import{_ as l,o as p,c as i,a as n,b as a,w as c,e as s,d,r as o}from"./app.4d248835.js";const r={},u=n("h1",{id:"redefine",tabindex:"-1"},[n("a",{class:"header-anchor",href:"#redefine","aria-hidden":"true"},"#"),s(" redefine")],-1),m={class:"custom-container tip"},k=n("p",{class:"custom-container-title"},"\u63D0\u793A",-1),v=s("\u63A8\u8350\u4F7F\u7528 "),h=s("retransform"),b=s(" \u547D\u4EE4"),f={href:"https://arthas.aliyun.com/3.x/doc/arthas-tutorials?language=cn&id=command-mc-redefine",target:"_blank",rel:"noopener noreferrer"},_=n("code",null,"mc-redefine",-1),g=s("\u5728\u7EBF\u6559\u7A0B"),x=n("div",{class:"custom-container tip"},[n("p",{class:"custom-container-title"},"\u63D0\u793A"),n("p",null,[s("\u52A0\u8F7D\u5916\u90E8\u7684"),n("code",null,".class"),s("\u6587\u4EF6\uFF0Credefine jvm \u5DF2\u52A0\u8F7D\u7684\u7C7B\u3002")])],-1),y=s("\u53C2\u8003\uFF1A"),w={href:"https://docs.oracle.com/javase/8/docs/api/java/lang/instrument/Instrumentation.html#redefineClasses-java.lang.instrument.ClassDefinition...-",target:"_blank",rel:"noopener noreferrer"},j=s("Instrumentation#redefineClasses"),C=n("h2",{id:"\u5E38\u89C1\u95EE\u9898",tabindex:"-1"},[n("a",{class:"header-anchor",href:"#\u5E38\u89C1\u95EE\u9898","aria-hidden":"true"},"#"),s(" \u5E38\u89C1\u95EE\u9898")],-1),L={class:"custom-container tip"},I=n("p",{class:"custom-container-title"},"\u63D0\u793A",-1),S=s("\u63A8\u8350\u4F7F\u7528 "),T=s("retransform"),E=s(" \u547D\u4EE4"),q=d(`

\u6CE8\u610F

\u6CE8\u610F\uFF0C redefine \u540E\u7684\u539F\u6765\u7684\u7C7B\u4E0D\u80FD\u6062\u590D\uFF0Credefine \u6709\u53EF\u80FD\u5931\u8D25\uFF08\u6BD4\u5982\u589E\u52A0\u4E86\u65B0\u7684 field\uFF09\uFF0C\u53C2\u8003 jdk \u672C\u8EAB\u7684\u6587\u6863\u3002

\u63D0\u793A

reset\u547D\u4EE4\u5BF9redefine\u7684\u7C7B\u65E0\u6548\u3002\u5982\u679C\u60F3\u91CD\u7F6E\uFF0C\u9700\u8981redefine\u539F\u59CB\u7684\u5B57\u8282\u7801\u3002

\u63D0\u793A

redefine\u547D\u4EE4\u548Cjad/watch/trace/monitor/tt\u7B49\u547D\u4EE4\u4F1A\u51B2\u7A81\u3002\u6267\u884C\u5B8Credefine\u4E4B\u540E\uFF0C\u5982\u679C\u518D\u6267\u884C\u4E0A\u9762\u63D0\u5230\u7684\u547D\u4EE4\uFF0C\u5219\u4F1A\u628Aredefine\u7684\u5B57\u8282\u7801\u91CD\u7F6E\u3002 \u539F\u56E0\u662F jdk \u672C\u8EAB redefine \u548C Retransform \u662F\u4E0D\u540C\u7684\u673A\u5236\uFF0C\u540C\u65F6\u4F7F\u7528\u4E24\u79CD\u673A\u5236\u6765\u66F4\u65B0\u5B57\u8282\u7801\uFF0C\u53EA\u6709\u6700\u540E\u4FEE\u6539\u7684\u4F1A\u751F\u6548\u3002

\u53C2\u6570\u8BF4\u660E

\u53C2\u6570\u540D\u79F0\u53C2\u6570\u8BF4\u660E
[c:]ClassLoader \u7684 hashcode
[classLoaderClass:]\u6307\u5B9A\u6267\u884C\u8868\u8FBE\u5F0F\u7684 ClassLoader \u7684 class name

