JVM-周阳讲解

待我称王封你为后i 2023-06-20 06:54 9阅读 0赞

![format_png][]

![format_png 1][]

![format_png 2][]

![format_png 3][]

![format_png 4][]

![format_png 5][]

![format_png 6][]

![format_png 7][]

![format_png 8][]

![format_png 9][]

![format_png 10][]

1.  `package com.shi.jvm;`
2.   
3.  `public class StackTest {`
4.   
5.  `/**`
6.  `* 递归调用`
7.  `*/`
8.  `public static void add() {`
9.  `add();`
10. `}`
11.  
12. `/**`
13. `* 栈满了异常`
14. `* Exception in thread "main" java.lang.StackOverflowError`
15. `* @param args`
16. `*/`
17. `public static void main(String[] args) {`
18. `add();`
19. `}`
20.  
21. `}`

![format_png 11][]

![format_png 12][]

![format_png 13][]

1.  `package com.shi.jvm;`
2.   
3.  `public class HeapTest {`
4.   
5.  `public static void main(String[] args) {`
6.   
7.  `/**`
8.  `* 堆内存异常`
9.  `* 输出结果：当前最大可用内存多少M : 1724`
10. `* Exception in thread "main" java.lang.OutOfMemoryError: Java heap space`
11. `* at com.shi.jvm.HeapTest.main(HeapTest.java:8)`
12. `*/`
13. `System.out.println("当前最大可用内存多少M : "+Runtime.getRuntime().maxMemory()/1024/1024);`
14. `//创建一个大对象`
15. `byte[] b = new byte[1*1024*1024*1725];`
16. `System.out.println("大对象创建成功");`
17. `}`
18.  
19. `}`

![format_png 14][]

![format_png 15][]

![format_png 16][]

![format_png 17][]

![format_png 18][]

![format_png 19][]

![format_png 20][]

1.  `package com.shi.jvm;`
2.   
3.  `import java.util.Random;`
4.  `/**`
5.  `* -Xms1024m -Xmx1024m -XX:+PrintGCDetails`
6.  `堆初始化内存，堆最大内存 打印出堆GC回收信息`
7.  `* @author shiye`
8.  `*`
9.  `*/`
10. `public class HeapSpaceTest {`
11.  
12.  
13. `public static void main(String[] args) {`
14.  
15. `/**`
16. `* 输出： MAX_MEMERY = 1808269312（字节）1724.5MB`
17. `TOTAL_MEMERY = 122683392（字节）117.0MB`
18. `* @param args`
19. `*/`
20. `// long maxMemory = Runtime.getRuntime().maxMemory();//返回Java虚拟机试图使用的最大内存量`
21. `// long totalMemory = Runtime.getRuntime().totalMemory();//返回当前使用的java虚拟机的内存总量`
22. `// System.out.println("MAX_MEMERY = " + maxMemory +"（字节）" + (maxMemory/(double)1024/1024) + "MB");`
23. `// System.out.println("TOTAL_MEMERY = " + totalMemory +"（字节）" + (totalMemory/(double)1024/1024) + "MB");`
24.  
25.  
26. `//-Xms8m -Xmx8m -XX:+PrintGCDetails`
27. `String str = "www.shiye";`
28. `while(true) {`
29. `str += str + new Random().nextInt(9999);`
30. `}`
31. `/**`
32. `* 结果： Exception in thread "main" java.lang.OutOfMemoryError: Java heap space`
33. `*/`
34. `}`
35. `}`

![format_png 21][]

![format_png 22][]

![format_png 23][]

![format_png 24][]

![format_png 25][]

![format_png 26][]

![format_png 27][]

![format_png 28][]

![format_png 29][]

![format_png 30][]

![format_png 31][]

![format_png 32][]

![format_png 33][]

