Simulate Java OutOfMemoryError

Simulate Java OutOfMemoryError

Here am simulating java OutOfMemoryError, lets discuss brief details about OutOfMemoryError.

Why OutOfMemoryError error will arise?

          OutOfMemoryError will arise when allotted Heap size of the Java virtual will be exceeds during runtime.

Where object will be saved in Java?

          Basically all java class objects will be saved during runtime in HeapMemory.

Sample Java Program to simulate OutOfMemoryError

In below program name is object of String, so name value will be saved to Heap space of JVM.

          Calling method1 infinite time will cause java.lang.OutOfMemoryError: Java heap space error, because below line in method1 is causing this error. If you comments below line you don’t get this error.

                         name+=";"+name;

package com.blogspot.microtechinfo;

public class JavaOutOfMemory {

            private static String  name="Marimuthu Rajagopal";

          private static int count=0;

         

          /**

           * @param args

           */

          public static void main(String[] args) {

                   // TODO Auto-generated method stub

                        while(true)

                   {

                             method1();

                   }

          }

          private static void method1()

          {

                  

                         name+=";"+name;

                   System.out.println("count="+ ++count);

                  

          }

         

}

 Output:

  

when count is 20 i will be getting  java.lang.OutOfMemoryError: Java heap space,It will vary based on machine.

count=1

count=2

count=3

count=4

count=5

count=6

count=7

count=8

count=9

count=10

count=11

count=12

count=13

count=14

count=15

count=16

count=17

count=18

count=19

count=20

Exception in thread "main" java.lang.OutOfMemoryError: Java heap space

          at java.util.Arrays.copyOfRange(Unknown Source)

          at java.lang.String.(Unknown Source)

          at java.lang.StringBuilder.toString(Unknown Source)

          at com.blogspot.microtechinfo.JavaOutOfMemory.method1(JavaOutOfMemory.java:21)

          at com.blogspot.microtechinfo.JavaOutOfMemory.main(JavaOutOfMemory.java:15)