1. 下载btrace程序
2. 查找要注入的程序的pid
3. 编写btrace代码
4. 开始注入

   ~/Downloads/btrace-bin-1.3.5/bin/btrace 48650 TraceMethodArgsAndReturn.java 

   1. 48650 是主程序的pid

     <dependency>
            <groupId>com.sun.tools.btrace</groupId>
            <artifactId>btrace-agent</artifactId>
            <version>1.0.5</version>
        </dependency>
        <dependency>
            <groupId>com.sun.tools.btrace</groupId>
            <artifactId>btrace-boot</artifactId>
            <version>1.0.5</version>
        </dependency>

import java.util.Random;

public class CaseObject {

    private static int sleepTotalTime = 0;

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

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

import static com.sun.btrace.BTraceUtils.*;
import com.sun.btrace.annotations.*;

@BTrace public class TraceMethodArgsAndReturn{
    @OnMethod(
            clazz="CaseObject",
            method="execute",
            location=@Location(Kind.RETURN)
    )

    public static void traceExecute(@Self Object instance,int sleepTime,@Return boolean result){
        println("call CaseObject.execute");
        println(strcat("sleepTime is:", str(sleepTime)));
        // 获取类的属性
        int field = (Integer) get(field("CaseObject", "sleepTotalTime"), instance);
        println("sleepTotalTime is:"+field);
        println(strcat("return value is:", str(result)));
        // 查看调用栈
        jstack();
    }
}