[format_png]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9vc2NpbWcub3NjaGluYS5uZXQvb3NjbmV0Lzc5NTQzNzM4Yjg2NTU2NGRiZWU3MDFlMzI2MGNjNTQ1MDZhLmpwZw?x-oss-process=image/format,png
[format_png 1]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9vc2NpbWcub3NjaGluYS5uZXQvb3NjbmV0LzkzZDBjNGZlNjQ2ZTRlZGNlZDU1ZmVlYzA3MzExZjdlNDJmLmpwZw?x-oss-process=image/format,png
[format_png 2]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9vc2NpbWcub3NjaGluYS5uZXQvb3NjbmV0LzRmZTA2YTA5MmQ0NWNlOTJlMzdjYTAxNjJmOTQwYjYyMjZiLmpwZw?x-oss-process=image/format,png
[format_png 3]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9vc2NpbWcub3NjaGluYS5uZXQvb3NjbmV0LzE1NTNiYmEzM2JhOTNlMzRjMGU2NDhjZjE3NjcyNWVkZDA1LmpwZw?x-oss-process=image/format,png
[format_png 4]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9vc2NpbWcub3NjaGluYS5uZXQvb3NjbmV0LzJmZDgzZjhjYzk2YzgzY2QzYmIyZGNmODAyYmJhZTQxZjhkLmpwZw?x-oss-process=image/format,png
[format_png 5]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9vc2NpbWcub3NjaGluYS5uZXQvb3NjbmV0LzE2MjQ1ZjBjNjgzZmY2NTJkN2FkNmY0ODBmZDNhYWQ4Y2JhLmpwZw?x-oss-process=image/format,png
[format_png 6]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9vc2NpbWcub3NjaGluYS5uZXQvb3NjbmV0L2Q3YWJkMmY1NzliNjU3NmU4ZTMxZGQwODVhMTkwZTg3YjRlLmpwZw?x-oss-process=image/format,png
[format_png 7]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9vc2NpbWcub3NjaGluYS5uZXQvb3NjbmV0L2FkNDMzNWM4MGM3ZmM5YTQ0NDc2YmQxZTIyMTMwMzI0M2Y1LmpwZw?x-oss-process=image/format,png
[format_png 8]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9vc2NpbWcub3NjaGluYS5uZXQvb3NjbmV0L2Y1OTEzNDk5MGJjN2ZjMDU5ZWI4ZDY0MjZkMDMwYmQwMzY3LmpwZw?x-oss-process=image/format,png
[format_png 9]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9vc2NpbWcub3NjaGluYS5uZXQvb3NjbmV0LzZhOWNjMmE2YmE0OGM4MWNmYzliYmYwNDM5ZmEzYzdhNjRhLmpwZw?x-oss-process=image/format,png
[format_png 10]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9vc2NpbWcub3NjaGluYS5uZXQvb3NjbmV0LzdhYmVjM2NjYjhkODVlNzUwNzYwYmE3YTZhODJkM2MxYjUyLmpwZw?x-oss-process=image/format,png
[format_png 11]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9vc2NpbWcub3NjaGluYS5uZXQvb3NjbmV0L2JhMjk4ODRlNWMyMmFkMjI1NWRjODFhYzJmNDk4NjQwN2IzLmpwZw?x-oss-process=image/format,png
[format_png 12]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9vc2NpbWcub3NjaGluYS5uZXQvb3NjbmV0LzYxNjdhNjAzYzZhMTk0OGI3YjVhNzkxYTg4M2Y3MDNjYzcwLmpwZw?x-oss-process=image/format,png
[format_png 13]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9vc2NpbWcub3NjaGluYS5uZXQvb3NjbmV0Lzk1ODMzNzc0ODcwYTQ1YWE5NzI1YWI2NWRkNWJlZWVlZDc1LmpwZw?x-oss-process=image/format,png
[format_png 14]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9vc2NpbWcub3NjaGluYS5uZXQvb3NjbmV0Lzk4YWM2MTY1ZmE5YjBkYjdkZTQ4YTY3NjY4OTFmYjQxZGQ4LmpwZw?x-oss-process=image/format,png
[format_png 15]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9vc2NpbWcub3NjaGluYS5uZXQvb3NjbmV0LzQ4YzJmNDE2YmU2ODE2ZGE5OGM5ODhiYWI3NjI4ZTgyMjQ0LmpwZw?x-oss-process=image/format,png
[format_png 16]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9vc2NpbWcub3NjaGluYS5uZXQvb3NjbmV0LzE2ZTE3NWY0MDIxZDMwMGM0YWNjN2Q4ZTNlODBhNTExMzc5LmpwZw?x-oss-process=image/format,png
