# java-arthas

**Repository Path**: codepilipala/java-arthas

## Basic Information

- **Project Name**: java-arthas
- **Description**: arthas使用
- **Primary Language**: Unknown
- **License**: Not specified
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2024-09-18
- **Last Updated**: 2024-09-18

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

#### 安装使用
```text
下载arthas
wget https://arthas.aliyun.com/arthas-boot.jar

下载jdk17
wget https://download.oracle.com/java/17/latest/jdk-17_linux-x64_bin.tar.gz

解压jdk17
tar xf /home/jdk17/jdk-17_linux-x64_bin.tar.gz

指定jdk17运行arthas
/home/jdk17/jdk-17.0.12/bin/java -jar arthas-boot.jar
```

#### arthas基本和常用命令
```text
version 打印当前arthas版本
session 显示当前会话
pwd 当前工作目录
history 历史命令
help 帮助
quit 退出当前会话，但不影响其他会话
stop 终止Arthas服务器，所有会话被销毁
reset 重置所有增强类。当arthas服务器被关闭时，所有增强类都会被重置stop
echo 将参数写入标准输出,echo '...'
cls 清除屏幕
cat 打印文件
base64 对字符串或文件进行base64编码

monitor 监视方法执行统计信息
watch 显示指定方法调用的输入/输出参数，返回对象和抛出异常
getstatic 获取静态属性值
vmtool jvm工具，可以调用实例方法等
sc 检查jvm加载的类信息
sm - 检查已加载类的方法信息
ognl 执行ognl表达式
thread 查看当前线程信息
jad 反编译指定类
mc - 内存编译器，将.java文件编译成.class内存中的文件
jvm 查看jvm信息
logger-打印记录器信息，更新记录器级别
mbean - 显示 Mbean 信息
memory-显示 JVM 内存信息
perfcounter-显示 JVM 性能计数器信息
sysenv — 查看系统环境变量
sysprop——查看/修改系统属性
dump - 将加载的类以字节码形式转储到指定位置
```

#### sm 检查已知加载类的方法信息
```text
[arthas@51644]$ sm com.example.service.MemberService
com.example.service.MemberService <init>()V
com.example.service.MemberService init()V
com.example.service.MemberService getMembers(Lcom/example/model/MemberQuery;)Ljava/util/List;
com.example.service.MemberService getMembers(Ljava/lang/Integer;)Ljava/util/List;
com.example.service.MemberService getMember(Ljava/lang/Long;)Lcom/example/model/Member;
com.example.service.MemberService getMemberById(Ljava/lang/Integer;)Lcom/example/model/Member;
com.example.service.MemberService getMemberId(Ljava/lang/String;)Ljava/lang/Long;
com.example.service.MemberService lambda$getMemberId$4(Ljava/lang/String;Lcom/example/model/Member;)Z
com.example.service.MemberService lambda$getMembers$3(Lcom/example/model/MemberQuery;Lcom/example/model/Member;)Z
com.example.service.MemberService lambda$getMembers$2(Ljava/lang/Integer;Lcom/example/model/Member;)Z
com.example.service.MemberService lambda$getMember$1(Ljava/lang/Long;Lcom/example/model/Member;)Z
com.example.service.MemberService lambda$getMemberById$0(Ljava/lang/Integer;Lcom/example/model/Member;)Z
Affect(row-cnt:12) cost in 24 ms.
```

