I am using a 64 bit Win 7 Pc with 64-bit JVM and we get the error: Java heap space. So we want to increase the Java heap size but not for one application but for every application or in general.
We tried with the java -xmx command but it didn't work...
We tried setting the system variable JAVA_OPTS but again it didn't work...
The array size is fixed improve it to automatically increase the array size by creating a new larger array and copying the contents of the current array into it .I am using a course class and here is the code for the class
public class Course {
private String courseName;
private int numberOfStudents;
private String[] students = new String[100];
public Course(String courseName)
[Code] ....
As you can see I have the array set to size 100, how do i make so it increments each time the user adds a student.
I'm working on an assignment that says the following.
" The array size is fixed in Listing 10.6. Improve it to automatically increase the array size by creating a new larger array and copying the contents of the current array to it.Implement the dropStudent method.Add a new method named clear() that removes all students from the course.
Write a test program that creates a course, adds three students, removes one, and displays the students in the course."
10.6 Listing
public class Course {
private String courseName;
private String[] students = new String[100];
private int numberOfStudents;
}
public Course(String courseName) {
this.courseName= courseName;
[Code]...
My Test Code based off of book
public static void main(String[] args) {
Course course1= new Course("Business");
course1.addStudent("Jay");
course1.addStudent("Silent Bob");
course1.addStudent("Dante");
course1.dropStudent("Jay");
[Code]....
My adjusted 10.6
public class Course {
private String courseName;
private String[] students = new String[100];
private int numberOfStudents;
}
public Course(String courseName) {
this.courseName= courseName;
[Code]...
The problem I'm having is, for the first part of the question where I need to automatically increase the array size. I'm really not great at this stuff. I have tried breaking it down, but can't "get it", I guess.
I assume, it'd be a loop that checks to see if the student array is full and if so, do the increaseArray() part, by maybe multiplying the student array and then assigning it. I just don't know how to do it haha.
My *best* attempt at the loop so far has been
if (students == students.length){
int bigArray = 2*students.length;
String increaseArray()= new String[students];
System.arraycopy(students, 0, increaseArray, 0, students.length);
students= increaseArray;
but,yeah... Doesn't seem to be right.
I am trying to make a code that copies the users String to a char array. However, I am in a predicament: since I would not know the exact size of the users String I am left with the options of either making my array large by default, filled in with, lets say 25, empty spaces per index OR starting out with a default size of 1, with an empty space, and then some how increase the size from there.
At this moment I am leaning on the first option, creating a large default array and then deleting the unused values. However, this brings me to my actual question: if I set the non used indexes to null, if that wont give me an error, would that change the size of my array?
Ex:
//lets say i finally copied all of the values and this is the result
char[] word = {'b', 'o', 'b', ' ', ' '};
for(int i = word.length(); i > 0; i--){
if(word[i] == ' ')//delete the value so the size decreases
word[i] = null;//if possible
}
When I try to write the .xlsx file using apache POI, XSSFWorkbook API and run this program in Eclipse STS, I am getting the java.lang.OutOfMemoryError: Java heap space error. Then I searched the net and add these -Xms512m -Xmx1024m in the eclipse VM arguments. Even though I am getting the same error. Again i increase heap size but i am getting the different error like "occurred during initialization of VM, Could not reserve enough space for object heap". how to increase the heap size or any other API to read, delete and write the .xlsx file. I am having 4GB ram in my machine. Apache POI is very good for .xls but if it is .xlsx performance wise it is very slow.
View Replies View RelatedI am not a java developer, but I am using a java code that was available online to convert a large XML file to CSV file. The input file size is big, it is around 3GB. I got an error that it is out of memory, it is expectedly due to the large input file that i am trying to convert. Splitting of this file is not possible,
This is what I ran : xml2csv-conv data.xml data.csv
Error:
Exception in thread "main" java.lang.OutOfMemoryError: Java heap space
at com.sun.org.apache.xerces.internal.dom.DeferredDoc umentImpl.createChunk(Unknown Source)
at com.sun.org.apache.xerces.internal.dom.DeferredDoc umentImpl.ensureCapacity(Unknown Source)
at com.sun.org.apache.xerces.internal.dom.DeferredDoc umentImpl.createNode(Unknown Source)
at com.sun.org.apache.xerces.internal.dom.DeferredDoc umentImpl.createDeferredTextNode(Unknown Source)
at com.sun.org.apache.xerces.internal.parsers.Abstrac tDOMParser.character
[code]....
Additional information: I am running this from a Windows8 64 bit machine with 8GB physical RAM.
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 have a question regarding the permissions set for generated heap dumps.
I have some Jetty servers running on Linux (Java 6 64 bit / Java 7 64 bit) with the following Java arguments:
-XX:+HeapDumpOnOutOfMemoryError
-XX:HeapDumpPath=/opt/apps/heapdump
When there is a out-of-memory exception a heap dump is automatically generated by the JVM. But it seems that the heap dump permisions are set to read-write for owner only (600).
