java.lang.Object
- org.apache.lucene.index.FieldInfo

```
public final class FieldInfo
extends Object
```
Access to the Field Info file that describes document fields and whether or not they are indexed. Each segment has a separate Field Info file. Objects of this class are thread-safe for multiple readers, but only one thread can be adding documents at a time, with no other reader or writer threads accessing this object.

Nested Class Summary

Nested Classes
Modifier and Type	Class	Description
`static class`	`FieldInfo.DocValuesType`	DocValues types.
`static class`	`FieldInfo.IndexOptions`	Controls how much information is stored in the postings lists.

Field Summary

Fields
Modifier and Type Field Description

String name
Field's name

int number
Internal field number

Constructor Summary

Constructors
Constructor	Description
`FieldInfo(String name, boolean indexed, int number, boolean storeTermVector, boolean omitNorms, boolean storePayloads, FieldInfo.IndexOptions indexOptions, FieldInfo.DocValuesType docValues, FieldInfo.DocValuesType normsType, Map<String,String> attributes)`	Sole Constructor.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`Map<String,String>`	`attributes()`	Returns internal codec attributes map.
`String`	`getAttribute(String key)`	Get a codec attribute value, or null if it does not exist
`long`	`getDocValuesGen()`	Returns the docValues generation of this field, or -1 if no docValues updates exist for it.
`FieldInfo.DocValuesType`	`getDocValuesType()`	Returns `FieldInfo.DocValuesType` of the docValues.
`FieldInfo.IndexOptions`	`getIndexOptions()`	Returns IndexOptions for the field, or null if the field is not indexed
`FieldInfo.DocValuesType`	`getNormType()`	Returns `FieldInfo.DocValuesType` of the norm.
`boolean`	`hasDocValues()`	Returns true if this field has any docValues.
`boolean`	`hasNorms()`	Returns true if this field actually has any norms.
`boolean`	`hasPayloads()`	Returns true if any payloads exist for this field.
`boolean`	`hasVectors()`	Returns true if any term vectors exist for this field.
`boolean`	`isIndexed()`	Returns true if this field is indexed.
`boolean`	`omitsNorms()`	Returns true if norms are explicitly omitted for this field
`String`	`putAttribute(String key, String value)`	Puts a codec attribute value.
`void`	`setDocValuesGen(long dvGen)`	Sets the docValues generation of this field.

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

- Field Detail
  - name
```
public final String name
```
    Field's name
  - number
```
public final int number
```
    Internal field number
- Constructor Detail
  - FieldInfo
```
public FieldInfo(String name,
                 boolean indexed,
                 int number,
                 boolean storeTermVector,
                 boolean omitNorms,
                 boolean storePayloads,
                 FieldInfo.IndexOptions indexOptions,
                 FieldInfo.DocValuesType docValues,
                 FieldInfo.DocValuesType normsType,
                 Map<String,String> attributes)
```
    Sole Constructor.
- Method Detail
  - getIndexOptions
```
public FieldInfo.IndexOptions getIndexOptions()
```
    Returns IndexOptions for the field, or null if the field is not indexed
  - hasDocValues
```
public boolean hasDocValues()
```
    Returns true if this field has any docValues.
  - getDocValuesType
```
public FieldInfo.DocValuesType getDocValuesType()
```
    Returns FieldInfo.DocValuesType of the docValues. this may be null if the field has no docvalues.
  - setDocValuesGen
```
public void setDocValuesGen(long dvGen)
```
    Sets the docValues generation of this field.
  - getDocValuesGen
```
public long getDocValuesGen()
```
    Returns the docValues generation of this field, or -1 if no docValues updates exist for it.
  - getNormType
```
public FieldInfo.DocValuesType getNormType()
```
    Returns FieldInfo.DocValuesType of the norm. this may be null if the field has no norms.
  - omitsNorms
```
public boolean omitsNorms()
```
    Returns true if norms are explicitly omitted for this field
  - hasNorms
```
public boolean hasNorms()
```
    Returns true if this field actually has any norms.
  - isIndexed
```
public boolean isIndexed()
```
    Returns true if this field is indexed.
  - hasPayloads
```
public boolean hasPayloads()
```
    Returns true if any payloads exist for this field.
  - hasVectors
```
public boolean hasVectors()
```
    Returns true if any term vectors exist for this field.
  - getAttribute
```
public String getAttribute(String key)
```
    Get a codec attribute value, or null if it does not exist
  - putAttribute
```
public String putAttribute(String key,
                           String value)
```
    Puts a codec attribute value.
    This is a key-value mapping for the field that the codec can use to store additional metadata, and will be available to the codec when reading the segment via getAttribute(String)
    If a value already exists for the field, it will be replaced with the new value.
  - attributes
```
public Map<String,String> attributes()
```
    Returns internal codec attributes map. May be null if no mappings exist.

Modifier and Type	Field	Description
`String`	`name`	Field's name
`int`	`number`	Internal field number

Class FieldInfo

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

name

number

Constructor Detail

FieldInfo

Method Detail

getIndexOptions

hasDocValues

getDocValuesType

setDocValuesGen

getDocValuesGen

getNormType

omitsNorms

hasNorms

isIndexed

hasPayloads

hasVectors

getAttribute

putAttribute

attributes