#### jad反编译指定类
```text
[arthas@51644]$ jad com.example.service.MemberService

ClassLoader:                                                                                                                                                                                                        
+-org.springframework.boot.loader.launch.LaunchedClassLoader@5305068a                                                                                                                                               
  +-jdk.internal.loader.ClassLoaders$AppClassLoader@46fbb2c1                                                                                                                                                        
    +-jdk.internal.loader.ClassLoaders$PlatformClassLoader@17e29da5                                                                                                                                                 

Location:                                                                                                                                                                                                           
nested:/home/arthas/arthas-test.jar/!BOOT-INF/classes/!/                                                                                                                                                            

       /*
        * Decompiled with CFR.
        * 
        * Could not load the following classes:
        *  com.example.model.Member
        *  com.example.model.MemberQuery
        *  jakarta.annotation.PostConstruct
        *  org.springframework.stereotype.Service
        */
       package com.example.service;
       
       import com.example.model.Member;
       import com.example.model.MemberQuery;
       import jakarta.annotation.PostConstruct;
       import java.util.ArrayList;
       import java.util.List;
       import org.springframework.stereotype.Service;
       
       @Service
       public class MemberService {
           private Integer executeCountPrivate = 0;
           public Integer executeCountPublic = 0;
           private static Integer executeStaticCountPrivate = 0;
           public static Integer executeStaticCountPublic = 0;
           private static List<Member> memberList = new ArrayList<Member>();
       
           @PostConstruct
           public void init() {
/*70*/         memberList.add(new Member(Long.valueOf(1L), "member1", "member1@naver.com", Integer.valueOf(1)));
/*71*/         memberList.add(new Member(Long.valueOf(2L), "member2", "member2@naver.com", Integer.valueOf(1)));
/*72*/         memberList.add(new Member(Long.valueOf(3L), "member3", "member3@naver.com", Integer.valueOf(1)));
/*73*/         memberList.add(new Member(Long.valueOf(4L), "member4", "member4@naver.com", Integer.valueOf(1)));
/*74*/         memberList.add(new Member(Long.valueOf(5L), "member5", "member5@naver.com", Integer.valueOf(1)));
/*75*/         memberList.add(new Member(Long.valueOf(6L), "member6", "member6@naver.com", Integer.valueOf(1)));
/*76*/         memberList.add(new Member(Long.valueOf(7L), "member7", "member7@naver.com", Integer.valueOf(2)));
/*77*/         memberList.add(new Member(Long.valueOf(8L), "member8", "member8@naver.com", Integer.valueOf(2)));
/*78*/         memberList.add(new Member(Long.valueOf(9L), "member9", "member9@naver.com", Integer.valueOf(2)));
           }
       
           public List<Member> getMembers(MemberQuery memberQuery) {
/*42*/         return memberList.stream().filter(member -> {
/*44*/             if (memberQuery.id() != null && !memberQuery.id().equals(member.id())) {
/*45*/                 return false;
                   }
/*47*/             if (memberQuery.status() != null && !memberQuery.status().equals(member.status())) {
/*48*/                 return false;
                   }
/*50*/             if (memberQuery.name() != null && !member.name().contains(memberQuery.name())) {
/*51*/                 return false;
                   }
/*53*/             return memberQuery.mobilePhone() == null || member.mobilePhone().contains(memberQuery.mobilePhone());
               }).toList();
           }
       
           public List<Member> getMembers(Integer status) {
/*36*/         return memberList.stream().filter(member -> member.status().equals(status)).toList();
           }
       
           public Member getMember(Long id) {
/*30*/         return memberList.stream().filter(member -> member.id().equals(id)).findFirst().orElse(null);
           }
       
           public Member getMemberById(Integer id) {
/*22*/         executeStaticCountPrivate = executeStaticCountPrivate + 1;
/*23*/         executeStaticCountPublic = executeStaticCountPublic + 1;
/*24*/         return memberList.stream().filter(member -> member.id().equals(id)).findFirst().orElse(null);
           }
       
           public Long getMemberId(String name) {
/*62*/         return memberList.stream().filter(member -> member.name().equals(name)).map(Member::id).findFirst().orElse(null);
           }
       }

Affect(row-cnt:1) cost in 863 ms.
```

#### base64
```text
新建一个明文字符串到文件进行编码
[arthas@51644]$ echo '213456' > 11.txt
[arthas@51644]$ base64 11.txt
MjEzNDU2Cg==

新建一个编码后的文本到文件，进行解码
[arthas@51644]$ echo 'MjEzNDU2Cg==' > 22.txt
[arthas@51644]$ base64 -d 22.txt
213456
```

#### 监视功能 monitor
```text
class-pattern	类名表达式匹配
method-pattern	方法名表达式匹配
[E]	开启正则表达式匹配，默认为通配符匹配
[c:]	统计周期，默认值为120秒

默认统计60s
monitor com.example.service.MemberService getMember

自定义统计时间
monitor com.example.service.MemberService getMember -c 5
```
![img_1.png](img_1.png)

