MappingIterator (jackson-databind 2.10.0 API)

java.lang.Object
- com.fasterxml.jackson.databind.MappingIterator<T>

All Implemented Interfaces:

Closeable, AutoCloseable, Iterator<T>
```
public class MappingIterator<T>
extends Object
implements Iterator<T>, Closeable
```
Iterator exposed by ObjectMapper when binding sequence of objects. Extension is done to allow more convenient exposing of IOException (which basic Iterator does not expose)

Field Summary

Fields
Modifier and Type	Field and Description
`protected boolean`	`_closeParser` Flag that indicates whether input `JsonParser` should be closed when we are done or not; generally only called when caller did not pass JsonParser.
`protected DeserializationContext`	`_context` Context for deserialization, needed to pass through to deserializer
`protected JsonDeserializer<T>`	`_deserializer` Deserializer for individual element values.
`protected JsonParser`	`_parser` Underlying parser used for reading content to bind.
`protected JsonStreamContext`	`_seqContext` Context to resynchronize to, in case an exception is encountered but caller wants to try to read more elements.
`protected int`	`_state` State of the iterator
`protected JavaType`	`_type` Type to bind individual elements to.
`protected T`	`_updatedValue` If not null, "value to update" instead of creating a new instance for each call.
`protected static MappingIterator<?>`	`EMPTY_ITERATOR`
`protected static int`	`STATE_CLOSED` State in which iterator is closed
`protected static int`	`STATE_HAS_VALUE` State in which "hasNextValue()" has been succesfully called and deserializer can be called to fetch value
`protected static int`	`STATE_MAY_HAVE_VALUE` State in which no recovery is needed, but "hasNextValue()" needs to be called first
`protected static int`	`STATE_NEED_RESYNC` State in which value read failed

Constructor Summary

Constructors
Modifier	Constructor and Description
`protected`	`MappingIterator(JavaType type, JsonParser p, DeserializationContext ctxt, JsonDeserializer<?> deser, boolean managedParser, Object valueToUpdate)`

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`protected <R> R`	`_handleIOException(IOException e)`
`protected <R> R`	`_handleMappingException(JsonMappingException e)`
`protected void`	`_resync()`
`protected <R> R`	`_throwNoSuchElement()`
`void`	`close()`
`static <T> MappingIterator<T>`	`emptyIterator()` Method for getting an "empty" iterator instance: one that never has more values; may be freely shared.
`JsonLocation`	`getCurrentLocation()` Convenience method, functionally equivalent to: `iterator.getParser().getCurrentLocation()`
`JsonParser`	`getParser()` Accessor for getting underlying parser this iterator uses.
`FormatSchema`	`getParserSchema()` Accessor for accessing `FormatSchema` that the underlying parser (as per `getParser()`) is using, if any; only parser of schema-aware formats use schemas.
`boolean`	`hasNext()`
`boolean`	`hasNextValue()` Equivalent of `next()` but one that may throw checked exceptions from Jackson due to invalid input.
`T`	`next()`
`T`	`nextValue()`
`List<T>`	`readAll()` Convenience method for reading all entries accessible via this iterator; resulting container will be a `ArrayList`.
`<C extends Collection<? super T>> C`	`readAll(C results)` Convenience method for reading all entries accessible via this iterator
`<L extends List<? super T>> L`	`readAll(L resultList)` Convenience method for reading all entries accessible via this iterator
`void`	`remove()`

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

Methods inherited from interface java.util.Iterator
forEachRemaining

- Field Detail
  - EMPTY_ITERATOR
```
protected static final MappingIterator<?> EMPTY_ITERATOR
```
  - STATE_CLOSED
```
protected static final int STATE_CLOSED
```
    State in which iterator is closed
    
    See Also:
    
    Constant Field Values
  - STATE_NEED_RESYNC
```
protected static final int STATE_NEED_RESYNC
```
    State in which value read failed
    
    See Also:
    
    Constant Field Values
  - STATE_MAY_HAVE_VALUE
```
protected static final int STATE_MAY_HAVE_VALUE
```
    State in which no recovery is needed, but "hasNextValue()" needs to be called first
    
    See Also:
    
    Constant Field Values
  - STATE_HAS_VALUE
```
protected static final int STATE_HAS_VALUE
```
    State in which "hasNextValue()" has been succesfully called and deserializer can be called to fetch value
    
    See Also:
    
