Java and JVM program

One o'clock eye

No matter how complex Java procedures, the program has started a number of threads, they are in the Java virtual machine in the process. With all the threads of a JVM, all variables are in the same process, they all use the memory area of ​​the JVM process. When the system following situations, JVM process will be terminated:

• The program runs to the end of the last normal.

• Run the program to use System.exit () or Runtime.getRuntime (). Exit () End the program codes.

• During program execution encounters an uncaught exception or error ended.

• Platform where the program is forcibly terminated JVM process.

Two combat

A.java

public class A
{
   // 定义该类的类变量
   public static int a = 6;
}

ATest1.java

public class ATest1
{
   public static void main(String[] args)
   {
      // 创建A类的实例
      A a = new A();
      // 让a实例的类变量a的值自加
      a.a ++;
      System.out.println(a.a);
   }
}

ATest2.java

public class ATest2
{
   public static void main(String[] args)
   {
      // 创建A类的实例
      A b = new A();
      // 输出b实例的类变量a的值
      System.out.println(b.a);
   }
}

Three runs

1 run ATest1

7

2 runs ATest2

6