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The stack to heap
If there is a variable in the stack frame of type reference, such as:
package com.tian.my_code.test; public class JvmCodeDemo { public Object testGC(){ int op1 = 10; int op2 = 3; Object obj = new Object(); Object result=obj; return result; }}If obj points to an Object in the stack, result points to the same Object as obj.
Using the command
javac -g:vars JvmCodeDemo.java
Compile it and use it again
javap -v JvmCodeDemo.class >log.txt
Then open the log.txt file
If you are still in doubt, you can combine the bytecode diagram and diagram above to make it easier to understand.
The method area points to the heap
Static variables, constants and other data are stored in the method area.
In a typical method area, an element points to an object in the heap.
The heap points to the method area
The method area contains information about the class, and the object is stored in the heap. To create an object, there is the corresponding class information, and this class information is in the method area.
Java object memory layout
A Java object has three parts in memory: the object header, the instance data, and the alignment population
Recommended reading:
The Art of Concurrent Programming in Java. PDF
Forty-five Habits of Highly Effective Programmers: The Instruction of Agile Development. PDF
The Java Web Enterprise Project in Action. PDF
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