[format_png 17]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9vc2NpbWcub3NjaGluYS5uZXQvb3NjbmV0LzcxYTdjNGEzYWIyOWUyOGNiMzk1Mjg5ODkxNjU3NTU0MzgxLmpwZw?x-oss-process=image/format,png
[format_png 18]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9vc2NpbWcub3NjaGluYS5uZXQvb3NjbmV0LzA0ZmYwZGRiYzAyNzJlYjg3MDEyOGQ4ODYxYmNjZTg5YmY0LmpwZw?x-oss-process=image/format,png
[format_png 19]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9vc2NpbWcub3NjaGluYS5uZXQvb3NjbmV0LzI3ZmY3MWFkYjAxNGVkNTk4NDNmNjA3Mzg2YTYwNDcwYjUwLmpwZw?x-oss-process=image/format,png
[format_png 20]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9vc2NpbWcub3NjaGluYS5uZXQvb3NjbmV0LzhhNzg1ZmIxN2ZlYTNlM2Y3MDdjYTg2MDIyZTRjNGE5NTRlLmpwZw?x-oss-process=image/format,png
[format_png 21]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9vc2NpbWcub3NjaGluYS5uZXQvb3NjbmV0L2MyNzk5Zjc1NzYyZjgzMzIwMTQ2YjE3MjE0ZGE3MDY2NzhkLmpwZw?x-oss-process=image/format,png
[format_png 22]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9vc2NpbWcub3NjaGluYS5uZXQvb3NjbmV0LzcwNTBmMjczNWMxOGM5MDM5OTU0M2U4OGZlZTRmNmM4OGUwLmpwZw?x-oss-process=image/format,png
[format_png 23]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9vc2NpbWcub3NjaGluYS5uZXQvb3NjbmV0L2ZlZGMwNmZlYmU1MzZiMjg3MGZlYjk4OTg4M2EzN2ViNWZlLmpwZw?x-oss-process=image/format,png
[format_png 24]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9vc2NpbWcub3NjaGluYS5uZXQvb3NjbmV0L2NhYzUwNjdlOTk5ZDUzNTQ5MjhiYjI1MTU3MGNkOGFhNTk3LmpwZw?x-oss-process=image/format,png
[format_png 25]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9vc2NpbWcub3NjaGluYS5uZXQvb3NjbmV0L2IyY2RkYjA1MzI2ODkwN2FmMTRhNGYyZWNiMjkzNjU2Njk4LmpwZw?x-oss-process=image/format,png
[format_png 26]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9vc2NpbWcub3NjaGluYS5uZXQvb3NjbmV0L2JiYjBiMDBhYWU4YmU1MmY5MGNjNzUwZGFmM2UxMzdmNjQ4LmpwZw?x-oss-process=image/format,png
[format_png 27]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9vc2NpbWcub3NjaGluYS5uZXQvb3NjbmV0L2RkYzMyOTk4YTM5MTM5Yjk5ZTE5OGRjZDA5ZDljMTU5YjFiLmpwZw?x-oss-process=image/format,png
[format_png 28]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9vc2NpbWcub3NjaGluYS5uZXQvb3NjbmV0L2U3OWFhZmNmOTVkMjYxMzM4ZWNjMmYwNzA3OTk3OGY1OGRhLmpwZw?x-oss-process=image/format,png
[format_png 29]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9vc2NpbWcub3NjaGluYS5uZXQvb3NjbmV0LzFkYzM1MjUxZjllZTVhMWRiYWY5ODM2YzBiZWI4ZjY3MmM1LmpwZw?x-oss-process=image/format,png
[format_png 30]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9vc2NpbWcub3NjaGluYS5uZXQvb3NjbmV0L2I4MmVhNDhlYWU0YWM2MDUyYTI2ODhlYjkzYjVlNDk0Y2M1LmpwZw?x-oss-process=image/format,png
[format_png 31]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9vc2NpbWcub3NjaGluYS5uZXQvb3NjbmV0LzhjNzc3M2M1NWMyNDhhZmM0ZDUyYWMxMDhkOWNmZDliMDUxLmpwZw?x-oss-process=image/format,png
[format_png 32]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9vc2NpbWcub3NjaGluYS5uZXQvb3NjbmV0L2M4ZjE1N2EwOTZmYzNhYjg4MzFlYTAwYTFjYTA1MWZjOWQyLmpwZw?x-oss-process=image/format,png
[format_png 33]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9vc2NpbWcub3NjaGluYS5uZXQvb3NjbmV0L2Q1NGJlZTA3NTE5Mzk3ZWJmODBmNTJiZmQ5ZmFiZDZhYWQ2LmpwZw?x-oss-process=image/format,png