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纠错与更改所有文章的图床

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Dragon
2021-03-22 20:01:15 +08:00
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docs/Java/JVM/JVM系列-第7章-对象的实例化内存布局与访问定位.md
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@@ -8,8 +8,7 @@ categories:
- 1.内存与垃圾回收篇
keywords: JVM，虚拟机。
description: JVM系列-第7章-对象的实例化内存布局与访问定位。
cover: 'https://cdn.jsdelivr.net/gh/youthlql/lql_img/JVM/logo.png'
top_img: 'https://cdn.jsdelivr.net/gh/youthlql/lql_img/blog/top_img.jpg'
cover: 'https://cdn.jsdelivr.net/gh/youthlql/lqlp@v1.0.0/JVM/logo.png'
abbrlink: debff71a
date: 2020-11-14 19:38:42
---
@@ -37,7 +36,7 @@ date: 2020-11-14 19:38:42
<img src="https://cdn.jsdelivr.net/gh/youthlql/lql_img_002/JVM/chapter_007/0001.png">
<img src="https://cdn.jsdelivr.net/gh/youthlql/lqlp@v1.1.0/JVM/chapter_007/0001.png">
### 对象创建的方式
@@ -212,7 +211,7 @@ class Account{
对象的内存布局
---------
<img src="https://cdn.jsdelivr.net/gh/youthlql/lql_img_002/JVM/chapter_007/0002.png">
<img src="https://cdn.jsdelivr.net/gh/youthlql/lqlp@v1.1.0/JVM/chapter_007/0002.png">
@@ -243,7 +242,7 @@ class Account{
图解内存布局
<img src="https://cdn.jsdelivr.net/gh/youthlql/lql_img_002/JVM/chapter_007/0003.png">
<img src="https://cdn.jsdelivr.net/gh/youthlql/lqlp@v1.1.0/JVM/chapter_007/0003.png">
@@ -252,7 +251,7 @@ class Account{
**JVM是如何通过栈帧中的对象引用访问到其内部的对象实例呢？**
<img src="https://cdn.jsdelivr.net/gh/youthlql/lql_img_002/JVM/chapter_007/0004.png">
<img src="https://cdn.jsdelivr.net/gh/youthlql/lqlp@v1.1.0/JVM/chapter_007/0004.png">
定位，通过栈上reference访问
@@ -263,7 +262,7 @@ class Account{
1. 缺点：在堆空间中开辟了一块空间作为句柄池，句柄池本身也会占用空间；通过两次指针访问才能访问到堆中的对象，效率低
2. 优点：reference中存储稳定句柄地址，对象被移动（垃圾收集时移动对象很普遍）时只会改变句柄中实例数据指针即可，reference本身不需要被修改
<img src="https://cdn.jsdelivr.net/gh/youthlql/lql_img_002/JVM/chapter_007/0005.png">
<img src="https://cdn.jsdelivr.net/gh/youthlql/lqlp@v1.1.0/JVM/chapter_007/0005.png">
@@ -272,4 +271,4 @@ class Account{
1. 优点：直接指针是局部变量表中的引用，直接指向堆中的实例，在对象实例中有类型指针，指向的是方法区中的对象类型数据
2. 缺点：对象被移动（垃圾收集时移动对象很普遍）时需要修改 reference 的值
<img src="https://cdn.jsdelivr.net/gh/youthlql/lql_img_002/JVM/chapter_007/0006.png">
<img src="https://cdn.jsdelivr.net/gh/youthlql/lqlp@v1.1.0/JVM/chapter_007/0006.png">