Java 实现栈溢出,堆溢出,堆外内存例子

• idea vm参数设置

　　

• 栈溢出(其实就是递归调用没结束)
  

     public  static  void  stackOverFlow(){
  
               stackOverFlow();
  
      }
  

  

 

• 堆溢出
  

     static class TestBean{}
      /**
       *
       * 堆溢出 Java heap space
       */
      public  static  void  outOfMemory(){
          try {
              while (true){
                  list.add( new TestBean());
  
              }
          }catch (Exception e){
              System.out.println(e);
          }
  
      }

  

• 运行是常量异常
  

    static  List  arrayList=new ArrayList();
      public  static  void    outOfMemoryPremGen(){
  
          int i=0;
          while (true){
              list.add(String.valueOf(i++).intern());
          }
      }

  

• Unsafe 分配堆外内存(java nio就是这样实现)

  //Unsafe 分配内存
      private static final Unsafe unsafe = Unsafe.getUnsafe();
      private  final  static  int size=1024*1024;
      public  static   void getSyseMmory(){
          while (true){
              unsafe.allocateMemory(size);
          }
  
      }