add ognl command doc. #240

core/src/main/java/com/taobao/arthas/core/command/klass100/OgnlCommand.java

@@ -27,7 +27,7 @@ import com.taobao.middleware.logger.Logger;
 @Summary("Execute ognl expression.")
 @Description(Constants.EXAMPLE
                 + "  ognl '@java.lang.System@out.println(\"hello\")' \n"
-                + "  ognl -x 2 '@Singleton@getInstance() \n"
+                + "  ognl -x 2 '@Singleton@getInstance()' \n"
                 + "  ognl '@Demo@staticFiled' \n"
                 + "  ognl '#value1=@System@getProperty(\"java.home\"), #value2=@System@getProperty(\"java.runtime.name\"), {#value1, #value2}'\n"
                 + "  ognl -c 5d113a51 '@com.taobao.arthas.core.GlobalOptions@isDump' \n"

site/src/site/sphinx/commands.md

@@ -7,7 +7,7 @@
 * [sysprop](sysprop.md)
 * [getstatic](getstatic.md)
 
-
+* [ognl](ognl.md)
 
 * [sc](sc.md)
 * [sm](sm.md)

site/src/site/sphinx/en/commands.md

@@ -7,6 +7,8 @@ All Commands
 * [sysprop](sysprop.md)
 * [getstatic](getstatic.md)
 
+* [ognl](ognl.md)
+
 * [sc](sc.md)
 * [sm](sm.md)
 * [dump](dump.md)

site/src/site/sphinx/en/ognl.md

@@ -0,0 +1,60 @@
+ognl
+===
+
+> Execute ognl expression.
+
+Since 3.0.5.
+
+### Parameters
+
+|Name|Specification|
+|---:|:---|
+|*express*|expression to be executed|
+|`[c:]`| The hashcode of the ClassLoader that executes the expression, default ClassLoader is SystemClassLoader. |
+|[x]|Expand level of object (1 by default).|
+
+
+### Usage
+
+* [Special usages](https://github.com/alibaba/arthas/issues/71)
+* [OGNL official guide](https://commons.apache.org/proper/commons-ognl/language-guide.html)
+
+Call static method:
+
+```bash
+$ ognl '@java.lang.System@out.println("hello")'
+null
+```
+
+Get static field:
+
+```bash
+$ ognl '@demo.MathGame@random'
+@Random[
+    serialVersionUID=@Long[3905348978240129619],
+    seed=@AtomicLong[125451474443703],
+    multiplier=@Long[25214903917],
+    addend=@Long[11],
+    mask=@Long[281474976710655],
+    DOUBLE_UNIT=@Double[1.1102230246251565E-16],
+    BadBound=@String[bound must be positive],
+    BadRange=@String[bound must be greater than origin],
+    BadSize=@String[size must be non-negative],
+    seedUniquifier=@AtomicLong[-3282039941672302964],
+    nextNextGaussian=@Double[0.0],
+    haveNextNextGaussian=@Boolean[false],
+    serialPersistentFields=@ObjectStreamField[][isEmpty=false;size=3],
+    unsafe=@Unsafe[sun.misc.Unsafe@28ea5898],
+    seedOffset=@Long[24],
+]
+```
+
+Execute a multi-line expression, and return a list:
+
+```bash
+$ ognl '#value1=@System@getProperty("java.home"), #value2=@System@getProperty("java.runtime.name"), {#value1, #value2}'
+@ArrayList[
+    @String[/opt/java/8.0.181-zulu/jre],
+    @String[OpenJDK Runtime Environment],
+]
+```

site/src/site/sphinx/ognl.md

@@ -0,0 +1,61 @@
+ognl
+===
+
+> 执行ognl表达式
+
+从3.0.5版本增加
+
+### 参数说明
+
+|参数名称|参数说明|
+|---:|:---|
+|*express*|执行的表达式|
+|`[c:]`|执行表达式的 ClassLoader 的 hashcode，默认值是SystemClassLoader|
+|[x]|结果对象的展开层次，默认值1|
+
+
+### 使用参考
+
+* OGNL特殊用法请参考：[https://github.com/alibaba/arthas/issues/71](https://github.com/alibaba/arthas/issues/71)
+* OGNL表达式官方指南：[https://commons.apache.org/proper/commons-ognl/language-guide.html](https://commons.apache.org/proper/commons-ognl/language-guide.html)
+
+
+调用静态函数：
+
+```bash
+$ ognl '@java.lang.System@out.println("hello")'
+null
+```
+
+获取静态类的静态字段：
+
+```bash
+$ ognl '@demo.MathGame@random'
+@Random[
+    serialVersionUID=@Long[3905348978240129619],
+    seed=@AtomicLong[125451474443703],
+    multiplier=@Long[25214903917],
+    addend=@Long[11],
+    mask=@Long[281474976710655],
+    DOUBLE_UNIT=@Double[1.1102230246251565E-16],
+    BadBound=@String[bound must be positive],
+    BadRange=@String[bound must be greater than origin],
+    BadSize=@String[size must be non-negative],
+    seedUniquifier=@AtomicLong[-3282039941672302964],
+    nextNextGaussian=@Double[0.0],
+    haveNextNextGaussian=@Boolean[false],
+    serialPersistentFields=@ObjectStreamField[][isEmpty=false;size=3],
+    unsafe=@Unsafe[sun.misc.Unsafe@28ea5898],
+    seedOffset=@Long[24],
+]
+```
+
+执行多行表达式，赋值给临时变量，返回一个List：
+
+```bash
+$ ognl '#value1=@System@getProperty("java.home"), #value2=@System@getProperty("java.runtime.name"), {#value1, #value2}'
+@ArrayList[
+    @String[/opt/java/8.0.181-zulu/jre],
+    @String[OpenJDK Runtime Environment],
+]
+```