Btrace学习笔记二

Btrace拦截行号

被拦截对象(Btrace只能在本地运行)

拦截行号的btrace脚本

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

@BTrace
public class PrintArgsSimple {
    @OnMethod(
            clazz = "mooc.birdsky.java.performance.Controller.BtraceController" ,
            location = @Location(value=Kind.LINE,line=12)
    )
    public static void line(@ProbeClassName String pcn, @ProbeMethodName String pmn,int line){
        BTraceUtils.println("line:"+line);
        BTraceUtils.println("pcn"+pcn);
        BTraceUtils.println("pmn"+pmn);
    }
}

运行btrace脚本

btrac 311 /Users/wangsen/java/performance/src/main/java/mooc/birdsky/java/performance/btrace/PrintArgsSimple.java

运行结果

pcn:mooc.birdsky.java.performance.Controller.BtraceController
pmn:hello
line:12

line=-1,拦截全部行

curl http://localhost:8080/btrace/exception
运行结果打印19、20、22、25。

line:19
pcnmooc.birdsky.java.performance.Controller.BtraceController
pmnexception
line:20
pcnmooc.birdsky.java.performance.Controller.BtraceController
pmnexception
line:22
pcnmooc.birdsky.java.performance.Controller.BtraceController
pmnexception
line:25
pcnmooc.birdsky.java.performance.Controller.BtraceController

高级专题

• 复杂对象：btrace -cp 设置classpath
• 环境变量：clazz和method都支持正则表达式。