深入学习JVM调优(二)

Btrace

Btrace可以动态地向目标应用程序的字节码注入追踪代码

安装Btrace

首先我们去github下载，然我去下载！

开始安装

1.解压到指定的目录
2.新建环境变量BTRACE_HOME,设置成项目的地址
3.添加Path: %BTRACE_HOME%\bin

运行Btrace

第一种： 在JVisualVM中添加Btrace插件，添加classpath

第二种: 使用命令行 btrace < pid> < trace_script>

引入依赖

<dependency>
        <groupId>com.sun.btrace</groupId>
        <artifactId>btrace-agent</artifactId>
        <version>1.3.11</version>
        <type>jar</type>
        <scope>system</scope>
        <systemPath>F:/JaveWeb/btrace/build/btrace-agent.jar</systemPath>
    </dependency>
    <dependency>
        <groupId>com.sun.btrace</groupId>
        <artifactId>btrace-boot</artifactId>
        <version>1.3.11</version>
        <type>jar</type>
        <scope>system</scope>
        <systemPath>F:/JaveWeb/btrace/build/btrace-boot.jar</systemPath>
    </dependency>
    <dependency>
        <groupId>com.sun.btrace</groupId>
        <artifactId>btrace-client</artifactId>
        <version>1.3.11</version>
        <type>jar</type>
        <scope>system</scope>
        <systemPath>F:/JaveWeb/btrace/build/btrace-client.jar</systemPath>
    </dependency>

编写脚本

package com.nyist.controller;

import com.sun.btrace.AnyType;
import com.sun.btrace.BTraceUtils;
import com.sun.btrace.annotations.BTrace;
import com.sun.btrace.annotations.Kind;
import com.sun.btrace.annotations.Location;
import com.sun.btrace.annotations.OnMethod;
import com.sun.btrace.annotations.ProbeClassName;
import com.sun.btrace.annotations.ProbeMethodName;



@BTrace
public class PrintArgSimple {


    @OnMethod(
            clazz = "com.nyist.controller.BTraceController",

            method = "arg1",

            location = @Location(Kind.ENTRY)
    )
    public static void anyRead(@ProbeClassName String pcn,
                               @ProbeMethodName String pmn,
                               AnyType[] args
    ) {

        BTraceUtils.printArray(args);

        BTraceUtils.println("className: " + pcn);
        BTraceUtils.println("MethodName: " + pmn);
        BTraceUtils.println();
    }
}

然后我们启动我们的项目

package com.nyist.controller;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;


@RestController
@RequestMapping("/btrace")
public class BTraceController {

    @RequestMapping("/arg1")
    public String arg1(@RequestParam("name") String name) {
        return "hello: " + name;
    }
}

结果是：