#### 检测函数调用返回值
```text
class-pattern	类名表达式匹配
method-pattern	方法名表达式匹配
express	观察表达式
condition-express	条件表达式
[b]	在方法调用之前观察before
[e]	在方法异常之后观察 exception
[s]	在方法返回之后观察 success
[f]	在方法结束之后(正常返回和异常返回)观察 finish
[E]	开启正则表达式匹配，默认为通配符匹配
[x:]	指定输出结果的属性遍历深度，默认为 1
```
1. 查看请求前参数,如果params不指定下标，好像是拿不到请求参数。这是获取请求前参数，所以返回参数为null
```shell
[arthas@51644]$ watch com.example.service.MemberService getMemberId "{params[0],returnObj}" -b
Press Q or Ctrl+C to abort.
Affect(class count: 1 , method count: 1) cost in 33 ms, listenerId: 34
method=com.example.service.MemberService.getMemberId location=AtEnter
ts=2024-09-18 01:21:51; [cost=0.023436ms] result=@ArrayList[
@String[member3],
null,
]
```
2. 查看请求异常
3. 查看请求结束
```shell
[arthas@51644]$ watch com.example.service.MemberService getMemberId "{params[0],returnObj}" -s
Press Q or Ctrl+C to abort.
Affect(class count: 1 , method count: 1) cost in 33 ms, listenerId: 35
method=com.example.service.MemberService.getMemberId location=AtExit
ts=2024-09-18 01:22:36; [cost=0.43463ms] result=@ArrayList[
@String[member3],
@Long[3],
]
```
4. 查看类变量 需要设置设置深度2
```shell
[arthas@51644]$ watch com.example.service.MemberService getMemberId "{target}" -x 2
Press Q or Ctrl+C to abort.
Affect(class count: 1 , method count: 1) cost in 34 ms, listenerId: 36
method=com.example.service.MemberService.getMemberId location=AtExit
ts=2024-09-18 01:24:31; [cost=0.397346ms] result=@ArrayList[
@MemberService[
executeCountPrivate=@Integer[0],
executeCountPublic=@Integer[0],
executeStaticCountPrivate=@Integer[65340],
executeStaticCountPublic=@Integer[65340],
memberList=@ArrayList[isEmpty=false;size=9],
],
]
```
5. 查看类全部变量值 需要设置设置深度3
```shell
[arthas@51644]$ watch com.example.service.MemberService getMemberId "{target}" -x 3
Press Q or Ctrl+C to abort.
Affect(class count: 1 , method count: 1) cost in 33 ms, listenerId: 37
method=com.example.service.MemberService.getMemberId location=AtExit
ts=2024-09-18 01:25:11; [cost=0.451643ms] result=@ArrayList[
@MemberService[
executeCountPrivate=@Integer[0],
executeCountPublic=@Integer[0],
executeStaticCountPrivate=@Integer[65348],
executeStaticCountPublic=@Integer[65348],
memberList=@ArrayList[
@Member[Member[id=1, name=member1, mobilePhone=member1@naver.com, status=1]],
@Member[Member[id=2, name=member2, mobilePhone=member2@naver.com, status=1]],
@Member[Member[id=3, name=member3, mobilePhone=member3@naver.com, status=1]],
@Member[Member[id=4, name=member4, mobilePhone=member4@naver.com, status=1]],
@Member[Member[id=5, name=member5, mobilePhone=member5@naver.com, status=1]],
@Member[Member[id=6, name=member6, mobilePhone=member6@naver.com, status=1]],
@Member[Member[id=7, name=member7, mobilePhone=member7@naver.com, status=2]],
@Member[Member[id=8, name=member8, mobilePhone=member8@naver.com, status=2]],
@Member[Member[id=9, name=member9, mobilePhone=member9@naver.com, status=2]],
],
],
]
```
6. 获取类指定变量值，设置深度2
```shell
[arthas@51644]$ watch com.example.service.MemberService getMemberId "{target.executeCountPrivate}" -x 2
Press Q or Ctrl+C to abort.
Affect(class count: 1 , method count: 1) cost in 33 ms, listenerId: 38
method=com.example.service.MemberService.getMemberId location=AtExit
ts=2024-09-18 01:25:41; [cost=0.405499ms] result=@ArrayList[
@Integer[0],
]
```
7. 查看类静态变量
```shell
[arthas@51644]$ getstatic com.example.service.MemberService memberList
field: memberList
@ArrayList[
@Member[Member[id=1, name=member1, mobilePhone=member1@naver.com, status=1]],
@Member[Member[id=2, name=member2, mobilePhone=member2@naver.com, status=1]],
@Member[Member[id=3, name=member3, mobilePhone=member3@naver.com, status=1]],
@Member[Member[id=4, name=member4, mobilePhone=member4@naver.com, status=1]],
@Member[Member[id=5, name=member5, mobilePhone=member5@naver.com, status=1]],
@Member[Member[id=6, name=member6, mobilePhone=member6@naver.com, status=1]],
@Member[Member[id=7, name=member7, mobilePhone=member7@naver.com, status=2]],
@Member[Member[id=8, name=member8, mobilePhone=member8@naver.com, status=2]],
@Member[Member[id=9, name=member9, mobilePhone=member9@naver.com, status=2]],
]
Affect(row-cnt:1) cost in 4 ms
```
8. 获取类的实例
```shell
[arthas@51644]$ vmtool --action getInstances --className com.example.service.MemberService -express 'instances[0]'
@MemberService[
    executeCountPrivate=@Integer[0],
    executeCountPublic=@Integer[0],
    executeStaticCountPrivate=@Integer[65689],
    executeStaticCountPublic=@Integer[65689],
    memberList=@ArrayList[isEmpty=false;size=9],
]
```
9. 调用类实例方法
```shell
先传一个不存在的ID去调用
[arthas@51644]$ vmtool --action getInstances --className com.example.service.MemberService -express 'instances[0].getMemberById(33)'
null

传一个实际存在的ID去调用
[arthas@51644]$ vmtool --action getInstances --className com.example.service.MemberService -express 'instances[0].getMemberById(1)'
@Member[
    id=@Long[1],
    name=@String[member1],
    mobilePhone=@String[member1@naver.com],
    status=@Integer[1],
]
```
10. sc查看类详情信息
```shell
[arthas@51644]$ sc -d com.example.service.MemberService
 class-info        com.example.service.MemberService                                                                                                                                                                
 code-source       nested:/home/arthas/arthas-test.jar/!BOOT-INF/classes/!/                                                                                                                                         
