如何使用btrace探针静态法？

Question

我需要探索一种静态方法。但是无法探测到方法调用。有人能提供帮助吗？

我的java代码：

// CaseObject.java
package test;

public class CaseObject{

    private static int sleepTotalTime=0;

    public boolean execute(int sleepTime) throws Exception{
        System.out.println("sleep: "+sleepTime);
        sleepTotalTime+=sleepTime;
        Thread.sleep(sleepTime);
        return true;
    }

    public static boolean execute2(int sleepTime) throws Exception{
        System.out.println("sleep: "+sleepTime);
        sleepTotalTime+=sleepTime;
        Thread.sleep(sleepTime);
        return true;
    }
}

// Case2.java
package test;

import java.util.Random;

public class Case2 {

    public static void main(String[] args) throws Exception {
        Random random = new Random();
        boolean result = true;
        while (result) {
            result = CaseObject.execute2(random.nextInt(1000));
            Thread.sleep(1000);
        }
    }

}

我的

// TraceMethodArgsAndReturn2.java
import static com.sun.btrace.BTraceUtils.*;
import com.sun.btrace.annotations.*;

@BTrace public class TraceMethodArgsAndReturn2{
    @OnMethod(
            clazz="test.CaseObject",
            method="execute2",
            location=@Location(Kind.RETURN)
    )
    public static void traceExecute(@Self test.CaseObject instance,int sleepTime,@Return boolean result){
        println("call CaseObject.execute2");
        println(strcat("sleepTime is:",str(sleepTime)));
        println(strcat("sleepTotalTime is:",str(get(field("test.CaseObject","sleepTotalTime"),instance))));
        println(strcat("return value is:",str(result)));
    }
}

我运行它的方式如下：./btrace/bin/btrace -cp /tmp/a/目标/classes/ 8477 ./btrace/TraceMethodArgsAndRetur2.java

Answer 1

好吧，我发现了问题.@Self不应使用。

Answer 2

通常，您可以探测这样的静态方法：

@OnMethod(clazz = "java.lang.Integer", method = "valueOf")
public static void onValueOf(int name) {
  println("***********************");
  jstack();
}