All Superinterfaces:

java.lang.Iterable<History.Entry>

All Known Implementing Classes:

DefaultHistory
```
public interface History
extends java.lang.Iterable<History.Entry>
```
Console command history management interface.
The History interface provides functionality for storing, retrieving, and navigating through previously entered commands. It allows users to recall and reuse commands they've typed before, which is a fundamental feature of interactive command-line interfaces.
History implementations typically support:
- Adding new entries as commands are executed
- Navigating backward and forward through history
- Persisting history to a file for use across sessions
- Filtering or ignoring certain commands based on patterns
Each history entry contains the command text along with metadata such as the timestamp when it was executed.
The default implementation is DefaultHistory.
Since:

2.3

See Also:

LineReader.getHistory(), LineReaderBuilder.history(History)

Nested Class Summary

Nested Classes
Modifier and Type Interface Description

static interface History.Entry
Represents a single history entry containing a command line and its metadata.

Method Summary

All Methods Instance Methods Abstract Methods Default Methods
Modifier and Type	Method	Description
`default void`	`add(java.lang.String line)`
`void`	`add(java.time.Instant time, java.lang.String line)`	Adds a new item to the history with the specified timestamp.
`void`	`append(java.nio.file.Path file, boolean incremental)`	Append history to the file.
`void`	`attach(LineReader reader)`	Initialize the history for the given reader.
`java.lang.String`	`current()`	Return the content of the current buffer.
`int`	`first()`	Returns the index of the first element in the history.
`java.lang.String`	`get(int index)`	Returns the history item at the specified index.
`int`	`index()`	Returns the current index in the history.
`default boolean`	`isEmpty()`	Checks if the history is empty.
`default boolean`	`isPersistable(History.Entry entry)`	Check if an entry should be persisted or not.
`default java.util.ListIterator<History.Entry>`	`iterator()`
`java.util.ListIterator<History.Entry>`	`iterator(int index)`	Returns a list iterator over the history entries starting at the specified index.
`int`	`last()`	Returns the index of the last element in the history.
`void`	`load()`	Load history.
`boolean`	`moveTo(int index)`	Move to the specified index in the history
`void`	`moveToEnd()`	Move to the end of the history buffer.
`boolean`	`moveToFirst()`	Moves the history index to the first entry.
`boolean`	`moveToLast()`	This moves the history to the last entry.
`boolean`	`next()`	Move the pointer to the next element in the buffer.
`boolean`	`previous()`	Move the pointer to the previous element in the buffer.
`void`	`purge()`	Purge history.
`void`	`read(java.nio.file.Path file, boolean checkDuplicates)`	Read history from the file.
`void`	`resetIndex()`	Reset index after remove
`default java.util.Iterator<History.Entry>`	`reverseIterator()`
`default java.util.Iterator<History.Entry>`	`reverseIterator(int index)`
`void`	`save()`	Save history.
`int`	`size()`	Returns the number of items in the history.
`void`	`write(java.nio.file.Path file, boolean incremental)`	Write history to the file.

Methods inherited from interface java.lang.Iterable
forEach, spliterator

- Method Detail
  - attach
```
void attach(LineReader reader)
```
    Initialize the history for the given reader.
    
    Parameters:
    
    reader - the reader to attach to
  - load
```
void load()
   throws java.io.IOException
```
    Load history.
    
    Throws:
    
    java.io.IOException - if a problem occurs
  - save
```
void save()
   throws java.io.IOException
```
    Save history.
    
    Throws:
    
    java.io.IOException - if a problem occurs
  - write
```
void write(java.nio.file.Path file,
           boolean incremental)
    throws java.io.IOException
```
    Write history to the file. If incremental only the events that are new since the last incremental operation to the file are added.
    
    Parameters:
    
    file - History file
    
    incremental - If true incremental write operation is performed.
    
    Throws:
    
    java.io.IOException - if a problem occurs
  - append
```
void append(java.nio.file.Path file,
            boolean incremental)
     throws java.io.IOException
```
    Append history to the file. If incremental only the events that are new since the last incremental operation to the file are added.
    
    Parameters:
    
    file - History file
    
    incremental - If true incremental append operation is performed.
    