    Constant Field Values
  - _type
```
protected final JavaType _type
```
    Type to bind individual elements to.
  - _context
```
protected final DeserializationContext _context
```
    Context for deserialization, needed to pass through to deserializer
  - _deserializer
```
protected final JsonDeserializer<T> _deserializer
```
    Deserializer for individual element values.
  - _parser
```
protected final JsonParser _parser
```
    Underlying parser used for reading content to bind. Initialized as not null but set as null when iterator is closed, to denote closing.
  - _seqContext
```
protected final JsonStreamContext _seqContext
```
    Context to resynchronize to, in case an exception is encountered but caller wants to try to read more elements.
  - _updatedValue
```
protected final T _updatedValue
```
    If not null, "value to update" instead of creating a new instance for each call.
  - _closeParser
```
protected final boolean _closeParser
```
    Flag that indicates whether input JsonParser should be closed when we are done or not; generally only called when caller did not pass JsonParser.
  - _state
```
protected int _state
```
    State of the iterator
- Constructor Detail
  - MappingIterator
```
protected MappingIterator(JavaType type,
                          JsonParser p,
                          DeserializationContext ctxt,
                          JsonDeserializer<?> deser,
                          boolean managedParser,
                          Object valueToUpdate)
```
    Parameters:
    
    managedParser - Whether we "own" the JsonParser passed or not: if true, it was created by ObjectReader and code here needs to close it; if false, it was passed by calling code and should not be closed by iterator.
- Method Detail
  - emptyIterator
```
public static <T> MappingIterator<T> emptyIterator()
```
    Method for getting an "empty" iterator instance: one that never has more values; may be freely shared.
    
    Since:
    
    2.10 Existed earlier but public since 2.10
  - hasNext
```
public boolean hasNext()
```
    Specified by:
    
    hasNext in interface Iterator<T>
  - next
```
public T next()
```
    Specified by:
    
    next in interface Iterator<T>
  - remove
```
public void remove()
```
    Specified by:
    
    remove in interface Iterator<T>
  - close
```
public void close()
           throws IOException
```
    Specified by:
    
    close in interface Closeable
    
    Specified by:
    
    close in interface AutoCloseable
    
    Throws:
    
    IOException
  - hasNextValue
```
public boolean hasNextValue()
                     throws IOException
```
    Equivalent of next() but one that may throw checked exceptions from Jackson due to invalid input.
    
    Throws:
    
    IOException
  - nextValue
```
public T nextValue()
            throws IOException
```
    Throws:
    
    IOException
  - readAll
```
public List<T> readAll()
                throws IOException
```
    Convenience method for reading all entries accessible via this iterator; resulting container will be a ArrayList.
    
    Returns:
    
    List of entries read
    
    Throws:
    
    IOException
    
    Since:
    
    2.2
  - readAll
```
public <L extends List<? super T>> L readAll(L resultList)
                                      throws IOException
```
    Convenience method for reading all entries accessible via this iterator
    
    Returns:
    
    List of entries read (same as passed-in argument)
    
    Throws:
    
    IOException
    
    Since:
    
    2.2
  - readAll
```
public <C extends Collection<? super T>> C readAll(C results)
                                            throws IOException
```
    Convenience method for reading all entries accessible via this iterator
    
    Throws:
    
    IOException
    
    Since:
    
    2.5
  - getParser
```
public JsonParser getParser()
```
    Accessor for getting underlying parser this iterator uses.
    
    Since:
    
    2.2
  - getParserSchema
```
public FormatSchema getParserSchema()
```
    Accessor for accessing FormatSchema that the underlying parser (as per getParser()) is using, if any; only parser of schema-aware formats use schemas.
    
    Since:
    
    2.2
  - getCurrentLocation
```
public JsonLocation getCurrentLocation()
```
    Convenience method, functionally equivalent to: iterator.getParser().getCurrentLocation()
    
    Returns:
    
    Location of the input stream of the underlying parser
    
    Since:
    
    2.2.1
  - _resync
```
protected void _resync()
                throws IOException
```
    Throws:
    
    IOException
  - _throwNoSuchElement
```
protected <R> R _throwNoSuchElement()
```
  - _handleMappingException
```
protected <R> R _handleMappingException(JsonMappingException e)
```
  - _handleIOException
```
protected <R> R _handleIOException(IOException e)
```

Class MappingIterator<T>

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface java.util.Iterator

Field Detail

EMPTY_ITERATOR

STATE_CLOSED

STATE_NEED_RESYNC

STATE_MAY_HAVE_VALUE

STATE_HAS_VALUE

_type

_context

_deserializer

_parser

_seqContext

_updatedValue

_closeParser

_state

Constructor Detail

MappingIterator

Method Detail

emptyIterator

hasNext

next

remove

close

hasNextValue

nextValue

readAll

readAll

readAll

getParser

getParserSchema

getCurrentLocation

_resync

_throwNoSuchElement

_handleMappingException

_handleIOException