java Eclipse内存分析器（MAT）：不显示当前正在运行的进程

Question

我试图分析我的一个Java程序（使用Swing）中的内存泄漏，所以我下载了EclipseMat

到目前为止我所做的：

1. 通过单击Run按钮从Eclipse中运行程序
2. 切换到内存分析透视图
3. 在程序运行时选择“从本地运行的VM获取堆转储”

它表明没有进程在运行。基本上是这样的：

此处的图像：MAT : Eclipse is not showing any running process

根据关于SO的大多数回答，您需要通过将其参数设置为-jdkhome:[您的jdk安装的根文件]来配置HPROF jmap转储提供程序

我已经做到了。但我仍然找不到任何正在运行的进程。如果有必要的话，我将JRE与JDK一起安装，而不是单独安装

Answer 1

对我来说，我发现了错误 ^路径MemoryAnalyzer-1.10.0.20200225-win32.win32.x86_64\mat\workspace\.metadata\.log
检查jps:open wincmd并键入jps返回jps不存在
配置jps到环境的路径

Answer 2

如果您想要的是堆转储，那么可以使用%JAVA_HOME%/bin/jvisualvm。exe（与JDK一起提供）对进程进行堆转储。然后可以使用MAT、jvisualvm或任何其他工具对其进行分析

Answer 3

显然，这是一个更深层次的问题，与Windows中的文件夹权限有关

根据this，本地应用程序可能无法检测到的原因有两个：

Resolution: This can happen on Windows systems, it's caused by misconfigured jvmstat technology used to detect the running applications. There are two possible causes:

1. Insufficient permissions for %TMP%\hsperfdata_username folder - make sure you're able to create a file in the directory and eventually update the permissions for full folder access. Alternatively you can just re-create the folder which should automatically set the correct access rights. See see this forums.sun.com thread for more details.

2. Having %TMP%\hsperfdata_username folder on a FAT disk - by default jvmstat doesn't work on FAT disks due to security restrictions. You can bypass the security check by setting the -XX:+PerfBypassFileSystemCheck flag for both VisualVM and the monitored application. See the JDK bug #5042659 for more details.

这是因为（according to this thread从上面存档）：

Do you mind cd'*** to the directory that TMP is defined as and see if there is a directory named hsperfdata_ where is your login. That is the directory where the instrumentation buffers are mapped (as shared memory files). Each time a java process starts it should create a file in that directory.

因此，我从中了解到，Java应该将一个文件写入%TMP%\hsperfdata_<username>文件夹。该文件帮助内存分析器检测Java进程。缺乏适当的权限意味着无法写入文件，并且内存分析器无法检测Java进程

所以解决方法就是给这个特定文件夹适当的权限