When I create files then they have by default read-write for owner and group/all read access (644).
$ ls -l
total 795432
-rw------- 1 bamboop bamboo 811322265 Apr 14 09:18 java_pid337.hprof
-rw-r--r-- 1 bamboop bamboo 6 Apr 14 12:57 test
Here the umask set for the server running the Java processes
$ umask
0022
I need to process 10000 xml files and verify and insert the data into database. I am loading all the files in the file object and iterating one by one. I am getting the memory issue. How to handle this?
View Replies View RelatedWe are writing our own classes and methods. My instructor has provide the code
/*-------------------------------------------------------------------------
import java.util.*;
public class Assignment5 {
public static void main (String[] args) {
[Code].....
I am having trouble with the question counter. I need the counter to increase when c, d or e are entered. I think I need to set up a if or while loop but I'm not sure how to setup the variables. This is what I have for the counter so far.
[public int getNumberOfQuestions(){
numQuestions = 0;
numQuestions ++;
return numQuestions;
}
Consider the sequence of digits from 1 through N (N<=9) in increasing order: 1 2 3 4 N
Insert either a +(for addition) or a - (for subtraction) between each of the digits so that the resultant sum is zero. Print all possible combinations that sum to zero.
Example: Enter a number: 7
1+2-3+4-5-6+7=0
1+2-3-4+5+6-7=0
1-2+3+4-5+6-7=0
1-2-3-4-5+6+7=0
class Father
{
public int a=5;
private int b=10;
[code]...
what is the size of obj from above code?
In class we were give the algorithm for a non-decreasing algorithm here:
This is pseudo code given for the non-decreasing.
for j = 2 to A.length
key = A[j]
i = j - 1
while i > 0 and A[i] > key
A[i+1] = A[i]
i = i -1
A[i = 1] = key
//I was asked to make it non-increasing, so this is what I have.
for j = A.length - 1 to 1
key = A[j]
i = j - 1
while i > 0 and A[i] < key
A[i+1] = A[i]
i = i + 1
A[i-1] = key
Is there anything wrong with this algorithm? Will it give me the non-increasing sort?
I searched everywhere but i didn't found anything about the real size of primitive boolean type used by java.
View Replies View RelatedOkay so I need to be able to read a file and then be able to find the longest sequence of increasing numbers.
So if the file was this, (this is Ass1Q2_test4.txt)
97 47 56 36 60 31 57 54 12 55
35 57 41 13 82 80 71 93 31 62
89 36 98 75 91 46 95 53 37 99
25 45 26 17 15 82 80 73 96 17
75 22 63 96 96 36 64 31 99 86
12 80 42 74 54 14 93 17 14 55
14 15 20 71 34 50 22 60 32 41
90 69 44 52 54 73 20 12 55 52
39 33 25 31 76 45 44 84 90 52
94 35 55 24 41 63 87 93 79 24
the output should be,
(5,0) with cost 12
(6,0) with cost 14
(6,1) with cost 15
(6,2) with cost 20
(7,2) with cost 44
(7,3) with cost 52
(7,4) with cost 54
(6,3) with cost 71
(5,3) with cost 74
(4,3) with cost 96
Greatest path is of length 10.
Now, the code that I have works, kind of. Instead of recurring several times at each point, it only recurs once.
So say I'm looking at (1,1). With (1,1) being 57. The area around it looks like this.
97 47 56
35 57 41
89 36 98
Now when I look at it, there are several paths it can take. It can go 57, 97 or 57, 89 or 57, 98. However, I'm pretty sure that it just uses the first one that corresponds with the first if statement that is valid. So I start checking north of the value, then northeast, then east, then southeast, which at southeast is where I find my first greater than value. After it finds it's first valid number, it then continues from that number, instead of checking if there are other longer paths stemming from the original value.
In conjunction with that, you can see that the printout just returns all paths from each value. Which isn't what I want. I need a way to store the longest current path, then check each path after to see if it's longer. If it is, it's replaced, if not, it stays the same.
I've also attached Ass1Q2_test4.txt
import java.util.*;
import java.io.*;
public class MaxIncreasingSub {
[Code].....
package name;swing library found in javax called to use the graphical contents.
import javax.swing.*;
//creating the contents for the calculator
public class calc {
JButton btn1= new JButton("1 ");
JButton btn2= new JButton("2");
JButton btn3= new JButton("3");
[code]....
I have tried different sizes for the 'TextField' but when I change the size, the position changes instead of the size itself.
We are shipping in our company the JRE bundled with the client application in order to ensure the compatibility. But when upgrading from jre6 to jre8 the size increased by 50 MB!
Is there a reliable and secure way to reduce the footprint of the JRE? Are there "light distributions" or a list of libs/files that can be safely removed?
