This is the new *Amazon CloudFormation Template Reference Guide*. Please update your bookmarks and links. For help getting started with CloudFormation, see the [Amazon CloudFormation User Guide](https://docs.amazonaws.cn/AWSCloudFormation/latest/UserGuide/Welcome.html).

# AWS::EMR::Step HadoopJarStepConfig
<a name="aws-properties-emr-step-hadoopjarstepconfig"></a>

A job flow step consisting of a JAR file whose main function will be executed. The main function submits a job for Hadoop to execute and waits for the job to finish or fail.

## Syntax
<a name="aws-properties-emr-step-hadoopjarstepconfig-syntax"></a>

To declare this entity in your Amazon CloudFormation template, use the following syntax:

### JSON
<a name="aws-properties-emr-step-hadoopjarstepconfig-syntax.json"></a>

```
{
  "[Args](#cfn-emr-step-hadoopjarstepconfig-args)" : {{[ String, ... ]}},
  "[Jar](#cfn-emr-step-hadoopjarstepconfig-jar)" : {{String}},
  "[MainClass](#cfn-emr-step-hadoopjarstepconfig-mainclass)" : {{String}},
  "[StepProperties](#cfn-emr-step-hadoopjarstepconfig-stepproperties)" : {{[ KeyValue, ... ]}}
}
```

### YAML
<a name="aws-properties-emr-step-hadoopjarstepconfig-syntax.yaml"></a>

```
  [Args](#cfn-emr-step-hadoopjarstepconfig-args): {{
    - String}}
  [Jar](#cfn-emr-step-hadoopjarstepconfig-jar): {{String}}
  [MainClass](#cfn-emr-step-hadoopjarstepconfig-mainclass): {{String}}
  [StepProperties](#cfn-emr-step-hadoopjarstepconfig-stepproperties): {{
    - KeyValue}}
```

## Properties
<a name="aws-properties-emr-step-hadoopjarstepconfig-properties"></a>

`Args`  <a name="cfn-emr-step-hadoopjarstepconfig-args"></a>
A list of command line arguments passed to the JAR file's main function when executed.  
*Required*: No  
*Type*: Array of String  
*Update requires*: [Replacement](https://docs.amazonaws.cn/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement)

`Jar`  <a name="cfn-emr-step-hadoopjarstepconfig-jar"></a>
A path to a JAR file run during the step.  
*Required*: Yes  
*Type*: String  
*Pattern*: `[\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\r\n\t]*`  
*Minimum*: `0`  
*Maximum*: `10280`  
*Update requires*: [Replacement](https://docs.amazonaws.cn/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement)

`MainClass`  <a name="cfn-emr-step-hadoopjarstepconfig-mainclass"></a>
The name of the main class in the specified Java file. If not specified, the JAR file should specify a Main-Class in its manifest file.  
*Required*: No  
*Type*: String  
*Pattern*: `[\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\r\n\t]*`  
*Minimum*: `0`  
*Maximum*: `10280`  
*Update requires*: [Replacement](https://docs.amazonaws.cn/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement)

`StepProperties`  <a name="cfn-emr-step-hadoopjarstepconfig-stepproperties"></a>
A list of Java properties that are set when the step runs. You can use these properties to pass key value pairs to your main function.  
*Required*: No  
*Type*: Array of [KeyValue](aws-properties-emr-step-keyvalue.md)  
*Update requires*: [Replacement](https://docs.amazonaws.cn/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement)