MQHeaderContext

java.lang.Object
- com.ibm.mq.jmqi.JmqiObject
- - com.ibm.mq.headers.MQHeaderContext

```
public abstract class MQHeaderContext
extends com.ibm.mq.jmqi.JmqiObject
```
An MQMessageContext is used by instances of MQHeaderFactory when decoding message content. An MQMessageContext encapsulates a message and the current format, encoding and CCSID associated with its content at the current position.

Field Summary
- Fields inherited from class com.ibm.mq.jmqi.JmqiObject
  COMP_JM, COMP_JN, COMP_JO

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`abstract int`	`available()`
`static MQHeaderContext`	`createMQHeaderContext(java.io.DataInput messageP)` Create an MQMessageContext object to wrap a message
`static MQHeaderContext`	`createMQHeaderContext(java.io.DataInput messageP, java.lang.String format, int encoding, int characterSet)` Create an MQMessageContext object to wrap a message
`abstract java.io.DataInput`	`getDataInput()`
`int`	`nextCharacterSet()` get the character set of the next header or message content.
`int`	`nextEncoding()` get the encoding of the next header or message content.
`java.lang.String`	`nextFormat()` get the format of the next header or message content.
`void`	`setCharacterSet(int characterSet)` Sets the CCSID of this message context, used in the decoding of headers.
`void`	`setEncoding(int encoding)` Sets the numeric encoding of this message context, used in the decoding of headers.
`void`	`setFormat(java.lang.String format)` Sets the format of this message context, used in the decoding of headers.
`abstract int`	`sniff()`

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

- Method Detail
  - createMQHeaderContext
```
public static MQHeaderContext createMQHeaderContext(java.io.DataInput messageP)
```
    Create an MQMessageContext object to wrap a message
    
    Parameters:
    
    messageP - the message to be wrapped
    
    Returns:
    
    an appropriate MQHeaderContext implementation
  - createMQHeaderContext
```
public static MQHeaderContext createMQHeaderContext(java.io.DataInput messageP,
                                                    java.lang.String format,
                                                    int encoding,
                                                    int characterSet)
```
    Create an MQMessageContext object to wrap a message
    
    Parameters:
    
    messageP - the message to be wrapped
    
    format - the message format (see CMQC.MQFMT_*)
    
    encoding - the message encoding (see CMQC.MQENV_*)
    
    characterSet - the Coded Character Set id
    
    Returns:
    
    an appropriate MQHeaderContext implementation
  - nextFormat
```
public java.lang.String nextFormat()
```
    get the format of the next header or message content.
    
    Returns:
    
    the format of the next header or message content.
  - nextEncoding
```
public int nextEncoding()
```
    get the encoding of the next header or message content.
    
    Returns:
    
    the encoding of the next header or message content.
  - nextCharacterSet
```
public int nextCharacterSet()
```
    get the character set of the next header or message content.
    
    Returns:
    
    the character set of the next header or message content.
  - setFormat
```
public void setFormat(java.lang.String format)
```
    Sets the format of this message context, used in the decoding of headers.
    
    Parameters:
    
    format - the format of this message context.
  - setEncoding
```
public void setEncoding(int encoding)
```
    Sets the numeric encoding of this message context, used in the decoding of headers.
    
    Parameters:
    
    encoding - the numeric encoding. see (CMQC.MQENC_* for values).
  - setCharacterSet
```
public void setCharacterSet(int characterSet)
```
    Sets the CCSID of this message context, used in the decoding of headers.
    
    Parameters:
    
    characterSet - the Coded Character Set Identifier.
  - available
```
public abstract int available()
                       throws java.io.IOException
```
    Returns:
    
    the number of bytes remaining to be read in the message.
    
    Throws:
    
    java.io.IOException
  - getDataInput
```
public abstract java.io.DataInput getDataInput()
```
    Returns:
    
    the message.
  - sniff
```
public abstract int sniff()
                   throws java.io.IOException
```
    Returns:
    
    the next four bytes in the message as an integer, and rewinds the message to the current position.
    
    Throws:
    
    java.io.IOException

Fields inherited from class com.ibm.mq.jmqi.JmqiObject

Methods inherited from class java.lang.Object

createMQHeaderContext

createMQHeaderContext

nextFormat

nextEncoding

nextCharacterSet

setFormat

setEncoding

setCharacterSet

available

getDataInput

sniff