I have a simple JavaFX Application that open a Browser and shows google page. After exit the Application and free all objects, I can see that the JavaFX objects like Scene, Stage, WebView and WebEngine are alive in the heap memory after call GC. I can see this objects with JProfiler and other Profiler tools.
This is my Test code:
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javafx.application.Application;
import javafx.application.Platform;
To test the application click on Start Button to show google web page, click on Stop Button to stop the application, run a Profiler tool, and call gc, the JavaFX classes are alive. I am using java version "1.7.0_51" and windows 8.1 Is there something wrong in my code? Or this is the normal behavior?
I would like to know how much of memory is free and used my java program.I have used Runtime.totalMemory and freeMemory() functions. However, how come used memory is so different than java.exe process show in windows task manager?
I have two unix systems in which on one system I installed sun solaris jdk and on another system I installed IBM jdk.
Java programs which consume more heap memory are getting failed on sun solaris jdk system where as same programs are successfully getting executed on IBM jdk system .
My question is does sun solaris 64 bit jdk needs more heap than IBM 64 bit jdk ??
Given a string, compute a new string where identical chars that are adjacent in the original string are separated from each other by a "*". My implementation :
package com.tcs.dash; public class StringBuild { public String edit(String userIp){ StringBuilder builder = new StringBuilder(userIp); String replaceText = ""; for(int i = 0; i < builder.length() - 1; i++){ if(builder.charAt(i) == builder.charAt(i+1)){ replaceText = builder.charAt(i) + "*" + builder.charAt(i+1); builder = builder.replace(i, i+1, replaceText); } } return builder.toString(); } }
I am getting error at line 13. An exception actually.
I/P given = aaaa
Console:
Exception in thread "main" java.lang.OutOfMemoryError: Java heap space at java.util.Arrays.copyOf(Unknown Source) at java.lang.AbstractStringBuilder.expandCapacity(Unknown Source) at java.lang.AbstractStringBuilder.ensureCapacityInternal(Unknown Source) at java.lang.AbstractStringBuilder.replace(Unknown Source) at java.lang.StringBuilder.replace(Unknown Source) at com.tcs.dash.StringBuild.edit(StringBuild.java:13) at com.tcs.dash.StringBuildExample.main(StringBuildExample.java:14)
I was wondering where is the memory allocated for an applet; by the browser; by the JVM; some applet specific java option? I get an out of memory error when running my applet (loading pictures).
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)
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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 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?
I am using simple jdbc connection to connect to Sybase as shown above , problem is security team is able to see password as clear text in heap, How to avoid it.
I'm new to programming and I would just like to know what happens inside the memory once you run a java application. How do the memory allocate space for your objects or variables? Where does it start?does it start in memory location 1 first when I create my first variable or object? What is the use of variables and how is it used by the memory?Also if I create a variable named String s1 then I created another variable again named s1= "myString" Did I create a new object or I just edited the value of the s1 variable??
And if I create a variable int num1 = 10 then I created another variable int num1 = 12 did I create another one or I just edited the num1 variable?? Also how much memory would an object have? Does it depend on how many primitives objects like arrays or strings it have?Also I want to develop 3D games also, in the future is Java going to be great as I know machines in the future will have massive amounts of RAM and the JVM will be better...
I just made an application with javafx that cycles videos in a folder. I had to set the next video firing the setonendofmedia event, so they are in a cycle, but the problem is that the application loads every video at the beginning, so after a while it fills memory and crashes.Is there another way to cycle videos without pre-load them or a way to flush memory every while?
But reading this article ( JavaFX - APIDesign ) I understand that the algorithm is obsolete. It does not quite find what is the algorithm that improves the integration of javafx and swing without using separate threads.
I am buildning a paint application in java, where the user can choose from a combobox wheather he/she wants to draw a rectangle or by free hand. The objects are stored in an arrayList. The user can also choose in the menubar to go back one step, which means to remove the last drawn item from the arrayList and then loop through the arraylist to draw the remaining objects.
It works fine with rectangles. When I create a rectangle it creates only one rectangle, which I add to the arrayList. My problem is with the free hand. When I draw by free hand (using mousePressed and mouseDragged) I add every "dot" of the line as an object. Which means that when I remove the last item in the arrayList it only removes one dot of the line, not the whole line.
I need to add the dots together as one line, but how can I do that?
if (e.getSource().equals(comboBox)) { JComboBox cb = (JComboBox)e.getSource(); if (cb.getSelectedItem().equals("Rectangle")) { this.addMouseListener(new MouseAdapter() {
I can't recolate and align the button, the circle or the line where i want it to on the canvas. I want to be able to move the line where i want it, now it seems like all objects are stuck in the middle of the scene or canvas.
I was doing a project in a usual Java Application, but now maybe I have to use some tools that are contained in javafx.scene.media.MediaPlayer so I wonder if can it all work? Will javafx methods and such works?
I have to use javafx.scene.media.MediaPlayer beacuse I have to create a very simple audio player (one jbutton and one jcombobox).
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];
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);
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.
I 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();
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...
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.
I am working on program and have been struggling to get around step 5 and 6 given below.
I have got on with the first couple of points. Where to begin with steps 5 and 6.
Java Code:
class Hourglass { int height; int bottomHalf; public Hourglass (int h) { height =h; } public Hourglass (){ height=3; }
/*Write a method dropGrain that simulates one grain of sand falling into the bottom half of the Hourglass. If all the sand is already at the bottom before a grain is dropped, this method should cause the hourglass to be flipped, meaning that all the sand will be in the top again. Then, one grain of sand should fall. */
//Hint: this method can be quite short. All you need to do is update one attribute.
public void dropGrain(){ }
/*Write a method getHeapHeight() which returns the height of the heap of sand in the bottom of the hourglass.
Hint: a triangle of height h contains h*h grains (=1+3+5+...+h).
So determining the height when the amount of sand in the bottom half is a square (1,4,9,16,...) is easy. Think about what happens if the amount of sand is not exactly a square.*/
public int getHeapHeight() { } mh_sh_highlight_all('java');
I 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
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Additional information: I am running this from a Windows8 64 bit machine with 8GB physical RAM.
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