Write a program that asks the user for an integer andthen prints out all its factors in increasing order. Use a class FactorGenerator with a constructor FactorGenerator(int numberToFactor) and methods nextFactor and hasMoreFactors. Supply a class FactorTester whose main methods reads a user input, constructs a FactorGenerator object and prints the factors.
Here is what I have so far for my main class and tester class
public class FactorGenerator
{
int factor;
int number;
int x;
FactorGenerator(int numberToFactor)
{
number = numberToFactor;
}
[Code]....
I have a major problem. the text size is like 6 or 8 pt font and I can't read it. I'm trying to run a downloaded exe program which uses the jre7 which I had to download beforehand. the font size stays at 6 or 8 even if I try to change it in windows settings. it's a high res monitor on a lenovo yoga laptop. is there a way for me to edit the java code and manually change the font size?
View Replies View RelatedI want to print data on invoice receipt size of 20.5 x 14 cm(hard copy). In which I try to put text at some absolute location. I tried iText first. In that I try to set page size by following code. here what is unite used in bracket of rectangle?
Document document = new Document(new Rectangle(552,377));
PdfWriter.getInstance(document, new FileOutputStream("report.pdf"));
document.open();
...
...
...
document.close();
Second I tried Jasper report. In that I set page size to 20.5 x 14 cm. But how can I take value from my java application's textfield and put it in to some absolute location in iReport.As I know jasper report take value from database but how can I take value from java application's textfiled?
I am more familiar with iText. How can I print custom invoice using iText or Jasper Report.I am developing java application using netbeans.
When I add an element to my array, I have to make sure that it stays a heap, ie every child is smaller than its parent. However the method that I am using for this, trickling up, is not updating the elements properly, it pretty much just leaves is as is.
Here is the relevant code:
public class MaxIntHeap {
int[] array;
int actualSize = 0;
public MaxIntHeap(){
array = new int[20];
[code].....
in my class is implement a heap and use some of the methods we were provided. The methods I was provided to code and use are "siftDown", "isEmpty" and "heapify". I'm pretty sure the code I have written for "heapify" and "isEmpty" is correct, where I think I am finding fault is the code for my "siftDown". Would you mind taking a look at my code and see why when adding integers to the heap object that I have created in the main code, that they are not being output correctly?
public class Tester {
public static void main(String[] args) {
Heap myHeap = new Heap();
myHeap.insert(9);
myHeap.insert(15);
myHeap.insert(6);
myHeap.insert(4);
myHeap.insert(10);
myHeap.insert(9);
myHeap.insert(3);
[code]....
I am in the process of implementing Priority queue, as I understand that there are many data structures you could use to implement. I implemented it with the an array, which it works absolutely fine. However I have limitations on what collections I can use from the collections classes. I fact I cant use any of the collections classes. Meaning I cant use array.
I’m trying to implement Priority Queue using heap. And implementing heap using binary trees. But however I have a few questions which I need to clarify and I cant think of any other way of resolving it. Ofcourse I can implement my own simple array class using linked list.
Inserting into heap would be quite simple, as I just need to find the right last position from left to right leaf to insert the node into the tree. However after inserting, you may want to make sure that leaf node values are > than root node. Therefore, the root node will always be with the highest priority.
I call these steps where you compare from top down as bubbledown and bubbleup. To do this I really need a for each node within the treee node to have attribute pointing to its root node. So in case of bubbleup I always have a pointer for a given node to its root, without it would mean I would to traverse through the entire tree to identify its root. Which I believe is very inefficient.
Or have I taken this completely wrong? Or is it the case that heap are only best with arrays and therefore use array (by implement it using linked list?)
maximum heap size is set at 1.5GB and consumption of memory at peak load is about 1.1GB. when it reaches 1.1GB, application starts to hang. what could be the problem? shouldn't it be hanging at the point where memory is about equal to the max heap setting? no heap dumps were generated. is this due to server hardware or something? already got the garbage collection data and nothing seemed unusual.
View Replies View RelatedI am learning to use heaps and as an exercise I am trying to write a program using a heap class I have created to sort words. I have read in words from a file and added them to the heap successfully. I am having some trouble figuring out how I can print out a sorted list of the words. From my understanding of how a min-heap works, if I remove from the min/root node they will always be removed in sorted order. So far I have tried out to do a simple for loop but, only half of the heap is being removed. Not sure if my logic is incorrect of there is an error somewhere in my removeMin() function specifically in the while loop.
public static void main(String[] args) {
Heap heap = new Heap();
heap = read( heap );
for( int i = 0; i < heap.getSize(); i++){
heap.removeMin();
[Code] ....
What is the ratio of Memory(RAM) to heap space ? ie: When JVM will throw OutOfMemoryError based on heap available to JVM ?
OutofMemoryError - Memory:RAM size