Context (Apache Flume 1.8.0 API)

java.lang.Object
- org.apache.flume.Context

```
public class Context
extends Object
```
The context is a key-value store used to pass configuration information throughout the system.

Constructor Summary

Constructors
Constructor and Description

Context()

Context(Map<String,String> paramters)

Constructors
Constructor and Description
`Context()`
`Context(Map<String,String> paramters)`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`clear()` Removes all of the mappings from this map.
`boolean`	`containsKey(String key)` Returns true if this Context contains a mapping for key.
`Boolean`	`getBoolean(String key)` Gets value mapped to key, returning null if unmapped.
`Boolean`	`getBoolean(String key, Boolean defaultValue)` Gets value mapped to key, returning defaultValue if unmapped.
`Integer`	`getInteger(String key)` Gets value mapped to key, returning null if unmapped.
`Integer`	`getInteger(String key, Integer defaultValue)` Gets value mapped to key, returning defaultValue if unmapped.
`Long`	`getLong(String key)` Gets value mapped to key, returning null if unmapped.
`Long`	`getLong(String key, Long defaultValue)` Gets value mapped to key, returning defaultValue if unmapped.
`com.google.common.collect.ImmutableMap<String,String>`	`getParameters()` Gets a copy of the backing map structure.
`String`	`getString(String key)` Gets value mapped to key, returning null if unmapped.
`String`	`getString(String key, String defaultValue)` Gets value mapped to key, returning defaultValue if unmapped.
`com.google.common.collect.ImmutableMap<String,String>`	`getSubProperties(String prefix)` Get properties which start with a prefix.
`void`	`put(String key, String value)` Associates the specified value with the specified key in this context.
`void`	`putAll(Map<String,String> map)` Associates all of the given map's keys and values in the Context.
`String`	`toString()`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - Context
```
public Context()
```
  - Context
```
public Context(Map<String,String> paramters)
```
- Method Detail
  - getParameters
```
public com.google.common.collect.ImmutableMap<String,String> getParameters()
```
    Gets a copy of the backing map structure.
    
    Returns:
    
    immutable copy of backing map structure
  - clear
```
public void clear()
```
    Removes all of the mappings from this map.
  - getSubProperties
```
public com.google.common.collect.ImmutableMap<String,String> getSubProperties(String prefix)
```
    Get properties which start with a prefix. When a property is returned, the prefix is removed the from name. For example, if this method is called with a parameter "hdfs." and the context contains: { hdfs.key = value, otherKey = otherValue } this method will return a map containing: { key = value} Note: The prefix must end with a period character. If not this method will raise an IllegalArgumentException.
    
    Parameters:
    
    prefix - key prefix to find and remove from keys in resulting map
    
    Returns:
    
    map with keys which matched prefix with prefix removed from keys in resulting map. If no keys are matched, the returned map is empty
    
    Throws:
    
    IllegalArguemntException - if the given prefix does not end with a period character.
  - putAll
```
public void putAll(Map<String,String> map)
```
    Associates all of the given map's keys and values in the Context.
  - put
```
public void put(String key,
                String value)
```
    Associates the specified value with the specified key in this context. If the context previously contained a mapping for the key, the old value is replaced by the specified value.
    
    Parameters:
    
    key - key with which the specified value is to be associated
    
    value - to be associated with the specified key
  - containsKey
```
public boolean containsKey(String key)
```
    Returns true if this Context contains a mapping for key. Otherwise, returns false.
  - getBoolean
```
public Boolean getBoolean(String key,
                          Boolean defaultValue)
```
    Gets value mapped to key, returning defaultValue if unmapped.
    
    Parameters:
    
    key - to be found
    
    defaultValue - returned if key is unmapped
    
    Returns:
    
    value associated with key
  - getBoolean
```
public Boolean getBoolean(String key)
```
    Gets value mapped to key, returning null if unmapped.
    Note that this method returns an object as opposed to a primitive. The configuration key requested may not be mapped to a value and by returning the primitive object wrapper we can return null. If the key does not exist the return value of this method is assigned directly to a primitive, a NullPointerException will be thrown.
    
    Parameters:
    
    key - to be found
    
    Returns:
    
    value associated with key or null if unmapped
  - getInteger
```
public Integer getInteger(String key,
                          Integer defaultValue)
```
    Gets value mapped to key, returning defaultValue if unmapped.
    
    Parameters:
    
    key - to be found
    
    defaultValue - returned if key is unmapped
    
    Returns:
    
    value associated with key
  - getInteger
```
public Integer getInteger(String key)
```
    Gets value mapped to key, returning null if unmapped.
    Note that this method returns an object as opposed to a primitive. The configuration key requested may not be mapped to a value and by returning the primitive object wrapper we can return null. If the key does not exist the return value of this method is assigned directly to a primitive, a NullPointerException will be thrown.
    
    Parameters:
    
    key - to be found
    
    Returns:
    
    value associated with key or null if unmapped
  - getLong
```
public Long getLong(String key,
                    Long defaultValue)
```
    Gets value mapped to key, returning defaultValue if unmapped.
    
    Parameters:
    
    key - to be found
    
    defaultValue - returned if key is unmapped
    
    Returns:
    
    value associated with key
  - getLong
```
public Long getLong(String key)
```
    Gets value mapped to key, returning null if unmapped.
    Note that this method returns an object as opposed to a primitive. The configuration key requested may not be mapped to a value and by returning the primitive object wrapper we can return null. If the key does not exist the return value of this method is assigned directly to a primitive, a NullPointerException will be thrown.
    
    Parameters:
    
    key - to be found
    
    Returns:
    
    value associated with key or null if unmapped
  - getString
```
public String getString(String key,
                        String defaultValue)
```
    Gets value mapped to key, returning defaultValue if unmapped.
    
    Parameters:
    
    key - to be found
    
    defaultValue - returned if key is unmapped
    
    Returns:
    
    value associated with key
  - getString
```
public String getString(String key)
```
    Gets value mapped to key, returning null if unmapped.
    
    Parameters:
    
    key - to be found
    
    Returns:
    
    value associated with key or null if unmapped
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object

Class Context

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

Context

Context

Method Detail

getParameters

clear

getSubProperties

putAll

put

containsKey

getBoolean

getBoolean

getInteger

getInteger

getLong

getLong

getString

getString

toString