在java堆转储中这些奇怪的类名是什么意思？ [英] What do those strange class names in a java heap dump mean?

问题描述

我试图在java进程中跟踪内存泄漏，使用 jmap 和 jhat 每次我这样做，我会看到特定对象类型的奇怪的符号，如 [S 为字符串数组和 [C 字符数组。我不记得什么意思了，而且这很难google。

（编辑）：证明我的观点，事实证明 [S 是一组short， [C 是char数组。）

任何人都关心，列出所有不同的类名称和它们的含义？或者指向我这样的表？

具体来说，我想知道什么 [Ljava.lang.Object;

解决方案

您可以在 Class.getName（）：

< blockquote>

如果此类对象表示不是数组
类型的
引用类型，则返回类
的二进制名称，如em> Java™
语言规范，Second
版本。

如果此类对象表示
原始类型或void，那么返回的
的名称是一个 String 等于对应于
原始类型或void的Java
语言关键字。 p>

如果此类对象表示一个
类的数组，则内部
形式的名称由
的名称组成元素类型前面有一个或
多个'['字符，表示数组嵌套的
深度。元素类型名称的
编码为
如下：

 
元素类型编码
 boolean Z 
字节B 
 char C 
类或接口L  classname ; 
 double D 
 float F 
 int I 
 long J 
 short S 
 

I'm trying to track down a memory leak in a java process, using jmap and jhat. Every time I do this I see those weird notation for specific object types, like [S for string arrays and [C for Character arrays. I never remember what means what, and it's very hard to google this stuff.

(EDIT: to prove my point, it turns out that [S is array of short and [C is array of char.)

Anyone care to make a table listing all the different class names and what they mean? Or point me to such table?

Specifically I'd like to know what [Ljava.lang.Object; means.

解决方案

You'll find the complete list documented under Class.getName():

If this class object represents a reference type that is not an array type then the binary name of the class is returned, as specified by the Java™ Language Specification, Second Edition.

If this class object represents a primitive type or void, then the name returned is a String equal to the Java language keyword corresponding to the primitive type or void.

If this class object represents a class of arrays, then the internal form of the name consists of the name of the element type preceded by one or more '[' characters representing the depth of the array nesting. The encoding of element type names is as follows:

Element Type        Encoding
boolean             Z
byte                B
char                C
class or interface  Lclassname;
double              D
float               F
int                 I
long                J
short               S 

这篇关于在java堆转储中这些奇怪的类名是什么意思？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！