\u4F7F\u7528\u53C2\u8003

   redefine /tmp/Test.class
   redefine -c 327a647b /tmp/Test.class /tmp/Test\\$Inner.class
   redefine --classLoaderClass sun.misc.Launcher$AppClassLoader /tmp/Test.class /tmp/Test\\$Inner.class

\u7ED3\u5408 jad/mc \u547D\u4EE4\u4F7F\u7528

jad --source-only com.example.demo.arthas.user.UserController > /tmp/UserController.java

mc /tmp/UserController.java -d /tmp

redefine /tmp/com/example/demo/arthas/user/UserController.class

\u4E0A\u4F20 .class \u6587\u4EF6\u5230\u670D\u52A1\u5668\u7684\u6280\u5DE7

\u4F7F\u7528mc\u547D\u4EE4\u6765\u7F16\u8BD1jad\u7684\u53CD\u7F16\u8BD1\u7684\u4EE3\u7801\u6709\u53EF\u80FD\u5931\u8D25\u3002\u53EF\u4EE5\u5728\u672C\u5730\u4FEE\u6539\u4EE3\u7801\uFF0C\u7F16\u8BD1\u597D\u540E\u518D\u4E0A\u4F20\u5230\u670D\u52A1\u5668\u4E0A\u3002\u6709\u7684\u670D\u52A1\u5668\u4E0D\u5141\u8BB8\u76F4\u63A5\u4E0A\u4F20\u6587\u4EF6\uFF0C\u53EF\u4EE5\u4F7F\u7528base64\u547D\u4EE4\u6765\u7ED5\u8FC7\u3002

  1. \u5728\u672C\u5730\u5148\u8F6C\u6362.class\u6587\u4EF6\u4E3A base64\uFF0C\u518D\u4FDD\u5B58\u4E3A result.txt

    base64 < Test.class > result.txt

  2. \u5230\u670D\u52A1\u5668\u4E0A\uFF0C\u65B0\u5EFA\u5E76\u7F16\u8F91result.txt\uFF0C\u590D\u5236\u672C\u5730\u7684\u5185\u5BB9\uFF0C\u7C98\u8D34\u518D\u4FDD\u5B58

  3. \u628A\u670D\u52A1\u5668\u4E0A\u7684 result.txt\u8FD8\u539F\u4E3A.class

    base64 -d < result.txt > Test.class

  4. \u7528 md5 \u547D\u4EE4\u8BA1\u7B97\u54C8\u5E0C\u503C\uFF0C\u6821\u9A8C\u662F\u5426\u4E00\u81F4

redefine \u7684\u9650\u5236

public class MathGame {
    public static void main(String[] args) throws InterruptedException {
        MathGame game = new MathGame();
        while (true) {
            game.run();
            TimeUnit.SECONDS.sleep(1);
            // \u8FD9\u4E2A\u4E0D\u751F\u6548\uFF0C\u56E0\u4E3A\u4EE3\u7801\u4E00\u76F4\u8DD1\u5728 while\u91CC
            System.out.println("in loop");
        }
    }

    public void run() throws InterruptedException {
        // \u8FD9\u4E2A\u751F\u6548\uFF0C\u56E0\u4E3Arun()\u51FD\u6570\u6BCF\u6B21\u90FD\u53EF\u4EE5\u5B8C\u6574\u7ED3\u675F
        System.out.println("call run()");
        try {
            int number = random.nextInt();
            List<Integer> primeFactors = primeFactors(number);
            print(number, primeFactors);

        } catch (Exception e) {
            System.out.println(String.format("illegalArgumentCount:%3d, ", illegalArgumentCount) + e.getMessage());
        }
    }
}
`,17);function N(U,M){const e=o("RouterLink"),t=o("ExternalLinkIcon");return p(),i("div",null,[u,n("div",m,[k,n("p",null,[v,a(e,{to:"/doc/retransform.html"},{default:c(()=>[h]),_:1}),b])]),n("p",null,[n("a",f,[_,g,a(t)])]),x,n("p",null,[y,n("a",w,[j,a(t)])]),C,n("div",L,[I,n("p",null,[S,a(e,{to:"/doc/retransform.html"},{default:c(()=>[T]),_:1}),E])]),q])}const A=l(r,[["render",N],["__file","redefine.html.vue"]]);export{A as default};