 name              com.example.service.MemberService                                                                                                                                                                
 isInterface       false                                                                                                                                                                                            
 isAnnotation      false                                                                                                                                                                                            
 isEnum            false                                                                                                                                                                                            
 isAnonymousClass  false                                                                                                                                                                                            
 isArray           false                                                                                                                                                                                            
 isLocalClass      false                                                                                                                                                                                            
 isMemberClass     false                                                                                                                                                                                            
 isPrimitive       false                                                                                                                                                                                            
 isSynthetic       false                                                                                                                                                                                            
 simple-name       MemberService                                                                                                                                                                                    
 modifier          public                                                                                                                                                                                           
 annotation        org.springframework.stereotype.Service                                                                                                                                                           
 interfaces                                                                                                                                                                                                         
 super-class       +-java.lang.Object                                                                                                                                                                               
 class-loader      +-org.springframework.boot.loader.launch.LaunchedClassLoader@5305068a                                                                                                                            
                     +-jdk.internal.loader.ClassLoaders$AppClassLoader@46fbb2c1                                                                                                                                     
                       +-jdk.internal.loader.ClassLoaders$PlatformClassLoader@17e29da5                                                                                                                              
 classLoaderHash   5305068a                                                                                                                                                                                         

Affect(row-cnt:1) cost in 52 ms.
```
11. 使用sc + getstatic 指定classloader获取类静态变量值。
    如果类被多个classloader所加载，可以使用sc指定classloader以防执行的时候报解析或者找不到的异常
```shell
[arthas@51644]$ getstatic -c 5305068a com.example.service.MemberService memberList
field: memberList
@ArrayList[
    @Member[Member[id=1, name=member1, mobilePhone=member1@naver.com, status=1]],
    @Member[Member[id=2, name=member2, mobilePhone=member2@naver.com, status=1]],
    @Member[Member[id=3, name=member3, mobilePhone=member3@naver.com, status=1]],
    @Member[Member[id=4, name=member4, mobilePhone=member4@naver.com, status=1]],
    @Member[Member[id=5, name=member5, mobilePhone=member5@naver.com, status=1]],
    @Member[Member[id=6, name=member6, mobilePhone=member6@naver.com, status=1]],
    @Member[Member[id=7, name=member7, mobilePhone=member7@naver.com, status=2]],
    @Member[Member[id=8, name=member8, mobilePhone=member8@naver.com, status=2]],
    @Member[Member[id=9, name=member9, mobilePhone=member9@naver.com, status=2]],
]
Affect(row-cnt:1) cost in 5 ms.
```
12. 使用sc + ognl 指定classloader获取类静态变量值。但是出于安全原因可以会禁止ognl，ognl是一个强大的表达式语言，
    用来获取和设置java属性，列表映射等。它旨在提供一个更高抽象度的语法来对java对象图进行导航。
```shell
[arthas@51644]$ ognl -c 5305068a @com.example.service.MemberService@executeStaticCountPublic
@Integer[65788]
```