Java内存

Java 内存.png

参考：https://www.cnblogs.com/iliuyuet/p/5603618.html

测试代码：

public class stack {
public static void main(String args[]) {
int a = 3;
int b = 3;

    //看不到真正的内存地址的,只能看到虚拟机映射的地址,HASHCODE
    int aHashCode = System.identityHashCode(a);
    int bHashCode = System.identityHashCode(b);
    
    System.out.println(aHashCode + "\t" + bHashCode);
    
    a = 4;
    aHashCode = System.identityHashCode(a);
    System.out.println(aHashCode + "\t" + bHashCode);
    
    String str1 = "abc";
    String str2 = "abc";
    
    int str1HashCode = System.identityHashCode(str1);
    int str2HashCode = System.identityHashCode(str2);
    System.out.println(str1HashCode + "\t" + str2HashCode);
    
    // == 比较对象是否相等， equals()比较类里的数值是否相等
    System.out.println(str1 == str2);
    System.out.println(str1.equals(str2));
    
    String str3 = new String("abc");
    String str4 = new String("abc");
    
    int str3HashCode = System.identityHashCode(str3);
    int str4HashCode = System.identityHashCode(str4);
    System.out.println(str3HashCode + "\t" + str4HashCode);
}

}