• Skip to primary navigation
  • Skip to content
  • Skip to primary sidebar
  • Skip to footer
  • Core Java
  • Design Patterns
  • JSP
  • Servlets
  • Building Tools
  • jQuery
  • Spring
  • Hibernate
  • Mongo DB
  • More
    • HTML
    • SCJP
    • AJAX
    • UML
    • Struts
    • J2EE
    • Testing
    • Angular JS

J2EE Reference

  • Home
  • About Us
    • Java Learning Centers
  • Contact Us

Heap memory

Difference between Stack and Heap memory

June 15, 2017 By j2eereference Leave a Comment

Lets see some of the main differences between Stack and Heap memory.

1) Stack memory is used to store local variables and references to other objects in the method whereas heap memory is used to store objects.
2) Size of heap memory is much bigger than the stack memory.
3) Each thread has their own stack which stores local variables and these variables are not accessible globally whereas objects stored in heap are globally accessible.
4) Heap memory size is bigger where we can create and store objects in any order whereas stack memory follows LIFO(Last In First Out) order.
5) We can change the size of heap memory using jvm parameters : -Xms for initial heap memory and –Xmx for maximum heap memory. For stack , use –Xss to specify stack size for each thread.
6) If stack memory is filled up then you will get java.lang.StackOverFlowError . If there is no space left to allocate new Object in Heap memory then you will get java.lang.OutOfMemoryError: Java Heap Space.

Program to generate StackOverFlowError  exception :

Java
1
2
3
4
5
6
7
8
9
10
11
12
13
14
package com.j2eereference;
public class StackOverflowErrorDemo{
  public static void recursiveComputation(int count)
  {
    if(count == 0)
      return;
    else
      recursiveComputation(++count);
   }
  public static void main(String[] args)
   {
      StackOverflowErrorDemo.recursiveComputation(10);
   }
}

OutPut:
Exception in thread “main” java.lang.StackOverflowError
at com.j2eereference.StackOverflowErrorDemo.recursiveComputation(StackOverflowErrorDemo.java:13)
at com.j2eereference.StackOverflowErrorDemo.recursiveComputation(StackOverflowErrorDemo.java:13)

Program to generate OutOfMemoryError: Java heap space

Java
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
package com.j2eereference;
 
import java.util.ArrayList;
import java.util.List;
public class OutOfMemoryDemo
{
    private static List<String> heapList=new ArrayList<>();
    public static void main(String[] args)
      {
     while(true)
           {
            heapList.add(new String("Shobhna"));  
           }
       }
}

OutPut:
Exception in thread “main” java.lang.OutOfMemoryError: Java heap space
at java.util.Arrays.copyOf(Arrays.java:3210)
at java.util.Arrays.copyOf(Arrays.java:3181)
at java.util.ArrayList.grow(ArrayList.java:261)
at java.util.ArrayList.ensureExplicitCapacity(ArrayList.java:235)
at java.util.ArrayList.ensureCapacityInternal(ArrayList.java:227)
at java.util.ArrayList.add(ArrayList.java:458)
at com.j2eereference

 

7) Stack memory allocation is simple as compared to heap memory allocation as Stack uses LIFO order,so stack memory is fast as compared to heap memory.
8) Stack memory is used by  only threads whereas heap memory is used by whole application.
9) use stack when you know that how much memory is needed to allocate before compile time on the other hand, use heap if you are not sure about the amount of memory needed at runtime.

Related Posts

  • Java Buzzwords
  • Anonymous Inner Class in Java
  • Network Programming – java.net Package
  • Java Regular Expressions
  • Method Local Inner Class in Java
  • URL Processing in Java
  • What is ThreadMXBean in java?
  • What is serialVersionUID
  • What is exchanger in concurrency?
  • UncaughtExceptionHandler in java

Filed Under: Core Java Tagged With: Difference between Stack and Heap memory, Heap memory, OutOfMemoryError, Stack memory, StackOverFlowError

Primary Sidebar

FOLLOW US ONLINE

  • View J2eereference-166104970118637’s profile on Facebook
  • View j2eereference’s profile on Twitter
  • View j2eereference’s profile on LinkedIn

Subscribe by email

Recent posts

  • Java Buzzwords
  • Anonymous Inner Class in Java
  • Network Programming – java.net Package
  • Java Regular Expressions
  • Method Local Inner Class in Java
  • URL Processing in Java
  • Iterator Design Pattern Implementation using Java
  • Strategy Design Pattern Implementation using Java
  • Decorator Design Pattern
  • Adapter Design Pattern Implementation using Java
  • JSF Composite Components
  • JSF UI Components
  • What is JavaServer Faces (JSF)?
  • GOF Design Patterns
  • History and Need for Design Patterns

Footer

Core Java
Design Patterns
JSP
Servlets
HTML
Building Tools
AJAX
SCJP
jQuery
Testing
Spring
UML
Struts
Java Centers
Java Training
Home
About Us
Contact Us
Copyright © j2eereference.com. All right reserved.