如何以编程方式获取GC类直方图

以下代码显示相同的结果:

import javax.management.MBeanException;
import javax.management.ReflectionException;

import com.sun.management.DiagnosticCommandMBean;

import sun.management.ManagementFactoryHelper;

@SuppressWarnings("restriction")
public class ClassHistogram {

    public static void main(String[] args) throws MBeanException, ReflectionException {
        DiagnosticCommandMBean dcmd = ManagementFactoryHelper.getDiagnosticCommandMBean();

        String[] emptyStringArgs = {};
        Object[] dcmdArgs = { emptyStringArgs };
        String[] signature = { String[].class.getName() };
        System.out.println(dcmd.invoke("gcClassHistogram", dcmdArgs, signature));
    }

}

参考可用命令: https://docs.oracle.com/javase/8/docs/technotes/guides/troubleshoot/tooldescr006.html

这个 jcmd manpage 涵盖了这一点。

要从远程计算机或使用不同标识符调用诊断命令,可以使用com。太阳经营DiagnosticCommandMBean接口。有关DiagnosticCommandMBean接口的更多信息,请参阅 http://docs.oracle.com/javase/8/docs/jre/api/management/extension/com/sun/management/DiagnosticCommandMBean.html