关于jvm:Mac-18-如何使用jhsdb-调试

1、运行命令，输出明码 即可弹出
sudo java -cp $JAVA_HOME/lib/sa-jdi.jar sun.jvm.hotspot.HSDB
2、创立类，代码如下

/** * @author  * JVM参数 * -Xms30m -Xmx30m  -XX:MaxMetaspaceSize=30m  -XX:+UseConcMarkSweepGC -XX:-UseCompressedOops * * */public class JVMObject {    public final static String MAN_TYPE = "man"; // 常量    public static String WOMAN_TYPE = "woman";  // 动态变量    public static void  main(String[] args)throws Exception {        Teacher T1 = new Teacher();        T1.setName("李四");        T1.setSexType(MAN_TYPE);        T1.setAge(36);        for(int i =0 ;i<15 ;i++){            System.gc();//被动触发GC 垃圾回收 15次--- T1存活        }        Teacher T2 = new Teacher();        T2.setName("张三");        T2.setSexType(MAN_TYPE);        T2.setAge(18);        Thread.sleep(Integer.MAX_VALUE);//线程休眠    }}class Teacher{    String name;    String sexType;    int age;    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    public String getSexType() {        return sexType;    }    public void setSexType(String sexType) {        this.sexType = sexType;    }    public int getAge() {        return age;    }    public void setAge(int age) {        this.age = age;    }}

运行代码，运行之前请先设置虚拟机参数（垃圾回收器CMS）
-Xms30m -Xmx30m -XX:MaxMetaspaceSize=30m -XX:+UseConcMarkSweepGC -XX:-UseCompressedOops

3、在命令行上 jps 命令查看该类的过程ID