    Throws:
    
    java.io.IOException - if a problem occurs
  - read
```
void read(java.nio.file.Path file,
          boolean checkDuplicates)
   throws java.io.IOException
```
    Read history from the file. If checkDuplicates is true only the events that are not contained within the internal list are added.
    
    Parameters:
    
    file - History file
    
    checkDuplicates - If true, duplicate history entries will be discarded
    
    Throws:
    
    java.io.IOException - if a problem occurs
  - purge
```
void purge()
    throws java.io.IOException
```
    Purge history.
    
    Throws:
    
    java.io.IOException - if a problem occurs
  - size
```
int size()
```
    Returns the number of items in the history.
    
    Returns:
    
    the number of history items
  - isEmpty
```
default boolean isEmpty()
```
    Checks if the history is empty.
    
    Returns:
    
    true if the history contains no items
  - index
```
int index()
```
    Returns the current index in the history.
    
    Returns:
    
    the current index
  - first
```
int first()
```
    Returns the index of the first element in the history.
    
    Returns:
    
    the index of the first history item
  - last
```
int last()
```
    Returns the index of the last element in the history.
    
    Returns:
    
    the index of the last history item
  - get
```
java.lang.String get(int index)
```
    Returns the history item at the specified index.
    
    Parameters:
    
    index - the index of the history item to retrieve
    
    Returns:
    
    the history item at the specified index
  - add
```
default void add(java.lang.String line)
```
  - add
```
void add(java.time.Instant time,
         java.lang.String line)
```
    Adds a new item to the history with the specified timestamp.
    
    Parameters:
    
    time - the timestamp for the history item
    
    line - the line to add to the history
  - isPersistable
```
default boolean isPersistable(History.Entry entry)
```
    Check if an entry should be persisted or not.
    
    Parameters:
    
    entry - the entry to check
    
    Returns:
    
    true if the given entry should be persisted, false otherwise
  - iterator
```
java.util.ListIterator<History.Entry> iterator(int index)
```
    Returns a list iterator over the history entries starting at the specified index.
    
    Parameters:
    
    index - the index to start iterating from
    
    Returns:
    
    a list iterator over the history entries
  - iterator
```
default java.util.ListIterator<History.Entry> iterator()
```
    Specified by:
    
    iterator in interface java.lang.Iterable<History.Entry>
  - reverseIterator
```
default java.util.Iterator<History.Entry> reverseIterator()
```
  - reverseIterator
```
default java.util.Iterator<History.Entry> reverseIterator(int index)
```
  - current
```
java.lang.String current()
```
    Return the content of the current buffer.
    
    Returns:
    
    the content of the current buffer
  - previous
```
boolean previous()
```
    Move the pointer to the previous element in the buffer.
    
    Returns:
    
    true if we successfully went to the previous element
  - next
```
boolean next()
```
    Move the pointer to the next element in the buffer.
    
    Returns:
    
    true if we successfully went to the next element
  - moveToFirst
```
boolean moveToFirst()
```
    Moves the history index to the first entry.
    
    Returns:
    
    Return false if there are no iterator in the history or if the history is already at the beginning.
  - moveToLast
```
boolean moveToLast()
```
    This moves the history to the last entry. This entry is one position before the moveToEnd() position.
    
    Returns:
    
    Returns false if there were no history iterator or the history index was already at the last entry.
  - moveTo
```
boolean moveTo(int index)
```
    Move to the specified index in the history
    
    Parameters:
    
    index - The index to move to.
    
    Returns:
    
    Returns true if the index was moved.
  - moveToEnd
```
void moveToEnd()
```
    Move to the end of the history buffer. This will be a blank entry, after all of the other iterator.
  - resetIndex
```
void resetIndex()
```
    Reset index after remove

Interface History

Nested Class Summary

Method Summary

Methods inherited from interface java.lang.Iterable

Method Detail

attach

load

save

write

append

read

purge

size

isEmpty

index

first

last

get

add

add

isPersistable

iterator

iterator

reverseIterator

reverseIterator

current

previous

next

moveToFirst

moveToLast

moveTo

moveToEnd

resetIndex