decimal, and outputs a value rounded to the nearest integer of the input.
Here is what I have so far, and I am seeing an error at Static Scanner Console that says Cannot Find Symbol for the class Scanner. and I am not sure how to resolve it.
Note the program so far is only asking for input - I have not gotten to the output part yet.
public class IT145Exercise13 { static Scanner console = new Scanner(System.in); /** * @param args the command line arguments */ public static void main(String[] args) { double decimal; int rounded;
[Code] ......
This is my second Java program (First was HelloWorld, which went really well )
Seems I need to include import java.util;
when I do, the error at the console line goes away.
I am not clear what this import statement is doing so will check that out.
i have to write more than 100000 rows in a excel sheet (file size more than 20 MB) via java.
when i use XSSF, i am getting below Error.
java.lang.OutOfMemoryError: Java heap space at org.apache.xmlbeans.impl.store.Saver$TextSaver.resize(Saver.java:1592) at org.apache.xmlbeans.impl.store.Saver$TextSaver.preEmit(Saver.java:1223) at org.apache.xmlbeans.impl.store.Saver$TextSaver.emit(Saver.java:1144)
[Code]....
when i use HSSF , i am getting the below Error. java.lang.OutOfMemoryError: Java heap space
I have tried increasing the java heap size , by giving upto -Xms1500m -Xmx2048m
I found an exercise online to create a small program . I have this code that I have done so far:
import java.util.Scanner; public class Test { public static void main(String args[]) { Scanner sc = new Scanner(System.in); long a = sc.nextLong(); long b = sc.nextLong(); long count = 0; // counter
[code]....
The program should read the numbers a and b and list how many numbers between a and b are divisible by either 2, 3 or 5. If the user types the number 5 and then 8.... it would look at all the numbers in between - 5,6,7,8 and check if any of them are divasable by either 2,3 or 5. And since the numbers 5,6,8 are it would return the number 3 to the user..Now the problem is that this program only works for small numbers, but when I try to input numbers such as 123456789012345678 and 876543210987654321... it doesn't run at all.
So there needs to be a quicker way on how the program checks the numbers divisibility instead of checking each one. Here is where I am lost. How to fix the program that it will read bigger numbers such as a=123456789012345678 b=87654321098765432..There must be a quicker way ...something that can modify the code so it finishes in the matter of seconds not hours. Something that will fasten the process of checking if the numbers are dividable.
I want to migrate some large application code base's from jdk1.4 to jdk1.6.
1. Is there any tool/s available that can be used for this migration (Because manually it is very difficult for a application with almost 15,000 java files and 15 * 10^6 KLOC within a limited time frame).
2. Steps that should be followed in such cases.
3, If any tool is not available for such activity what are the salient points that are needed to be considered while migrating.
I would want to use one of Swing components to display the students instead of displaying them on the stdout. How I could go about calling this method in some Swing components that can display all the students in the studentdb?
I need to encrypt/decrypt file contents using RSA . But the default nature of RSA I could not upload files larger than 177 bytes for key length 1024 bytes . How it can avoid , I look it for a 100 times yet...
I am calculating an exponent without using BigInteger. However, I find that using long is not enough to handle my code. Is there a way to handle large numbers without using BigInteger?
public static void main (String[] args){ int base = 3; int exponent; long total = 1L; boolean n; Scanner input = new Scanner(System.in);
I have an application which has 10 million rows and 1000 columns in Oracle. Each value has a different set of calculations that are stored in User Defined PLSQL functions.
Data is displayed in form of data grid. When a user updates any value, the calculation is performed using plsql function and value is stored in database. Is there an easy way through which calculation is performed on the fly and i get maximum performance ?
I'm programming an android app where I want to send large sets of data from an MySQL Table to the app and write this data to an SQLite database.So I know i have send an HttpRequest and I can send data with json, but how can I handle large datasets like tables?I think its no good idea to just concatinate a string together in php and then send it?
In my programming class we need to create a large test array of Longs to iteratively sum/reverse the array and recursively sum/reverse the array.creating the array and where to go from there.
We have a website used for downloading large files as large as 6gb and sometimes larger. We have all files in FTP server. The websit is JSP/Servlet /Tomcat combination. Below is code sample. I need a solution to increase the download speed. I understand it is bound to network bandwidth but are the steps that we need to take while we have such large files.I read about multipart downloads,gunzip streaming.
//first connect to FTP server and login and keep connection Calendar cal=Calendar.getInstance(); startTime=cal.getTime(); fis=ftp.downloadFile(ftpclient,separator+resourceID); response.setContentType("application/*"); response.setHeader("Content-Disposition", "attachment; filename="" + downloadFileName + "";"); byte[] bytes = new byte[1024];
reading a large json file which is really huge and it contains pair of id and URL in a array as shown below.. i need to get this all id and URL from this file in my java code and need to perform operations . how to read such a big file and store the contents in java code to process it further.
