Common error in Java Virtual machine

1. The simplest memory overflow

public class Heapoom {    heapoom[] testlist= new heapoom[100000];    public static void Main (string[] args) {        list
　　
2, virtual machine stack and local method stack Overflow (-XSS: stack memory capacity)
Two kinds of exceptions:
A Stackoverflowerror exception is thrown if the thread requests a depth greater than the maximum allowed depth for the virtual machine.
Throws a OutOfMemoryError exception if the virtual machine cannot request enough memory space on the scale stack.
Single Thread time stack overflow:
public class StackOverflow {    private int stacklength = 1;    public void Stackleak () {        stacklength++;        Stackleak ();    }    public static void Main (string[] args) throws Throwable {        StackOverflow stackoverflowerror = new StackOverflow (); 
   
    try {            stackoverflowerror.stackleak ();        } catch (Throwable e) {            System.out.println ("Stack depth:" +stackoverflowerror.stacklength);            throw e;}}    }
   
Stack overflow under multi-threading:
A memory overflow exception can be generated by constantly creating threads. In this case, the larger the memory allocated for each thread's stack, the more likely it is to produce a memory overflow exception.
The reason is that there is a limit to the memory assigned to each process by the operating system, such as 32-bit Windows limited to 2GB. The virtual machine provides parameters to control the maximum value of both the Java heap and the two-part memory of the method area. The remaining memory is 2GB minus XMX (maximum heap capacity), minus maxpermsize (maximum method area capacity)
public class Stackoverthread {    private void Donnotstop () {        while (true) {            donnotstop ()        }    }    public void Stackleakbythread () {if        (true) {            thread thread = new Thread (new Runnable () {public                void run () {                    donnotstop ();                }            });            Thread.Start ();        }    }    public static void Main (string[] args) {        Stackoverthread stackoverthread = new Stackoverthread ();        Stackoverthread.stackleakbythread ();    }}
　　
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Common error in Java Virtual machine