arthas/tutorials/katacoda/command-sm-en/sm.md

> Search method from the loaded classes.

`sm` stands for search method. This command can search and show method information from all loaded classes. `sm` can only view the methods declared on the target class, that is, methods from its parent classes are invisible.


### Options

|Name|Specification|
|---:|:---|
|*class-pattern*|pattern for class name|
|*method-pattern*|pattern for method name|
|`[d]`|print the details of the method|
|`[E]`|turn on regex matching while the default mode is wildcard matching|
|`[c:]`|The hash code of the special class's classLoader|
|`[classLoaderClass:]`| The class name of the ClassLoader that executes the expression. |
|`[n:]`|Maximum number of matching classes with details (100 by default)|

### Usage

* View methods of `java.lang.String`:

`sm java.lang.String`{{execute T2}}

```bash
$ sm java.lang.String
java.lang.String-><init>
java.lang.String->equals
java.lang.String->toString
java.lang.String->hashCode
java.lang.String->compareTo
java.lang.String->indexOf
java.lang.String->valueOf
java.lang.String->checkBounds
java.lang.String->length
java.lang.String->isEmpty
java.lang.String->charAt
java.lang.String->codePointAt
java.lang.String->codePointBefore
java.lang.String->codePointCount
java.lang.String->offsetByCodePoints
java.lang.String->getChars
java.lang.String->getBytes
java.lang.String->contentEquals
java.lang.String->nonSyncContentEquals
java.lang.String->equalsIgnoreCase
java.lang.String->compareToIgnoreCase
java.lang.String->regionMatches
java.lang.String->startsWith
java.lang.String->endsWith
java.lang.String->indexOfSupplementary
java.lang.String->lastIndexOf
java.lang.String->lastIndexOfSupplementary
java.lang.String->substring
java.lang.String->subSequence
java.lang.String->concat
java.lang.String->replace
java.lang.String->matches
java.lang.String->contains
java.lang.String->replaceFirst
java.lang.String->replaceAll
java.lang.String->split
java.lang.String->join
java.lang.String->toLowerCase
java.lang.String->toUpperCase
java.lang.String->trim
java.lang.String->toCharArray
java.lang.String->format
java.lang.String->copyValueOf
java.lang.String->intern
Affect(row-cnt:44) cost in 1342 ms.
```

* Specify ClassLoader

Find ClassLoaderHash：

`sc -d demo.MathGame | grep classLoaderHash`{{execute T2}}

```bash
$ sc -d demo.MathGame | grep classLoaderHash
 classLoaderHash   70dea4e
```

* Specify Classloader

Note that the hashcode changes, you need to check the current ClassLoader information first, and extract the hashcode corresponding to the ClassLoader.

if you use`-c`, you have to manually type hashcode by `-c <hashcode>`.

```bash
$ sm -c 70dea4e demo.MathGame
```

For classloader with only one instance, it can be specified by `--classLoaderClass` using class name, which is more convenient to use.

`sm --classLoaderClass sun.misc.Launcher$AppClassLoader demo.MathGame`{{execute T2}}

  * PS: Here the classLoaderClass in java 8 is sun.misc.Launcher$AppClassLoader, while in java 11 it's jdk.internal.loader.ClassLoaders$AppClassLoader. Currently katacoda using java 8.
  
```bash
$ sm --classLoaderClass sun.misc.Launcher$AppClassLoader demo.MathGame
demo.MathGame <init>()V
demo.MathGame primeFactors(I)Ljava/util/List;
demo.MathGame main([Ljava/lang/String;)V
demo.MathGame run()V
demo.MathGame print(ILjava/util/List;)V
Affect(row-cnt:5) cost in 2 ms.
```

The value of `--classloaderclass` is the class name of classloader. It can only work when it matches a unique classloader instance. The purpose is to facilitate the input of general commands. However, `-c <hashcode>` is dynamic.

* View method `java.lang.String#toString` details:

`sm -d java.lang.String toString`{{execute T2}}

```bash
$ sm -d java.lang.String toString
 declaring-class  java.lang.String
 method-name      toString
 modifier         public
 annotation
 parameters
 return           java.lang.String
 exceptions

Affect(row-cnt:1) cost in 3 ms.
```