利用arthas查看java服务里指定对象的大小

package org.example.test;

import org.springframework.stereotype.Component;

import java.util.HashMap;
import java.util.Map;

@Component
public class Test {
    private static Map<String, String> cache = new HashMap<>();
}

目的：查询Test类里名为cache的map大小

执行命令：ognl '#obj = @org.example.test@cache, @jdk.nashorn.internal.ir.debug.ObjectSizeCalculator@getObjectSize(#obj)'