{ "Array": [ { "id": "1test", "URL": "http://servername/test/1test.html" }, { "id": "2test", "URL": "http://servername/test/2test.html" } ....................many id and URL in the same Array which makes the file Huge.. ] }
I have a program that works, but I would like to know an easier way to record and print from a large array.
Here is what I have
package pa2; import java.io.IOException; public class PA2Delegate { //long[] array = new long[100000]; int arraySize = 100000; int iterations = 9999; Long[] array;
Our client has a user facing web application running on Jboss. There is a separate admin application (in its own ear) but deployed on same Jboss server on which user facing web application is running.
They need a screen to upload large amount of data into database. Their original files were in excel with size > 60 mb. We suggested following to them:
a. Change upload format to CSV - this brought down file sizes to 25-30 mb b. Upload process will be MDB - asynchronous processing of data so that admin web app does not stop responding
We also suggested following to them:
a. Host admin app on a different machine so that user facing site does not respond slow during data processing b. We can provide incremental upload feature and they should upload files in the chunks of 4-5 mb, specifically if they have user a web page to upload such files - they don't buy this argument though. c. Data processing can be a separate script instead of a part of admin web application. They can FTP files to a designated location and this script will process those files.
I have following questions:
Q1 - Have you seen upload of such large datafiles to a web application? I see sites like Zoho CRM or Salesforce do not support such data imports and mostly fail or not respond. Q2 - Is there a set of guidelines/best practices to upload large data files of this nature? How do insurance companies or others with enormous set of data accomplish such tasks (what is the architecture of such programs)?
I have application written in rest with Jersey-Jackson for JSON processing. All the resources produce and consume JSON. Now, the problem is, it is a server intensive application and large number of request will be hitting the server with large JSON request object. Now, because of this reason, when the JSON object gets converted in to Java object with String fields in it mapping to JSON request values large number of string objects are getting created which is resulting in frequent GC.
Right now I have 12 methods, each roughly 40 lines long, and I am contemplating whether I should simplify some of the pairs (12 methods, but every other method is very similar to each other, so 6 pairs) into one method.
The main pro of simplifying them is that my class will be much smaller, right now its about 555 lines of code. However a con is that it might not be as straight forward, at first glance at least.
Here is what I am talking about. Two original methods that are very similar:
void rotateRightClockwise(int rotations){//rotates FRONTS's RIGHT! CONFIRMED String a, b, c;//temp values for(int i = 1; i <= rotations; i++){//confirmed a = cube.cube[1][2].square[2];//3 b = cube.cube[1][2].square[5];//6 c = cube.cube[1][2].square[8];//9
[Code] ....
The only difference between these two methods, other than the last chunk for each method, is the I have to change the 2nd square bracket, [], values from lines 9-23 for cube[][]. That's it. So I am thinking of combining them into something like this...
private void rotateRight(int rotations, int x, int y){ String a, b, c;//temp values for(int i = 1; i <= rotations; i++){//confirmed a = cube.cube[1][2].square[2];//3 b = cube.cube[1][2].square[5];//6 c = cube.cube[1][2].square[8];//9
[Code] .....
And then after calling this similar method, I would finish off the last chunk from each methods, since they are too different (ie lines 26-38).
The reason why I ask this is because I am trying to build up my portfolio and I want to know if the employer would look at this and say "that was a good move by compacting your code" or "this is not that straight forward".
I am familiar with php, but I don't know Java. We need a program, that will be able to scrape large amount of title tags from large sites, fast. I've been trying Seo Spider by Screaming Frog, and Xenu's Link Sleuth, but these programs are not good enough. They hang up, they save all the data in RAM, I think, and after a relatively short period of scraping, they stop working, become unresponsive, and so on.
Somebody recommended me getting a custom made program in Java, which would be able to scrape title tags only, from large sites (I am talking 25 - 50 million pages or more). I was told that it would not have a graphic interface, or anything like that. Nothing like this is needed too, we just need to have title tags.
I have a question regarding best practice in using local variables as my method return variable. I have a method like this:
myReturnObject getMyObject(String input) { myReturnObject myObject = null; try { myObject = helperObject.someOtherMethod().getObject(input); //getObject has return type myReturnObject } catch (Exception e) { //log any problems } return myObject; }
And I'm wondering if I rewrite like this if I'll see some performance optimization benefit:
myReturnObject getMyObject(String input) { try { return helperObject.someOtherMethod().getObject(input); //getObject has return type myReturnObject } catch (Exception e) { //log any problems } return null; }
myObject can be quite large -- so I'm wondering if I can omit the myReturnObject local variable instance if it'll save some work from the garbage collector.
I need to built a file upload service which should be memory effective. I should avoid loading the entire file into memory,Since I may have multiple http request which will pile up the Heap memory. Any effective way to upload a large file(For ex:1GB file) using http Streaming. I need to do the file upload on a single http call. Let's consider a scenario where 1 GB file to be uploaded using 512MB Heap memory. Not Sure If practically I can achieve this or not.
